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Ed
R Danson
September
16
1846
London
·、
FR
medruesday
1817
ARTES
SCIENTIA
LIBRARY VERITAS
OF THE
UNIVERSITY OF MICHIGAN
Bee
TWEBOR
SI QUERIS PENINSULAM AMENAM
CIRCUMSPICE
W.BU UN
9.07.01
BEQUEST of
H.H. BARTLETT
She
C

Bostoch
1800

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Ρ Η Υ Τ Ο L
P H Y T 0 L 0 G ;
GIA;
I AOR THE
PHILOSOPHY
OF
AGRICULTURE
AND
G A RD ENING.
WITH THE THEORY OF DRAINING MORASSES,
IIACE AND WITH AN07375
IMPROVED CONSTRUCTION OF THE DRILL PLOUGH.
By ERASMUS DARWIN, M. D. F. R. S.
AUTHOR OF ZOONOMIA, AND OF THE BOTANIC GARDEN.
Suadent hæc CREATORIS leges a ſimplicibus ad compoſita.
LIN, ORD. NAT.
LONDON:
PRINTED FOR J. JOHNSON, ST. PAUL'S CHURCH-YARD
BY T. BENSLEX, BOLT COURT, FLEET STREET.
1800.

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1800
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DEDICATION.
To Sir John Sinclair, Baronet, to whoſe unre-
mitted exertions, when Preſident of the Board of
Agriculture, many important improvements in the
cultivation of the earth were accompliſhed and re-
corded; this Work, which was began by the inſtiga-
tion of his letters to the author, is dedicated with
great reſpect.
Derby, Jan, 1, 17998
A 2
CONTENTS

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CONTENTS
Introduction.
WX
PART THE FIRST.
PHYSIOLOGY
OT
VEGETATION.
SECT. I. Individuality of the Buds of Vegetables:
II. Their Abſorbent Veſels.
III. Their Umbilical Veſſels.
IV. Their Pulmonary Arteries and Veins.
V. Their Aortal Arteries and Veins.
VI. Their Glands and Secretions.
VII. Their Organs of Reproduction.
VIII. Their Muſcles, Nerves, and Brain..
PART THE SECOND.
ECONOMY OF VEGETATION.
IX. The Growth of Seeds, Buds, and Bulbs.
X. Manures, or the Food of Plants.
XI. Of Draining and Watering Lands.
XII. Aeration and Pulverization of the Soil.
XIII. Of Light, Heat, Eletricity.
XIV. Diſeaſes of Plants.
TART

vi
CONTENTS.
PART THE THIRD.
***
AGRICULTURE AND HORTICULTURE.
XV. Production of Fruits.
XVI. Production of Seeds.
XVII. Production of Roofs and Barks.
XVIII. Production of Leaves and Wood,
XIX. Production of Flowers.
XX. Plan for diſpoſing a part of the Syſtem of Linneus into more
Natural Claſſes and Orders.
APPENDIX.
Improved Conſtruction of the Drill Plough.
INTRO

INTRODUCTION
Bone
AGRICULTURE and GARDENING, though of ſuch great utility in
producing the nutriment of mankind, continue to be only Arts,
conſiſting of numerous detached facts and vague opinions, without a
true theory to connect them, or to appreciate their analogy; at a
time when many parts of knowledge of much inferior conſequence:
have been nicely arranged, and digeſted into Sciences..
Our imperfect acquaintance with the phyſiology and economy of
vegetation is the principal cauſe of the great immaturity of our know-
ledge of Agriculture, and Gardening. I ſhall therefore firſt attempt
a theory of vegetation, deduced principally from the experiments of
Hales, Grew, Malpighi, Bonnet, Du Hamel, Buffon, Spallanzani,
Prieſtley, and the Philoſophers of the Linnæan School, with a few
obſervations and opinions of my own; ſome of which have in part
already appeared in Zoonomia, and in the notes to the Botanic Gar-
den, but are here corrected and enlarged. To the former of which
works I hope this may be eſteemed a ſupplement, as it is properly ani
continuation of the ſubject.
a
My
DOJOT

viil
INTRODUCTION.
My inducement to commence this work, after it was ſuggeſted to
me by the letters of Sir John Sinclair, was, a belief, that the expe-
riments and obſervations already made on the growth of plants, with
the modern improvements in chemiſtry, were ſufficiently numerous
and accurate for the eſtabliſhment of a true theory of vegetation ;
ſo much wanted to connect the various facts in the memory, to ap-
preciate their value, and to compare them with each other; and
finally to direct the proſecution of future experiments to uſeful
purpoſes.
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PHYTOLOGIA,

PHYTOLOGIA.
7
PART THE FIRST.
PHYSIOLOGY OF
VEGETATION,
SECT. I.
THE INDIVIDUALITY OF THE BUDS OF VEGETABLES.
3
1. Vegetables are inferior animals. A bud torn from a tree will grow ; vines and
hawthorns ſo planted. Many kinds of fruit ingrafted on one tree. 2. The bark
and branches of hollow trees remain alive. Caudex of herbaceous plants. Caudex
of buds. 3. Which deſcending, form a new bark over the old one. Theſe bark
.
veſſels occaſionally inofculate. Upper lip of wounds of the bark grows downwards.
4. Flower-buds are individual beings; do not ſo certainly grow by inoculation as
leaf-buds; are biennial plants like leaf-buds, but die in autumn without enlarging
the ſize of the tree by their progeny. 5. In what vegetables differ from animals ;
they have not muſcles of locomotion ; nor organs of digeſtion. 6. In what they re-
ſemble animals. They have abſorbent, umbilical, placental, and pulmonary veſſels,
arteries, glands, organs of reproduktion, with muſcles, nerves, and brain. 7. Pro-
.
greſs of a young bud, and of a ſeed. The plumula, radicle, and caudex of a bud.
8. Buds and ſeeds are biennial beings. How they differ. The difunion of the pith
diftinguiſhes buds from each other, and thus evinces their individuality.
1
1. We have ſo accuſtomed ourſelves to conſider life and irritability
to be aſſociated with palpable warmth and viſible motion, that we find
a renitency in ourſelves to aſcribe them to the comparatively cold and
motionleſs fibres of plants. But to reaſon rightly on many vegetable
phenomena we ſhall find it neceſſary firſt to ſhew, that vegetables
are in reality an inferior order of animals.
If a bud be torn from the branch of a tree, or cut out and planted
B
in
a

2
Sect. I. 2.
INDIVIDUALITY
a
in the earth with a glaſs cup inverted over it, to prevent the exhala-
tion from being at firſt greater than its power of abſorption ; or if it
be inſerted into the bark of another tree, it will grow, and become a
plant in every reſpect like its parent. This evinces that
every
bud
of a tree is an individual vegetable being; and that a tree therefore
is a family or ſwarm of individual plants, like the polypus, with its
young growing out of its fides, or like the branching cells of the
coral-infect.
The preſent moſt approved method of propagating vines in hot-
houſes conſiſts in cutting off a ſingle eye of a vine-ſtalk with about
an inch of the ſtem above the eye, and two or three inches below
it; and ſetting this aſlant in the bark-bed with the eye about an inch
or leſs beneath the ſurface, pointing upwards; and I have ſeen a quick-
ſet or hawthorn hedge, cretægus, propagated in the ſame manner by
planting twigs in the ground with one bud only above the ſoil.
Mr. Barns, in a treatiſe on Propagating Fruit-trees (1759, Bald-
win, London) aſſerts, that he cut a branch into as many pieces, as
there were buds or leaves upon it; and wiping the two wounded
ends dry, he quickly applied to each a cement previouſly warmed,
which conſiſted chiefly of pitch, and planted them in the earth with
unfailing ſucceſs. The uſe of this cement I ſuſpect to conſiſt in its
.
preventing the bud from bleeding to death, though the author aſcribes
it to its antiſeptic quality. And laſtly, in the inoculation and ingraft-
ing of fruit-trees, five or ſix different kinds of pears are frequently
ſeen on the branches of one tree, which could not then properly be
termed an individual being.
2. When old oaks, or willows, loſe by decay almoſt all their folid
internal wood, it frequently happens, that a part of the ſhell of the
ftem continues to flouriſh with a few healthy branches. Whence it
appears, that no part of the tree is alive but the buds, and the bark,
and the root-fibres ; that the bark is only an intertexture of the cau-
dexes

Secr. I. 2.
3
OF BU D S.
dexes of the numerous buds, as they paſs down to ſhoot their radicles
into the earth; and that the folid timber of a tree ceaſes to be alive;
and is then only of ſervice to ſupport the numerous family of buds in
the air above the herbaceous vegetables in their vicinity.
A bud of a tree therefore, like a vegetable ariſing from a ſeed,
conſiſts of three parts; the plumula or leaf, the radicle or root-fibres,
and the part which joins theſe two together; which is called the
caudex by Linneus when applied to intire plants; and may, therefore,
be termed caudex gemmæ when applied to buds.
In herbaceous plants the caudex is generally a broad flat circular
plate, from which the leaf-ftem aſcends into the air, and the radicles
or root-fibres deſcend into the earth. Thus the caudex of a plant of
wheat lies between the ſtem and the radicles, at the baſis of the
lowermoſt leaf, and occaſionally produces new ſtems and new radicles
from its ſides. Thus the caudex of the tulip lies beneath the prin-
cipal bulb, and generates new ſmaller bulbs in the bofom of each
bulb-leaf, beſides one principal or central bulb; the caudex of orchis,
and of ſome ranunculuſes, lies above their bulbous roots; whereas the
caudexes of the buds of trees conſtitute the longitudinal filaments of
the bark, reaching from the plumula or apex of the bud on the
branch to the baſe of it, or its root-fibres beneath the ſoil.
Nor is this elongation of the caudexes of the buds of trees unana-
logous to what happens to ſome herbaceous plants, as in wheat; when
the grain is buried two or three inches beneath the ſoil, an elonga-
tion of the caudex occurs almoſt up to the furface, where another ſet
of fibrous roots are protruded, and the upright ſtem commences.
The fame happens to tulip-roots when planted too deep in the earth,
as I have witneſſed, and I ſuppoſe to thoſe of many other vege-
tables.
This caudex of the buds of trees not only deſcends as above de-
ſcribed, but alſo aſcends from each bud to that above it; as on the
long
B2

4
INDIVIDUALITY
SECT. I. 4.
long ſhoots of vines, willows, and briars ; in this reſpect reſembling
the wires of ſtrawberries and other creeping plants. Thus the caudex
of perennial herbaceous plants conſiſts of a broad plate, buried be-
neath the ſoil to protect it from the froſt; while the caudex of
buds of trees conſiſts of a long vaſcular cord extending from the bud
on the branch to the radicle beneath the earth, and endures the winter
froſts without injury.
3. Theſe buds are properly biennial plants, as they are generated
in one ſummer, and in the next either produce ſeeds and die, or pro-
duce other buds, whoſe caudexes form a new bark over the former
one, that of the laſt year firſt becoming a ſofter or more porous wood,
called alburnum, or fap-wood, and gradually hardening into folid
timber, which ceaſes to pofieſs vegetable life.
Theſe long caudexes of the individual buds of trees, which conſti-
tute their bark, are well feen in the cloth made from the mulberry-
bark brought from Otaheite. On inſpecting this cloth the long fibres
are ſeen in fome places to adhere, where it is probable they occaſion-
ally inofculate, like ſome of the veſſels in animal bodies; becauſe
when ſome buds are cut off, the neighbouring ones flouriſh with
greater vigour, being ſupplied with more of the nutritious juices,
This informs us why the upper lip of an horizontal wound made
in the bark of a tree grows downwards with ſo much greater
expedition than the under one grows upwards to meet it; as the de-
ſcending caudexes of the individual buds are ſupplied directly with
nutriment from the vegetable arteries after the oxygenation of
the blood in their leaves ; whereas the under lip of the wound is nou-
riſhed only by the lateral or inofculating vefſels, which ſupplies us
with another argument againſt the individuality of trees, and in fa-
vour of that of buds.
4. The buds producing flowers are each an individual being as well
3
as

Sect. I. 5,6.
OF BUD S.
5
as the leaf-buds above deſcribed, though they are probably not ſo eaſily
capable of tranſplantation into the bark of other trees by inocula-
tion; as, I believe, it is from the miſtake of the gardeners in chooſing
flower-buds inſtead of leaf-buds to inoculate with, that ſo many buds
die in this mode of propagation. Nor does the exiſtence of many
male and female parts in one flower deſtroy its individuality any more
than the number of paps of a low or bitch, or the number of their
cotyledons, each of which during geſtation belongs to a ſeparate
fetus.
The flower-buds as well as the leaf-buds are properly biennial
plants, as they are produced in the ſummer of one year, and periſh
in the autumn of the next; but as the new buds generated by leaf-
buds continue to adhere to the parent, they are furniſhed with their
numerous caudexes, which form a new bark over the old one, whereas
the flower-buds generate ſeeds, which when mature fall upon the
ground, and thus they die in the autumn without increafing the ſize
of the parent-tree by the adheſion of their progeny like the leaf-buds.
5. Theſe buds of plants, which are each an individual vegetable
being, in many circumſtances reſemble individual animals; but as ani-
mal bodies are detached from the earth, and move from place to place
in ſearch of food, and take that food at conſiderable intervals of time,
and prepare it for their nouriſhment within their own bodies, after it
is taken; it is evident, that they muſt require many organs
and
powers,
which are not neceffary to a ſtationary bud. As vegetables are im-
moveably fixed to the ſoil, from whence they draw their aliment ready
prepared, and this uniformly, and not at returning intervals; it fol-
lows, that in examining their anatomy we are not to look for muſcles
of locomotion, as legs and arms; nor for organs to receive and pre-
pare their aliment as a mouth, throat, ftomach, and bowels, by
which contrivances animals are enabled to live many hours without
new ſupplies of food from without.
6. The parts, which we may expect to find in the anatomy of
vegetables,

6
Sect. I. 6.
INDIVIDUALITY
vegetables, which correſpond to thoſe in the animal economy, are firſt
a threefold fyſtem of abſorbent vefſels, one branch of which is de-
figned to imbibe the nutritious moiſture of the earth, as the lacteals
imbibe the chyle from the ſtomach and inteſtines of animals; another
to imbibe the water of the atmoſphere, opening its mouths on the
cuticle of the leaves and branches, like the cutaneous lymphatic vef-
fels of animals; and a third to imbibe the ſecreted fluids from the in-
ternal cavities of the vegetable ſyſtem, like the cellular lymphatics of
animals.
Secondly, in the vegetable fetus, as in ſeeds or buds, another ſyſ-
tem of abſorbent veſſels is to be expected, which may be termed um-
bilical vefſels, as deſcribed in Sect. III. of this work, which ſupply
nutriment to the new bud or feed, ſimilar to that of the albumen of
the egg, or the liquor amnii of the uterus; and alſo another ſyſtem
of arterial veſſels, which may be termed placental ones, correſpond-
ing with thoſe of the animal fetus in the egg or in the womb, which
ſupply the blood of the embryon with due oxygenation before its na-
tivity. in
bo
Thirdly, a pulmonary fyſtem correſpondent to the lungs of aerial
animals, or to the gills of aquatic ones, by which the fluid abſorbed
by the lacteals and lymphatics may be expoſed to the influence of the
air. This is done by the leaves of plants, or the petals of flowers ;
thoſe in the air reſembling lungs, and thoſe in the water reſembling
gills.
Fourthly, an arterial ſyſtem to convey the fluid thus elaborated to
the various glands of the vegetable for the purpoſes of its growth, nu-
trition, and ſecretions; and a ſyſtem of veins to bring back a part of
the blood not thus expended.
Fifthly, the various glands which ſeparate from the vegetable blood
the honey, wax, gum, refin, ſtarch, ſugar, effential oil, and other ſe-
cretions.
Sixthly, the organs adapted to the lateral or viviparous generation
colo
of

SECT. I. 7.
OF BUDS.
7
a
а.
of plants by buds, or to their ſexual or oviparous propagation by
feeds.
Seventhly, longitudinal muſcles to turn their leaves to the light,
and to expand or cloſe their petals or their calyxes; and vaſcular
muſcles to perform the abſorption and circulation of their fluids,
with their attendant nerves, and a brain, or common ſenſorium, be-
longing to each individual feed or bud ; to each of which we ſhall
appropriate an explanatory ſection.
7. An embryon bud, therefore, whether it be a leaf-bud or a flower-
bud, is the viviparous offspring of an adult leaf-bud, and is as indivi-
dual as a feed, which is its oviparous offspring. It confifts, firſt, of
a central organization or caudex like the corculum of a feed, which
contains the rudiments of arteries, veins, abſorbent veſſels, and glands,
with an internal pith or brain.
Secondly, it is furniſhed with a ſyſtem of umbilical veſſels, which
are inſerted into the alburnum or fap-wood of the tree, or form a part
of it, and deſcending into the earth ſupply it in the early ſpring with
its firſt nutrition, like the ſeminal roots, ſo called, which paſs from
the corculum of the feed, and are ſpread on the cotyledons, as ſeen
in the garden bean, repreſented in Plate I. Fig. 1. which is taken
from Dr. Grew's Anatomy of Plants.
Thirdly, this umbilical fyſtem probably contains alſo what
may
be
termed a placental artery, terminating on the coats of the lateral air-
veſſels, which penetrate the bark of trees horizontally, for the pur-
poſe of oxygenating the blood of the vegetable fetus, like thoſe dif-
tributed from the umbilical veſſels of the chick on the air-bag at the
broad end of the egg. See Sect. II. 4. and III. 1-4.
Fourthly, it contains the rudiments of organs adapted to lateral ge-
neration or the production of new buds; or to ſexual propagation,
and the conſequent production of ſeeds.
In the early ſpring the umbilical veſſels ſupply the embryon buds
trees with fap-juice, which is then ſeen to exſude from wounds of
the
}
1

8
SECT. I. 8.
INDIVIDUALITY
the alburirum, as in the vine, vitis; the birch, betula ; and the maple,
acer; which I ſuppoſe to become oxygenated in the circulation of the
vegetable fetus by the horizontal air-veſſels of the bark.
As the ſeaſon advances, the leaf-bud puts forth a plumula, like a
ſeed, which ſtimulated by the oxygen of the atmoſphere riſes up-
wards into leaves to acquire its adapted pabulum, which leaves con-
ftitute its lungs; it alſo protrudes from its long caudex, which forms
the new bark over the old one, a radicle, which ſtimulated by moiſ-
ture paſſes downwards, and deſcends into the earth to acquire its
adapted pabulum ; and it thus becomes an adult vegetable being with
the power of producing new buds.
The flower-bud under ſimilar circumſtances puts forth its bractes
or floral-leaves, which ſerve the office of lungs to the pericarp and
calyx; and expands its petals, which ſerve the office of lungs to the
anthers, and ſtigmas, which are the ſexual organs of reproduction,
and which die and fall off, when the ſeed is impregnated ; and thus,
like the leaf-bud, it becomes an adult vegetable being with the power
of producing ſeeds.
8. As the flower-bud produces many ſeeds during the ſummer, ſo
the leaf-bud produces many budlets during the ſummer, as may be
ſeen in the long ſhoots of the vine and willow, vitis .et falix. In this
climate both the buds and ſeeds are properly biennial vegetables ; that
is, they are produced in one ſummer, and periſh in the next. But the
feed differs from the bud in this circumſtance, that it drops on the
earth, and is thus ſeparated from its dead parent in the autumn;
whereas the bud continues to adhere to its dead parent, and grows
over it as it advances.
Now as the internal pith of a bud appears to contain or produce
the living principle, like the brain and medulla oblongata, or ſpinal
marrow of animals, we have from hence a certain criterion to diſtin-
guiſh one bud from another, or the parent bud from the numerous
budlets,
a

PLATE I.
I

PLATE I.
Fig. 1. repreſents the umbilical veſſels ſpread on the lobes of a bean, when it begins
to vegetate, as mentioned in Sect. I. 7. but more particularly deſcribed in Sect. III.
1. 3; which are believed to conſiſt of a ſyſtem of abſorbent veſſels, and another ſyſtem of
placental veſſels, for the purpoſe of acquiring nutriment, and of oxygenating the vege-
table blood. The plate is copied from Grew, Tab. I. f. 14. a the plumula, b the cor-
culum, cc the lobes. See Sect. I. 7. and III. 1. 3.
Fig. 2. is copied from Malpighi, Tab. II. Fig. 6, and repreſents the longitudinal
fibres of the bark of willow, which adhere together, and ſeparate from each other alter-
nately, with horizontal apertures between them ; which are believed to be air-veſſels,
for the purpoſe of oxygenating the blood of the embryon buds, like the air-bag at the
broad end of an egg. bbb are the longitudinal filaments of the bark, a a a are the ho-
rizontal perforations.
Duhamel obſerved by a microſcope fimilar apertures of different diameters in the bark
of oak; the ſmaller ones he believed to be the excretory ducts of the perſpirable matter,
and larger ones I ſuppoſe to be air-veſſels. The extreinities of ſome of theſe in the birch-
tree ſtood above the level of the cuticle. Phyſique des Arbres, Plate I. Fig. 7. and 11.
See Sect. I. 7. and II. 4. of this work.

Plate I.
Sect. I.
Fig. 1.
α ο α β α και
α
Fig. 2.
11
ΟΟΙΙΠΠΙΙΙΙ
ο αοαοα και


Secr. 1. 8.
9
OF BUDS.
budlets, which are its offspring, as there is no communication of the in-
ternal pith between them.
This obſervation was made by ſlitting the young branches of horſe-
cheſnut, æfculus hippocaſtanum; of aih, fraxinus; of willow, falix;
and of elder, ſambucus nigra ; and I plainly diſcerned that there ex-
iſted no communication of pith between the lateral budlets and their
parent ſhoots, or between the central larger budlet at the ſummit of
the branch, and its parent ſhoot. This alſo afforded me one reaſon
to conclude that the different joints of wheat, triticum, of ſouthiſtle,
fonchus, and of teaſel, dypſacus, are different buds growing on each
other, thoſe at the ſummit only producing ſeeds; becauſe there is a
diviſion which ſeparates the pith contained in each joint of their hol-
low ftems, as is further explained in Sect. IX. 2. 4. and 3. I. and
which perfectly evinces the individuality of buds.
С
SECT.
.

10
SECT. II. 1.
ABSORBENT VESSELS.
SECT. II.
THE ABSORBENT VESSELS OF VEGETABLES.
1. Roots, leaves, bark, ſap-wood, ſhewn to abſorb by not moiſtening them, by placing
them in water. 2. Abſorbent veſſels coloured by a decoction of madder, by dilute
ink. They form a ring in the ſap-wood beneath the bark, with a ring of arteries
exterior to them. 3. Abſorbents erroneouſly believed to be air-veſſels, are viſibly
full of Sap-juice in a vine-ſtalk. Vegetable veſſels have rigid ſides, which do not
collapſe, and hence become full of air when cut; not ſo in animal veſſels. 4. Some
horizontal veſſels in trees are truly air-veſels for the embryon bud, like the air in
the broad end of the egg. 5. Abſorbent veſſels conſiſt of long cylinders; air will
paſs through them either way in the dead vegetable ; are not reſpiratory organs, as
they exiſt in the roots of trees. May receive air diſſolved in water. 6. Abſorbent
veſſels aɛt either direct or retrograde. A forked branch in water. An inverted
tree. A ſuspended tree. So in the operation of an emetic, and in ruminating cows.
7. They conſiſt of a ſpiral line without valves; and by its vermicular contraktion
forcibly carry on their contained fluids either way. 8. Thoſe of the root aɛt occa-
fionally in winter ; but vines in hot-houſes muſt have their roots guarded from
froſt
in Spring. Accumulated ice deſtroys trees in Spring. 9. They ſometimes abſorb
poiſonous fluids, as ſpirit of wine, ſolution of arſenic, vitriolic acid; roots ſaid to
creep aſide from bad
ſoil erroneous. 10. Abſorbents of trees like the receptacle of
chyle.
1. The exiſtence of that branch of the abſorbent veſſels of vege-
tables, which reſembles the lacteals of animal bodies, and imbibes
their nutriment from the moiſt earth, is evinced by their growth, ſo
long as moiſture is applied to their roots, and their quickly withering
when it is withdrawn.
Beſides

Sect. II. 2.
II
ABSORBENT VESSELS.
Beſides theſe abſorbents in the roots of plants there are others, which
open
their mouths on the external ſurfaces of the bark and leaves to
abſorb the moiſture of the atmoſphere, reſembling the cutaneous
lymphatics of animal bodies; the exiſtence of theſe is ſhewn, becauſe
a leaf plucked off and laid with its under ſide on water will not wither
ſo ſoon as if left in the dry air. The ſame if the bark alone of a
branch, which is ſeparated from a tree, be kept moiſt with water.
A third branch of abſorbent veſſels opens its mouths on the internal
ſurfaces of the cells and cavities of the vegetable ſyſtem to abſorb the
ſecreted fluids, after they have performed their adapted offices, ſimilar
to the cellular lymphatics of animal bodies, as may be fhewn by
moiſtening the alburnum or fap-wood, and the internal ſurface of the
bark of a branch detached from a tree, which will not then ſo ſoon
her as if left in the dry air unmoiſtened.
Another means of demonſtrating the abſorbent powers of the parts
of vegetables is by inſerting them into glaſs tubes, or into tall narrow
veſſels filled with water, and obſerving how much more rapidly the
ſurface of the water ſubſides than in ſimilar veſſels by evaporation
alone.
2. By the following experiment theſe vegetable abſorbent veſſels
were made agreeably viſible by a common magnifying glaſs. I placed
in the ſummer of 1781 ſome twigs of a fig-tree with leaves on them
about an inch deep in a decoction of madder (Rubia tinct), and others
in a decoction of logwood (hæmatoxylum campechenſe), along with
ſome ſprigs cut off from a plant of picris. Theſe plants were choſen
becauſe their blood is white. After ſome hours, and on the next
day, on taking out either of theſe, and cutting off from its bottom
about an eighth of an inch of the ſtalk, an internal circle of red points
appeared, which I believed to be the ends of abſorbent veſſels coloured
red with the decoction, and which probably exiſted in the newly
formed alburnum, or fap-wood, while an external ring of arteries was
C 2
feen
a
a

ABSORBENT VESSELS.
SECT. II. 3.
ſeen to bleed out haſtily a milky juice, and at once evinced both the
abſorbent and arterial ſyſtem.
Many ſimilar experiments were made by M. Bonnet, by placing
parts of the ſtem or roots of various vegetables, as of kidney-beans,
peach-tree, and elder, in dilute ink; in all theſe the veſſels of the bark
were uncoloured, and thoſe of the pith; but thoſe beneath the bark,
;
which he terms woody, were coloured black, which I ſuppoſe to have
been the circle of abſorbent veſſels above mentioned. Uſage de Feu-
illes, Plate XXIX.
3. Theſe abſorbent veſſels have been called bronchia by Malpighi
and Grew, and ſome other philoſophers, and erroneouſly thought to
be air-veſſels ; in the ſame manner as the arteries of the human body
were fuppofed to convey air by the antients, till the great Harvey
by more exact experiments and juſter reaſoning evinced, that they
were blood-vefſels. This opinion has been ſo far credited becauſe
air is ſeen to iſſue from wood, whether it be green or dry, if it be
covered with water, and placed in the exhauſted receiver of an air-
pump; and theſe veſſels have therefore been ſuppoſed to conſtitute
a vegetable reſpiratory organ ; but it will be ſhewn hereafter, that the
leaves of plants are their genuine lungs, and that the abſorbent veſſels
and arteries become accidentally filled with air in the dead parts
of
vegetables.
For as the veſſels of vegetables are very minute, and have rigid
coats, their fides do not collapſe when they are cut or broken, as
their juices flow out or exhale; they muſt therefore receive air into
them. This may be readily ſeen by inſpecting with a common lens
the end of a vine-ſtalk two or three years old, when cut off hori-
zontally. At firſt the veſſels, which are feen between the partitions
radiated from the center, appear full of juice ; but in a minute or
leſs this juice either paſſes on, or exhales; and the veſſels appear empty,
that is filled with air. This experiment I have twenty times repeated
with

Sect. II. 4.
13
ABSORBENT VESSELS.
а
a
with uniform ſucceſs, and it is ſo eaſily made by haſtily applying a
common lens after the diviſion of a vine-ſtalk, that I think there can
be no error in it; and it is wonderful that theſe veſſels, which are
found in the alburnum, and conſiſt of a ſpiral line, whether they may
properly be called abſorbent or umbilical veſſels, or conſiſt of both,
ſhould ever have been ſuppoſed to be air-veſſels.
There is nevertheleſs an experiment by Dr. Hales, which would
at firſt view countenance the aſſertion, that vegetables abſorb air. He
cemented the lower end of a ſmall twig of a tree with leaves on it
into a glaſs tube about four inches long, and ſet the other end of the
tube an inch deep in water, and obſerved in a little time, that the water
roſe an inch in the tube; but this muſt happen from the vegetable
veſſels emptying themſelves by the aſcent of their juices, and having
rigid coats, and therefore not contracting, a portion of the air was
forced into them by the preſſure of the atmoſphere, as in the above
obſervation on the vine-branch cut horizontally.
This reception of air does not happen to the veſſels of animal bo-
dies, when they are emptied of their blood, owing to the leſs rigidity
of their coats; whence the weight of the atmoſpheric air preſſes
their fides together, and cloſes the veſſel, inſtead of paffing into it.
In the ſame manner no air would paſs into the veſſels of the lungs of
animals in reſpiration, unleſs the preſſure of the atmoſphere on their
ſides was prevented by the action of the muſcles, which enlarge the
cavity of the thorax by elevating the ribs.
4. There are nevertheleſs certain horizontal veſſels of large di-
ameter, which paſs through the bark of trees to the alburnum, which
probably contain air, as they are apparently empty, I believe, in the
living vegetable; for the bark of trees conſiſts of longitudinal fibres,
which are joined together, and appear to inofculate at certain diſtances,
and recede from each other between thoſe diſtances like the meſhes
of a net, in which ſpaces ſeveral horizontal apertures are ſeen to pe-
netrate through the bark to the alburnum, according to Malpighi,
who
O
1

14
SECT. II. 5.
ABSORBENT VESSELS.
a
a
who has given a figure of them, which is copied in Plate I. Fig. 2. of
this work. Very fine horizontal perforations through the bark of
trees are alſo mentioned by Duhamel, which he believes to be per-
ſpiratory or excretory organs, but adds, that there are others of much
larger diameter, ſome round and ſome oval, and which in the birch-
tree ſtand prominent, and pierce the cuticle or exterior bark. Phy-
fique des arbres, T. 1. Tab. III. Fig. 8. and 11.
Theſe veſſels probably contain air during the living ſtate of the tree,
as they pierce the external bark, which frequently conſiſts of many
doubles, like a roll of linen cloth ; as a new cuticle is annually pro-
duced beneath the old one, like a new ſcarf-ſkin beneath a bliſter in
animal bodies; and the old one ſometimes continues, and ſometimes
peels off like the cuticle of a ſerpent, as is ſeen on the trunks of many
cherry-trees and birches. Theſe veſſels, when contracted in dry tim-
ber, appear like horizontal inſertions in many planed boards, in
which the ſpiral abſorbent veſſels become by their contraction the lon-
gitudinal fibres, as appears in the figure of a walking cane given by
Dr. Grew, Tab. XX.
Theſe horizontal veſſels I ſuppoſe to contain air incloſed in a thin
moift membrane, which may ſerve the purpoſe of oxygenating the
fluid in the extremities of ſome fine arteries of the embryon buds, in
the ſame manner as the air at the broad end of the egg is believed to
oxygenate the fluids in the terminations of the placental veſſels of the
embryon chick, as further noticed in Sect. III. 2. 6. and III. 1. 4.
5. The abſorbent veſſels of trees in paſſing down their trunks.
confift of long hollow cylinders, whoſe fides I believe to be compoſed
of a ſpiral line, and are of ſuch large diameters in ſome vegetables as to
be viſible to the naked eye, when they become dry and empty, as in
Air will rapidly paſs through theſe veſſels in either direction,
as may be ſeen in lighting a cane fome inches long at either end, and
drawing the ſmoke through the pores of it into the mouth, as through
a tobacco-pipe. Dr. Hales readily paffed both air and water through
a
cane.
a recent

SECT. II. 6.
15
ABSORBENT VESSELS.
a recent vegetable ſtick both upwards and downwards, by ſetting one
end of it in a cup of water in the receiver of an air-pump, and ex-
hauſting the air, Veg. Stat. p. 154 ; whence he concludes with Grew,
that theſe are air-vefſels or lungs for the purpoſe of reſpiration, and
that they receive atmoſpheric air in their natural ſtate.
There is one objection to their uſe as air-veffels, which is, that
they have no communication with the horizontal air-veſſels above de-
ſcribed; for by blowing forcibly through a piece of dry cane immerf-
ed deep in water, no air is ſeen to bubble out of the ſides, but only
from the bottom of it. It may indeed be ſuppoſed, that the longi-,
tudinal cavities in dry cane may not conſiſt of the abſorbent veſſels
above deſcribed, but of the interſtices between them, as the coats of
thoſe abſorbent veffels, conſiſting of a ſpiral line, may be thought to
cloſe up by their vermicular contraction; and their interſtices, con-
fiſting of vegetable cellular membrane, may be fuppofed, when dry, to
become the tubes in cane. But in this caſe the longitudinal canals
in dry cane would not be circular cylinders, whereas they are ſo re-
preſented in a figure of a piece of cane much magnified by Dr. Grew,
Tab. XX. who has in the ſame figure given the mouths of hori-
zontal air-veſſels of circular form and larger diameter.
But there is another inſuperable objection to this idea of their uſe,
which is, that theſe veſſels equally exiſt in the roots of plants as in
their trunks; and according to Malpighi with larger diameters; and
probably terminate externally only in the roots ; and, as they are
there not expoſed to the atmoſphere, they cannot ſerve the purpoſe
of reſpiration ; air nevertheleſs in its combined ſtate, or even as dif-
folved in water, may be abſorbed by theſe veſſels; and may appear,
when the preſſure of the atmoſphere is removed in the exhauſted
receiver ; or when expanded by heat, as is ſeen in the froth at one end
of a green ſtick, when the other end is burning in the fire.
6. Theſe vegetable abſorbents differ from thoſe of animals in the
facility, with which they carry their fluids either way; for a forked
branch
a
a

16
Sect. II. 7.
ABSORBENT VESSELS.
a
branch of a tree, torn from its trunk, and having one of its forks
with the leaves on it inverted in a veſſel of water, will continue for
ſeveral days unwithered, nearly as well as if the whole had been placed
upright in the water. A willow rod on the fame account will
grow
almoſt equally well, whether the apex or baſe of it be ſet in the
ground; and Dr. Bradley, I think, mentions a young gooſeberry-tree
having been taken up, and replanted with its branches in the earth,
and its roots in the air ; and that the branches put forth root-fibres,
and the roots put forth leaf-buds. There is likewiſe a curious expe-
riment by Dr. Hales, who attached the eaſtern branch of a young
tree to its neighbour by inarching, and its weſtern branch to another
of its neighbours in the ſame manner; and after they were united,
he cut the ftem of the middle tree from its root, and thus left it hang-
ing in the air by its two inarched arms, where it flouriſhed with con-
fiderable vigour.
This power of carrying their fluid contents in a retrograde direc-
tion is alſo poſſeſſed in fome degree by the abſorbents of animals,
particularly in their diſeaſed ſtate, and even in the operation of an
emetic, as ſhewn in Zoonomia, Vol. I. Sect. 29; and is viſible in the
oeſophagus or throat of cows, who convey their food firſt down-
wards, and afterward upwards by a direct and retrograde motion of
the annular cartilages, which compoſe the gullet, for the purpoſe of
rumination.
7. The ſtructure of theſe large vegetable abſorbents, erroneouſly
called air-vefſels, probably conſiſts of a ſpiral line, and not of a veſſel
interrupted with valves, and differs in this conſtruction from animal
lymphatics; for firſt, on breaking almoſt any tender vegetable, as a
laſt year's ſprig of a roſe-tree, or the middle rib of a vine-leaf, and
gradually extending fome of the fibres, which adhere the longeſt,
this ſpiral ſtructure becomes viſible even to the naked eye, and diſ-
tinctly fo by the uſe of a common lens, as is delineated in Duhamel's
Phiſique des arbres, T. 1. Tab. II. Fig. 17, 18, 19, and in Plate LI.
and
a
a
a

Sect. II. 8. ABSORBENT VESSELS.
17
and LII. of Grew's Anatomy of Plants (fol. edit.), and by this eaſy
experiment both that abſorbent ſyſtem, which imbibes nouriſhment
from the earth, and brings it to the caudex of each bud; and that
which imbibes moiſture from the air, and a part of the perſpirable
matter on the ſurface of the leaf, and brings it to the caudex of each
bud, are agreeably demonſtrated. See Plate II. Fig. I. And that theſe
veſſels of large diameter, with their ſides conſiſting of a ſpiral line,
are not arteries or veins, is evinced by inſpecting a ftem of euphor-
bia, ſpurge; or the ſtalk of a fig-leaf, ficus, immediately on dividing
them, as the milky juice oozes from a ring of veſſels exterior to thoſe
large abſorbents.
Secondly, that theſe veſſels are not furniſhed with frequent valves
is countenanced by the experiments before mentioned in No. 5 of this
ſection, one of which conſiſted of lighting a piece of cane, and draw-
ing the ſmoke through it, as through a tobacco-pipe, in either direc-
tion; and the other in placing a bit of recent twig with one end of it
in a cup of water in the receiver of an air-pump, and caufing both
air and water to paſs through it in either direction.
If the minuter branches of vegetable abſorbents be of a ſimilar ſtruc-
ture, it is eaſy to conceive how a vermicular or periſtaltic motion of
the veſſel, beginning at the loweſt part of it, each ſpiral' ring fuc-
ceſſively contracting itſelf, till it fills up the tube, muſt forcibly puſh
forwards its contents without the aid of valves; and if this vermicular
motion ſhould begin at the upper end of the veſſel, it muſt with equal
facility carry its contained fluid in a retrograde or contrary direction.
8. As the abſorbent veſſels in the roots of plants are protected
from the froft in ſome degree by the earth which covers them; they
feem at all times to be ſufficiently alive to drink up and puſh for-
wards their adapted fluid, ſince if a branch of a tree is brought into
a warm room, it will in general pullulate in the winter, as ſoon as
the veſſels of the upper part of the branch are rendered ſufficiently ir-
ritable by warmth to act in concert with the abſorbents of the root,
D
Nevertheleſs,
a

18
ABSORBENT VESSELS. SECT. II. 9, 10.
Nevertheleſs, in ſevere froſts it is neceſſary to guard all the parts of
the ſtem which is expoſed to the open air, as is experienced in the
vines brought through holes into hot-houſes, otherwiſe after the buds
are put out a ſevere froſt ſo affects the ſtems on the outſide of the
houſe as to deſtroy all the fruit of that year. Kenedy on Gardening,
Vol. I. p. 270. And it is obſerved in Mr. A. Aikin's Natural Hiſtory
of the Year, that much ice was carried from the ſtreets in London in
1794, and piled round ſome elm trees in Moorfields, many of which
were deſtroyed in the enſuing ſpring by the flow melting of it.
9. The abſorbent veſſels of vegetables, like thoſe of animal bodies,
are liable to err in the ſelection of their proper aliment, and hence they
ſometimes drink up poiſonous fluids, to the detriment or deſtruction
of the plant. Dr. Hales put the end of a branch of an apple-tree, part
of which was previouſly cut off, into à quart of rectified ſpirit of wine
and camphor, which quantity the ſtem imbibed in three hours, which
killed one half of the tree. Veg. Stat. p. 43. Some years ago I ſprinkled
on ſome branches of a wall-tree a very ſlight ſolution of arſenic, with
intent to deſtroy inſects; but it at the ſame time deſtroyed the branches
it was thrown upon. And I was informed by Mr. Wedgewood, that
the fruit-trees planted in his garden near Newcaſtle in Staffordſhire,
which conſiſted of an acid clay beneath the factitious foil, became
unhealthy as ſoon as their roots penetrated the clay; and on inſpec-
tion it appeared, that the ſmall-fibres of the roots, which had thus
penetrated the clay, were dead and decayed, probably corroded by the
vitriolic acid of the clay, beneath which is a bed of coals.
It is, however, aſſerted by M. Buffon, that the roots of many plants
will creep aſide to avoid bad earth, or to approach good. Hift. Nat.
Vol. III. But this is perhaps better accounted for by ſuppoſing, that the
roots put out no abſorbent veſſels, where they are not ſtimulated by
proper juices; and that an elongation of roots in conſequence only
ſucceeds, when they find proper nutriment.
10. Theſe long and large cylindrical abſorbent veſſels, which paſs
from
a

PLATE II.
2

R
PLATE II.
Repreſents the ſpiral veſſels of a vine-leaf conſiderably magnified, copied from Grew,
Tab. LI. On ſlowly tearing aſunder almoſt any tender vegetable ſhoot or leaf, the
ſpiral ſtructure of theſe veſſels becomes viſible to the naked eye. They have been er-
roneouſly believed to be air-veſſels; but as they exiſt equally in the roots of plants, as in
their barks, and have no communication with the horizontal perforations of the cuticle
of the bark, they cannot be air-veſſels, and are therefore believed to conſtitute the ab-
forbent veſſels of the adult vegetable, and the umbilical ones of the embryon bud. A
ſimilar plate of the ſpiral ſtructure of theſe veſſels is given by Duhamel. As they are
larger than the vegetable blood-veſſels, and paſs along the whole caudex of each bud
from its plumula to its radicle, as well as to the cutaneous abſorbents, thoſe of the trunks
of trees or herbaceous plants may be thought to reſemble the receptaculum chyli of ani-
mal bodies. See Sect. II. 7.

Sect II. 7
min
China Maskuminarinnar
honnanananananananana
minnnnnnnnnnnnnn
Plate II.
manninn
Mannnnnnn
wwwmmmmmmmmm


Srct. II. 10.
19
ABSORBENT VESSELS
from the roots of trees up to the ſummit of the caudex of each bud at
the foot-ſtalk of the leaf, I ſuppoſe to be analogous to the receptacle
of the chvle of animals, as the ſmall abſorbent branches of the roots
probably unite beneath the ſoil into thoſe large vefſels, which are
ſo eaſily viſible; hence the caudex of each bud conſiſts of an elon-
gation of abſorbent veſſels, and of arteries and veins reaching from
the union of the root-branches to the foot-ſtalk of each leaf, and the
plumula of the bud in its bofom, as deſcribed in Sect. I. 7.
D 2
SECT

20
UMBILICAL VESSELS.
Sect. III.
SECT. III.
THE UMBILICAL VESSELS OF SEEDS AND BUDS.
ment.
و
.
1. 1. Seeds are a ſexual offspring like eggs. Some ſeeds and eggs contain two kinds
of nouriſhment. Other ſeeds and Spawn of fiſh contain but one kind of nouriſh-
2. Air-bag in eggs, and in ſome fruits ; not in ſeeds, nor in ſpawn.
3. Veſſels improperly called umbilical; thoſe properly called umbilical conſiſt of ab-
forbents, and a placental artery and vein. Seed embryon and chick begin their
growth by the a&tion of their abſorbents. 4. Seminal roots of Grew, and chorion
of the chick of Malpighi, are reſpiratory organs. 5. In what the chick differs from
the feed-embryon. Nothing is found in ſeeds fimilar to the yolk of the egg. II. 1. Buds
and bulbs are a paternal offspring ; exactly reſemble their parents.
2. Have um-
bilical veſſels, in which the fap-juice riſes in the ſpring. Why the bark is then
eaſily ſeparated from the alburnum. 3. Sugar in the ſap-juice exiſts in the albur-
num, and in roots. Dry rot of timber owing to fermentation. Why lower branches
firſt pullulate. 4. Sap aſcends not by capillary attraction, but by the irritative
motions of abſorbent veſſels. Inſtances of vegetable irritability. Abſorbent ves-
ſels ſometimes aɛt as capillary Syphons, and as capillary tubes. 5. Umbilical ver-
ſels coaleſce. Why trees do not bleed in ſummer. 6. Umbilical veſſels of buds like
thoſe of ſeeds. Poſeſs air-veſſels like thoſe of the chick. Buds, like eggs, ſeparate
from the parent; their umbilical veſſels improperly called placental ones, as they
convey nutriment; bence plants become dwarfs if the cotyledons of the feed are de-
ſtroyed. Birch-trees die if ſmeared with oil or pitch. 7. Reſervoir of nutriment
in the alburnum of trees, and in the roots of biennial plants. Experiment of boiling
the alburnum and fermenting the liquor. As buds are formed at midſummer, they
may then be tranſplanted by inoculation, but in the ſpring must be ingrafted, and
grow by inofculation of veſſels, like inflamed parts of animals. 8. A pauſe in
vegetation at midſummer. New umbilical veſſels act in autumn, and the bark ſepa-
rates eaſily as in ſpring. Honey-dew. Sap-juice riſes in winter occaſionally both in
ever-

SECT. III. 1. 1. UMBILICAL VESSELS.
21
ever-green trees and deciduous ones, and after the ſummit of the plant is cut off
9. Umbilical veſſels and abſorbents ſeen in a vine-ſtalk, the latter exterior to the
former. Exiſt in the alburnum.
I. 1. The ſeeds of vegetables are a ſexual offspring correſponding
with the eggs of animals, and contain, like them, not only the rudi-
ment of the new organization, but alſo a quantity of aliment laid up
for its early nouriſhment.
The
eggs
of birds contain two kinds of albumen, or white, one
lefs viſcid than the other, which is firſt conſumed, and the yolk or
vitellum, which is drawn up into the bowels of the chick at its ex-
clufion from the ſhell, and ſerves it for nouriſhment a day or two,
till it can learn to ſelect and digeſt grains or inſects. In like manner
many
ſeeds are furniſhed with two kinds of nouriſhment, the muci-
laginous or oily meal of the feed-lobes, and the faccharine or aceſcent
pulp of the fruit, as in pears, plums, cucumbers, which ſupply nu-
triment to the embryon plant, till it is able to ſtrike into the earth ſuf-
ficient roots for the purpoſe of abſorbing its nutritious juices.
The ſpawn of fiſh, and of frogs, and of inſects, as of ſnails and bees,
which are almoſt as innumerable as the ſeeds of plants, and are in the
ſame manner excited into life by the warmth of the ſun, are analo-
gous to thoſe ſeeds, I believe, which are not ſurrounded with fruit,
and which contain but one kind of nouriſhment for the embryon
plant, as grains of corn, and legumes; but perhaps theſe have not
yet been ſufficiently attended to by philoſophers.
Theſe eggs of animals and ſeeds of vegetables are produced by the
congreſs of male and female organs; the former ſupplying the ſpeck
of animation or cicatricula in the egg, and the corculum or heart in
the ſeed ; and the latter producing the nidus, or neſt for its recep-
tion, and the nutritive material for its firſt ſupport. Thus the eggs
of fowls are formed long before they are impregnated, and are ſome-
times laid in their unimpregnated ſtate; and the ſeeds of legumes are
viſible

22
UMBILICAL VESSELS. Sect. III. I. 2, 3.
2.
viſible many days before the flower opens, and in confequence before
they are impregnated, as obſerved by Spallanzani.
The
eggs of birds contain a bag of air at their broad end for the
purpoſe of oxygenating the blood of the chick. In this one circum-
ſtance the feeds of plants ſeem to differ from the eggs of birds, as
they contain no air-bag, though it is probable they may agree with
the ſpawn of fiſh, which I ſuppoſe poſſeſs no included air. When the
ſeeds fall on the ground in their natural ſtate of growth, or are buried
an inch or two beneath the foil, which has recently been turned over,
and thus contains much air in its interſtices, their coats do not
continue dry like the ſhells of eggs during incubation, but immedi-
ately become moiſt membranes, like the external membrane of the
ſpawn of fiſh immerſed in water, and in conſequence can admit the
oxygenation of the air through them to an adapted fet of arteries on
their internal ſurface, according to the curious obſervations of Dr.
Prieſtley on the oxygenation of the blood by the air through the moiſt
membranes of the lungs.
It ſhould be here obſerved, that many feeds, before they fall on the
moiſt earth, are included in a bag of air, as thoſe of the ſtaphylea,
bladder-nut; of the phyſalis alhekengi, winter-cherry; of colutea,
bladder-ſenna; in the pods of peas and beans; in the cells ſurround-
ing the ſeeds of apples and pears; and in the receptacle of ketmia,
which probably ſerves to oxygenate the blood of the infant ſeed, which
in theſe plants may thus be of forwarder growth, before it is ſhed upon
the ſoil.
3. There exiſts a ſeries of glands, and their ducts, improperly
called umbilical vefſels by ſome writers, which ſupplies the ſeed with
nouriſhment from the parent plant, ſo long as it adheres to the ova-
rium of its mother, as the veſſels by which a pea adheres to the pod, in
which it is included ; in fruits and nuts, where the kernel is covered
with a ſtone or ſhell, a long cord of veſſels paſſes into the bottom of the
ſtone or ſhell, and riſing to the top bends round the lobes of the ker-
I
nel,

Sect. III. I. 3. UMBILICAL VESSELS.
23
a
a
nel, and is inſerted near or into the corculum or heart of the feed,
where the living principle reſides, and affords not only preſent nu-
trition to the vegetable embryon, but alſo fecretes the farinaceous or
oily materials for its future nouriſhment, which conſtitute the cotyle-
dons of the feed.
But the veſſels, which may be properly called umbilical, paſs from
the heart or corculum of the feed, which is the living embryon of
the future plant, into the ſeed-lobes, commonly called cotyledons, and
imbibe from thence a ſolution of the farinaceous or oily matter there
depoſited for the nutriment of the new vegetable. Theſe veſſels are
delineated in their magnified appearance by Dr. Grew, Plate LXXIX.
fol. edition, and are by him termed ſeminal roots. See Plate I. Eig. I.
Theſe umbilical veſſels probably conſiſt of a ſyſtem of abſorbents,
which ſupply nutriment to the embryon plant from the cotyledons
of the feed, and alſo of a ſyſtem of placental arteries and veins ſpread
on the humid membrane, which covers the cotyledons, and is moiſ-
tened by its contact with the earth, for the purpoſe of oxygenating
the vegetable blood. This idea is countenanced by many plants
bringing up their cotyledons, or feed-lobes, out of the ground into
the air, which are then converted into leaves, and perform the office
of lungs, after they have given up beneath the ſoil the nutriment,
which they previouſly contained, as in the young kidney-bean, pha-
ſeolus ; fo the white corol of the helleborus niger, chriſtmas roſe, is
changed into a green calyx by looſing one ſyſtem of arteries after the
impregnation of the ſeeds.
The ſeed-embryon therefore reſembles the chick in the egg, firſt
as when vivified by the influence of external warmth they both begin
their growth by the abſorbent ſyſtem of veſſels being ſtimulated into
action by their adapted nutriment; and the fluids thus puſhed for-
wards ſtimulate into action the other parts of the ſyſtem, conſiſting at
firſt principally of arteries and glands.
Secondly, they ſeem to reſemble each other in their poſſeſſing each
of

24
4.
UMBILICAL VESSELS. Sect. III. I.
.
of them an abſorbent ſyſtem of veſſels, which imbibe the nutritious
matters laid up for them in the albumen or white of the egg, and in
the cotyledons or lobes of the ſeed; and alſo of a placental fyftem of
arteries for the purpoſe of oxygenating their fluids, as deſcribed above
in the ſeed, and which appears in the egg to be ſpread on a mem-
brane, which covers the white, as is ſhewn in the plates of Mal-
pighi, and called by him the chorion, and expoſes the blood of the
chick to the oxygen of the air contained at the broad end of the egg
through a moiſt membrane.
4. The uſe of the large apparent artery ſpread on the cotyledons
of a germinating feed of a garden-bean, called feminal roots-by Grew,
as ſhewn in Plate I. Fig. 1, and that ſpread on the chorion of the
chick in the egg, ſo called by Malpighi, and ſhewn in Tom. II. Fig.
54, and by Fabricius ab Aquapendente, Tab. I. Fig. 13, which
muſt be an artery, as it carries red blood, are believed to be reſpiratory
organs, like the placental vefſels of the fetus of viviparous animals,
becauſe the cotyledons of fome feeds rife out of the ground, and be-
come leaves, after the nutriment they contained is expended, and
are then called feminal leaves, as in the kidney-bean, phafeolus; and
becauſe thoſe which do not riſe out of the ground periſh beneath the
foil, as ſoon as the young plant gains its leaves, which are its aerial
reſpiratory organ.
Secondly, the chorion of the chick conſiſts of a membrane includ-
ing the white, or albumen, and is not only in contact with the air-
bag at the broad end of the egg, which, as the chick advances, co-
vers more than half of the internal ſurface of the ſhell, but alſo with
the membrane which lines all the other part of the ſhell, as appears
in Plate III. which is copied from Malpighi: yet this extenſive
chorion, with the numerous arteries and veins which are ſpread upon
its ſurface, is not drawn up into the body of the chick like the yolk
and its including membrane, but periſhes at the nativity of the chick
like the placental veſſels of the fetus of viviparous animals; or ſome-
a
times,

SECT. III. I. 5.
25
UMBILICAL VESSELS.
times, I fuppofe, before its nativity, as the chick perforates the air-
bag, and is heard to chirp, before it is excluded from the ſhell.
Hence it would appear, that both the artery attending the ſeminal
roots above mentioned, and this artery on the chorion of the chick,
muſt perform ſome more important office than to ſupply nouriſhment
to the coats of the abſorbent veſſels, which imbibe the mucilage of
the ſeed, or the white of the egg, and which abſorbents muſt them-
ſelves poſſeſs their proper vafa vaforum. And what more important
office can they have than that of oxygenating the blood of the vege-
table or animal embryon? And this becomes more probable as they
both periſh at its nativity like the placenta and cotyledons of vivi-
parous animals.
a
5. As the incubation of the chick advances, it differs from the feed-
embryon in the production of inteſtines, with a ftomach, on the in-
ternal ſurfaces of which the mouths of the abſorbents now terminate;
and laſtly in the production of a mouth and throat to receive and
ſwallow the remainder of the albumen, in which it ſwims; whereas
the ſeed-embryon ſhoots down new roots into the earth with an ab-
ſorbent fyſtem to acquire its nutriment, as that from the cotyledons
of the feed becomes exhauſted. See Sect. VII. 1, 2.
Nor is there any thing ſimilar to the yolk of the egg found in the
feeds of vegetables, which is drawn up into the inteſtines of the
young
chick about the time of its exclufion from the ſhell to ſerve it with
nutriment for a day or two, till it can learn of its parent by imitation
to ſelect and ſwallow its adapted food. Nor is the fetus of vivipar-
ous animals furniſhed with any thing ſimilar to the yolk of oviparous
ones, as they have milk ready prepared for their firſt nutriment in
the breaſt of the mother.
As ſoon as the new foliage of the plant riſing out of the ground
becomes expanded, and the root deſcending penetrates the earth with
its fibrous ramifications, the umbilical ſyſtems of veſſels ceaſe to act,
both the abſorbents, which previouſly ſupplied the young embryon
E
with

26 UMBILICAL VESSELS. Sect. III. II. 1, 2.
a
with nutriment from the cotyledons, and alſo the placental artery,
which was ſpread on the exterior membrane of the cotyledons for the
purpoſe of oxygenation. Theſe veſſels now either coaleſce and decay
beneath the ſoil, or wither and fall off, when raiſed above it in the
form of ſeed-leaves.
II. 1. The ſeeds of plants are thus a ſexual or amatorial
progeny,
produced principally by the male part of the flower, and received
into a proper nidus, and ſupplied with nutriment by the female part
of it, and which can thus claim both a father and a mother. But the
buds of vegetables are a linear pogeny, produced and nouriſhed by a
father alone, to whom they adhere, not falling off like the ſeeds, as
is farther treated of in Zoonomia, Vol. I. Sect. XXXIX. II. 2. and in
Sect VII. I. 3. of this work. For in this moſt ſimple kind of ve-
getable reproduction, by the buds of trees, and by the bulbs of ſome
plants, and by the wires of others, which are their viviparous pro-
geny, the caudex of the leaf is the parent of the bud or bulb, or wire,
which riſes in its bofom, according to the obſervation of Linneus.
This linear or paternal progeny of vegetables in buds or bulbs, or
wires, is attended with a very curious circumſtance, which is that
they exactly reſemble their parents, when they are arrived at their
maturity, as fhewn in Sect. VII. 1. 3. as is obſerved in grafting
fruit-trees, and in propagating flower-roots, or ſtrawberries, or po
tatoes, by their wires or roots; whereas the feminal offspring of
plants, as it derives its form in part from the mother as well as fa-
ther, is liable to perpetual variation, both which events are employed
to great advantage by ſkilful gardeners.
2. As the embryons in the buds are the viviparous offspring of ve-
getables, it becomes neceſſary, as they have no mouths, that they
ſhould be furniſhed like the embryons in the feeds with umbilical
veſſels to fupply them with nouriſhment, till they acquire roots with
another ſet of abſorbent veſſels to imbibe moiſture from the earth, and
leaves to act like lungs for the purpoſe of oxygenating their blood.
Theſe

SECT. III. II. 3. UMBILICAL VESSELS.
27
Theſe umbilical veſſels, which ſupply the buds of plants with nou-
riſhment in the early ſpring, and unfold their foliage, have been much
attended to by Dr. Hales and Dr. Walker (Edinb. Phil. Tranſact.
Vol. I.) The former obſerved, that the fap from the ſtump of a virre,
which he had cut off in the beginning of April, aroſe twenty-one
feet high in glaſs tubes affixed to it for that purpoſe, but which in a
few weeks ceaſed to bleed. Dr.Walker alſo marked the progreſs of
the aſcending fap in various branches of trees, and obſerved, that in
cold weather it ſtopped many hours in a day, as well as in the night,
and found likewiſe as ſoon as the leaves became expanded, that the
wounded trees ceaſed to bleed.
The veſſels, which convey the ſap-juice with ſuch amazing force, are
ſituated in or compoſe the alburnum, or ſap-wood, of the trunk or root
of the tree; nor is it ſurprizing, that ſome of it when preſſed by ſo
high a column ſhould exſude into the cells between the alburnum
and bark, as in theſe cells much fap-juice was obſerved by Dr. Walker,
and this accounts for the great eaſe with which the barks of willows
and of oaks are ſeparated in the ſpring from their wood. The abſorb
ent mouths of theſe fap-veſſels open externally in the moiſt earth on
the roots of trees, and alſo into the air on their trunks; and thus mix
the aqueous fluids, which they thus imbibe, with the faccharine and
mucilaginous materials depoſited previouſly in the alburnum of theſe
roots and trunks.
3. This aſcending ſap-juice during the ſpring ſeaſon is in ſome
trees ſo ſweet, that it is uſed in making wine, as that of the birch-
tree in this country; and ſugar is procured in ſuch quantity from a
maple in Penſylvania, that from each tree five or fix pounds of good
ſugar have been made annually without deſtroying it. Ruſh, on Sugar
Maple. Phillips, London. This fugar is depoſited I believe in the
fap-wood of the trunk and roots of trees, as in the manna-aſh, and
is diſſolved in the ſpring by the moiſture, which is drank up by the
abſorbents from the earth and atmoſphere, and forcibly carried on to
expand
E 2

28
UMBILICAL VESSELS. Sect. III. II. 4.
a
e
expand the buds. Its exiſtence in the ſap-wood as well as in the
roots is ſhewn from the pullulation of oak-trees, which have been
ftripped of their bark, and alſo from the expanſion of the eyes of a
vine-ſhoot, when it is cut from the tree, and planted in the earth, as
deſcribed in Sect. XV. 1. 3.
This ſuggeſts to us the reaſon why the wood of trees is ſo much
ſooner ſubject to decay, when they are felled in the vernal months;
becauſe the ſugar, which the fap-wood then contains, ſoon runs into
fermentation, and produces what is called the dry rot; whence the
cuſtom has prevailed of debarking oaks in the ſpring, and felling
them in the autumn; and it is probable that the wood of all other
trees would laſt much longer, if it was thus managed, as the growth
of the new leaves would exhauſt the ſugar of the fap-wood.
Sweet juices for a ſimilar purpoſe of expanding the buds of herba-
ceous plants are depoſited during the autumn in their roots, as in tur-
nep, beet, tragapogon; or in the knots or joints of the ſtem, as in
graſſes, and the ſugar-cane; which like the farina and oil in ſeeds, and
the dulcet mucilage of fruits, and the honey of flowers, were deſigned
for the food of the young progeny of plants, but become the fufte-
nance of mankind !
As the faccharine matter which is thus depoſited in the roots, or in
the alburnum, or in the joints of plants, muſt be diluted by the
moiſture abſorbed from the earth by their roots, we underſtand why
the leaves of the lower branches of trees are firſt expanded, as is ſeen
diſtinctly in the hawthorn hedges in April, as theſe muſt firſt receive,
the aſcending fap-juice, as was obſerved by Dr.Walker in his ac-
count of the maple.
4. The force of the riſing fap from a vine-ſtump in the bleeding
ſeafon, as diſcovered by Dr. Hales, is at fome times equal to the
whole preſſure of the atmoſphere, which is about fourteen pounds on
a ſquare inch of ſurface. This great power in raiſing the fap he aſ-
cribes to capillary attraction, and to the variations of heat during the
day

Sect. III. II. 4. UMBILICAL VESSELS.
29
a
day and night. In regard to capillary attraction, however high it may
raiſe a fluid in very ſmall tubes, it can not make it flow over them,
as the fap-juice did in Dr. Hales's vine-ſtump; nor can it raiſe a fluid
quite to a level with the upper rim of a glaſs tube, as the fluid is there
more attracted downwards by the glaſs beſides its gravity, and is left
in conſequence with a concave ſurface.
The means by which vegetable abſorbent veſſels in their living
ftate imbibe the fluids of the earth and atmoſphere, and carry them
forwards with ſo much force, muſt be ſimilar to thoſe, with which
animal abſorbent veſſels perform the fame office; that is by their
mouths being excited into action by the ſtimulus of the fluids, which
they abſorb.
This circumſtance is confirmed by the evident proofs of the irri-
tability of plants in various other inſtances, as the cloſing and open-
ing of the petals and calyxes of flowers by light and darkneſs, warmth
and cold, dryneſs and moiſture, and by the motions of the leaves of
mimoſa, or ſenſitive plant, and of dionoea muſcipula, by any me-
chanical ſtimulus. To this might be added a variety of inſtances of
the irritability of vegetables to the ſtimulus of heat, being increaſed
after a previous expoſure to cold, exactly in the ſame manner as hap-
pens to animal bodies, which are enumerated in a note in the Botanic
Garden, Vol. I. Canto I. 1. 322, whence the reciprocal times of the
acting and the ceaſing to act of theſe vernal vegetable abſorbents, which
are here termed umbilical veſſels, in the experiments both of Dr.
Hales and Dr. Walker, may be readily explained by their having been
benumbed by the cold, or excited into action by the warmth of the
air or earth. See Sect. XIII. 2. 3.
From one experiment nevertheleſs of Dr. Walker's theſe veffels
occaſionally act as capillary fyphons, becauſe when he bent down a
branch much lower than its origin from the tree, and cut off the end
of it in the bleeding ſeaſon, the fap flowed from the extremity of
this branch fo bent down, when ſome wounds two or three feet
lower

30
UMBILICAL VESSELS. Sect. III. II. 5.
a
a
lower than the origin of this branch did not bleed. This may be
accounted for from the aſcent of the fluid in theſe veſſels being at
this time principally owing to the action of their abſorbent mouths,
and to their conſiſting of long cylinders with minute diameters and
rigid coats, like thoſe which are viſible to the eye in dry cane, through
which ſmoke will paſs in either direction, and which at this early ſea-
fon may not be excited into vegetable action; there is nevertheleſs a
power of abſorption exiſting in any part of them in the warmer ſea-
ſon, becauſe a branch or flower-ſtalk cut from the root, and ſet in a
glaſs of water, will drink up a conſiderable quantity of it. There is
alſo a fituation in their diſeaſed or dead ſtate, where they appear to
act for ſome years like capillary tubes, as in the decorticated part of a
pear tree, deſcribed in Sect. XV. 2, 3.
5. During the great action of theſe umbilical abſorbent veſſels the
buds become expanded, that is the young vegetable beings put forth
leaves, which are their lungs, and conſiſt of a pulmonary artery, vein,
and abſorbents, and alſo acquire a new bark over that of the branches,
trunk, and roots, of the laſt year, which conſiſts of aortal arteries,
veins, and abſorbents, and new radicles, which terminate in the ſoil.
At this time the umbilical veſſels, which exiſted in the alburnum, or
ſap-wood, ceaſe to act, and coaleſce into more ſolid wood, perhaps.
ſimply by the contraction of the ſpiral fibre, of which they are com-
poſed ; and the ſwarm of new vegetables, which conſtitute a tree, are
now nouriſhed by their proper lacteal and lymphatic ſyſtems.
A curious circumſtance now occurs, which is that wherever a tree
is now wounded, no moiſture appears. On the contrary, the wound
from Dr.Hales's experiments is in a ſtrongly abſorbing ſtate, inſomuch
that on applying water to wounds made in the ſummer ſeaſon, it was
found to be drank up with great force, as was ingeniouſly ſhewn by
mercurial fyphons contrived to reſiſt its abſorption.
This evinces, that though during the bleeding ſeaſon in the vernal
months the fap-juice is imbibed by the umbilical abſorbents, and car-
ried

SECT. III. II. 6. UMBILICAL VESSELS.
31
ried upwards probably by the annular contraction of the ſpiral fibres,
which I believe compoſe theſe abſorbent vefſels, in ſuch quantities as
to bleed wherever the alburnum is expoſed or wounded, yet that af-
terwards the exhalation by the numerous leaves becomes ſo great,
that the actions of the new radical and lateral abſorbents do not
ſupply a fluid ſo faſt, as it could otherwiſe be expended in the growth
of the plant, or diffipated into the air ; and as the veſſels, which paſs
down the trunks of trees, inofculate in variety of places, as is ſeen in
the cloth made at Otaheite from the bark of a mulberry-tree, when
a wound is made through ſome of theſe veſſels, the fluid, which
might otherwiſe ooze out, is carried away laterally by thoſe in their
vicinity; and as the veſſels of vegetables are rigid, and do not collapſe
when wounded like thoſe of animals; and as the circulation in them
is comparatively ſlow, but little of their contained fluids are poured
out of them when wounded in the ſummer months.
6. From all theſe obfervations it finally appears, that the umbilical
veſſels of each bud are fimilar to thoſe of a ſeed, which are called by
Dr. Grew feminal roots, and that like the umbilical cords, which
form the wires of ſtrawberries above ground, and of potatoes under
ground, they ſupply the new vegetable with nutriment, till the leaves
are expanded in the air, and new roots are puſhed out and penetrate
the earth.
There is alſo a curious analogy between theſe umbilical vefſels of
buds, which exiſt in the alburnum of trees, and thoſe belonging to the
chick in the egg, which conſiſts in their both poſſeſſing certain air-
vefſels; thoſe of trees paſs horizontally from the bark to the albur-
num, and that of the egg, exiſts at the broad end of it. Thus it is
probable, that the fluid in the fine extremities of the new veſſels of
the embryon bud becomes oxygenated by theſe horizontal air-veſſels,
in the ſame manner as the fluid in the terminations of the arteries on
the chorion of the chick is believed to become oxygenated by the air
contained
a
a

32
UMBILICAL VESSELS. Sect. III. II. 6.
a
contained at the broad end of the egg, as alluded to in Sect. II. 4.
and III. 1.4.
A circumſtance, in which the bud may be conceived to differ from
the egg, conſiſts in the ſeparation of the egg from its parent, as ſoon as
the fetus has acquired a certain maturity, along with its umbilical veſ-
fels, and its reſervoir of nutriment. But in vegetables fomething
fimilar occurs, for the parent bud is ſeparated by death in the autumn
from its embryon offspring; the leaf falls off, which was the lungs of
the parent bud, and the veſſels of its caudex, which formed the bark,
coaleſce into alburnum, or fap-wood, ſurrounding the umbilical veſ-
ſels of the new bud; which thus may be ſaid to looſe its parent like
the
egg, but retains its umbilical veſſels, and a reſervoir of nutriment,
which exiſts in the fap-wood, and alſo another fyftem of veſſels,
which conſtitute the new bark of the tree, conſiſting of the inter-
woven caudexes of each individual new bud.
But as the umbilical veſſels of plants above deſcribed, which con-
ſtitute the alburnum of the trunks of trees, and the ſeminal roots, ſo
called, of the growing ſeed, convey nutriment to the embryon bud, or
to the riſing plumula, as well as oxygenation, they are not fimilar
in that reſpect to the placenta of the animal fetus, and were impro-
perly called placental veſſels in the notes to the Botanic Garden, as
the placenta of the animal fetus is ſhewn in Zoonomia, Vol. I. Sect.
XXXVIII. to be an organ of reſpiration only, like the gills of fiſh,
and not an organ for nutrition.
Hence when the cotyledons of ſeeds are cut away from the riſing
plume, the plant becomes a dwarf for want of nutriment; and the
wounding or expoſing the alburnum of bleeding trees, as of the birch
or maple, in the vernal months to obtain the fap-juice retards the
expanſion of the new buds, and the conſequent growth of the tree.
Hence alſo it appears, why ſmearing the bark of a tree with pitch, or
oil, or paint, is liable to deſtroy the new buds, and conſequently the
5
tree,

Sect. III. II. 7. UMBILICAL VESSELS.
33
tree, by ſtopping up their ſpiracula ; and why covering an egg with
greaſe or varniſh is ſaid to prevent the production of a chicken, by
preventing a change of air at the broad end of it.
7. We may conclude that the umbilical veſſels of the new bud are
formed along with a reſervoir of nutritious aliment about midſummer
in the bark, which conſtitutes the long caudex of the parent bud, in
the ſame manner as a reſervoir of nutritious matter is formed in the
root or broad caudex of the turnep or onion, for the nouriſhment of
the riſing ſtem. And that theſe umbilical veſſels of the em-
bryon bud, and the reſervoir of nutriment laid up for it, which is
ſecreted by the glands of the parent bud, and now intermixed with
the preſent bark of the tree, become gradually changed into albur-
num, or ſap-wood, as the ſeaſon advances, in part even before the
end of ſummer, and entirely during the winter months.
That the alburnum of trees, which exiſts beneath the bark both of
the trunk and roots of them, contains the nutritious matter depoſited
by the mature leaves or parent buds for the uſe of the embryon buds,
appears not only from the faccharine liquor, which oozes from the
wounds made in the vernal months through the bark into the albur-
num of the birch and maple, betula et acer ; but alſo from the fol-
lowing experiment, which was conducted in the winter before the
vernal fap-juice riſes.
Part of a branch of an oak-tree in January was cut off, and divided
carefully into three parts, the bark, the alburnum, and the heart,
Theſe were ſhaved or raſped, and ſeparately boiled for a time in wa-
ter, and then ſet in a warm room to ferment; and it was ſeen that
the decoction of the alburnum or ſap-wood paſſed into rapid fermen-
tation, and became at length acetous, but not either of the other,
which evinces the exiſtence both of ſugar and mucilage in the albur-
num during the winter months; ſince a modern French chemiſt has
ſhewn by experiments, that ſugar alone will not paſs into the vinous
fermentation, but that a mixture of mucilage is alſo required; and
F
from

34
UMBILICAL VESSELS.
SECT. III. II. 7.
from this experiment it may be concluded, that in years of ſcarcity
the fap-wood of thoſe trees, which are not acrid to the taſte, might af-
ford nutriment by the preparation of being raſped to powder, and
made into bread by a mixture of flour, or by extracting their ſugar
and mucilage by boiling in water, as mentioned in Zoonomia, Part III.
Article I. 2. 3. 6.
Now as the embryon buds of deciduous trees of this climate are
formed about midſummer, fecreted by the generative glands in the
caudex of the parent leaf-bud, and are ſupplied with due nou-
riſhment from the fame ſource, not having yet ſhot out radicles of
their own from the lower end of their long caudexes into the earth,
they may be readily tranſplanted at this ſeaſon from one tree to ano-
ther by inoculation, or into different parts of the ſame tree; as the
new caudex of the young bud of one tree will readily unite with the
new caudex of that of another tree, and as they can be removed en-
tire during the early ſtate of their growth along with a part of the bark
only, as ſcarcely any alburnum is yet formed beneath the bark of the
young twig, from whence the bud is cut or torn.
But after their greater maturity, ſo that many buds exiſt on one
twig, or ſcion, and are already furniſhed with radicles paffing down
into the ground, as in the enſuing ſpring, it becomes neceſſary to
ingraft them by cutting off a part of the alburnum, as well as of the
bark of the new bud; and to apply theſe in contact with the bark
and alburnum of another tree, to which they may grow by inoſcu-
lation of vefſels; whence it appears why budding or inoculation muſt
be performed foon after midſummer, and ingrafting in the early
ſpring, as in the former the buds continue to grow by the junction
of the caudex or bark veſſels alone with thoſe of the tree into which
they are inſerted, and in the latter by the inoſculation of their vef-
ſels with thoſe of the bark and alburnum of the tree, to which they
are applied and bound.
.5
The

Sect. III. II. 8. UMBILICAL VESSELS.
35
;
The inofculation of the veſſels of a bud cut out of one tree and in-
ſerted into the bark and alburnum of another, as in the ingraftment
of ſcions, is exactly reſembled by a ſimilar operation on animal bo-
dies, when a tooth is taken from one perſon and inſerted into the head
of another, and where two inflamed parts grow together. Thus an
experienced anatomiſt is ſaid to have cut the two ſpurs from a young
cock, and applied them to the oppoſite ſides of his comb, which was
previouſly excoriated, where they continued to grow and appeared
like horns; and Talicotius, whoſe book lies by me, ſeriouſly aſſerts,
that he ſucceeded in making artificial noſes from a part of the ſkin of
the arm of his patients, and has publiſhed prints of the manner of
the operation, ſo ridiculed by the author of Hudibras. Cheirurgia
Caſparis Talicotii.
The growth of an inoculated bud on the bark of another tree,
where the upper part of the caudex of the inoculated bud joins with
the lower part of the caudex of another bud belonging to the ſtock,
is ſtill more nicely reſembled by the union of the head and tail part
of two different polypi in the experiment of Blumenbach, mention-
ed in Sect. VII. 3. 2. of this work.
8. As the leaves of trees become expanded, the fap-juice above de-
ſcribed ceaſes to flow, and the bark of the tree then adheres to the
alburnum. Afterwards from the middle of June to the middle of
Auguſt, as Dr. Bradley has obſerved, there ſeems to be a pauſe in ve-
getation; at which time the new buds in the boſom of each leaf feem
to be generated, and the bark, which during the two preceding
months adhered to the wood, now eaſily ſeparates, as in the ſpring,
according to the obſervation of Duhamel, Vol. II. 261; and vegeta-
tion, which appeared to languiſh during the heats of midſummer,
acquires new vigour at' the approach of autumn like that of ſpring.
This circumſtance, which ſeems to have puzzled many naturaliſts,
is to be explained from the action of the umbilical veſſels of the new
buds,
F 2

36
Sect. III. II. 8.
UMBILICAL VESSELS.
a
buds, which begin to enlarge as ſoon as they are formed, and in this
climate have their progreſs ſtopped by the cold during the winter,
and the moiſture which exſudes from the ſides of theſe veſſels, and
is extravaſated between the alburnum and the bark, cauſes an eaſy
ſeparation of them from each other.
From the new flow of ſap in theſe veſſels about midſummer, being
probably in part conveyed to the leaves by the rotrograde action of
their lymphatics in very hot weather, the honey-dew ſeems to ori-
ginate either as an exſudation from the leaf, or from the veſſels be-
ing punctured by the aphis, which drinks the vegetable chyle in ſuch
great quantity that it paſſes through the infect almoſt unchanged;
ſee Sect. XIV. 1. 7. and 3. 2; and thus cauſes the fuffufion of honey
on the leaves below them for a time in the heat of ſummer.
Add to this that M. Du Hamel, by nicely meaſuring ſome buds,
found that they were gradually enlarged at ſome times during the
winter, and concludes from thence that the fap-juice, which nouriſhes
them, continues to flow, though ſlowly, in the milder parts of the
winter days, Vol. II. p. 262; and adds, that it muſt riſe continually
during the winter months in ever-green trees, otherwiſe their fo-
liage would wither; and alſo in deciduous trees, becauſe the branch
of an ever-green tree will grow on a deciduous tree, and not loſe its
leaves in the winter, as the lauro-ceraſus on a cherry-tree, and an
ever-green oak on a common oak.
It muſt nevertheleſs be obſerved, that as the umbilical veſſels are a
part of the new bud, as the lacteals and other abſorbents are a part of
the chick or fetus, the perpetual action of theſe umbilical veſſels
muſt depend on the bud to which they belong, in the caudex of which,
between the plum ula and radicle, the brain or common ſenſorium,
and the conſequent vital energy, are believed to reſide; and that whe-
ther an ingraftment exiſts between the bud and the umbilical ab-
forbent vefſels or not. But as in thoſe animals which have a very
ſmall

Sect. III. II. 9.
37
UMBILICAL VESSELS.
ſmall portion of brain in the head compared with that in the ſpine of
the back, as in eels, ſnakes, worms, butterflies, if the head be cut off,
the other parts will continue to live with great activity for hours, and
even days; ſo it happens to theſe umbilical abſorbent vefſels, which
in vine-ſtumps, and many herbaceous plants, will continue to pour
out the fap-juice in great force and great quantity for many days af-
ter the exſection of the whole upper part of the plant.
The continuance of the motion of theſe umbilical veſſels confifting
of a ſpiral line, which are believed to be air-veſſels by many authors,
is mentioned by Malpighi; who aſſerts, that when he examined them
in the winter, he could often obſerve them for ſome time to continue
their vermicular motion ſo as to aſtoniſh him. See Duhamel. Phyſ.
des arb. Vol. I. p. 43.
9. The umbilical veſſels of this ſection, like the abſorbents of the
preceding one, both which are believed to conſiſt of a ſpiral line, as
ſhewn in Sect. II. 7. may be readily ſeen in cutting a vine-ſtalk ho-
rizontally, as they at firſt appear full of fluid ; but in a very little time,
as the fluid exhales or becomes effuſed, a circular area of round holes
appears to paſs longitudinally interior in reſpect to the bark; which I
ſuppoſe to conſiſt both of the umbilical veſſels, which bleed during the
vernal months, and of the other radical, cellular, and cutaneous ab-
ſorbents; the latter of which I ſuſpect to be exterior to the former,
and to reſide between the bark and the umbilical vefſels, though both
of them are believed to conſtitute the alburnum of the plant.
From many ingenious obſervations on vegetables monſieur de la
Baiſſe draws the following concluſions, which are aſſented to by M.
Bonnet, and which I ſhall here tranſcribe, as they ſo accurately co-
incide with the theory above delivered, and as they were deduced
from different experiments, are a confirmation of it.
He ſays,
66 that the veſſels deſtined to convey nouriſhment to plants are nei-
ther in the pith, nor in the bark, nor between the bark and the wood;
but

38
9.
UMBILICAL VESSELS. Sect. III. II.
but in the ligneous ſubſtance itſelf; or, to ſpeak more accurately, that
thoſe veſſels are themſelves the woody fibres included between the
pith and the bark of plants, which have their origin in the roots, and
extend themſelves to every part of the plant.” Bonnet uſage des
feuilles, p. 275.
I
1
SECT.

PLATE III.

PLATE
III.
Is copied from Malpighi Appendix de ovo Incubato, Tom. II. Fig. 54, and repre-
ſents the chick in the egg on the fourteenth day of incubation. The chick rolled up
ſwims in the amnios a a, which is kept moiſt -by very minute veſſels. Round this is
placed the yolk bb, to which adjoins the thicker part of the white. The whole is ſur-
rounded with chorion d d d. On this are ſpread the blood veſſels, of which the large
one e emerging from the navel of the chick, and generating the various branches fff,
terminates in a capillary network. In contact with theſe a redder ſet of veſſels paſſes
with ſimilar ramifications. Another ſet of veſſels g g ariſes from the navel, which are
ſmaller ones, and are propagated amidſt the ramification of ff. The lungs are white;
the ſtomach full of milk, or of coagulated albumen or white; and the inteſtines hang
out from the navel.
a
As two ſets of blood veſſels terminate on the chorion, and as one branch of the larger
ſet carries redder blood, and as the lungs are ſtill white; it ſeems evident, that this larger
fet of vefſels reſemble the placental arteries and vein of viviparous animals, and that the
blood receives its red colour by acquiring oxygen from the air included between the exter-
nal moiſt membrane and the ſhell of the egg ; which air at firſt is ſeen only at the broad
end, but afterwards extends from thence to the equator of the egg, and probably paſſes
through the other end of the ſhell to that part of the internal membrane, which adheres
to it. See an analogous plate in Fabricius ab Aquapendente, Tom. I. Fig. 13. See
alſo Sect. III. I. 4. and III. 2.6. of this work.

Sect. III. 1.2
Plate III.
d
d
b
d


Sect. IV. I. 1. PULMONARY ARTERIES AND VEINS. 39
SECT.
IV.
THE PULMONARY ARTERIES AND VEINS OF VEGETABLES.
2010
I. 1. Leaves not perſpiratory organs, nor excretory nor nutritious organs, nor electric
nor luminous ones. 2. Vital air in the atmoſphere, in water. Lungs of aerial
animals; gills of aquatic ones. 3. Leaves are the lungs of vegetables. Arteries
and veins viſible in a leaf of Spurge and picris coloured by madder, and in bloody
dock. 4. Upper ſurface only of the leaf reſpires, and repels moiſture, and dies if
Smeared with oil, and exhales much leſs than the under one. II. 1. Aquatic leaves
are like the gills of fiſh; have larger ſurfaces, as the uncombined oxygen in water is
leſs than in air; are divided like the leaves on high mountains. 2. Are furniſhed
with numerous points like gills of fiſh. 3. Which ſet at liberty oxygen from ſome
waters. III. 1. Root-leaves of many plants differ from ſtem-leaves. 2. As they
produce only buds. 3. They differ as common leaves from floral leaves. 4. And
ariſe ſometimes from the cotyledons. IV. 1. Floral leaves or bractes are reſpi-
ratory organs to the calyx and pericarp. 2. In ſome plants they do not appear
till the corol drops off. 3. Recapitulation. Leaves die in the exhauſted receiver.
V. 1. The corol is a pulmonary organ; its colours. 2. Its vaſcular texture,
its glands. Some flowers have no bračtes. The corol is not for defence. The
corol of belleborus niger changes to a calyx. 3. Corol of colchicum and crocus fall
off before the bractes appear. Vines bear alternate flowers and leaves. Fruit de-
prived of green leaves. 4. Vegetable uterus requires the bra&tes. Flowers enlarged
by deſtroying the green leaves. 5. Plants do not reſpire in their ſleep. 6. Con-
cluſion. The anthers and ſtigmas are ſeparate vegetable beings; live on honey and
acquire greater irritability, and amatorial ſenſibility.
3
1. 1. THERE have been various opinions concerning the uſe of the
leaves of plants in the vegetable economy. Some have contended, that
they are perſpiratory organs. This does not appear probable from an
experiment of Dr. Hales, Veg. Stat. p. 30. He found, by cutting off
branches

40
Sect. IV. I. 1.
PULMONARY ARTERIES
branches of trees with apples on them, and taking off the leaves, that
an apple exhaled about as much as two leaves, the ſurfaces of which
were nearly equal to that of the apple; whence it would appear, that
apples have as good a claim to be termed perſpiratory organs as
leaves.
Others have believed them the excretory organs of excrementi-
tious juices; but as the vapour exhaled from vegetables has no taſte,
this idea is no more probable than the other. Add to this, that in
moiſt weather they do not appear to perſpire or exhale at all, as ſhewn
by ſome ſtatical experiments of Dr. Hales, like thoſe of Sanctorius
on the perſpiration of the human body; which perſpiration has alſo
been ſuppoſed to be an excrement, which is ſhewn to be an erroneous
opinion ; and that its deſign is ſimply to preſerve the ſkin ſupple,
like the tears diffuſed on the eye-ball to preſerve its tranſparency, as
explained in Zoonomia, Vol. II. Claſs I. 1, 2. 14.
1,
Others have believed that vegetables abſorb much nutriment by
their leaves, and quote an experiment of Dr. Prieſtley's, who found
plants placed in water under glaſſes grew much faſter, when the air, in
which they grew, was occaſionally impregnated with putrid exhala-
tions. But there is another experiment of Dr. Prieſtley's, which
ſhould be mentioned, and that is, that he agitated one part of a veſſel
of water beneath a glaſs filled with putrid exhalation, and the whole
of the water preſently became very fetid. Hence we may conclude,
that in the firſt caſe the water, in which the vegetable grew, abſorbed
the putrid exhalations from the air over it, and that theſe were again
abſorbed from the water by the roots of vegetables, which correſpond
to the lacteals of the ſtomach and inteſtines of animals; and that they
thus received nouriſhment from the putrid vapours, and not by their
leaves, which we ſhall endeavour to fhew to be fimply reſpiratory
organs.
Other philoſophers have conceived, that the leaves of plants acquire
electricity from the air. In anſwer to theſe it may be obſerved, that

SECT. IV. I. 2.
41
AND
VEINS.
no electricity is ſhewn by experiments to deſcend through the ſtems
of trees, except in thunder ſtorms; and that if the final cauſe of ve-
getable leaves had been to conduct electricity from the air, they ought
to have been gilded leaves with metallic ſtems.
Others again have ſuppoſed that the leaves of plants acquire a
phlogiſtic material from the ſun's light, whence it was believed that
on this account they turn their upper ſurfaces to the ſun. But though
light is more or leſs attracted by all opake bodies, yet if the final
cauſe of vegetable leaves had been to abſorb light, they ought to have
been black and not green ; as by Dr. Franklin's experiment, who laid
ſhreds of various colours on ſnow in the ſun-fhine, the black funk
much deeper than any other colour, and conſequently abſorbed much
more light. The uſe of light in vegetable reſpiration will be treated
of in Sect. XIII.
2. The air of our atmoſphere has been ſhewn by the experiments
of Prieſtley, Cavendiſh, and Lavoiſier, to conſiſt of twenty-ſeven
parts of reſpirable air, called oxygene gas, with ſeventy-three parts of
unreſpirable air, termed azotic gas, which are mixed together, not
chemically combined; whereas water conſiſts of eighty-five hun-
dreth parts of oxygen to fifteen of hydrogen, which exiſt in their
ſtate of combination, and are not therefore fit for reſpiration. But in
water a conſiderable quantity of common air is alſo diſſolved, which
eſcapes on boiling; and even pure vital air was diſcovered in the
water of ſome ſprings by ſir Benj. Thomſon, when it was expoſed to
the ſun's light. Philofoph. Tranſact. The former of theſe fluids is
thus adapted to the reſpiration of aerial animals, and the latter to
that of aquatic ones; and the analogy between the aerial and aquatic
leaves of vegetables and the lungs and gills of animals embraces ſo
inany circumſtances, that we can ſcarcely withhold our affent to
their performing ſimilar offices.
The internal ſurface of the air-veſſels of the lungs of men are ſaid
to be equal to the external ſurface of the whole body, or about fif-
G
teen

42
SECT. IV. 1. 3.
Sect
PULMONARY ARTERIES
teen ſquare feet. On this ſurface the blood is expoſed to the influ-
ence of the reſpired air, through the medium of a thin moift pel-
licle. By this expoſure to the air it has its colour changed from deep
red to bright ſcarlet, and acquires fomething ſo neceſſary to the ex-
iſtence of life, that we can live ſcarcely a minute without this won-
derful proceſs.
In aquatic animals, as fiſh, the blood is expoſed to the air, which is
diffuſed in the water by the gills; the ſurface of which is probably
greater in proportion to the external ſurface of their bodies, than that
of the air-veſſels of the lungs of aerial animals to their external fur-
faces. Through theſe gills, or aquatic lungs, a current of water is
made perpetually, to paſs by the gaping of the fiſh, as it moves, like
the air in reſpiration; and from this water it is probable the ſame
material is acquired by the gills of fiſh as from the air by the lungs
of aerial animals.
3. The great ſurface of the leaves compared to that of the trunk
and branches of trees is ſuch, that it would ſeem to be an organ well
adapted for the purpoſe of expoſing the vegetable juices to the influ-
ence of the air. This however we ſhall fee afterwards is probably
performed only by their upper ſurfaces, which are expoſed to the light
as well as air, and on that account acquire greater oxygenation, as
will be ſhewn hereafter : yet even in this caſe the upper ſurfaces of
the leaves muſt bear a greater proportion to the ſurface of the bark of
the tree than that of the air-cells of the lungs of animals to their ex-
ternal ſurfaces.
Aerial or aquatic animals, by their muſcular exertions, produce a
current of air or water reciprocally to and from their lungs, and can
occaſionally change the place, where they reſpire, when the air or wa-
ter becomes vitiated. But as vegetables have but little muſcular
power to move their leaves, except in a few inſtances; and as the air
or water is frequently nearly ſtationary, where they exiſt, it ſeems to
have been neceſſary to expoſe their fluids to the air or water on à
greater
a

Sect. IV. I. 3. AND VEINS.
43
a
greater expanſe of ſurface than in the lungs or gills of animals, which
well accounts for the exuberant extent of their foliage.
In the lungs of animals the blood, after having been expoſed to
the air in the extremities of the pulmonary artery, is changed in co-
lour from deep red to bright ſcarlet, and is then collected and returned
by the pulmonary vein. So in the leaves of plants the vegetable
blood is rendered yellow in ſome plants, as in celandine, chelido-
nium; white in others, as in fig-leaves, ficus; and in ſpurge, eu-
phorbia ; and red in others, as in red beets, beta. And the ſtructure
of the leaf, as confifting of arteries and veins to expoſe the vegetable
blood to the influence of the air, and to return it to the caudex of
the bud at the foot-ſtalk of the leaf, beautifully became viſible by the
following experiment.
A ftalk with the leaves and feed-veſſels of large ſpurge (euphorbia
helioſcopia) in June 1791, had been ſeveral days placed in a decoc-
tion of madder, (rubia tinctoria) ſo that the lower part of the ftem
and two of the inferior leaves were immerſed in it. After having
waſhed the immerſed leaves in much clean water, I could readily
difcern the colour of the madder paſſing along the middle rib of each
leaf. This red artery was beautifully viſible both in the under and
upper ſurface of the leaf; but on the upper ſide many red branches
were ſeen going from it to the extremities of the leaf, which on the
other ſide were not viſible except by looking through it againſt the
light. On this under fide a ſyſtem of branching veſſels carrying a
pale milky fluid, were ſeen coming from the extremities of the leaf,
and covering the whole underſide of it, and joining into two large
veins, one on each ſide of the red artery in the middle rib of the leaf,
and along with it deſcending to the foot-ftalk or petiole. On ſlitting
one of theſe leaves with fciffars, and having a common inagnifying
lens ready, the milky blood was ſeen oozing out of the returning
vein on each ſide of the red artery in the middle rib, but none of the
red fluid from the artery.
G2
All

44
SECT. IV.1.4.
PULMONARY ARTERIES
All theſe appearances were more eaſily ſeen in a leaf of picris treated
in the ſame manner; for in this milky plant the ſtems and middle-
rib of the leaves are ſometimes naturally coloured reddiſh, and hence
the colour of the madder ſeemed to paſs further into the ramifications
of their leaf-arteries, and was there beautifully viſible with the re-
turning branches of milky veins on each ſide.
In a plant which was ſent to me under the name of fenecio bicolor,
but which I have not yet ſeen in flower, the upper ſurface of the
leaf is green like moſt other leaves, but during the vernal months
the under ſurface is of a deep red, whence I conclude that the vege-
table blood acquires the red colour in the terminations of the pulmo-
nary artery in the upper ſurfaces of the leaves, which becomes viſible
as it paſſes in the large veins on the inferior ſurface. In the ſame
manner the red colour of the blood is moſt viſible in the large veins
beneath the leaf of the red veined dock, rumex fanguinea.
4. From theſe experiments the upper ſurface of the leaf appeared to
be the immediate organ of reſpiration, becauſe the coloured fluid was
carried to the extremities of the leaf by veſſels moſt conſpicuous on
the upper ſurface, and there changed into a milky fluid, which is
the blood of the plant, and then returned by concomitant veins on
the under ſurface, which were ſeen to ooze when divided with foiſ-
fars, and which in picris particularly rendered the under ſurface of
the leaves greatly whiter than the upper one.
As the upper ſurface of leaves conſtitutes the organ of reſpiration,
on which the vegetable blood is expoſed in the terminations of arteries
beneath athin moiſt pellicle to theaction of theatmoſphere, theſe ſurfaces
in many plants ſtrongly repel moiſture, as cabbage-leaves, whence the
particles of rain lying over their ſurfaces without touching them, as
obſerved by Mr. Melville, (Efſays Literary and Philof. Edinb.) have
the appearance of globules of quick-ſilver. And hence leaves laid
with their upper ſurfaces on water wither as ſoon as in the dry air,
but continue green many days if placed with their under ſurfaces on
water,

SECT. IV. II. 1.
45
AND VEINS. O
W
water, as appears in the experiment of monfieur Bonnet, (Uſage des
Fevilles); hence fome aquatic plants, as the water-lily (nymphæa)
have the lower fides of their leaves floating on the water, while the
upper ſurfaces remain dry in the air.
This repulfion of the upper furfaces of the leaves of aerial plants
to water bears ſome analogy to the renitency of the larinx to the ad-
miſſion of water into the lungs of animals; for if a ſingle drop ac-
cidentally falls into the windpipe, a convulſive cough is induced till it
is regurgitated. For the ſame reaſon ſeveral plants cloſe together the
upper
ſurfaces of their leaves when it rains, in the ſame manner as
in their ſleep during the night, as mimoſa, the ſenſitive plant, and
the young ſhoots of chick-weed, alfine; and of kidney-bean, pha-
feolus.
As thofe inſects which have many ſpiracula, or breathing apertures,
as waſps and flies, are immediately ſuffocated by pouring oil upon
them, in the year 1783 I carefully covered with oil the ſurfaces of
ſeveral leaves of phlomis, of Portugal laurel, and balſams; and though
it would not regularly adhere, I found them all die in a day or two,
which ſhews another fimilitude between the lungs of animals and the
leaves of vegetables.
There is an ingenious experiment of M. Bonnet, (Uſage des feu-
illes) which ſhews that the upper ſurfaces of leaves exhale much leſs
than their under ſurfaces. He put the ſtalks of many leaves freſh
plucked from trees or herbaceous plants into glaſs tubes filled with
water; of theſe he covered with oil or varniſh the upper ſurface of
many leaves, and the under ſurface of many others, and uniformly
obſerved by the water ſinking in the tubes that the upper ſurfaces
exhaled much leſs than half the quantity exhaled by the under ſur-
faces, which thews them to be organs deſigned for different pur-
poſes.
II. 1. There exiſts a ſtrict analogy between the leaves of aquatic
plants, which are conſtantly immerſed beneath the water, and the gills
3
of

46
Sect. IV. II. 2.
PULMONARY ARTERIES
a
.
of aquatic animals, which conſiſts in the largeneſs of their ſurface,
owing to their hair-like ſubdiviſions, and to their being terminated
with innumerable points. The gills of fiſh conſiſt of many folds of
blood-vefſels lying over each other, each reſembling a fringe, or the
downy part on one ſide of a feather attached to the middle rib of it,
by which means they expoſe a greater ſurface of blood to the water
than is expoſed to the air by the internal membranes of the air-cells
of the lungs of other animals ; and undoubtedly for this final cauſe,
becauſe water contains leſs oxygen in its uncombined ſtate, which is
the material neceſſary to life, than air, though much more of it in its
combined ſtate, as water conſiſts of eighty-five parts of oxygen to fif-
teen parts of hydrogen; but it is the uncombined oxygen only dif-
ſolved in heat, and diffuſed in water, which can ſerve the purpoſe of
animal or vegetable reſpiration.
The apparatus for this purpoſe, according to Duverney's Anatomy
of a Carp, is truly curious. He found 4386 bones in the gills, which
had fixty-nine muſcles to give them their due motions. See Bo-
mare's Dictionaire raiſoneé, Art Poiffon. And Monro obſerved by the
numerous diviſions and folds of the membrane of the gills, that their
ſurface in a large ſkate was nearly equal to the furface of the human
body. Phyſiol. of Fiſh, p. 15. He adds that in the whole gills there
exiſt 144,000 ſubdiviſions or folds, and that the whole extent of this
membrane may be ſeen by a microſcope to be covered with a net-
work of exceedingly minute veſſels.
2. In this reſpect the gills of fiſh are reſembled by the ſubaquatic
leaves of plants, which are ſlit into long wires terminated in points, as
in trapa, onanthe, hottonia, the water-violet, and the water-ranun-
culus. This laſt plant, and ſome others, have frequently fome
leaves erect in the air, and others immerſed in water, ariſing from
the ſame ftem ; and it is curious to obſerve that the aerial leaves are
nearly entire, or divided only into a few lobes; whilſt the aquatic
leaves are ſlit into innumerable branches like a fringe, and have thus
5
their
;
a

Secr. IV. III. 1,
47
AND VEIN S.
their furfaces wonderfully enlarged for the purpofe of acquiring un-
combined oxygen from the air, which is diffuſed in the water, and
which abounds ſo much leſs there than in the atmoſphere; for the
fame purpoſe the plants on the ſummits of high mountains, where
the air is ſo much rarer, and conſequently abounds leſs with oxygen,
have their leaves much more divided than in the plains, as pimpinella,
petroſelinum, and others, that they may expoſe a more extenſive fur-
face of veffels to the influence of the thinner atmoſphere.
3. This great enlargement of the ſurface by ſo minute a diviſion
does not however ſeem to be the only uſe of this uniform ſtructure
of gills and aquatic leaves; but there is another very important one,
which hath hitherto I believe eſcaped the notice of philoſophers; and
that is that points and edges contribute much to the ſeparation of the
air, which is mechanically mixed or chemically diffolved in water, as
appears on immerſing a dry hairy leaf into water freſh from a pump,
on which innumerable globules of air, like quick-ſilver, appear on
almoſt every point. Nor is it improbable that points immerſed in wa-
ter may in a bright day contribute to decompoſe it, or certainly to ſet
at liberty its ſuperabundant oxygene, as occurs in the perſpiration of
leaves when expoſed to the ſunſhine, and to the green matter in the
experiments of Dr. Prieſtley, which is probably owing to the fine
points of both of them; and laſtly, when points of filk are immerſed
in ſpring water, which is frequently hyperoxygenated, as in the ex-
periments of Count Rumford, related in the Philoſ. Tranſact. See
Sect. XIII. I. 5.
III. 1. The root-leaves of many perennial plants, which do not
produce flowers in the firſt year from the ſeed, are different from thoſe
of future years, as in the rheum palmatum, palmated rhubarb, the
leaves are ſmall and nearly circular, and not divided into fingers till
the ſecond year; and in tulip the leaf the firſt year from the ſeed is
ſmall like a blade of graſs, riſing from a diminutive bulb. In other
perennial plants the root-leaf is undivided, but at the ſame time larger
than
a

48
PULMONARY ARTERIES Sect. IV. III. 2, 3, 4.
a
than thoſe on the riſing ſtem, as in geum, averns; in fenecio aureus,
and the campanula rotundifolia, ſo named from the round form of the
root-leaf, which is alſo much broader than thoſe on the ftem, as well
as undivided. The root-leaves of many biennial, and of ſome annual
plants, are likewiſe larger, as well as of a different form from thoſe
on the riſing flower-ſtem, as in turneps and carrots. And laſtly, the
foot-leaves of ſome plants, which riſe immediately from ſeeds, con-
fiſt of the cotyledons of the feed, and are thus different from the
leaves above them.
2. In reſpect to the root-leaves of palmated rhubarb and of tulips,
when theſe plants are raiſed immediately from feed, as theſe firſt
plants are not deſigned to generate flowers and conſequent ſeeds,
but to produce fimply another plant like a leaf-bud of a tree, leſs
oxygenation ſeems to have been neceſſary, and the leaves therefore
require leſs ſurface, and are in conſequence undivided. In reſpect
to the foot-leaves of geum, and of campanula rotundifolia, which
are larger than their ſtem-leaves, it is probable that they lay up a
reſervoir of nutritious matter for the riſing ſtem, like thoſe of tur-
neps and carrots, and thus require greater oxygenation, and in con-
ſequence a greater ſurface.
3. Another difference of root-leaves from thoſe of the ſtem in annual
plants often conſiſts in the latter being properly bractes or floral-
leaves, which will be ſpoken of below, while the root-leaf reſembles
thoſe belonging to the leaf-buds of trees. Thus in the riſing ſtem
of wheat the root-leaf produces the firſt joint above the ſoil, and the
ſecond and third leaf produce joint above joint, which are each a ſe-
parate bud riſing on that below it, as is ſeen by the diviſion of the
pith or hollow part of one joint from another, and at length the up-
permoſt leaf is a bracte or floral-leaf belonging to the ear.
4. And laſtly, the feed-leaves which riſe out of the ground with
the firſt joint of the flower-ſtem, as in kidney-bean, phaſeolus, as
they conſiſt of the placental artery, which was ſpread on the cotyle-
dons
a
a

Sect. IV. 4.2.
49
AND VEINS.
tence.
dons of the feed, and, now riſing out of the earth, when the nu-
tritive part has been diffolved in the terrein moiſture and abſorbed,
they ſerve the office of an aerial pulmonary organ, or lungs, which
before ſerved that of an aquatic one, or gills ; but wither and fall off
as the true leaves become expanded.
IV. 1. The common foliage of deciduous plants conſtitutes the
organ of reſpiration already ſpoken of, which belongs to the leaf-buds
during the ſummer months, and drops off in the autumn, when thoſe
buds periſh by the cold, or by the natural termination of their exif-
But there is another kind of foliage diſſimilar to the former,
conſiſting of bractes or floral-leaves, which ſupply an organ of ref-
piration to the calyx and pericarp of the flower-bud. Theſe frequently
differ in ſize, form, and colour from the other leaves of the plant, and
are ſituated on the flower-ſtalk often ſo near the fructification as to be
confounded with the calyx. In ſome plants there are two ſets of floral-
leaves, or bractes, one at the foot of the umbel, and another beneath
each diſtinct floret of it; and in others they appear in a tuft above
the flower, as well as on the ſtalk beneath it, as in fritillaria impe-
rialis, crown imperial; and in others they are ſo ſmall as to be termed
ſtipulæ or props.
All theſe kinds of bractes, or floral-leaves, ſerve the office of lungs
for the purpoſe of expoſing the vegetable blood to the influence of
the air, and of preparing it for the ſecretion, or production and nou-
riſhment of the vegetable uterus, or pericarp, and of the ſeeds pro-
duced and retained in it, frequently before their impregnation, and al-
ways after it.
2. It muſt be obſerved that in many plants theſe floral-leaves, or
bractes, do not appear till after the corol and nectaries, with the anthers
and ſtigmas, drop off; that is, not till after the ſeed is impregnated,
as in colchicum autumnale, crocus, hamamelis, and in ſome fruit-
trees. The production of the vegetable uterus, or pericarp, with the
unimpregnated feeds included in it, is in theſe plants accomplifhed or
H
evolved,

50
PULMONARY ARTERIES Sect. IV. 4. 3.
green leaves
evolved, like the bractes themſelves with the corol and ſexual organs,
by the ſap-juice, forced up in the umbilical veſſels from ſome previ-
ouſly prepared reſervoir, without the neceſſity of any expoſition to
the air in leaves or lungs, which are not yet formed, though it may
acquire oxygenation in the fine arteries of the embryon buds, which
are ſuppoſed to ſurround the horizontal air-vefſels obſerved in the
bark of trees.
As ſoon as the ſeeds become impregnated, the corol and nectaries
with the ſexual organs fall off, and the pericarp and its contained
feeds are then nouriſhed by the blood, which is aerated or oxygen-
ated in the bractes, or floral-leaves. Thus the flower of the colchi-
cum appears in autumn without any green leaves, and the pericarp
with its impregnated feeds riſes out of the ground in the enſuing
ſpring on a ftem ſurrounded with bractes, and with other
below them, which produce new bulbs in their boſoms.
The blood, which thus ſupplies nutriment to the pericarp and its
included feeds, does not ſeem to require ſo much oxygenation as that
which ſupplies nutriment to the embryon buds; whence the floral
leaves are in general much leſs than the root-leaves in many plants,
and than the common green leaves of almoſt all vegetables. And in
the plant mentioned in No. I. 3. of this ſection, under the name of
ſenecio bicolor, the under ſurfaces of the ſtem-leaves near the ex-
pected flower ceaſed to be red like thoſe of the radical leaves, which
ſeemed to ſhew that the vegetable blood was in them leſs oxygenated.
Whence it may be believed that leſs irritability may be neceſſary
for the growth of the feed than of the embryon bud, as the former
does not yet perhaps poſſeſs ſo much vegetable life as the latter. And
laftly, that as the anthers and ftigma require greater irritability, and
ſome ſenſibility, it was neceſſary a ſecond time to oxygenate the
blood which ſupplies them with nutriment in the corols of the flowers.
See Sect. VII. 2. 4.
3. Recapitulation of the arguments tending to ſhew that the leaves
of

SECT. IV. 5.1.
51
AND VEINS.
a
of vegetables are their lungs. 1. They conſiſt of an artery, which
carries the ſap to the extreme ſurface of the upper ſide of the leaf,
and there expoſes it under a thin moiſt pellicle to the action of the air;
and of veins, which there collect and return it to the foot-ſtalk of the
leaf, like the pulmonary ſyſtem of animals. 2. In this organ the
pellucid fap is changed to a coloured blood, like the chyle in paſſing
through the lungs of animals. 3. The leaves of aquatic plants are
furniſhed with a larger ſurface, and with points like the gills of
aquatic animals. 4. The upper ſides of aerial leaves repel moiſture,
like the larynx of animals. 5. Leaves are killed by ſmearing them
with oil, which in the ſame manner deſtroys inſects by ſtopping their
ſpiracula, or the air-holes to their lungs. 6. Leaves have muſcles
appropriated to turn them to the light, which is neceſſary to their
reſpiration, as will be ſhewn in the Section on Light. 7. To this
may be added an experiment of Mr. Papin related by M. Duhamel.
He put an intire plant into the exhauſted receiver of an air-pump,
and it ſoon periſhed; but on keeping the whole plant in this vacuum
except the leaves, which were expoſed to the air, it continued to live
a long time, which he adds is a proof that the leaves are the organs
of reſpiration. Phyfic des arbres, V.I. p. 169.
V. r. The organs of reſpiration already deſcribed conſiſt of the
green leaves belonging to leaf-buds, and of the bractes belonging to
flower-buds. But there is another pulmonary ſyſtem totally inde-
pendent of the green foliage, which belongs to the ſexual or amatorial
parts of the fructification only, I mean the corol or petals. In this
there is an artery belonging to each petal, which conveys the vegeta-
ble blood to its extremities, expoſing it to the light and air under a
delicate moiſt membrane covering the internal ſurface of the petal,
where it often changes its colour, as is beautifully ſeen in ſome party-
coloured poppies, though it is probable that ſome of the irrideſcent
colours of flowers may be owing to the different degrees of tenuity
of
H 2

52
Sect. IV. 5.2.
PULMONARY ARTERIES
of the exterior membrane of the petal refracting the light like ſoap-
bubbles.
The vegetable blood is then collected at the extremities of the
corol-arteries, and returned by correſpondent veins exactly as in the
green foliage, for the ſuſtenance of the anthers and ſtigmas, and for
the important ſecretions of honey, wax, eſſential oil, and the prolific
duſt of the anthers, and thus conſtitutes a pulmonary organ, as is
thewn by the following analogies.
2. Firſt, the vaſcular ſtructure of the corol, as above deſcribed, and
which is viſible to the naked eye; and its expoſing the vegetable
juices to the air and light during the day evinces that it is a pulmonary
organ.
Secondly, as the glands which produce the prolific duſt of the an-
thers, the honey, wax, and frequently ſome odiriferous eſſential oil,
are generally attached to the corol, and always fall off and periſh with
it, it is evident that the blood is elaborated or oxygenated in this
pulmonary ſyſtem for the purpoſe of theſe important ſecretions.
Thirdly, many flowers, as the colchicum and hamamelis, ariſe
naked in autumn, no green leaves appearing till the enſuing ſpring;
and many others put forth their flowers, and complete their impreg-
nation early in the ſpring, before the green foliage or bractes appear,
as mezereon, and ſome fruit-trees, which ſhews that theſe corols are
the lungs belonging to theſe parts of the fructification.
Fourthly, this organ does not feem to have been neceſſary for the
defence of the ftamens and piſtils, fince the calyx of many flowers, as
tragopogon, performs this office; and in many flowers thefe petals
themſelves are ſo tender as to require being ſhut up in the calyx dur-
ing the night. For what other uſe then can ſuch an apparatus of
vefſels be deſigned?
Fifthly, in the helleborus niger, Chriſtmas-roſe, after the ſeeds are
grown to a certain fize, the nectaries, and ſtamens, and ſtigmas, drop
off,

Sect. IV. 5.3.
53
AND VEIN S.
1
off, and the beautiful large white petals change their colour to a deep
green, and gradually thus become a calyx, incloſing and defending the
ripening ſeeds; hence it would ſeem that the white veſſels of the
corol ſerved the office of expoſing the blood to the action of the air,
for the purpoſes of ſeparating or producing the honey, wax, and pro-
lific duſt; and when theſe were no longer wanted, that theſe veſſels
coaleſced, like the umbilical veſſels of animals after their birth, and
thus ceaſed to perform that office, and loft at the ſame time their
white colour. Why ſhould they loſe their white colour unleſs they
at the ſame time loſt ſome other property beſides that of defending
the feed-veſſel, which they ſtill continue to defend ?
Sixthly, neither the common green leaves nor the bractes are ne-
ceffary to the progreſs of the corol, and ftamens, and ftigma, or to
the ſecretion of honey, after the laſt year's leaves are fallen off, as is
evinced by the flowers of colchicum in the autumn, and of crocus in
the ſpring, in both which the ſeeds riſe out of the earth with their
common leaves and bractes ſo long after the diſappearance of the
flower. In deciduous plants the common green leaves ſerve as lungs
in the ſummer and autumn to each individual bud, which then pro-
duces the new buds in its boſom, which are either leaf-buds or
flower-buds. In the enſuing ſpring the new common leaves are
the reſpiratory organ belonging to the leaf-buds, and the bractes are
the reſpiratory organ to the pericarp, and its included ſeeds before or
after impregnation; and the corols, as ſoon as expanded, become the
lungs to the amatorial parts of the fructification, and require neither
the green leaves nor bractes.
3. Hence the vine bears fruit at one joint without leaves, and
leaves at the other joint without fruit. Hence the flower of the col-
chicum riſes out of the ground without bractes or other green leaves,
and flouriſhes till the feed is impregnated; and the bractes, which riſe
out of the ground on the ſtem in the following ſpring, are lungs to
give maturity to the pericarp and ſeed; and the other green leaves are
for
I

54
PULMONARY ARTERIES
SECT.IV. 5.4.
m
for the purpoſe of producing new bulbs round the old one, but can
have nothing to do with the corol, anthers, ſtigmas, and nectaries,
which have long ſince fallen off, and periſhed. And laſtly, when cur-
rant or gooſeberry trees loſe their common green leaves, and their
bractes, by the depredation of inſects; the new leaf-buds become ſmall
and weak, but the corol, anthers, ftigmas, and nectaries, continue to
flouriſh, and the fruit becomes impregnated, though it is leſs ſweet
and of leſs ſize from the pericarp and included ſeed wanting their due
nutrition by the bractes before or after impregnation.
4. It hence appears that the flower-bud, after the corol, ftamens,
ſtigmas, and nectaries fall off, becomes ſimply a vegetable uterus,
for the purpoſe of ſupplying the growing embryons with nouriſh-
ment, and poſſeſſes a ſyſtem of abſorbent veſſels, which brings the
ſap-juice to the foot-ſtalk of the fruit, and which there changes into
a pulmonary artery, which conſtitutes the bractes or floral-leaves, and
expoſes the acquired juices to the oxygenation of the air, and con-
verts them into vegetable blood. This blood is collected again by
the veins of the bractes, and conveyed by an adapted or aortal artery
for the various ſecretions of ſaccharine, farinaceous, or aceſcent ma-
terials, for the nouriſhment of its included embryons, or the con-
ſtruction of the fruit and feed-lobes.
At the ſame time, as perhaps all the veſſels of trees inofculate, the
fruit may become ſweeter and larger when the green leaves as well as
the bracies continue on the tree; but the corols with the ſtamens,
ſtigmas, and nectaries, (the ſucceeding fruit not conſidered) ſuffer, I
believe, no injury, when the green leaves and even the bractes are
taken off, as by the depredations of inſects. Some floriſts have ob-
ſerved this circumſtance, and affirm that in many plants when the
leaves are pulled off, the flowers become ſtronger from their then
producing no bulbs, as in tulips and hyacinths. The inoſculation of
vegetable veſſels is evinced by the increaſed growth of one bud, when
others in its vicinity are cut away.
a
5. The

Sect. IV. 5.6. AND VEINS.
55
.
5. The ſleep of plants has been much ſpoken of by Lioneus and
others, but there is a wonderful circumſtance occurs in it, which has
not been noticed; which is, that it ſeems to reſemble the torpor of
winter-ſleeping inſects and other animals, as many plants do not ap-
pear to reſpire during this part of their exiſtence ; for ſome vegeta-
bles cloſe together the upper ſurfaces of their leaves, both during
their ſleep and in rainy weather, as mimoſa, ſenſitive-plant; pha-
ſeolus, kidney-bean; and the terminal foots of alfine, chickweed.
Many other plants cloſe their petals and calyxes during their ſleep as
well as in rain, as convolvulus ; and ſome even in the bright day-
light, as tragapogon; and yet all theſe plants are believed by gardeners
to grow, when young, faſter in the night.
We muſt obſerve, that this ſeep of plants, though it may reſemble
the torpor of winter-ſleeping animals, is not to be confounded with
the ſtate of deciduous plants in the winter, as that conſiſts in the
death of the laſt year's bud, and the embryon condition of the new
buds. It would hence appear, that perpetual reſpiration is leſs ne-
ceſſary to the vegetable than to the animal world ; and that as leſs is
waſted during the inactive ſtate of fleep, it is poſſible that young
plants may increaſe in weight, or grow faſter, during this ſtate of
inactivity, as animals are obſerved to reſpire leſs frequently during
their ſleep, and yet are believed when young to grow faſter during
their hours of reft than of exerciſe. So both in the experiments of
Dr. Hales and Dr. Walker on plants during the bleeding ſeaſon, the
afcent of the fap-juice not only ſtopped during the night, but ſome-
times became retrograde, which might nevertheleſs be aſcribed to the
torpor of the abſorbent ſyſtem induced by cold, as well as to that of
ſleep.
6. We may draw this general reſult, that the common leaves of
trees are the lungs of the individual vegetable beings, which form
during the ſummer new buds in their boſoms, whether leaf-buds or
flower-buds, and which in reſpect to the deciduous trees of this cli-
mate

56
PULMONARY ARTERIES Sect. IV. 5.6.
mate periſh in autumn; while the new buds remain to expand in the
enſuing ſpring. Secondly, that the bractes, or floral-leaves, are the
lungs of the pericarp or uterus, and to the growing ſeeds which it
contains, as the bractes on the ſtem of the crown-imperial, fritil-
laria imperialis, and the tuft above its flowers. And thirdly, that
the corol or petals are the lungs belonging to the anthers and ſtigmas,
which are the ſexual or amatorial parts of the plant, and to the nec-
taries for the ſecretion of honey, and to the other glands which affords
effential oil and wax.
Laſtly, the ſtamina and ſtigma with the petals and nectary, which
conftitute the vegetable males, and the amatorial part of the female,
as they in ſome plants appear before the green leaves or bractes, as in
colchicum and mezereon, and in all plants fall off when the female
uterus is impregnated, would appear to be diſtinct beings, totally
different both from the leaf-buds, which produce a viviparous pro-
geny; and alſo from the bractes with the calyx and pericarp, which
conſtitute the vegetable uterus.
They muſt at firſt receive nutriment from the vernal fap-juice, like
the expanding foliage of the leaf-buds, or the bractes of the flower-
buds. But when the corol becomes expanded, and conſtitutes a new
pulmonary organ, the vegetable juices are expoſed to the air in the
extremities of its fine arteries beneath a moiſt pellicle for the purpoſe
of greater oxygenation, and for the important ſecretion of honey;
and then the anthers and ſtigmas are ſupplied with this more nutri-
tious food, which they abſorb from its receptacle, the nectary, after
it has there been expoſed to the air, and are thus furniſhed with
greater irritability, and with the neceffary amatorial ſenſibility, and
live like bees and butterflies on that nutritious fluid. See Sect. VII.
11. 4.
SECT.

Secr. V. 1. AORTAL ARTERIES AND VEINS.
57
SECT. V.
30
THE AORTAL ARTERIES AND VEINS OF VEGETABLES.
3. Aortal arteries in vegetables have correſpondent veins. Shewn by experiment on
picris, tragopogon, and euphorbia. Seen in the calyx of flowers. Circulation
Shewn by ingrafting ſtriped-paffion-flower, and jaſmine, and hardier ſcions on can-
kered ſtems, from fruit-grafts on bad ſtocks degenerating. 2. Vegetable circula-
tion performed without a beart, as in the aorta and liver of fiſh. 3. Force of the
mouths of abſorbents greater than that of the heart in producing circulation. Why
there is no pulſation in the vena portarum. Circulation in the veins of animals
produced by abſorption. Very ſmall reſiſtance in the capillaries and glands.
Wounds in trees strongly abſorb fluids except in the bleeding ſeaſon. 4. Vegetable
veſſels too minute to carry red blood, bence not eaſily injected with coloured fluids.
Charcoal injected with quickſilver, or melted wax. 5. Recapitulation. Circula-
tion performed by irritability of the veſſels, and by the great power of abſorption,
and the ačtion of the ſides of veſſels corſiſting of a ſpiral line. 6. Veſſels unite at
the lower and upper caudex gemma. Abſorbents and umbilical veſſels conſiſt of
e spiral line. Experiment by placing euphorbium firſt in a decoction of galls, and
then in a ſolution of green vitriol. Junction of great vein, abſorbent trunk, and
pulmonary artery in the upper caudex gemme. Embryon bud
ſeen in conta&t with
the pith. Experiments with charcoal injected with white paint, fuet, wax, and
quickſilver.
1. The two principal arteries in animal bodies are the pulmonary
artery and the aorta. The former receives the blood from the right
cavity of the heart, and diſperſing it round all the air-cells which
terminate the bronchia, or air-pipes of the lungs, expoſes it to the in-
fluence of the atmoſphere through the thin moiſt membrane, which
lines them. This we have ſhewn in Sect IV. I. 3. to be reſembled
in its office by the vegetable arteries, which carry their blood up the
I
foot-

58
Sect. V. r.
AORTAL ARTERIES
a
a
foot-ſtalks of the leaves, and expoſe it on the upper ſurface of them
to the influence of the air through a thin moiſt pellicle, where it
changes its colour, and returns by correſpondent veins like the blood
of animals.
The aortal arteries of the more perfect animals receive the blood
from the left cavity of the heart, after it has been expofed to the
influence of the air in the lungs, and diſperſe it by numerous rami-
fications over the whole body for the purpoſes of ſecretion and nu-
trition. In leſs perfect animals the aorta itſelf has a pulſation, and
carries forward the blood without the aſſiſtance of a heart, as may be
ſeen in the back of a full-grown fill-worm by the naked eye, and
very diſtinctly by the uſe of a common lens. After the blood has
paſſed the various glands and capillaries, it is received by another fyf-
tem of veſſels, the veins, which conſtitute a kind of reſervoir for the
quantity of blood, that remains unexpended by the ſecretions, ex-
cretions, nutrition, and growth of the animal ; by theſe it is again
carried to the right cavity of the heart, and again expoſed in the
lungs to the influence of the air.
In a fimilar manner the branching veins, which bring the blood
from the leaves of plants, after it has been expoſed to the influence
of the air, unite at the foot-ſtalk of each leaf into more or fewer
trunks, as may be ſeen in tearing off the foot-ſtalk of a leaf of a
cheſnut-tree from the ſtem ; and there without the interpoſition of a
heart, like the circulation in the aorta of fiſh, and that in the livers
of red-blooded animals, theſe venous trunks take the office of arte-
ries, and diſperſe the blood downwards along the bark to the roots,
and to every other part of the vegetable ſyſtem, performing the va-
rious purpoſes of ſecretion, excretion, and nutrition, as was fhewn
in the experiment of placing a fig-leaf in a decoction of madder,
deſcribed in Seet. IV. 1. 3. of this work.
But as vegetables drink up their adapted nouriſhment perpetually
from the moiſt earth, and in conſequence muſt be ſuppoſed to take
up
a

Secr. V. 1.
59
AND VEIN S.
up no more than their perpetual waſte may require, I formerly be-
lieved, that this reſervoir, or venous ſyſtem, was not neceſſary in vege-
tables; and that therefore probably it did not exiſt. I was induced to
adopt this idea from having obſerved in cutting afunder a ſtem of large
d
ſpurge, euphorbia heliofcopia ; in which the riſing ſap could not be
miſtaken for the milky blood; that much more of the vegetable blood
flowed from the upper part of the plant than from the lower part of
it; and I therefore ſuſpected, that there was no returning veins cor-
reſpondent to the deſcending aortal arteries. But firſt this muſt ne-
ceſſarily occur from the veins returning from the root effuſing their
blood flower than the arteries of the upper part of the plant. And
fecondly, if there were no returning veins from the lower part of
the plant, there ought to have been no effuſion of blood from it. I
have ſince obſerved on cutting aſunder a large plant of picris, and alſo
a large plant of tragopogon ſcorzonera, and inſtantly inſpecting them
with a common lens; that two concentric circles of vefſels were
viſible, which oozed a milky juice; the internal circle of the upper
diviſion of the two plants, and the external one of the lower divi-
fion, appeared to bleed more copiouſly, and in quicker ſtreams, than
the external circle of the upper diviſion, and the internal one of the
lower diviſion; whence I concluded, that the veſſels of the internal
circles were arteries, and thoſe of the external ones veins; and that
the arteries of the upper part of the plant, which ariſe from the
up-
per part of the caudex of each individual bud, were thus ſeen to pour
out more blood, and in a quicker ſtream, than the veins of the lower
part of the plant, as they return from the roots.
Add to this, that as the pulmonary arteries in the green leaves of
plants, and in their petals, have correſpondent veins viſible to the eye;
and that theſe are alſo ſeen in the calyxes of ſome flowers, which
from their other evident uſes can not be eſteemed pulmonary organs :
There is the ſtricteſt analogy to believe, that the aortal arteries of the
bark of the trunk and roots have alſo their correſpondent veins.
Nevertheleſs
I 2

60
Secr. V. 1.
AORTAL ARTERIES
a
a
a
Nevertheleſs to evince that the veſſels returning from the roots
of plants, which oozed out a milky juice, were in reality not ab-
forbent veſſels, I cut off the ſtem of a large ſpurge plant, euphor-
bia helioſcopia, about a foot and half from the ground, and bent it
down into a cup of a decoction of madder, rubia tinctoria, in which it
was confined two or three minutes; and wiping the end clean, I pre-
fently cut off about an eighth of an inch of it with a ſharp penknife,
and obſerved with a common lens the large abſorbent veſſels to be
coloured with the madder, while the veins continued to effuſe a little
white blood; and thus demonſtrated both the exiſtence of abſorbent
veſſels and returning veins. See Sect. II. 2.
At the ſame time the upper part of the plant had alſo its ſtem ſet
in the decoction of madder, and after two or three minutes on cutting
off about the eighth of an inch of it, or ſimply by wiping the extre-
mity, the large abſorbent veſſels were ſeen by the naked eye to be
coloured with the madder, and the arteries continued to effuſe a large
quantity of milky blood. The fame experiments were tried on a plant
of tragopogon with the ſame event.
It ſhould be here obſerved, that the decoction of madder ſhould
be freſh made, as otherwiſe the colouring matter is liable to form it-
ſelf into molecules, too large to be imbibed by any other vefſels but
the trunks of the abſorbents, which may be ſaid to reſemble the re-
ceptaculum chyli of animals, as they paſs from the lower extremity
of the caudex of each bud to the upper one.
A proof of the circulation of the juices of plants has been deduced
from the communication of white ſpots from a grafted ſcion to the
whole of the tree in which it was ingrafted. Mr. Fairchild budded
a paffion-tree, whoſe leaves were ſpotted with yellow, into one which
bears long fruit. The buds did not take, nevertheleſs in a fortnight
yellow ſpots began to Thew themſelves about three feet above the in-
oculation, and in a ſhort time afterwards yellow ſpots appeared on
a fhoot,

Sect. V. 2.
61
AND VEIN S.
a
a ſhoot, which came out of the ground from another part of the plant.
Bradley on Gardening, Vol. II. p. 129.
And Mr. Lawrence obſerves, that the yellow ſtriped jaffamine has
afforded a demonſtration of the circulation of the juices in a tree; he
inoculated in Auguſt the buds of ſtriped jaffamine-trees into the
branches of plain ones; and aſſerts, that he has ſeveral times expe-
rienced, that if the bud lives but two or three months, it will com-
municate its virtue or diſeaſe to the whole circumfluent fap, and the
tree will become entirely ſtriped. Art of Gardening, p. 66. Theſe
are both of them important facts, as they are related from reſpectable
authorities.
And I think I have myſelf obſerved in two pear-trees about twenty
years old, whoſe branches were much injured by canker, that on in-
grafting hardier pear-ſcions on their ſummits, they became healthier
trees, which can only be explained from a better fanguification pro-
duced in the leaves of the new buds.
It has alſo been obſerved by an ingenious lady, that though fruit-
trees ingrafted on various kinds of ſtocks are ſuppoſed to bear fimilar
fruit, yet that this is not accurately fo; as on ſome ſtocks ſhe has known
the ingrafted fcions of apple-trees to ſuffer conſiderable change for the
worſe compared with the fruit of the parent-tree; whereas thoſe ſcions,
which can be made to grow by ſtriking roots into the earth, ſhe be-
lieves to ſuffer no deterioration. If this really occurs, it ſhould be
in a very ſlight degree, as the fruit is formed by the action of ſecre-
tion, and depends on the glands of the part more than on any ſlight
change of the vegetable blood, from which the ſecretion is ſelected or
produced. Nevertheleſs if the fact be aſcertained, it confirms the
truth of the exiſtence of a vegetable circulation.
2. The circulation of the vegetable juices in the leaves of plants,
and in their trunks and roots, is performed without a heart, and is
very ſimilar to that in the aorta of fiſh. In fiſh the blood, after hay-
ing paſſed through their gills, does not return to the heart, as from
the

62
Secr. V. 2.
AORTAL ARTERIES
the lungs of air-breathing animals; but the pulmonary vein, taking
the ſtructure of an artery, after having received the blood from the
gills, which there gains a more florid colour, diftributes it to the other
parts of their bodies. A fimilar ſtructure obtains in the livers of fiſh,
as well as in thoſe of air-breathing animals; the blood is collected
from the meſentery and inteſtines by the branches of their proper
veins, which unite on their entrance into the liver, branch out
again, and aſſume the office of an artery, under the name of vena
portarum, diſtributing the blood through that large viſcus for the
purpoſe of the ſecretion of bile; whence we ſee in theſe animals
two circulations independent of the power of the heart. Firſt, that
which begins in the meſentery and inteſtines, and paſſes through the
liver; and ſecondly, that beginning at the termination of the veins
of the gills, and paſſing through the other parts of the body; both
which circulations are carried on by the action of thoſe reſpective ar-
teries and veins. Monro's Phyſiology of Fiſh, p. 19.
The courſe of the fluids in the leaves, and in the trunks and roots
of vegetables, is performed in a ſimilar manner. Firſt, the abſorbent
veſſels of the roots, of the internal cells, and of the external bark, with
the venous blood returning from thoſe parts, unite at the foot-ſtalk
of the leaf; and then, like the vena portarum, an artery commences
without the intervention of a heart, and receiving the ſap and venous
blood ſpreads it in numerous ramifications on the upper ſurface of the
leaf; here it changes its colour, and becomes vegetable blood; and is
again collected by a pulmonary vein, and returns on the under ſur-
face of the leaf. This vein, like that which receives the blood from
the gills of fiſh, aſſumes the office of an artery, which correſponds
with the aorta of animals, and branching again diſperſes the blood
upward to the plumula or ſummit of the bud, from its caudex at the
foot-ſtalk of the leaf, and downward along the bark of the trunk to
the roots; where it is received by a vein correſponding to the vena cava
of animals, after having expended what was required for the ſecre-
a
tions,

Secr. V. 3:
63
AND VEINS.
tions, excretions, and nutritition, and returns to the caudex of the bud,
and to the foot-ſtalk of the leaf.
3.
The power, which produces a circulation without a heart in
vegetables, acts with an aſtoniſhing force. In ſome of the experi-
ments of Dr. Hales, who fixed glaſs tubes to vine-ſtumps in the ſpring,
the fap-juice roſe above thirty feet; and in ſome trees muſt proba-
bly ariſe ſtill higher in the vernal months before the leaves are ex-
pended; and this either ſolely by the activity of the abſorbent mouths
;
of theſe veſſels, or affifted by the vermicular action of their fides,
which appear to conſiſt of a ſpiral line, as deſcribed in Sect. II. 7. of
this work.
When the fap-juice riſes thirty-five feet high, which is about the
weight of the atmoſphere, the column preſſes about fourteen pounds
on every ſquare inch. Now if the area of the mouth of an abſorbent
veſſel be only one ten thouſandth part of the area of a ſquare inch, the
ten thouſandth part of fourteen pounds is the whole that counteracts
the efforts of each abſorbent mouth; and as the veſſels of vegetables
appear to have both very minute diameters, and very rigid fides, they
are thence prevented from aneuriſm or rupture by the preſſure of ſo
high a column of ſap-juice.
The ſame philoſopher, by fixing glaſs tubes to the arteries of horſes,
as near the heart as was practicable, found the blood in them to riſe
only nine or ten feet; whence it appears, that a circulation of blood
may be carried on more forcibly by the action of the mouths of ab-
ſorbent veſſels, than by the apparently more violent exertions of the
heart, the power of which was calculated by Borelli and others to be
ſo enormoufly great, as to equal the preſſure of ſome thouſand pounds,
as the counter preſſure of the moving blood acts on fo large a ſurface
as that of the whole internal fides of the heart.
But as a column of blood nine feet high preſſes with leſs than one
third of the weight of the atmoſphere, or about four pounds on every
ſquare inch of ſurface; and as the internal ſurface of the left cavity
of
a

64
Secr. V. 3.
AORTAL ARTERIES
a
of the heart of a horſe may not exceed thirty ſquare inches, its whole
power
does not overcome the reſiſtance of more than 120 pounds.
Hence it becomes intelligible, how the circulation of the blood in
the vena portarum of the liver is performed without any apparent
pulſation, or contraction of its fides like an artery, which ſome have
indeed ſuppoſed it to poffefs, but ſimply by the force of abſorption
exerted by the mouths of the veins, which ſupply it with blood.
Secondly, how the circulation of the blood in the bodies of fiſh, ex-
cept in their gills, is carried on through their ſyſtem without the ac-
tion of the heart. And thirdly, how the blood in the vena cava of
the human body, as well as the fluids imbibed by the lacteals and
lymphatics, are carried forwards to the heart by the power alone of
their abſorbent mouths, which drink up their blood from the capil-
laries, or their other fluids from the ſurfaces or cavities of the body.
And laſtly, how the whole circulation in vegetables is performed in
very minute veſſels without valves, and without a heart, ſolely by
the power of abſorption, circumſtances which have long perplexed
the phyſiology both of the animal and vegetable kingdoms.
Another circumſtance attending the circulation of the juices in ve-
getables, as well as the circulation of the blood in animal bodies, has
not been ſufficiently attended to; and that is, that the reſiſtance to the
paſſage of theſe fluids from the terminations of the arteries, in what
are termed capillaries, to the beginnings of the veins, and through
the glands of various kinds, is much leſs than is generally imagined,
as we ſee with what great force the mouths of both the vegetable
and animal abſorbents imbibe their fluids ; and that the beginnings of
the veins, and the mouths of the lacteals and lymphatics, and proba-
bly thoſe belonging to every kind of gland, poffefs this great power of
abſorption. And that on this account, when wounds are made in
trees in the ſummer months, when the umbilical fap-veſſels of the
root have ceaſed to act, ſuch wounds powerfully abſorb any fluid,
whether ſalutary or poiſonous, which is applied to them, which does
5
not

SECT.V.4, 5.
65
AND VEINS.
a
&
V
not occur during the bleeding ſeaſon, as the fap-juice from the dif-
fevered veſſels of the alburnum ſupplies a greater quantity of fluid
than the other parts of the wound can imbibe.
4. The red particles of blood have been ſaid by Lewenhook and
others, who have inſpected them in microſcopes, to be of the ſame
fize in all creatures. Hence nature has formed no very ſmall animals
with a general circulation of warm red blood; the mouſe and hum-
ming-bird are perhaps the leaſt. When it was neceſſary to form the
vefſels much more minute, a diluter kind of yellow or milky blood, or
one nearly tranſparent, conſtitutes the greateſt part of the vital fluid,
as in infects of various kinds, and in the white muſcles of fiſh;
whence aroſe a difficulty to the anatomiſt of viſibly injecting theſe
ſmaller ſeries of veſſels, as they are too minute to convey almoſt any
coloured particles.
In the vegetable world the finer fyſtems of their veſſels have ſtill
greater tenuity, and hence evade our eyes and microſcopes; and as
their coats poſſeſs at the ſame time a greater rigidity, they are in ge-
neral on that account alſo incapable of receiving coloured injections,
which has rendered the anatomy of plants ſo much more difficult to
inveſtigate than that of animals, and muſt apologiſe for the imperfec-
tions of this part of the work, but affords no argument againſt the
exiſtence of a vegetable circulation.
It is probable that by immerſing charcoal, nicely made by flow calci-
nation, in quickſilver, or even in melted coloured wax, as it fo greedily
abſorbs almoſt all fluids, when recently taken from the fire, or cooled
without the contact of air, we might produce beautiful vegetable pre-
parations, and give more accurate light into the anatomy of plants.
But the column of quickfilver employed to puſh forwards the injection
ſhould not be too high, left it ſhould rupture the veſſels it ought
only to fill, as I ſuppoſe has ſometimes happened in thus injecting
the glands or capillaries of animal bodies.
5. Recapitulation. We may finally conclude, that the circulation
K
of

66
Secr. V. 5
AORTAL ARTERIES
of vegetables is performed like that of animals by the irritability of
their veſſels to the ſtimulus of the fluids, which they abſorb and pro-
trude; that is, that the extremities of the branching veins of the
leaves forcibly abſorb the vegetable blood from the extremities of their
arteries, which correſpond with the pulmonary arteries of animals;
and that it is thus puſhed on to the foot-ſtalk of the leaf, where
the veins unite, and branching out again take the office of an artery
like the aorta in filh, without perceptible pulſation. The blood in
this artery is puſhed forwards by that behind it, the motion of which
was given by the power of abſorption in the pulmonary vein, tillitar-
rives at the extremities of theſe aortal branches, and is there again
forcibly abſorbed by the terminations of the correſpondent veins, and
again puſhed forwards to the caudex gemmæ, and to the foot-ſtalk.
of the leaf, like the blood in the vena cava of animals.
A part of this blood is at the ſame time forcibly ſelected and ab-
forbed by the various glands. for the purpoſes of the neceſſary ſecre-
tions, excretions, or nutrition ; and the ſap-juice or chyle and the
water, which is acquired by the abſorbent vefſels, that correſpond to
the lacteal and lymphatic veſſels of animals, is carried, as well as the
remainder of the blood, to the foot-ſtalk of the leaf. Here theſe ab-
ſorbent veſſels are believed to puſh their contents into the veins cor-
reſpondent to the vena cava of animals, and which now uniting with-
out the intervention of a heart, aſſume the name and office of the pul-
monary arteries; and branching out upon the leaf expoſe the return-
ing blood and new ſap-juice to the influence of the air. And finally,
all this is accompliſhed by the power of abſorption, as in the aortal ar* -
teries, and vena portarum, of fiſh, which is excited into action by the
irritability of the mouths of theſe veſſels to the ſtimulus of the fluids,
which they abſorb.
2d. A circulation of vegetable juices, in every reſpect ſimilar to that
in the common leaves above deſcribed, exiſts in the bractes or floral-
leaves, except that the leaves of the leaf-bud prepare their juices for
the

Secr. V.6.
67
AND VEINS.
the production and nouriſhment of other buds in their boſoms; but
theſe bractes, which are the lungs of the fructification, prepare their
juices for the nouriſhment of the pericarp and its included feeds, but
not for that of the corol with its anthers and ſtigmas, as theſe in
many flowers exiſt before the production of the floral-leaves, as in
colchicum and hamamelis.
3d. Another circulation of vegetable juices exiſts in the ſexual
parts of flowers, including the nectaries and corols. In the corols
the vegetable blood is expoſed to the influence of the air, and pre-
pared for the ſecretion of honey, which is the food or ſupport of the
anthers and ſtigmas, as treated of in the ſection IV. V. 1. and in Sec-
tion VII. 4. In theſe the progreſſion and circulation of the fluids muſt
be cauſed by the power of abſorption, which we have ſhewn to be a
greater force than that of the heart of animals.
4th. The progreſs of the fluids imbibed by vegetable lacteals from
the earth, and by their lymphatics from the air, and from the ſur-
faces of their internal cells, is evidently began and carried on by the
power of abſorption of their terminating mouths, and the annular
contraction of their ſpiral fibres.
5th. And laſtly, the wonderful force with which the ſap-juice is
drank up and protruded in the umbilical veſſels, which expands and
nouriſhes the buds of trees, and which forms the wires of ſtrawberries
above ground, and thoſe of potatoes under ground, with the great
variety of bulbs and root-ſcions, is to be aſcribed to this ſingle princi-
ple of abſorption. Except that ſome of theſe long cylindric veſſels
are evidently compoſed of a ſpiral line, as mentioned in Sect. II. 7. and
which may by the annular contraction of this ſpiral line carry the
fluids they have abſorbed with great force either in a forward or re-
trograde direction.
6. Finally I conclude, that the branching abſorbents of the roots
unite at the lower caudex of each bud, before it riſes out of the earth,
K 2
and
а

68
SECT. V.6.
AORTAL ARTERIES
and forms a large trunk, which paſſes up the alburnum of the tree to
the upper caudex of the bud at the foot-ſtalk of the leaf, and may
be compared to the receptaculum chyli of animals extended to fo
great a length; and that it there joins the great returning vein, which
alſo is compoſed of the branching veins of the roots uniting at the
lower caudex of the bud, and afcending terminates at the upper
caudex of it, where it becomes again branched, and forms the pul-
monary artery.
The aorta or great artery deſcends, I ſuppoſe, along with the great
vein, or vena cava above mentioned ; and branching in the roots be-
low, and on all other parts of the individual leaf-bud, performs the
offices of ſecretion and nutrition. The pulmonary arteries and veins
belong to the leaf; the former expoſes the blood to the atmoſphere
beneath a thin moiſt pellicle, whence it becomes oxygenated, and pro-
bably acquires ſome warmth, and phoſphoric acid, and the ſpirit of
vegetable life. The latter collects the aerated blood by its branches,
and conveys it to the upper caudex of the bud, at the foot-ſtalk of the
leaf, where it becomes the aorta or great artery above mentioned.
The ſides of the long abſorbent trunks, or receptacles of chyle,
which riſe from the lower caudex and terminate in the
of each bud, as well as the long trunks of the umbilical veſſels de-
fcribed in Sect. III. evidently confift of a ſpiral line, as well as thoſe
trunks of abſorbents, which imbibe aqueous fluids from the air, and
a part of their perſpirable matter on the ſurfaces of the leaves. But
whether the pulmonary and aortal arteries or great veins conſiſt of a
fimilar ftruure is not yet aſcertained.
I ſhall here relate the following experiments, which were made a
few days ago, to confirm or confute the ideas above delivered.
Some ftems of large ſpurge, euphorbia, were fet upright in a de-
coction of oak-galls, and others in a ſolution of green vitriol. On the
next day theſe were reciprocally removed from the one to the other,
as by this management I ſuppoſed that the black molecules would
be
upper caudex
a

Sect. V. 6.
69
AND VEINS.
be produced in the veſſels of the plants, and would thence appear
higher in thoſe veſſels than if the black molecules had been formed
by a mixture of the two fluids previous to their abſorption.
On cutting theſe horizontally ſlice after flice with a ſharp knife,
and inſpecting them with a common lens, the milky blood was ſeen
to ooze, as before deſcribed, from an external ring of the bark; and
an interior ring of coloured points was agreeably viſible many inches
up the ſtem ; but on ſlicing the ſtem from below up to the inſertion
of the leaves and buds in their boſoms, I perſuaded myſelf that I
could perceive the coloured abſorbents of the ſtem enlarged at the
part where each with the attendant vein changes into a pulmonary
artery, and paſſes into the leaf, forming three or more of the ribs of
it, and thus conſtituting the upper part of the caudex gemmæ.
Another circumſtance was beautifully viſible, which was, that the
coloured cylinder of abſorbent vefſels had evidently ſeparated to allow
the new bud to apply its interior termination to the pith; which pro-
bably, when it was ſecreted by the glands of the caudex of the parent
bud, found in this ſituation a proper nidus, and due nutriment for its
embryon ftate, as in the uterus of the female.
Some other kinds of experiments I directed with deſign to ſhew
the part of the lower caudex of each bud, where the branching ab-
ſorbents and veins of the root unite each into one trunk, before they
aſcend along the bole of the tree; and alſo to ſhew, as in the above
experiment, the upper caudex of each bud, where the veins are
joined by the abſorbents, and become the pulmonary arteries of each
leaf, but did not ſucceed quite to my wiſh, though what I could ob-
ferve ſeemed to confirm the above theory. I had not leiſure to re-
peat the experiments with ſufficient attention, but ſhall here in few
words deſcribe the manner of making them, hoping ſome one may
be induced to proſecute them with ſucceſs, and to inject vegetable
vefſels, as the anatomiſts do thoſe of animals.
A part of a leaf-ſtalk, and the joint to which it adhered, with
9
about
a

70
AORTAL ARTERIES, &c.
SECT.V. 6.
about half an inch of the ſtem above and below the joint, were cut
off from fome laſt year's twigs, and alſo the caudex of ſome herba-
ceous plants. Theſe were covered with fand in a crucible placed
on the fire, till they were red hot, ſo that the vegetable joints
were become charcoal. They were then taken out of the fand, and
ſome immerſed in melted fuet, others in melted bees-wax, others in
white paint, and one or two in an amalgama of quickſilver and zinc,
which happened to be prepared for the purpoſes of electricity. When
they were cold, on ſlicing them, ſome horizontally, and others ver-
tically, I perſuaded myſelf that the blood-veſſels above mentioned, as
well as the pulmonary vein and aortal artery, were viſible in the two
extremities of the long caudex of the bud, as well as the long trunks
of the arteries, veins, and abſorbents, which conſtitute the middle
part of it.
SECT.

Sect. VI.
71
GLANDS AND SECRETIONS.
SECT.
VI.
THE GLANDS AND SECRETIONS OF VEGETABLES.
I. 1. Glands of vegetables. Their veſſels are too minute for coloured injections. 2. They
pofleſs appetency. Are ſtimulated by the paſing blood. II. 1. Mucilage in all
vegetables. 2. Is a part of their nutriment, and convertable into ſugar.
III. I. Starch not ſoluble in cold water. Potatoe bread. 2. Starch produced
from mucilage, whence old grain better than new. Alum coagulates mucilage.
Uſe of it in bread. How diſtinguiſhed in bread by the eye. Is ſalutary in London
bread. Is uſed in: making hair-powder. 3. Froſt converts mucilage into ftarch;
ſnow pancakes. 4. Starch from poiſonous plants is wholeſome, and may be ob-
obtained by elutriation in times of ſcarcity. IV. 1. Oils may be ſeparated from
bitter or narcotic materials, as the latter adhere to the mucilage. V. 1. Sugar
formed by animal digeſtion. 2. By vegetable digeſtion. Sugar is nutritive, but
may injure the teeth. 3. In many roots it is found ready prepared. May be fe-
parated from mucilage by vinous Spirit. 4. Exiſts in fruit formed from auſtere.
acids by a vegetable proceſs. 5. By heat; by bruiſing auftere fruit; by drying
a
malt. Sugar converted into ſtarch as well as ſtarch into fugar. Uſe of ſugar to ve-
getables and animals. VI. i. Honey guarded from inſects, and from rain.
2. Is of great importance. Is expoſed to the air. Is reabſorbed, and is nutri-
tious. 3. Depredation of infeEts on honey is injurious to vegetation. So is the
honey-dew on trees. Bees alſo colleet farina from flowers. 4. Why the honey is .
expoſed to the air. Is the food of the anthers and ſtigmas. Differs from ſugar by
greater oxygenation. Benevolent economy of nature. VII. 1. Wax preſerves the
anther-duft from rain. Howe, wet ſeaſons injure wheat. 2. Wax colleEted from
ciſtus labdiniferus. Bees much injure flowers. 3: Wax from candleberry-
myrtle, and from croton ſebiferum. Preſerves or nouriſhes the immature ſeeds.
4.Wax depoſited on plants by inſects in China. Gives conſiſtence to oil. VIII. 1. Tur-
pentines and eſſential oils are inadmiſſible with water. Moiſt parts of vege-
tables are ſooneſt deſtroyed by frost. Evergreen trees contain moſt reſin. De-
fends the buds of deciduous plants. 2. Origin of petroleums jet, amber, fobii,
cool
.

72
GLANDS AND
SECT. VI. 1. 1, 2,
coal. 3 Eſſential oils agreeable. Poiſonous. Preſerve wood from infeets. Uſed
in Africa to poiſon weapons and pools of water. 4. Some eſſential oils burſt into
flame with nitric acid. Produce a vapour round di&tamnus fraxinella. 5. Elaſtic
reſin. Bird-lime. Refinous part of wheat-flower. IX. 1. Bitter, narcotic,
acrid juices, for the defence of plants. Opium exiſts in the poppy-head, but not in
the feed. So of hyoſcyamus. Narcotic matter in walnut-buſks not in the feed.
Oil of bitter almonds taſteleſs. 2. Acrid, aſtringent, emetic, cathartic, and
colouring matters. Many poiſonous plants in all our bedge-bottoms. 3. All
theſe are ſtrongeſt in the hybernaculum or winter-lodge of plants. When oaks
should be decorticated. X. 1. Acids in fruit and leaves of various kinds. Con-
vertible into ſugar. For the nutriment of ſeeds and buds. For the defence of the
plants.
1.1. The ſtructure of the glands of animals has not been yet fully
afcertained. They conſiſt of veſſels ſo minute as to exclude all co-
loured injections, except quickſilver; and the terminations of theſe
veffels are fo tender, that the neceſſary weight of the quickſilver is
liable to break them, and thus miſinform the obſerver, as mentioned
in Sect. V. 4. Little more is therefore known of them than their
effect, which is, that they ſecrete, that is ſeparate or produce, ſome
fluid from the blood; as bile, ſalvia, urine, milk.
The veſſels of vegetables being ſtill more minute, and more rigid,
the ſtructure of their glands is ſtill further removed from our diſco-
very. Their effects are however as evident as thoſe of the glands of
animals in the ſecretion or production of various fluids, which be-
come ſolid, as their aqueous parts are abſorbed or exhaled, as mucilage,
ſtārch, oil, ſugar, honey, wax, turpentines, effential oils, aromatics,
bitters, narcotics, acrids, acids, and a variety of other materials,
which fill our barns and granaries, and crowd the ſhops of the drug-
gift.
2. There can be no doubt from what has been already ſaid of the
circulation of vegetable juices, but that their various ſecretions muſt
be effected in a ſimilar manner to that in animal bodies, which is
believed

Sect. VI. 2. 1. 3. 1.
73
SECRETIONS.
believed to be performed by the mouth of each gland being irritated
into action by the ſtimulus of the blood, which is brought to it, and
that by a kind of appetite it drinks up a part of the blood, and con-
verts it to the fluid, which it ſecretes, which then becomes more or
leſs ſolid, as its aqueous parts are abſorbed or exhaled.
II. 1. Mucilage is found in all parts of plants, as being an eflential
conſtituent of vegetable as of animal bodies ; ſo when an extract is
made by boiling plants in water, the mucilage makes the greateſt part
of this extract. The mucilage called gum arabic is obtained from
mimoſa nilotica, gum tragacanth exſudes from aſtragalus tragacantha,
as a ſimilar gum exſudes from our cherry and plumb-trees; fagoe is
the pith of the lycas circinalis; and falep is the root of the orchis
dried in an oven.
This mucilage ſeems to ſerve as nouriſhment to the plant; firſt,
becauſe it is found in all vegetable as well as animal materials, as they
decompoſe in dunghills; ſecondly, becauſe it forwards the growth
of vegetables, when ſpread upon land; thirdly, becauſe thoſe trees,
which bleed much gum, are weakened and frequently die; and laſtly,
becauſe it is evidently laid up in the roots and feeds of various vege-
tables for the nouriſhment of the young plants. But in theſe it
ſeems to undergo a change either in part chemical, or wholly by the
digeſtive organs of the embryon plant, and is converted into ſugar,
as in the tranſmutation of barley into malt; and as appears from the
ſweet taſte of onions and potatoes, when boiled after they have ger-
minated; and as ſugar abounds in the vernal fap-juice of trees in
ſuch quantity as to be capable of fermentation.
III. 1. Starch is another kind of mucilage, which differs from
thoſe above mentioned in its property of not diffolving in cold water,
and can hence be eaſily ſeparated from them. If eight pounds of
good raw potatoes be grated by means of a bread-grater into cold
water ; and, after well agitating the mixture, the ſtarch be ſuffered
to ſubſide; and this ſtarch be then mixed with eight other pounds of
L
boiled

74
Sect. VI. 3. 2
GLANDS AND
boiled potatoes, as good bread may be made as from the beſt wheat
flour; as is affirmed by Monſ. Parmentier. From this it appears,
that the quantity of ſtarch in potatoes and in wheat produces the prin-
cipal difference of their reſpective flours. See Zoonomia, P. III. Ar-
ticle 1. 2. 3. 4.
2. There is reaſon to believe that the mucilage during the growth
of the plant is converted into ſtarch ; and that this proceſs continues
in grain ſome time after it is carried into the barn or granary, which
occaſions old wheat to produce better flour for the baker; and old
oats and old beans are univerſally believed to give more nouriſhment
to horſes. I ſhall here add a conjecture, that I ſuppoſe the uſe of alum
in making bread conſiſts in its coagulating the mucilage, and perhaps
thus contributing to convert it into ſtarch; for the bakers mix it
principally with new wheat; and affirm, that it makes the flour of
new wheat equal to old.
Where much alum is mixed with bread, it may be diſtinguiſhed by
the eye by a carious circumſtance, which is, that where two loaves
have ſtuck together in the oven, they break from each other with a
much ſmoother ſurface, where they had adhered, than thoſe loaves
do which do not contain alum.
Add to this, that alum is alſo uſed by the London bakers for the
purpoſe of clearing the river water, with which they are ſupplied,
which is frequently muddy; and alſo for inſtantaneouſly deſtroying
the volatile alkali, which is ſaid to exiſt in ſome London wells owing
to the vicinity of dunghills. Theſe purpoſes it probably fulfils by
coagulating the mucilage, which may occaſionally be mixed with
the water and ſupport the mud in it; or by uniting with the calca-
reous earth, or with the volatile alkali which it may contain, and de-
poſiting the new-formed gypſum, or its own argillaceous baſe, the
deſcent of which may carry down other impurities along with it,
in the ſame manner as ſome muddy wines have been rendered fine,
not by filtering them through fand, as then the mud retained on the
ſurface

SECT. VI. 3. 3, 4.
75
SECRETIONS.
a
a
ſurface of the fand ſoon prevents the deſcent of the wine through it,
but by paſſing clean fand in ſhowers by means of a riddle through the
wine. Alum is ſaid to be uſed by the Chineſe for the purpoſe of
cleaning the water of ſome ſtagnant reſervoirs; and when uſed in
ſmall quantity may in all theſe reſpects be rather ſalutary than in-
jurious to the bread of London.
Alum is ſaid alſo to be uſed in the manufactory of hair-powder,
which ſhould conſiſt of ſtarch without mucilage, that the hair may
not be glued together by the perſpirable matter of the head, or by an
accidental ſhower. Whether it has the property of converting mu-
cilage into ſtarch might be eaſily aſcertained by experiment, by waſhing
in cold water alone one parcel of wheat flour, and waſhing a fimilar
parcel in a ſolution of alum in water.
3. Another conjecture I ſhall introduce here is that it is probable that
the action of froſt alſo may tend to coagulate mucilage, or convert it
into ſtarch; for in the colder parts of Britain it is ſaid, that the corn
never ripens till they have froſty nights; and I well remember many
years ago having obſerved, that ſome book-binder's paſte made by
boiling wheat flour and water, after it had been frozen, ceaſed to co-
here on being preſſed together, like the crumbs of ſome bread; and
I have been told by ſome houſewives that their pancakes become
much lighter if ſnow be mixed with the flour inſtead of water. See
Sect. XVI. 3. 2.
4. Now as ſtarch is not ſoluble in cold water, the bitter and acrid
particles of plants may be waſhed from it along with the mucilage;
whence in times of ſcarcity this nouriſhing part of vegetables may
be obtained by elutriation from poiſonous plants ; on this circum-
ſtance principally depends the wholeſomeneſs of the bread made
from the caflava, the acrid and poiſonous particles being previoufly
waſhed away along with the mucilage. Monſ. Parmentier found the
ſtarch from the root of the white bryony to contain no acrimony,
and to be a wholeſome article of food.
IV. 1. Many
3
L2

76
SECT. VI. 4. 1. 5.1, 2.
GLANDS AND
And it is pro-
IV. 1. Many feeds contain much oil mixed with their mucilage,
or ſtarch ; as nuts, almonds, flax-feed, rape-ſeed. Some of theſe
contain alſo a bitter or narcotic material, as bitter almonds, apricot
kernels, acorns, horſe-cheſnuts; which, as it adheres to the muci-
lage, may be ſeparated from the oil; as in expreffing the oil from
bitter almonds, which is as good as from ſweet ones.
bable by grating to powder, and waſhing in cold water, the kernels
of acorns, and horſe-cheſnuts; or ſimply by preſſure, that a whole-
fome ſtarch, or oil, might be procured. It is probable alſo that the
roots of fern treated in this manner would afford good nouriſhment,
as theſe are ſaid to be eaten by the inhabitants of New Zealand, and
have been uſed in this country in times of great ſcarcity. And that
the roots of nymphæa, water-lily, might be thus made into whole-
ſome bread, (which are ſaid to have been eaten in Egypt by Hero-
dotus) and the roots of many other water-plants, which might thus
become articles of ſubaquatic agriculture, which is an art much
wanted in this country. See Sect. XI. 2. 5. and XVII. 2. 3.
V.1. The digeſtive power of animals ſeems to be principally ex-
erted in converting their food into ſugar; fince the chyle of all ani-
mals reſembles milk, which contains much ſugar, and thence ſpon-
taneouſly runs into fermentation, which terminates in the production
of acid, as in butter-milk. In Siberia the natives diſtil a ſpirituous
and intoxicating liquor from milk thus fermented. Gmelin. In the
diabetes there is reaſon to believe, that the chyle paſſes off into the
bladder without being previouſly mixed with the blood; and there is
a curious hiſtory of a patient in the infirmary at Stafford, who la-
boured under a diabetes, he eat and drank thrice as much as moſt
moderate men, and from fixteen to eighteen ounces, and even twenty
ounces of coarſe ſugar was extracted for ſome time daily from his
urine. Zoonomia, Vol. I. Sect. XXIX. 4.
2. In like manner the digeſtive powers of the young vegetable,
with the chemical agents of heat and moiſture, convert the ſtarch or
mucilage

Sect. VI. 5.3, 4.
SECRETIONS.
77
;
mucilage of the root or feed into fugar for its own nouriſhment; or
they obtain ſugar ready prepared for them from fome roots, as the
beet-root; from many fruits, as grapes, pears, peaches ; from the
milk of cocoa-nuts, and from the fap-juice of the ſugar-maple, birch,
and many other trees. And thus it appears probable, that ſugar is
the principal nutriment of both animal and vegetable beings. That
it is the moſt nutritive part of vegetable ſubſtances is evinced by the
well aſcertained fact, that the flaves in Jamaica grow fat in the
fugar-harveſt, though they endure at that time much more labour.
Yet there is an idle notion propagated amongſt the people that ſugar
is unwholeſome; it is indeed probable, that the moſt nouriſhing ma-
terials may be taken more eaſily to exceſs, but not that it is therefore
in general unwholeſome; at the ſame time it is probable, that ſome
fruits preſerved in ſyrup, or ſweet-meats, may contribute to deſtroy
the teeth; fince, if the ſugar ſhould become in a ſtate of decompo-
fition, and the faccharine acid ſhould abound, it will diſſolve calca-
reous earth with greater avidity than any other acid.
3. In many plants ſugar is found ready prepared, as above men-
tioned; thus in the beet-root, the cryſtals of it may be diſcerned by
a microſcope; and may be extracted from the mucilaginous matter of
the root by diffolving it in rectified ſpirit of wine ; which will unite
with ſugar but not with mucilage. In the joints of graſs and of corn
it
may
be diſcovered by the taſte. In the manna-afh, fraxinus ornus,
the ſame faccharine matter is produced along with the eſſential falt of
the plant, which is purgative; and in the ſugar-cane it abounds in
ſuch large quantity as to contribute much to the nouriſhment of
mankind. And, -and what ?-Great God of Juſtice! grant, that
it may ſoon be cultivated only by the hands of freedom, and may thence
give happineſs to the labourer, as well as to the merchant and con-
ſumer.
4. Another ſource of fugar in vegetables is in the fruit, which in
many plants changes from an auſtere acid to a ſaccharine acid, as in
gooſeberries,

78
SECT. VI. 5. 5.
GLANDS AND
gooſeberries, apples, oranges. This change continues to proceed af-
ter the pears and apples, or oranges, are taken from the tree into our
ſtorehouſes, but the fruit in this ſituation continues to ripen by a ve-
getable proceſs, as it can not be ſaid to be dead, becauſe it does not
yet undergo fermentation or putrefaction, or other chemical diffolu-
tion; and though its progreſs in ripening may be forwarded by
warmth, yet it muſt ſtill be aſcribed to a vegetable proceſs; as the
plants themſelves grow quicker when expoſed to additional heat.
5. But there are other means of increaſing or haſtening the fac-
charine proceſs in auſtere vegetable fruits, as by bruiſing them, or by
baking them, both which muſt deſtroy the life of the fruit; thus
when apples are bruiſed for the purpoſe of making cyder, they be-
come ſweeter even in the act of bruiſing them; and many pears
change from an auftere to a ſweet juice ſimply by the heat of baking;
and it is probable that malt acquires a great part, though not the
whole of its faccharine matter, in the act of drying. This chemia
cal production or increaſe of ſugar in vegetable juices is worth being
further inquired into; ſince if ſugar could be made from its elements
without the aſſiſtance of vegetation, ſuch abundant food might be
ſupplied as might tenfold increaſe the number of mankind !
It is a curious circumſtance not yet fufficiently underſtood, that not
only ſtarch appears to be convertible into ſugar by the vegetable pro-
ceſs of digeſtion, as in the germination of farinaceous feeds ; but that
ſugar is capable of being converted into ſtarch, as appears in the ri-
pening proceſs of ſome pears, which firſt contain a ſweet-juice, and
afterwards become mealy.
The uſe of this faccharine matter of the fruit or fap-juice in the ve-
getable economy is for the purpoſe of ſupplying the young feed or
bud with nouriſhment to enable it the better to ſtrike its roots into
the earth, and to elevate its leaves into the air, and thus by its
quicker
a

SECT. VI. 6. 1, 2. SECRETIONS.
79
a
quicker growth to rival its neighbours in their contentions for air, and
light, and moiſture, which are neceſſary for its exiſtence.
VI. 1. The production of honey is perhaps one of the moſt im-
portant vegetable ſecretions, except that of the prolific farina from the
anthers; and of the favilla, or new embryon, in the axilla of the leaf.
The glands for this purpoſe, or certainly the reſervoirs, which con-
tain the honey after it is ſecreted, are in many flowers viſible to the
naked eye; as in crown-imperial, fritillaria imperialis; in monkf-
hood, aconitum napellus; hellebore, ranunculus. It is nevertheleſs
probable, that this reſervoir of honey is frequently placed at a diſtance
from the gland, which ſecretes it, for the purpoſe of preſerving it
from infects and from rain, which is often effected both by a very
complicated apparatus, and by an acrid or poiſonous juice, as in the
aconites and the hellebores above mentioned.
As the nectary, or honey-gland, always falls off along with the
corol, and anthers, and ſtigmas; theſe appear to be parts or appen-
dages to each other. The vegetable blood is expoſed to the air in
the corol, and thus is oxygenated or prepared for the ſecretion of
this important fluid; which I ſuppoſe is again reabſorbed, and ſup-
plies nouriſhment to the anthers and ſtigmas. Some acrid juices, and
odorous particles, are at the ſame time ſecreted from the blood thus
oxygenated in the corol; which ſeem deſigned as one kind of dea
fence againſt the depredations of infects on this important reſervoir of
honey.
2. The univerſality of the production of honey in the vegetable
world, and the very complicated apparatus, which nature has con-
ſtructed in many flowers, as well as the acrid or deleterious juices ſhe
has furniſhed thoſe flowers with, as in the aconite, to protect this
honey from rain, and from the depredations of inſects, ſeem to im-
ply, that this Auid is of very great importance in the vegetable eco-
nomy; and alſo that it was neceſſary to expoſe it to the open air pre-
vious to its reabſorption into the vegetable veſſels.
In

80
SECT. VI. 6.3.
GLANDS AND
In the animal ſyſtem the lacrymal gland ſeparates its fluid into the
open air for the purpoſe of moiſtening the eye; of this fluid the part,
which does not exhale, is abſorbed by the puncta lacrymalia, and car-
ried into the noſtrils; but, as this is not a nutritive fluid, the analogy
goes no further than its ſecretion into the open air, and its reabſorp-
tion into the ſyſtem. The perſpirable matter is another material ſe-
creted by animal glands into the external air, and is in part reabſorbed,
and in part exhaled. And every other ſecreted fluid in the animal body
is in part abſorbed again into the ſyſtem, even thoſe which are eſteem-
ed excrementitious, as the urine; and others are probably entirely
reabſorbed, as the bile, ſaliva, and gaſtric juice.
That the honey is a nutritious fluid, perhaps the moſt ſo of any
vegetable production, appears from its great fimilarity to ſugar, and
from its affording ſuſtenance to ſuch numbers of inſects, which live
upon it ſolely during ſummer, and lay it up for their winter pro-
viſion. Theſe proofs of its nutritive nature evince the neceſſity of its
reabſorption into the vegetable ſyſtem for ſome uſeful purpoſe.
3. It is probable, that the depredations of inſects on this nutritious
fluid muſt be injurious to the products of vegetation; and would be
much more fo, but that the plants have either acquired means to
defend their honey in part, or have learned to make more, than is ab-
ſolutely neceſſary for their own economy. Thus in filene, catch-fly,
and in droſera, ſun-dew, it is defended by a viſcid juice from the
attack of inſects; in hellebore, and in aconite, it is defended by the
difficult paffage to it, and by the acrid juice of the plant, if inſects
ſhould endeavour to creep into the nectary, or pierce it with their
proboſcis; and in polygonum melampyrum, buck-wheat, and in ca-
calia fuaveolens, alpine colts-foot, there ſeems to be a ſuperabundant
quantity of honey ſecreted, as thoſe flowers are perpetually loaded
with bees and butterflies, inſomuch that at Kempton-land in Ger-
many, Mr.Worlidge ſays, in his Myſteries of Huſbandry, Ch. IX. 3.
3
that he ſaw forty great bee-hives filled with honey to the amount of
ſeventy
I

Secr. VI. 6.4.
81
SECRETIONS.
а.
ſeventy pounds in each in one fortnight by their being placed near a
large field of buck-wheat in flower ; and I well remember being my-
ſelf aſtoniſhed at ſeeing the number of bees on a field of buck-wheat
in Shropſhire, as well as on a plant of cacalia ſuaveolens in my gar-
den; from which the ſcent of honey could be perceived at many
feet
diſtance from the flower.
In the ſame manner the honey-dew on trees is very injurious to
them; in which diſeaſe the nutritive fluid, the vegetable fap-juice,
ſeems to be exſuded by a retrograde motion of the cutaneous lympha-
tics, as in the ſweating ſickneſs of the laſt century, or is devoured
by inſects, which pierce the lymphatic veſſels of the leaves at mid-
ſummer, feed on the vegetable chyle, and void it almoſt unchanged.
See Sect. III. II. 8. and XIV.I.7.
To prevent the depredation of infects on honey a wealthy man in
Italy is ſaid to have poiſoned his neighbour's bees, perhaps by mixing
arſenic with honey, againſt which there is a flowery declamation in
Quintillian, No. XIII. This mixture of honey and arſenic may be
uſed with effect to poiſon flies, which ſometimes abound in pernici-
ous multitudes; for the flies which frequent our houſes are liable to
great thirſt, as is ſeen by their drinking any fluid, which is diffufed
on a table; whence if a ſlight ſolution of arſenic, with a little ſugar,
be put thinly on a plate or two, and ſet on chimney-pieces or windows,
the flies will eagerly drink it, and periſh almoſt inſtantly. It is
pro-
bable that waſps might be thus deſtroyed in hot-houſes, if a little
honey was added to attract them by its odour.
As the uſe of the wax is to preſerve the duſt of the anthers from
moiſture, which would prematurely burſt them, the bees, which col-
lect this for the conſtruction of the combs or cells, and collect the fa-
rina alſo probably for bee-bread for their larvæ or maggots, muſt on
both theſe accounts alſo injure the vegetation of a country, where they
too much abound.
4. It is not eaſy to conje&ture, why it was neceſſary, that this ſecre-
M
tion
a

82
Sect. VI. 7. 1.
GLANDS AND
a
tion of honey ſhould be expoſed to the open air in the nectary or ho-
ney-cup; for which purpoſe fo great an apparatus for its defence
from inſects and from ſhowers became neceſſary. This difficulty
increaſes, when we recollect, that the ſugar in the joints of graſs, in
the ſugar-cane, and in the roots of beets, and in ripe fruits, is pro-
duced without expoſure to the air. But on ſuppoſition of its fupplying
nutriment to the anthers and ſtigmas, it may thus acquire greater
oxygenation for the purpoſe of producing the greater powers of ama-
torial ſenſibility, as mentioned in Sect. IV. 5. 6. and probably in this
circumſtance alone differs from fugar.
From this proviſion of honey for the male and female parts of
flowers, and from the proviſions of ſugar, ſtarch, and mucilage, in
the fruits, ſeeds, roots, and alburnum of plants, laid up for the nu-
triment of the young progeny; not only a very numerous claſs of in-
ſects, but a great part of the larger animals, procure their food. Surely
this muſt be called a wiſe proviſion of the Author of nature, as by
theſe means innumerable animals enjoy life and pleaſure without
producing pain to others; for the embryons in theſe buds, ſeeds, or
eggs, as well as the nutriment laid up for them, are not yet endued
with ſenſitive life. There is another ſource of nutriment provided for
young animals, which ſtill further evinces the benevolence of the Au-
thor of nature; and that is the milk furniſhed by the mother to her
offspring; by this beautiful contrivance the mother acquires pleaſure
in parting with a nutritious fluid, and the offspring in receiving it!
VII. 1. The wax is another vegetable ſecretion produced with the
fecundating duft on the anthers of flowers, which in wet ſeaſons it
preſerves from rain, to which it is impenetrable; for the farina, or
fecundating duft of plants, is liable to ſwell if expoſed to much moif-
ture, and to burſt its ſhell; and it either then becomes inert and in
effectual, or is waſhed away. Whence Mr.Wahlborn obſerves, that
as wheat, rye, and many of the graſſes, and plantain, lift up their
anthers on long filaments, and thus expoſe the encloſed fecundating
a
8
duft

Sect. VI. 7. 2, 3.
83
SECRETIONS.
duſt to be waſhed away by the rains; a ſcarcity of corn is produced
in wet ſummers; hence the neceſſity of a careful choice of feed-
wheat; as that, which had not received the duſt of the anthers, will
not grow, though it may appear well to the eye.
2. A ſubſtance fimilar to this is ſaid to be collected from extenſive
underwoods of the ciſtus labdaniferus in ſome eaſtern countries by this
ſingular contrivance; long leathern thongs are tied to poles, and
drawn over the flowers of theſe ſhrubs about noon, which thus col-
lect the wax or reſin with part of the anther duſt, which adheres to
the leathern thongs, and is occaſionally ſcraped off for uſe. Thus in
fome degree the depredation of the bee is imitated, except that ſhe
loads her thighs only with the anther-duſt, which according to Mr.
John Hunter conſtitutes the bee-bread found in hives for the ſupport
of the larva or bee-maggot; and that ſhe ſwallows the wax for the
conſtruction of her combs, as well as the honey for her winter pro-
vender; and thus every way injures the fecundity of flowers.
3. A wax in America is obtained from the myrica cerifera, candle-
berry myrtle, the berries of which are boiled in water, and the wax
ſeparates. The ſeeds of the croton ſebiferum are lodged in a kind of
tallow; in both theſe plants the wax or tallow probably ſerves the
purpoſe of preſerving the immature ſeeds from moiſture; or like the
oil found in flax-ſeed, rape-ſeed, and in many kernels, they may con-
ſtitute in part the nouriſhment of the new plant.
It muſt nevertheleſs be obſerved, that Mr. Sparman ſuſpects, that
the green wax-like ſubſtance on the berries of the myrica cerifera
depoſited by inſects. Voyage to the Cape, V. I. p. 145. And Du
Halde deſcribes a white wax made by inſects in great quantity round
the branches of a tree in China, which is called Tong-tſin. Deſcript.
of China, V.I. p. 230. And laſtly, fir G. Staunton mentions a white
wax on a plant in Cochin-China, which he believes to be ſtrewed on
the plant in the form of white powder, which has this ſingular pro-
perty, that one part of this white powder mixed with three parts of
olive
.
a
M 2

84
Sect. VI. 8. 1, 2, 3.
GLANDS AND
olive oil made hot, gave it when cold the confiſtence of bee's-wax.
Embaſſy to China, Vol. I. p. 354.
VIII. 1. Turpentines or bålſams, reſins, and eſſential oils, are ana-
logous to the vegetable fecretions laſt mentioned, in their being inad-
miffible with water. Thoſe vegetables, which contain in their veffels
the leaſt water, bear cold climates the beſt; becauſe when water is
frozen, it occupies more ſpace than before; and hence burſts the
bottles which contain it; in the ſame manner when any
fucculent
vegetable is frozen, its veſſels become burſt or bruiſed by the expan-
fion of the ice, and the plant is deſtroyed; on this account thoſe parts
of plants, which are the moſt juicy, as the laſt ſhoots of vines, are
fooneſt deſtroyed in winter. Hence many of the evergreen trees of
this climate are replete with turpentine or reſin, which by occupying
the place of ſo much water, contributes to their hardineſs. There is
alſo a partial ſecretion of balſam or turpentine in many deciduous
plants for the purpoſe of defending their buds during the winter,
both from froſt and from wet, which is repelled by their balſamic
varniſh, as on the buds of the populus tacamahacca.
2. The balſams and reſins of the ſhops are either extracted from
the wood by fire, or exſude from wounds of the tree; thus what is
called Venice turpentine is obtained from the larch by wounding the
bark about two feet from the ground, and catching it as it exſudes.
Sandarach is procured from common juniper, and incenſe from ano-
ther juniper ; and there is reaſon to believe that bitumen, or petro-
leum, with jet, amber, and all the foffile coal in the world, owes its
inflammable part to the recrements of deſtroyed foreſts of terebinthi-
nate vegetables, ſo important to the preſent race of mankind has been
this vegetable ſecretion !
3. The eſſential oils are fometimes raiſed by diſtillation from bal-
ſams or refins, as oil of turpentine ; but are chiefly extracted from
flowers; where their office has been to prevent the depredations of
inſects; though many of them are ſo agreeable to the human ſenſe of
ſmell,

Sect. VI. 8. 4,5
85
SECRETIONS.
ſmell, when theſe eſſential oils are diſſolved or mixed with water in
diſtillation, they have been called the ſpiritus rector of the plant, and
conſtitute the odour of it, whether aromatic or fetid.
Some of theſe effential oils poſſeſs the moſt poiſonous qualities, as
thoſe of lauro-ceraſus, and of tobacco; and are uſed by Indian nations
for the purpoſe of poiſoning their weapons, which they cover like a
varniſh. And hence fome of the reſinous woods are ſaid never to be
devoured by inſects, as the unperiſhable cheſts of cypreſs, in which
the Egyptian mummies have been preſerved for ſo many ages, and
the cedar in which black lead is incloſed for pencils.
The acrid poiſon of the large euphorbium of Africa exiſts in the oil
of that plant; as M.Vaillant obſerves, that the natives ſometimes poi-
fon the waters with ſlicing this plant into them, and that the poiſon-
ous oil ſwims upon the ſurface, and may thus be avoided by a care-
ful drinker. This in a country where water is ſcarce, and generally in
ſtagnant pools, may be readily effected; as a few ſpoonfuls of oil will
cover a large fheet of water, as it becomes diffuſed upon it without
friction, as mentioned in Botanic Garden, Vol. I. Addition. Note
XXIX.
ed Who
4. Some of the eſſential oils are fo inflammable as to burſt into a
vehement flame on being mixed with nitrous acid, as oil of cloves;
and even the ſmall quantity diffuſed in the air round the dictamnus
fraxinella will take fore on a ftill evening at the approach of a
lighted candle.
5. With theſe ſhould be arranged the elaſtic reſin called Caoutchouo,
which is ſaid to exfude from a tree in Guaiana, called Iatropha elaſtica,
by M. de la Borde, phyſician at Cayenne. A ſimilar elaſtic reſin is
ſaid to be obtained from a plant in Madagaſcar, called Finguere, a
kind of wild fig-tree, according to Abbe Rochon; and the bird-lime
extracted from the bark of the hollies of our climate ſeems to be a
fimilar material; as like the caoutchouc it becomes ſoft by heat, and
is impenetrable by water, but ſoluble in ether. Another elaſtic fub-
ftance

86
SECT. VI. 9. 1, 2.
GLANDS AND
ſtance, which is inſoluble in water, is procured from wheat by long
maſtication, or by agitating the flour of it in water; which has been
ſaid to approach to animal matter, and is believed to be the moſt nu-
tritious part of that aliment, and was once much talked of, or fold
under the name of alimentary powder for the nouriſhment of march-
ing armies.
IX. 1. The bitter, narcotic, and acrid juices of plants are ſecreted
by their glands for the defence of the vegetable from the depredation
of inſects and of larger animals. Opium is found in the leaf, ſtalk,
and head of the poppy, but not in the ſeeds. A fimilar narcotic qua-
lity exiſts in the leaf and ſtem of hyoſcyamus, henbane, but not in
the ſeeds. An acrid juice exiſts in huſks of walnuts, and in the pel-
licle, or ſkin, of the kernel; but not in the lobes, or nutritious part
of it. Theſe ſeem to have been excluded from the ſeed, left they
might have been injurious to the tender organs of digeſtion of the
embryon plant. In ſome ſeeds, however, there is a bitter quality, but
which refuſes to mix with the oleagenous part ; as the oil expreſſed
fron bitter almonds is as taſteleſs as that from the ſweet almonds.
2. Other vegetables poffefs glands adapted to the ſecretion of va-
rious fluids more or leſs aromatic, acrid, or aſtringent; as the herb of
water-creſs, the root of horſe-radiſh, the ſeeds of muſtard, the flowers
of roſes, the fruit of quince, and the bark of oak. To theſe ſhould
be added thoſe which have emetic and cathartic qualities; and other
vegetable preparations, which are uſed in the arts of dying, tanning,
varniſhing; and which ſupply the ſhops of the druggiſt with medi-
cines and with poiſons. All which deleterious juices ſeem to have been
produced for the protection of the plant againſt its enemies, as appears
by the number of poiſonous vegetables, which are ſeen in all our
hedge-bottoms and commons, as hyoſcyamus, cynogloffum, jacobæa,
and common nettles; which neither inſects nor quadrupeds devour,
and which are therefore of no known uſe but to themſelves; and
poffefs
3

Sect. VI. 9. 3. 10. 1. SECRETIONS.
87
poffefs a ſafer armour in this panapoly of poiſon, than the thorns of
hollies, briars, and gooſeberries.lond
3. As the bitter, narcotic, acrid, and terebinthinate, as well as the
farinaceous, oily, and faccharine matters, are ſecreted in ſummer
from the vegetable blood, and reſerved for the nutrition and defence
of the new buds and bulbs, they are in this climate generally found
more concentrated in the hybernaculum, or winter-lodge of plants,
before the new fap is raiſed by the umbilical or abſorbent veſſels in
the ſpring. Hence roots and barks, as well as fruits and ſeeds, are
beſt collected in autumn, or in winter, for the purpoſes of medicine
or of other arts.
Thus the bark of oaks ſhould be taken off for the uſe of the tanner
in the winter, or in early ſpring, before the leaves pullulate, as then
a great part of its aſtringent or bitter juices is reabſorbed, and carried
to the new foliage along with the faccharine fap-juice, which has
been depoſited in the cells of the alburnum or fap-wood. But as the
barks of trees become looſer, and much more eaſily detached from
the wood, when the fap-juice riſes in the ſpring, this is the beſt time
for debarking them; but the naked bole and branches ſhould ſtand till
autumn, till the faccharine matter collected in the alburnum has
been expended in unfolding the new leaves ; otherwiſe it will ſoon
ferment and putrefy; and the fap-wood will thus quickly decay by
what is termed the dry-rot of timber, as mentioned in Sect. III. 2. 3.
X. 1. The acids produced by vegetable ſecretion have of late been
much ſubjected to chemical inquiry, and have been found to be ſo
numerous, that they have been named from the vegetables, or parts
of vegetables, from which they have been extracted ; as the gallic
acid, malic acid, oxalic acid. Many unripe fruits contain an auſtere
acid, which is gradually converted into ſugar by vegetable or chemical
proceſſes for the nutriment of their feeds, as deſcribed in No. V. 4.
of this ſection. In other plants it exiſts in the foot-ſtalks of the leaves,
as

88
SECT. VI. 10. 1.
GLANDS, &c.
as in rheum, rhubarb; or in the leaves themſelves, as in oxalis, forrel;
in theſe ſituations alſo I ſuppoſe it is ſecreted both for the defence of
thoſe plants from the depredation of inſects and of larger animals;
and alſo for the purpoſe of its being converted into a faccharine juice
by the digeſtion of the young bud in the boſom of the leaf.
a
SECT.

SECT. VII.
89
ORGANS OF REPRODUCTION.
.
S E C T.
VII.
THE ORGANS OF REPRODUCTION OF VEGETABLES.
The theory of Linneus for vegetable reproduction too mechanical, and without analogy.
Every new fluid is ſecreted by glands, as the liquor amnii and albumen ovi. So
alſo is the favilla vitæ, or living entity. I. 1. Lateral progeny. The new bud
is ſecreted in the axilla of the leaf, and requires no female apparatus. It ad-
beres to its parent not by inoſculation of veſſels, but reſembles the chick in the egg.
2. Difference of the chick and fetus. Their nutriment and oxygenation. The em-
bryon may be ſeen in the buds of horſe-cheſnut. It is a paternal progeny. 3. This
lateral offspring reſembles the parent. Not univerſally fo. More perfeet than feeds.
Buds of diæcious plants bear ſimilar ſexes. The lateral progeny degenerates from
hereditary diſeaſes. Whence curled potatoes, blighted ſtrawberries, bears fruit at
the ſame time, and of the ſame kind. Plants live longer if prevented from flower-
ing. Art of producing double hyacinths, ranunculus, tulips. 4. Lateral progeny
of corallines and ſea-anemonies. Polypi are all males. Wires of knot graſs like
the joints of the tape-worm, which are all males. 5. Aphis, viviparous and ovi-
parous like vegetable generation. 6. Veſſels of the bud and leaf do not inofculate.
Viviparous, oviparous, and paternal generation. 7. Leaves on twigs like the pro-
geny of volvox. But in ſome twigs the pith is divided, and the buds ſucceſſive.
Hermaphrodite generation. Buds from every part of the caudex. Thoſe from be-
low the graft are like the ſtock. Find numerous uteri like eggs and ſpawn. Pa-
ternal generation preceded ſexual generation. The laſt more excellent. II. 1. Sexual
progeny. Seeds before impregnation. Eggs before impregnation. Seed-embryon
ſuſpended by oppoſite points like the cicatricula of the egg. 2. Seed-bud and flower.
Stamens and ſtigmas. Males bend to females, and females to males. Style of
Spartium bends round like a French horn. Onaniſm of epilobium. Male flowers of
valliſneria ſwim to the females. Flowers with long filaments injured by rain. Sub-
marine plants projeĉt a liquor. 3. The petals are reſpiratory organs. 4. Honey
is the food of the anthers and ſtigma ; which like butterflies propagate and die.
N
5. Seeds

90
Sect. VII.
ORGANS OF
5. Seeds are formed and nouriſhed by the umbilical veſſels previous to fecundation,
or by the bractes or floral-leaves. Diſperſion of ſeeds by plumes, by books, by twiſted
awns. Creep on the ground. Hygrometer of a geranium feed. 6. Sexual generation
the chef d'oeuvre of nature. Produces variety of Species. Mixed breed of cab-
bage. Mixed breeds of beans. An apple four on one ſide. Vegetable mules. 7. Ani-
mal mules. They externally reſemble the male, internally the
female. Mule from the
horſe and female aſs. From the mare and male aſs. From Spaniſh rams and
Swediſh ewes, and the contrary. From the goat of angora. Ram without horns.
8. How to improve the varieties of fruits and flowers, and produce new ones.
Many plants were originally mules, and many animals. How to produce new ani-
mal monſters, both quadrupeds and fiſh, by the method of Spallanzani. Mules more
frequent in antient times. III. Vegetable generation. 1. A triple tree by in-
graftment. The caudex of each bud is triple. Lateral or paternal mules. Con-
ferva fontinalis ſplits. 2. The lateral propagation of the polypus. The bydra
Stentorea ſplits. Two halves of different polypi unite. So the vegetable filaments
or caudexes in ingrafted trees. 3. Triple lateral mule. Each part of the triple
caudex is produced from that in its vicinity, not from the plumula of the bud.
4. Worms multiplied by dividing them. So the caudexes of the buds of trees.
5. The parts of the long caudexes of trees are ſecreted from the adjoining parts of
the parent caudexes, and combine beneath the cuticle of the tree. Every part of
a compound caudex can produce a new bud, reſembling the part of the compound
ſtock, where it riſes. Lateral mules confift of parts from three or four parents.
Could there be a threefold ſexual mule? 6. Power of attraction. Aptitude to be
attraeted. Chemical combinations by ſingle attraction. By double affinity. 7. Union
of animated bodies with inanimate matter, as in ſwallowing food. In abſorption
by the lacteals. Vitality of the blood. Fibrils with nutritive appetencies. Mole-
cules with nutritive propenſities. 8. Fibrils with formative appetencies, and mole-
cules with formative propenſties ſecreted beneath the cuticle of trees, and coaleſce.
Hunger and love, thirſt, fuckling children, they reciprocally ſtimulate and embrace
each other. 9. Great ſecret of nature. Formative or nutritive particles in the
blood more than neceſſary. Secreted by numerous glands. Arranged under the
cuticle of trees. Acquire new appetencies, and produce new parts. 10. In fexual
generation they are ſecreted by two glands only. Thoſe of the anther and pericarp
unite in the matrix, 11. Without formative molecules as well as formative fibrils
8
there

SECT VII.
91
REPRODUCTION.
there could be no mules, or any reſemblance to the mother. The new doĉtrine of
threefold vegetable mules applied to animal generation. 12. Concluſion.
The theory of Linneus in reſpect of the reproduction of vegeta-
bles maintains, that the internal medullary part muſt be joined with
the external or cortical part of the plant for the purpoſe of produc-
ing a new one. If the medulla be ſo vigorous as to burſt through its
containing veſſels, and thus mix with the cortical part, a bud is pro-
duced either on the branches or roots of vegetables; otherwiſe the
medulla is extended, till it terminates in the piſtillum, or female part
of the flower; and the cortical part is likewiſe elongated, till it termi-
nates in the anthers, or male part of the flower; and then the fe-
cundating duft from the latter being joined to the prolific juices of
the former, produces the ſeeds or new plants; at the ſame time the
inner rind is extended into the corol or petal, and the outer bark into
the calyx.
After the ſeeds are thus produced, the parent bud dies; and in this
reſpect the buds bear a very great analogy to thoſe annual inſects, which
change from their caterpillar or larva-forms, putting forth painted
wings and organs of reproduction, and after depofing their eggs ceaſe
to exiſt. See the account of the vegetable kingdom by Linneus, pre-
fixed to the ſyſtem of vegetables tranſlated by a botanical ſociety at
Lichfield. Leigh and Sotheby, London.
However ſimple and ingenious the firſt part of this theory may ap-
pear, in which the medulla is ſuppoſed to extend itſelf, till it burſts
the incloſing or cortical part, and joining with that produces a new
bud; yet it ſeems too mechanical for a living organized ſyſtem ; and
ſo totally different from any thing we know of ſexual production
either in animals or flowers, as not readily to ſatisfy a reaſoning
mind.
Every new fluid or ſolid produced in the organic ſyſtem of vegeta-
ble or animal bodies is ſecreted from their blood, as the various fluids
of
;
N2

92
Sect. VII. 1. 1, 2.
ORGANS OF
of bile, faliva, tears, in animals ; and thoſe of gum, refin, ſugar, in
vegetables. Amongſt theſe are the juices which conſtitute the nu-
tritious fluid of the amnios in the uterus of viviparous animals, or that
of the albumen of the egg in oviparous ones. And laſty, the flavilla
vitæ, the new ſpark of being, or living entity, is alſo ſecreted from
the blood of male animals by adapted glands to be received into a pro-
per nidus, and nouriſhed by the female.
I.
LATERAL. PROGENY.
1. As the leaf with its petiole, or foot-ſtalk, and its caudex down
the bark of a tree, with its radicle beneath, conſtitutes an individual
plant; and the bud in its boſom ſucceeds, and is evidently produced
by it; it may be concluded from the ſtrongeſt analogy that this new
progeny is ſecreted from a gland or glands of the parent; and that,
as it adheres to the parent, it requires no female apparatus for its re-
ception, nouriſhment, or oxygenation.
I was formerly induced to believe, that there was a communication
of blood, or inoſculation of vefſels between the parent leaf, and the
new bud in its boſom, as expreſſed in Zoonomia, Sect. XXXIX. 2. 2.
and that this conſtituted the difference between paternal geſtation and
maternal geſtation. But that the veſſels between the new bud and
the parent leaf-bud do not inofculate may be well ſeen by taking
away the bark of the foot-ſtalk of a leaf, and of the new bud in its
bofom; as the remains of the arteries of the late leaf, as well as the
rudiment of the new bud, are ſeen to terminate in the alburnum, or
to penetrate the pith, but without any apparent communication; and
I therefore ſuſpect, that the embryon bud is not ſerved with vegeta-
ble blood from the veſſels of the parent, but that it acquires both nu-
triment and oxygenation much in the ſame manner as the chick in
the egg. See Sect. III. 1. 5.
2. The condition of the chick in the egg differs from that of the
fetus

SECT. VII. 1. 2.
93
REPRODUCTION.
a
fetus in the womb of viviparous animals in the whole of its nutriment
being at firſt provided for it, which conſiſts of the albumen, or white
of the egg, which is contained in cells, and is of different degrees of
conſiſtency, that which is moſt fluid being firſt conſumed; whereas
the liquor amnii, or nutriment of the fetus in utero, is gradually ſe-
creted by adapted glands from the blood of the mother, as it is
wanted.
Another difference between the condition of the chick and of the
fetus conſiſts in the manner, by which their blood acquires its neceſ-
ſary oxygenation. In the fetus this is done by means of the placental
veſſels, whoſe extremities are inſerted into the blood-veſſels of the
uterus, and receive oxygen through their moiſt membranes from the
paſſing currents of the mother's blood, as deſcribed in Zoonomia,
Vol. I. Sect. XXXVIII. Whereas in the egg after a few days incu-
bation a membrane is ſeen, which includes the albumen, and ſpreads
the extremities of its fine blood-veſſels on the moiſt membrane, which
covers the air at the broad end of the egg; which air is occaſionally
renewed, as would appear by its being ſeen ſo eaſily to paſs through
the ſhell, when an egg is covered with water in the exhauſted re-
ceiver of an air-pump.
The condition of the embryon bud, when the parent leaf-bud dies,
I conceive to be fimilar to that of the chick in the egg, when that is
ſeparated from its parent. Each of them has at this time a reſervoir
of nutriment provided for it; that of the chick conſiſts of the albu-
men, or white of the egg above mentioned ; and that of the bud con-
fiſts of mucilage and ſugar, which are depoſited in the alburnum or
ſap-wood, or in the roots of the plant. And ſecondly, I conceive
that the extremities of a fine ſyſtem of veſſels belonging to the bud
may terminate on the moiſt membrane, which covers the horizontal
air-veſſels deſcribed in Sect. III. 2. 6. as thoſe on the chorion of the
chick terminate on the air-bag of the egg, and thus acquire the ne-
eeffary oxygenation of their vegetable blood.
This

94
Sect. VII. 1. 3.
ORGANS OF
a
This analogy between the vegetable and animal fetus in reſpect to
their production, nouriſhment, and oxygenation, is as forcible in ſo
obſcure a ſubject, as it is curious; and may in large buds, as of the
horſe-cheſnut, be almoſt ſeen by the naked eye. If with a penknife
the remaining rudiment of the laſt year's leaf, and of the new bud in
its boſom, be cut away flice by ſlice, the ſeven ribs of the laſt year's
leaf will be ſeen to have ariſen from the pith in ſeven diſtinct points,
making a curve; and the new bud to have been produced in their
center, and to have pierced the alburnum and bark, and grown with-
out the affiſtance of a mother.
And laſtly, by in part cutting, and in part tearing, the pith and
alburnum from the bottom of a new leaf-ſtalk of horſe-cheſnut about
the middle of May, an oval prominence may be ſeen in the internal
part of the leaf-ſtalk, which fills up a ſpace between the veſſels of
the bottom of the leaf-ſtalk and thoſe of the new bud, and ſeems to
connect them by its extremities, and to preſs on the pith beneath it.
From this apparent gland I conjecture that the now living fibres, or
animalcules, are probably ſecreted, which form the new bud adher-
ing to the pith, and nouriſhed by the parent leaf; that thus a paternal
progeny is produced without the aſſiſtance of a mother.
3.
This paternal offspring of vegetables in their buds and bulbs is
attended with a very curious circumſtance; and that is, that they
exactly reſemble their parents, as is obſervable in grafting fruit-trees,
and in propagating flower-roots; whereas the feminal offspring of
plants, being generated by two parents, and certainly ſupplied with
nutriment by the mother, is liable to perpetual variation. This alſo
in the vegetable claſs diæcia, where the male flowers are produced on
one tree, and the females on another, the buds of the male trees uni-
formly produce either male flowers, or other buds ſimilar to them-
ſelves; and the buds of the female trees either produce female flowers,
or other buds ſimilar to themſelves; whereas the ſeeds of theſe trees
produce either male or female plants. See Sect. III. 2. 1.
a
This

Sect. VII. 1.3. REPRODUCTION.
95
a
a
>
This ſimilarity of buds and bulbs to their parents is to be under-
ſtood only to exiſt after the maturity of the plant, that is after it has
produced a ſexual offspring in flowers and ſeeds; for a bulb, as of a
tulip, and a bud of a fruit-tree, when firſt raiſed from their feeds, are
very ſmall, but produce one or more improved bulbs, or improved
buds annually, for ſome years; which differ from their parent bulbs
or buds in the ſize, form, and colour of their leaves, till it arrives at
its maturity, or acquires the power of generating a ſexual progeny ;
from whence it appears, that the leaf-buds of thoſe trees, and the leaf-
bulbs of thoſe roots, which have acquired their puberty, if it may be
ſo called; that is, their power of generating flowers, are a more per-
fect progeny than the ſeeds of thoſe plants, as theſe latter, when ſe-
parated from their parent either by tranſplantation or by ingrafting,
can immediately produce ſeeds, or a ſexual progeny; but the buds
from many feeds are ſome years before they can produce ſeeds. The
ſame is probably true of many annual or biennial plants, as of wheat;
which produce many ſucceſſive buds upon each other previous to the
flower-bud, as appears by the joints of the ſtem ; all which may be
conſidered as individual plants growing on each other like the annual
ſucceſſion of the buds of trees.
Another curious occurrence in this lateral production of vegetables
by their buds has been lately publiſhed by Mr. Knight in the Phil.
Tranſ. for the year 1795, who obſerves, that thoſe apple-trees, which
have been continually propagated for above a century by ingrafting, are
now become ſo diſeaſed by canker, or otherwiſe, that though the fruit
continues of the fame flavour, the trees are not worth propagating; as
theſe grafts, though tranſplanted into other trees, he eſteems to be
ſtill an elongation of the original tree, and muſt feel the effect of age
like the tree they were taken from. If this idea ſhould prove true
on further examination, there is reaſon to ſuſpect the ſame may occur
in the too long propagation of plants from bulbs and wires, as potatoes
and ſtrawberries, which may have occaſioned the curled tops of pota-
toes,

96
Sect. VII. 1. 3.
ORGANS OF
toes, and the black blight in the flowers of the hautbois ſtrawberry,
which ſome have aſcribed to its only bearing male flowers; the cure
of which muſt ariſe from our applying to other varieties more lately
derived from a ſeminal offspring.
This degeneracy of trees or perennial herbaceous plants propagated
by buds or root-ſcions is not I think to be aſcribed ſimply to the age
of the original ſeedling-tree, becauſe each ſucceſſive generation of
buds or bulbs are as diſtinct from the parent, as the generation by
ſeeds. But as the lateral progeny of vegetables have no fource of
improvement after they have arrived at their maturity, but are liable
like other plants and animals to injuries from food and climate, which
injuries produce hereditary diſeaſes, it is to this circumſtance that
their degeneracy ought rather to be aſcribed; whereas the ſexual pro-
geny of vegetables are liable to improvement by the intermixture of
the individuals of the ſame, or even of different ſpecies to counteract
the effects of hereditary diſeaſes.
Another curious fimilarity which buds bear to their parent tree is
alſo obſerved by Mr. Knight, Phil. Tranſ. for 1795. Part II. p. 292.
Cuttings from ſeedling apple-trees of two years old were inſerted
on ſtocks of twenty years old, and in a bearing ſtate; but theſe have
now been grafted nine years; and, though they have been frequently
tranſplanted to check their growth, they have not yet produced a
ſingle bloſſom. I have ſince grafted ſome very old trees with cuttings
from ſeedling apple-trees of five years old. Their growth has been
extremely rapid, and there appears no probability that their time of
producing fruit will be accelerated, or that their health will be in-
jured by the great age of the ſtocks. A ſeedling apple-tree uſually
bears fruit in thirteen or fourteen years; and I therefore conclude,
that I have to wait for a bloſſom, till the trees, from which the
grafts were taken, attain that age; though I have reaſon to believe
from the form of their buds that they will be extremely prolific.
Every cutting therefore taken from the apple, and probably from
5
every
66
a

Sect. VII. 1.4.
97
REPRODUCTION.
every other tree, will be affected by the ſtate of the parent ſtock. If
that be too young to produce fruit, it will grow with vigour, but will
nøt bloffom; and if it be too old, it will immediately produce fruit,
but will never make a healthy tree, and conſequently never anſwer
the intention of the planter.
“The durability of the apple and pear I have long ſuſpected to be
different in different varieties; but that none of either would vege-
tate with vigour much, if at all, beyond the life of the parent ftock,
provided that died from mere old age. The oak is much more long-
lived in the north of Europe than with us, though the timber is leſs
durable; the climate of this country, being colder than its native one,
may in the ſame way add to the durability of the elm; which may
poſſibly be further increaſed by its not producing ſeeds in this cli-
mate; as the life of many annuals may be increaſed to twice its na-
tural period, if not more, by preventing their feeding."
It is obſerved above, that the firſt bulb of a tulip raiſed from ſeed
а
produces a more perfect bulb annually for five or ſix years, and perhaps
more than one leſs perfect ones, before it acquires the power of ge-
nerating ſeeds. Now when this period arrives, if the feed-Item be
pinched off, I ſuppoſe that the next year's bulb or bulbs will become
more vigorous or luxuriant, and if this be continued for three or four
years I ſuſpect the double flowers, which are perhaps owing to a more
luxuriant growth, may be formed; and that in this, with ſuperfluous
nouriſhment by manure, warmth, and moiſture, conſiſts the art of
obtaining hyacinths, ranunculus, and ſometimes tulips, with ſuch
wonderful multiplication of petals or nectaries. See Sect. XIX.
4. The analogy, which exiſts between this lateral production of
vegetables and that of ſome tribes of inſects, is worth inveſtigation.
1. This paternal or lateral generation of plants, which conftitutes the
buds on the ſtems of trees, and the ſcions on their roots, which con-
tinue to adhere to them, are ſo far reſembled by the branching in-
fects, which form the corals or corallines; and by many other fea-
0
animals,
3. 1.

98
Sect. VII. 1. 5.
ORGANS OF
a
animals, as the ſea anemonies, which are ſaid to adhere to the ſhores,
or ſubmarine earth, by one extremity, while they pullulate, or ſpread
out by the other into living ramifications of unmeaſurable lengths.
Thoſe who have attended to the habits of the polypus, which is
found in the ſtagnant water of our ditches in July, affirm, that the
young ones branch out from the ſide of the parent like the buds of
trees; and after a time ſeparate themſelves from them. This is ſo
analogous to the manner in which the buds of trees appear to be pro-
duced, that theſe polypi may be conſidered as all male animals, pro-
ducing embryons, which require no mother to ſupply them with a
nidus, or with nutriment and oxygenation.
Secondly, this paternal or lateral vegetable progeny is beautifully
ſeen in the wires of knot-graſs, polygonum aviculare ; and in thoſe of
ſtrawberries, fragaria veſca; and in the roots of potatoes. The la-
teral generation of theſe plants by wires, while each new plant is
thus chained to its parent, and continues to put forth another and
another, as the wire creeps onward on or beneath the ground, is ex-
actly reſembled by the tape-worm, or tænia, ſo often found in the
bowels, ſtretching itſelf in a chain quite from the ſtomach to the
rectum. Linneus aſſerts, " that it grows old at one extremity, while
it continues to generate young ones at the other, proceeding ad infi-
nitum, like a root of graſs. The ſeparate joints are called gourd-
worms, and propagate new joints like the parent without end, each
joint being furniſhed with its proper mouth and organs of digeſtion."
Syſtema Naturæ, vermes, tenia. In this animal there evidently ap-
pears a power of reproduction without any maternal apparatus for
the purpoſe of ſupplying nutriment and oxygenation to the embryon,
as it remains attached to its father till its maturity, and in this reſpect
exactly reſembles the lateral generation of vegetables.
5. This ſubject of the lateral production of vegetables from male
parents without the intervention of a female is further reſembled by
the innumerable progeny of the aphis, which riſes from an egg in the
ſpring,
>

Sect. VII. 1, 6, 7. REPRODUCTION.
99
ſpring, as a vegetable riſes from a feed, and produces a viviparous
offspring for many generations like the fucceflive buds of a ſeedling
apple-tree, or of a feedling tulip; and then it generates both males
and females, which copulate and depoſit eggs, like the anthers and
ſtigmas of flowers, and their conſequent ſeeds; which at length ap-
pear on ſeedling apple-trees and on ſeedling tulips ; as is further
ſpoken of in Sect. IX. 2. 7. and XIV. 1.6.
6. Whence I conclude, that in ſexual viviparous generation the
new entity, or embryon, is ſecreted by the male, and received into a
nidus prepared for it by the female, and nouriſhed by fluids fecreted
into the uterus, as they are required, which is probably owing to the
ſtimulus of the fetus againſt the ſides of it; that in ſexual oviparous
generation a reſervoir of nutriment is prepared, and incloſed in the
egg, previous to the reception of the embryon, which is ſecreted by
the male, and depoſited in this reſervor of nutriment; becauſe the
fetus in theſe animals is to be ſeparated from the parent before its due
maturity; and the egg, in which it is incloſed, may be conſidered as
an uterus, or womb, ſeparated from the mother. And laſtly, that
in paternal or male generation the new entity, or embryon, is as cer-
tainly ſecreted from a gland of the male, but probably remains in an
adapted reſervoir belonging to this gland, correſpondent to the ve-
ficulæ feminales of moſt viviparous animals, and that here it exiſts
like the cicatricula in the egg, and has a reſervoir of nutriment pre-
pared for it like that in the egg to ſupport it; when the paternal
leaf-bud by its death is ſeparated from it in the autumn, as the
ſeparated from its living mother.
7. The production of buds in the axilla of every leaf may thus be
eaſily conceived, as the new buds are furniſhed with their caudexes
or bark-filaments over thoſe of their dead parents, which ſhoot out
root-fibres beneath in the enſuing ſpring, and that I ſuppoſe both in
deciduous plants and in evergreens ; as in the latter alſo I believe the
arent leaf-bud annually falls off, though not by the immediate in-
fluencc
egg is
O 2

ORGANS OF
SECT. VII. 1.7
fluence of the cold of autumn. But how long a twig or ſcion of leaves
as in the vine or willow, fucceed each other, ſome producing em-
bryon buds in their bofoms before others become expanded, is not
eaſy to underſtand; but the embryons of all theſe new leaves, though
not of the buds in their boſoms, probably exiſted in the paternal womb,
though in different degrees of maturity, which accords with the ob-
ſervations of ſome naturaliſts on the ſucceſſive generations of the vol-
vox globator, which Linneus afferts to be diaphanous, and that it car-
ries within itſelf ſons and grandfons to the fifth generation, but which
are probably living fetuſes produced by the father, of different degrees
of maturity, and to be detruded at different periods of time like the
unimpregnated eggs of various ſizes, which are found in poultry. See
Zoonomia, Vol. I. Sect. XXXIX. 2. and Linnei Syſtem. Naturæ.
Vermes. Volvox.
In ſome trees however, as in the vine, vitis, and in many herbace-
ous plants, as in wheat, fouthiſtle, teaſel, triticum, ſonchus, dypſacus,
each ſucceſſive joint of the plant is evidently an individual vegetable
being ; becauſe the pith, which conſtitutes the brain or fpinal marrow
of each individual, terminates at every joint by a diviſion, as ſpoken of
in Sect I. 8. whence in theſe vegetables every ſucceſſive joint appears
to be produced by that beneath it ; whereas where there is no diviſion
of the pith, the twig ſeems to be fimply an elongation of the caudex
of the leaf-bud, like the wires of ſtrawberries, and other creeping
plants.
It ſhould neverthelefs be added, that there are many hermaphrodite
inſects, as ſhell-ſnails and dew-worms, which contain both male and
female organs of generation, and as they are perpetually ſeen to co-
pulate with each other, it is believed, that they can not impregnate
themſelves. Now it may be conceived, that the buds of trees poffefs
both male and female organs of generation, and that they can impreg-
nate themſelves, and that thus the new buds might be termed an
hermaphrodite offspring rather than a paternal one. This would
however
3

Sect. VII. 1.7
REPRODUCTION.
a
however produce a confuſion of terms, as the eggs of ſnails and of
worms, as mentioned above, are properly an hermaphrodite off-
ſpring.
Another circumſtance occurs in this paternal generation, which dif-
fers from that of thoſe hermaphrodite inſects above alluded to, which
is, that though in vegetables the new embryon is generally produced
in the bofom of the leaf-ſtalk, which is believed to be its parent; yet
new buds are occaſionally protruded from almoſt any part of the bark,
when the ſummit of a branch is taken off, or the ſide branches of a
tree, ſo as to admit light and air, and a ſupply of more nutriment ;
whence it would feem, that though hermaphrodite inſects poffefs but
one male and one female apparatus for the production and reception
of the new entity or embryon, yet that in paternal generation the pro-
lific fluid is occaſionally ſecreted in any part of the caudex of each in-
dividual bud from its ſummit on the branch of a tree to its termina-
tion in the root; and that wherever a proper nidus can be found,
which is ſupplied with nutriment, and expoſed to light and air, that
there the new embryon can adhere and grow ; although this occurs.
moſt conveniently, and thence moſt frequently, in the boſom of the
leaf-ſtalk, where the prolific fluid is probably firſt ſecreted, and the
nutriment moſt copiouſly ſupplied from the vegetable blood newly
oxygenated in the leaf. In this I ſuppoſe to conſiſt the great differ-
ence between paternal and ſexual generation ; and that this mode of
reproduction forms an exception to the general axiom of the great
Harvey, “ all things froin eggs."
The exiſtence of a power of generation in every part of the caudex
of a vegetable bud from the ſummit to the root is not only ſhewn by
the new buds, which grow on the trunks of trees, which were felled
in the ſpring, but alſo from a curious circumſtance which occurs in
ingrafted trees; which is, that whenever after many years any new
buds or ſcions grow from the ſtock beneath the graft, it is always
fimilar to the parent ſtock, and not to the ingrafted fcion ; which
thews,
a
7

102
SECT. VII. 1. 7.
ORGANS OF
a
thews, that this new bud was generated in the old ſtock, and not
that it was owing to an abſorption and depoſition of a prolific fluid
ſecreted in any part of the ingrafted head. It muſt however be re-
membered, that the caudex of each bud extends from the leaf-ſtalk
to the root, whether it be a ſimple caudex as in a ſeedling tree, or
a compound one as in a grafted tree; and that the generation of new
buds in perennial herbaceous plants exiſts in every part of the broad
caudex on the root, as it does here in every part of the long caudex
on the trunk. Nothing known in the animal world reſembles this
univerſality of the generative faculty throughout almoſt the whole
of an individual vegetable being, except the number of new polypi
faid to ariſe at the ſame time from different parts of the fame indi-
vidual animal.
Wherever the new vegetable embryons are ſecreted, they alſo
find a ſituation or uterus, where they can adhere and be nouriſhed to
almoſt any number; which however is not unfupported by ſome
analogy even in viviparous animals; as there have been many in-
ſtances of extra-uterine fetuſes, which have attached or inſerted their
veſſels into the peritoneum, or on the viſcera of the mother, in the
ſame manner as they naturally attach or inſert them into the fides of
the true uterus. And in reſpect to the number of uteri produced we
may recollect the number of eggs, and of fiſh-ſpawn, or frog-ſpawn,
or of ſeeds, which may all be termed ſo many diſtinct uteri, as they
contain every thing, which is found in the uteri of viviparous ani-
mals.
The aphis, and probably many other inſects, poſſeſs both the ſo-
litary and ſexual mode of propagation, as is poſſeſſed by moſt veget-
ables; but the polypus and tenia, and hydra ſtentorea, and volvox,
appear only to be reproduced by the folitary or lateral generation; and
it is probable that the truffle amongſt vegetables, and ſome ſub-
marine plants, and others of the claſs cryptogomia, whoſe feeds
have not been yet diſcovered, may ſtill be only propagated by the
lateral

Sect. VII. 2. 1. REPRODUCTION.
103
lateral mode of reproduction, as is well obſerved in an ingenious
work by a lady of very accurate botanic knowledge, called “Botanic
Dialogues, deſigned for the uſe of ſchools," one volume octavo,
Johnſon, London ; but which may be ſtrongly recommended to the
adult in botany as containing much uſeful information agreeably
imparted.
This curious ſubject of lateral or ſolitary generation is well worthy
more accurate inveſtigation, as it is the fimpleſt, and was probably
the firſt mode of reproduction which exiſted; and if any accurate
knowledge can ever be acquired of animal generation, it will poſſibly
occur from a more nice attention to the production of the buds and
bulbs of vegetables ! which is further ſpoken of in Sect. IX. 2 and
3.
At the ſame time it muſt be obſerved, that the ſexual reproduction is
the chef d'ouvre, the maſter-piece of nature, as by the paternal or
lateral reproduction the ſame ſpecies only are propagated ad infinitum;
whereas by the fexual mode of reproduction a countleſs variety of
animals are introduced into the world, and much pleaſure is afforded
to thoſe, which already exiſt in it.
II.
SEXUAL PROGENY.
1. We come now to the ſeminal mode of the produ&tion of vege-
tables, which originates from the congreſs of the male and female
parts of flowers, and may be therefore termed the ſexual or amatorial
progeny of vegetation.
From the accurate experiments and obſervations of Spallanzani it
appears, that in the Spartium Junceum, ruſh-broom, the very mi-
mute feeds were diſcerned in the pod at leaſt twenty days before the
flower is in full bloom; that is, twenty days before fecundation. At
this time alſo the powder of the anthers was viſible, but glued faſt to
their fummits. The ſeeds however at this time, and for ten days
after the bloſſom had fallen off, appeared to conſiſt of a gelatinous
8
fubftance.

104
Secr. VII. 2. 1.
ORGANS OF
a
3
а
a
ſubſtance. On the eleventh day after the falling of the bloſſom the
ſeeds became heart ſhaped, with the baſis attached by an appendage
to the pod, and a white point at the apex; this white point was on
preſſure found to be a cavity including a drop of liquor.
On the twenty-fifth day the cavity, which at firſt appeared at the
apex, was much enlarged, and ſtill full of liquor ; it alſo contained a
very ſmall ſemi-tranſparent body of a yellowiſh colour, gelatinous,
and fixed by its two oppoſite ends to the ſides of the cavity.
In a month the feed was much enlarged, and its ſhape changed
from a heart to a kidney; the little body contained in the cavity was
increaſed in bulk, and was leſs tranſparent, and gelatinous, but there
yet appeared no organization.
On the fortieth day the cavity now grown larger was quite filled
with the body, which was covered with a thin membrane; after this
membrane was removed, the body appeared of a bright green, and
was eaſily divided by the point of a needle into two portions, which
manifeſtly formed the two lobes; and within theſe attached to the
lower part the exceedingly ſmall plantule was eaſily perceived.
The foregoing obſervations evince, 1. That the feeds exiſt in the
ovarium many days before fecundation. 2. That they remain for ſome
time ſolid, and then a cavity containing a liquid is formed in them.
3.
That after fecundation a body begins to appear within the cavity
fixed by two points to the ſides, which in proceſs of time proves to
be two lobes containing a plantule. 4. That the ripe ſeed conſiſts of
twe lobes adhering to a plantule, and ſurrounded by a thin membrane,
which is itſelf covered with a hulk or cuticle. Spallanzani's Differta-
tions, Vol. II. p. 253-
The analogy between ſeeds and eggs has long been obſerved, and
is confirmed by the mode of their production. The egg is known
to be formed within the hen long before its impregnation. C. F.
Wolf aſſerts, that the yolk of the egg is nouriſhed by the veſſels of
the mother, and that it has from thoſe its arterial and venous branches;
but
a
a
th a huko

SECT. VII. 2. 2.
105
REPRODUCTION.
.
but that after impregnation theſe veſſels gradually become imper-
vious and obliterated ; and that new ones are produced from the fetus,
and diſperſed into the yolk. Haller's Phyſiol. Tom. VIII. p. 94. The
young feed after fecundation I ſuppoſe is nouriſhed in a ſimilar man-
ner from the gelatinous liquor, which is previouſly depoſited for that
purpoſe; the uterus of the plant producing or ſecreting it into a re-
ſervoir or amnios, in which the embryon is lodged; and that the
young embryon is furniſhed with veſſels to abſorb a part of it, as in
the very early ſtate of the embryon in the egg.
Another curious analogy ſeems to exiſt between the embryon of
the feed and of the egg in their mode of ſuſpenſion. The cicatricula
of the
egs reſts on the yolk, which is ſuſpended by two points, called
chalazæ, ſomewhat above its center of gravity; whence, however the
egg is moved, this embryon is always kept upwards, probably the
better to receive the warmth of the mother during incubation. The
ſeed-embryon ſeems to be ſupported in the ſame manner by the above
relation of Spallanzani by two points, and may thus receive a greater
warmth from the ſummer fun.
2. The ſeeds are thus produced in their unimpregnated ſtate in the
vegetable uterus, and nouriſhed by the flower-bud, which was formed
in the deciduous trees of this climate during the preceding ſummer,
and which now puts forth the bractes, or floral-leaves, for the oxy-
genation of its blood; and protrudes its roots and abſorbents into the
ground from the lower part of its caudex, for the purpoſe of acquir-
ing nouriſhment; and on the ſummit of this ſexual apparatus are at
the ſame time produced the corol and nectaries of the flower, with the
ftamens, and ſtigmas, which are evidently deſigned to give fecunda-
tion to the vegetable ſeeds, or eggs, previouſly depoſited in the peri-
carp or uterus; becauſe, as ſoon as theſe are impregnated, the corot
and nectaries, with the ſtamens, and ſtigmas, fall off and difappear.
The anthers have been proved by many experiments to be neceſ-
ſary to the fecundation of the vegetable feeds by the farina, or duſt,
P
which

106
SECT, VII. 2. 2.
Sect
ORGANS OF
a
2
which they diſperſe, and which adheres to the moiſt ftigma on the
ſummit of the ſtyle or pericarp. The amatorial attachment between
theſe ſtigmas and the anthers on the ſummits of the ſtamens has at-
tracted the notice of all botaniſts. In many flowers the anthers or
males bend into contact with the ftigmas or females, as in kalmia,
fritillaria perſica, parnaſſia, cactus, and ciftus. In the kalmia the ten
ſtamens lie round the piſlil, like the radii of a wheel, and each anther
is concealed in a nich of the corol to protect it from cold and moiſ-
ture; theſe anthers riſe ſeparately from their niches, and approach
the ftigma of the piſtil for a time, and then recede to their former
ſituations. In the fritillaria perfica the fix ftamens are of equal
lengths, and the anthers lie at a diſtance from the piſtil; of theſe
three alternate ones approach firſt, and ſurround the female; and
when theſe decline, the other three approach ; and in parnaſſia the
males alternately approach and recede from the female; and laſtly
in the moſt beautiful flowers of cactus grandiflorus, and of ciſtus lab-
daniferus, where the males are very numerous, ſome of them are
perpetually bent into contact with the female; and as they recede,
others advance.
In other flowers the females bend into contact with the males, as
in nigella, epilobium, ſpartium, collinſonia. In nigella, devil in the
buſh, the females are very tall compared to the males, and bending
down over them in a circle, give the flower ſome reſemblance to a
regal crown. The female of the epilobium anguſtifolium, willow-
herb, bends down amongſt the males for ſeveral days, and becomes
upright again when impregnated. In the ſpartium ſcoparium, com-
mon broom, the males or ſtamens are in two ſets, one ſet riſing
quarter of an inch above the other. The upper ſet does not arrive
at their maturity ſo ſoon as the lower; and the ſtigma, or head of
the female, is produced amongſt the upper or immature ſet. But as
foon as the piſtil grows tall enough to burſt open the keel-leaf, or head
of the flower, it bends itſelf round in an inſtant like a French horn,
and
a
a

Sect. VII. 2. 2.
107
REPRODUCTION.
a
.
and inſerts its head, or ſtigma, amongſt the lower or mature ſet of
males. The piſtil or female then continues to grow in length; and
in a few days the ſtigma arrives again amongſt the upper ſet, by the
time they become mature. This wonderful contrivance is readily
ſeen by opening the keel-leaf of the flowers of broom, before they
burſt ſpontaneouſly. And laſtly, in the collinfonia the two males
widely diverging from each other, the female bends herſelf into con-
tact firſt with one of them; and after a day or two leaves this, and
applies herſelf to the other; the anther of which was not mature ſo
foon as the former. See Sect. VIII. 8. of this work.
Dr. Peſchier of Geneva thinks, he has diſcountenanced this idea of
amatorial ſenſibility of vegetables by two experiments, which are re-
lated in Journal de Phyſique de Lametherie, T. II. p. 343. One of
theſe conſiſted of his tying down the ſtigma of epilobium anguſtifo-
lium, and yet in due time the anthers burſt and ſhed their pollen, and
thus committed a kind of vegetable Onaniſm; and alſo that he caf-
trated the ſtamens of this flower, and yet the ſtigma opened and aroſe,
as if the anthers had been preſent. The other experiment conſiſted
in his confining a branch of barbery, berberis, in a glaſs, and ſubjeét-
ing the ſtamina of the flowers to the vapour of nitrous acid, which
by this ſtimulus aroſe from their petals to the ſtigma, and after a few
minutes again retired to their petals. Both theſe experiments rather
ſeem to confirm than to enfeeble the analogy between plants and
animals; as the amatorial motions of theſe flowers were thus pro-
duced by internal or external ſtimuli, as in the healthy or diſeaſed
ſtates of animals.
Another mode, in which the prolific duſt is diſperſed, is by the
burſting of the anther, and its conſequent diffuſion in air, either ſo
as to make a cloud near the females, which exiſt in the ſame flower,
or on the ſame plant, which is the moſt uſual manner; or by its
being carried by the winds to a greater diſtance, as in the flowers of
the claſs monccia, or one houſe. So in urtica, nettle, the male
flowers
a
P 2

103
.
ORGANS OF
.
Sect. VII. 2. 2flowers are ſeparate from the female, and the anthers are ſeen in fair
weather to burſt with force, and to diſcharge their duft, which ho-
vers about the plant like a cloud.
In plants of the claſs diccia, or two houſes, the fecundating farina
is carried to the diſtance of many miles by the winds, as has been
proved by the impregnation of ſome female date trees, which were at
a great diſtance from the male ones. And the male flowers them.
felves of valliſneria are carried many miles down the rivers, which it
inhabits, to the female ones. This plant has its roots at the bottom
of the Rhone; the flowers of the female plant float on the ſurface of
the water, and are furniſhed with an elaſtic ſpiral ſtalk, which ex-
tends or contracts, as the water riſes and falls. The flowers of the
male plant are produced under water, and as ſoon as their farina, or
duft, is mature, they detach themſelves from the plant, and riſe to
the ſurface, continue to flouriſh, and are wafted by the air, or borne
by the currents, to the female flowers. In this reſembling thoſe
tribes of inſects, where the males at certain ſeaſons acquire wings, but
not the females, as ants, coccus, lampyris, phalæna, brumata, licha-
nella. See valliſneria in the Families of Plants, tranſlated from Lin-
neus. Johnſon, London.
The plants, which grow in the air, are frequently injured in wet
ſeaſons by the moiſture occaſioning the cells of the anthers, which .
contain the fecundating farina, to burſt, and to ſhed it on the ground.
To which a ſcarcity of the quantity of wheat, or an imperfection of
its fecundating quality, and the uftilago, or ſmut, have rationally been
afcribed, as its anthers are expoſed on long filaments to the weather,
On this account many flowers cloſe their corols before rain, and the
aquatic plants of rivers perform their impregnations in the air. But
M. Bonnet remarks another method of the diſperfion of the fecun-
dating influence of fome marine plants, in which the male organ does
not project a fine powder, but a liquor, which forms a perceptible
cloud in the water; and adds, that the male ſalamander darts his
5
ſemen
2

Sect. VII. 2. 3. 4.
109
REPRODUCTION.
a
ſemen into the water, where it forms a whitiſh cloud, which is af-
terwards received by the ſwollen anus of the female, and the be-
comes impregnated. Nor is this vegetable impregnation in water
unanalogous to other animal impreguations, as the ſpawn of frogs and
of fiſh is delivered from the female before it is fecundated; and its
fecundation is ſeen to ſucceed in water; and Spallanzani found, that
the ſeminal fluid even of dogs, as well as of frogs, retained its pro-
lific quality when diluted with much water. Bonnet's Cuvres Phi-
lof. in a letter to Spallanzani,
3. The other parts, which riſe on the edge of the pericarp, and ex-
pand themſelves before the impregnation of the ſeed, are the corol
and nectaries. The former of theſe has been ſhewn to be a reſpiratory
organ for the purpoſe of oxygenating the blood to a greater degree
than in the green foliage, as it is there expoſed to the air beneath a
finer pellicle, and acquires variety of colours. See Sect. IV. 5. 1. to
which may be added, that as the corol in helleborus niger, Chriſt-
mas roſe, changes after the fecundation of the ſeed into a calyx, lof-
ing its white colour, and becoming green. So in many flowers the
calyx falls off along with the corol ; in theſe it ſhould be eſteemed a
part of or appendage to the corol; whereas thoſe calyxes, which are
permanent after the corol falls off, are properly parts of the pericarp
or vegetable uterus.
4. The nectary, or honey-cup, is evidently an appendage to the
corol, and is the reſervoir of the honey, which is ſecreted by an ap-
propriate gland from the blood after its oxygenation in the corol, as
mentioned in Sect. IV. 5. 5. and is abſorbed for nutriment by the
ſexual parts of the flower. This purpoſe however has as yet eſcaped
the reſearches of philoſophical botaniſts. M. Pontedera believes it
deſigned to lubricate the vegetable uterus. (Antholog. p. 49.) Others
have ſuppoſed, that the honey, when reabſorbed, might ſerve the pur-
poſe of the liquor amnii, or white of an egg, as a nutriment for the
young embryon, or fecundated ſeed, in its early state of exiſtence.
Bus

IIO
MORGANS OF
SECT. VII. 2. 4.
But as the nectary is found equally general in male flowers as in fe-
male ones, and as the young embryon, or ſeed, grows before the
petals and nectary are expanded, and after they fall off; theſe ſeem
to be inſurmountable objections to both the above-mentioned opi-
nions. Jo
In
many tribes of inſeets, as the filk-worm, and perhaps in all the
moths and butterflies, the male and female parents die, as ſoon as the
eggs are impregnated and excluded, the eggs remaining to be per-
fected and hatched at ſome future time. The ſame thing happens to
the male and female parts of flowers; the anthers and filaments,
which conſtitute the male parts of the flower, and the ſtigma and
ſtyle, which conſtitute the ſenſitive or amatorial organ of the female
part of the flower, fall off and die, as ſoon as the ſeeds are impreg-
nated, and along with theſe the petals and nectary. Now the moths
and butterflies above mentioned, as ſoon as they acquire the paſſion
and the apparatus for the reproduction of their ſpecies, loſe the power
of feeding upon leaves, as they did before, and become nouriſhed by
what?-by honey alone. 19919
bna
- Hence we acquire a ſtrong analogy for the uſe of the nectary, or
ſecretion of honey, in the vegetable economy; which is, that the
male parts of flowers, and the female parts, as ſoon as they leave their
fetus-ſtate, expanding their petals, (which conftitute their lungs) be-
come ſenſible to the paſſion, and gain the apparatus, for the repro-
duction of their ſpecies; and are fed and nouriſhed with honey like
the inſects above deſcribed ; and that hence the nectary begins its
office of producing honey, and dies or ceaſes to produce honey, at
the ſame time with the birth and death of the anthers and the ſtig-
mas; - which, whether exiſting in the ſame or in different flowers,
are ſeparate and diſtinct animated beings.
Previous to this time the anthers with their filaments, and the
ſtigmas with their ſtyles, are in their fetus-ſtate ſuſtained in ſome
plants by their umbilical vefſels, like the unexpanded leaf-buds, as in
3
colchicuma

Sect. VII. 2. 4.
III
REPRODUCTION.
colchicum autumnale, and daphne mezereon ; and in other plants
by the bractes, or floral-leaves, as in rhubarb, which are expanded
long before the opening of the flower; the feeds at the ſame time
exiſting in the vegetable womb yet unimpregnated, and the duſt yet
unripe in the cells of the anthers. After this period the petals become
expanded, which have been ſhewn to conſtitute the lungs of the
flower ; the umbilical veſſels, which before nouriſhed the anthers and
the ftigmas, coaleſce, or ceaſe to nouriſh them; and they acquire
blood more oxygenated by the air, obtain the paſſion and power of
reproduction, are ſenſible to heat, and light, and moiſture, and to me-
chanic ſtimulus, and become in reality inſects fed with honey ; fimi-
lar in every reſpect except that all of them yet known but the
male flowers of valliſneria, continue attached to the plant, on which
they are produced.
So water inſects, as the gnat, and amphibious animals, as the tad-
pole, acquire new aerial lungs, when they leave their infant ſtate for
that of puberty. And the numerous tribes of caterpillars are fed upon
the common juices of vegetables found in their leaves, till they ac-
quire the organs of reproduction; and then they feed on honey, all
I believe except the filk-worm, which in this country takes no nou-
riſhment after it becomes a butterfly. And the larva or maggot of the
bee, according to the obſervations of Mr. Hunter, is fed with raw
vegetable matter, called bee-bread, which is collected from the an-
thers of flowers, and laid up in cells for that purpoſe, till the maggot
becomes a winged bee, acquires greater ſenſibility, and is fed with
honey. Phil. Tranf. 1792.
Весе
Laſtly, though the filaments and ſtyle, as well as the corolla and
nectary, belong to the ſexual organs of vegetables; yet it is the an-
thers alone of the ſtamina, and ſtigmas alone of the piſtilla, which
poſſeſs the power, and I ſuppoſe the paſſion of reproduction, as
appears from the mutilated filaments of many flowers, as of curcuma,
of linum or flax of this country, of gratiola, and hemlock-leaved ge-
ranium,

3
112
ORGANS OF
Sect. VII. 2. 5.
sanium, which have half their ſtamina unterminated by anthers, and
in conſequence produce no prolific farina. And ſecondly, from the
forets, which form the rays of the flowers of the order fruſtraneous
polygamy of the claſs fyngeneſia, as the ſun-flower, which are fur-
niſhed with a ſtyle only, and no ſtigma, and are thence barren. There
is alſo a ſtyle without a ſtigma in the whole order of diccia gynan-
dria, the male flowers of which are thence barren, and ſhews the
neceſſity of the exiſtence of the ſtigma to the fecundation of the ve-
getable uterus, probably owing to its amatorial action in conveying
the living principle to the included feeds like the fallopian tubes of
the animal womb.
5.
The ſeeds are produced in the pericarp, and at firſt acquire nu-
triment by the umbilical veſſels previous to their fecundation, like the
unexpanded leaf-buds; and then by the caudex down the bark with
its radicles, which is oxygenated by the bractes, or floral-leaves, as
foon as theſe are expanded, they afterwards become in one day im-
pregnated in fome flowers, as in the oenothera, cactus grandiflorus,
and ciſtus; and the corol or petals, with the ſtamens and ſtigmas, and
nectaries, wither and fall off. In other flowers many days elapfe be-
fore the various cells of feeds are fecundated, and theſe more ani-
mated parts of ſexual reproduction periſh. But in all caſes the ſeeds
remain in the pericarp or uterus after fecundation as before it, except
in thoſe plants, which are called proliferus, as the polygonum vivi-
parum, and magical onions, which immediately begin to vegetate;
in all other plants the feed either ſleeps till the enſuing ſpring, as in
the colchicum and hamamelis; or they continue to grow to maturity,
and to be nouriſhed in the pericarp by the blood of the parent flower-
bud, which is oxygenated in the bractes or floral-leaves, till they be-
come perfected like eggs, and fall on the ground, or are otherwiſe
difperfed, for the purpoſe of taking root in the earth.
Whence it appears, that in the fexual reproduction of vegetables
the amatorial organ is diſtinct from the uterus, as is probably the caſe
in

Sect. VII. 2. 5.
113
REPRODUCTION.
;
in animals; which in female quadrupeds would ſeem to fleep after
impregnation during the time of geſtation and lactefcence, and after-
wards to revive; whereas this amatorial organ in vegetable flowers
periſhes, when the uterus is impregnated, along with the male organs,
neither of which are any longer of uſe in theſe annual beings.
The various methods, which nature has employed for the diſperſion
of ſeeds, are worth the attention of the farmer and gardener, both for
the purpoſe of preventing the growth of noxious feeds, and of col-
lecting the profitable ones. The pericarp of ſome plants burſts with
ſudden violence, when the feed is mature, and diſperſes it to conſider-
able diſtance; as that of wood-forrel, oxalis acetocalla; and of im-
patiens, touch me not. The ſeeds of many plants of the claſs fyn-
geneſia are furniſhed with a plume, by which admirable mechaniſm
they are diſſeminated by the winds far from their parent ſtem, and
look like a ſhuttlecock, as they fly. Other feeds are diſſeminated by
animals; of theſe ſome attach themſelves to their hair or feathers by
a gluten, as miſletoe ; others by hooks, as clivers, galium aperine ;
burdock, aretium lappa ; hound's-tongue, cynogloffum. Others are
ſwallowed whole for the ſake of the fruit, and voided uninjured, as
the hawthorn, cratægus, juniper, and ſome graſſes. And the ſeeds of
aquatic plants, and of thoſe which grow on the banks of rivers, are
carried many miles by the currents into which they fall.
Other ſeeds are ſeparated from each other, and diſperſed by the
twiſting of the awn at the ſummit of them, when moiſtened by rain,
as a black oat, avena fatua, with hairy awns, which ſeems to crawl
like an inſect when moiſtened ; geranium alſo, and barley; and as
this happens in wet weather, the moiſt ground is then fit to receive
and nouriſh them. The awns of the geranium have been uſed as
hygrometers by ſticking the baſe of the feed into a cork for a pedeſtal,
and marking diviſions on a paper circle beneath it; and the awn of
barley is furniſhed with ſtiff points, which, like the teeth of a faw, are
all turned towards one end of it; as this long awn lies upon the ground,
Q
it
a

114
Sect. VII. 2. 6.
ORGANS OF I
it extends itſelf in the moiſt air of night, and puſhes forward the
barley-corn, which it adheres to; in the day it ſhortens as it dries;
and as theſe points prevent it from receding, it draws up its pointed
end; and thus, creeping like a worm, will travel many feet from the
parent ftem; and may thus be uſed as a travelling hygrometer, when
laid on a cloth on the floor, like the automaton of Mr. Edgeworth,
deſcribed in Botanic Garden, article Impatiens, Vol. II.
6. The formation of the organs for ſexual generation, in contra-
diſtinction to thoſe for lateral generation, in vegetables, and in ſome
animals, as the polypus, the tænia, and the volvox, ſeems the chef
d'oeuvre, the maſter-piece of nature, as appears from many flying in-
ſects, as moths and butterflies, which ſeem to undergo a general
change of their forms ſolely for the purpoſe of ſexual reproduction;
and in all other animals theſe organs are not complete till the maturity
of the creature; whereas the lateral generation commences with the
infancy of the germ or bud, as on the roots of young herbs, and on
the ſtems of infant trees.
There feems nevertheleſs to be one circumſtance, in which the fo-
litary generation of the buds of plants, when the plants are at their
maturity, is ſuperior to the fexual generation by ſeeds. This conſiſts in
the progeny of the former being more perfect than that of the latter,
in reſpect to the power of the reproduction of their fpecies. Thus
in many plants, as in tulips and apple-trees, the young vegetable from
the ſeed produces other bulbs, or buds, for ſome years, which ſeem
annually to improve, till at length they acquire a puberty, if it may
be ſo called, and become furniſhed with ſexual organs for the purpoſe
of feminal reproduction ; whereas the leaf- buds, or leaf-bulbs, of the
apple-tree and tulip during their firſt years produce other leaf-buds,
or leaf-bulbs, rather more perfect than their parents; and when theſe
bulbs, and buds, arrive at their puberty, or maturity, ſo as to be ca-
pable of ſexual generation, their new bulbs and new buds alſo, if
taken from their dying parents, and tranſplanted or ingrafted, or left
8
adhering

Sect. VII. 2. 6. REPRODUCTION.
I15
adhering to them, are immediately capable of producing flowers, and
a conſequent feminal progeny.
As the progeny by lateral generation fo exactly reſembles the parent
ſtock, it follows, that though any new variety, or improvement, may
be thus continued for a century or two, as in grafted fruit-trees, yet
that no new variety or improvement can be obtained by this mode
of generation; though ſome hereditary diſeaſes, as the canker, are
believed to ariſe in ingrafted trees, which have long been propagated
by lateral generation, as explained in No. 1. 3. of this Section.
But from the ſexual, or amatorial, generation of plants new varie-
ties, or improvements, are frequently obtained ; as many of the
young plants from ſeeds are diffimilar to the parent, and ſome of them
ſuperior to the parent in the qualities we wiſh to poffefs; which is
another proof that the anthers and ſtigmas of plants are animated be-
ings, different from the green foliage of the tree on which they grow;
as they produce varieties in the form of their offspring like ſexual ani-
mals, which buds do not.
Beſides the production of different, and ſometimes more excellent,
varieties in the ſpecies of vegetables from feeds, another advantage
occurs from ſexual generation, which is the production of new ſpecies
of plants, or mules, by ſhedding the fecundating duſt of ſome flowers
on the ſtigmas of others of a different ſpecies, though generally of the
а
fame genus.
A mule cabbage is deſcribed in the Bath Agriculture, Vol. I.
Art. 4, which is ſaid to fatten a beaſt ſix weeks ſooner than turneps.
It is there faid, “ that the fort of cabbage principally raiſed is the
tallow-loaf or drum-head cabbage ; but it being too tender to bear
ſharp froſt, I planted ſome of this ſort and the common purple-cab-
bage uſed for pickling, (it being the hardieſt I am acquainted with)
alternately; and when the ſeed-pods were perfectly formed, I cut
down the purple, and left the other for ſeed. This had the deſired
effect, and produced a mixt ſtock of a deep green colour with purple
veins,
a
Q2

116
Sect. VII. 2. 6.
ORGANS OF
a
veins, retaining the fize of the drum head, and acquiring the hardi-
neſs of the purple."
In another curious paper of the Bath Society, Vol. V. p. 38, Mr.
Wimpey relates, that he planted a field with garden-beans in rows
about three feet aſunder in the following order, mazagan, white-
bloſſom, long-podded, Sandwich-toker, and Windfor-beans. The
mazagan and white-bloſſom were thraſhed firſt, when to his great
furpriſe he found many new ſpecies of beans; thoſe from the maza-
gan were mottled black and white; the white-bloſſoms were brown
and yellow inſtead of their natural black; and they were both much
larger than uſual. See Seet. XVI. 4. of this work.
There is an apple deſcribed in Bradley's work, which is faid to have
one ſide of it a ſweet fruit, which boils ſoft, and the other ſide a four
fruit, which boils hard. This Mr. Bradley ſo long ago as the year
1721 ingeniouſly aſcribes to the farina of one of theſe apples imprego
nating the other ; which would ſeem the more probable, if we con-
fider, that each diviſion of an apple is a ſeparate womb, and may
therefore have a ſeparate impregnation, like puppies of different kinds
in one litter. The ſame is ſaid to have occurred in oranges and lemons,
and grapes of different colours.
SA
Vegetable mules are ſaid to be numerous, and, like the mules of
the animal kingdom, not always to continue their ſpecies by feed.
There is an account of a curious mule from the antirrhinum linaria,
toad-flax, in the Amenit. Academ. V.I. No. 3. and many hybrid
plants are deſcribed in No. 32. The urtica alienata is an evergreen
plant, which appears to be a nettle from the male flowers, and a pel-
litory (parietaria) from the female ones and the fruit, and is hence be-
tween both. Murray, Syſt. Veg. Amonſt the Engliſh indigenous
plants, the veronica hybryda, mule ſpeedwell, is ſuppoſed to have
originated from the officinal one, and the fpiked one; and the Sib-
thorpia Europæa to have for its parents the golden ſaxifrage and marſh
pennywort. Pulteney's View of Linneus, p. 253.
There
a

SECT. VII. 2.7.
117
REPRODUCTION.
There is another vegetable fact publiſhed by M. Koelruter, which
he calls a complete metamorphoſis of one natural ſpecies of plants
66
into another;" which ſhews, that in ſeeds as well as in buds, the
embryon proceeds from the male parent, though the form of the
ſubſequent mature plant is in part dependent on the female. M. Ko-
elruter impregnated a ſtigma of the nicotiana ruſtica with the farina of
the nicotiana paniculata, and obtained prolific feeds from it. With the
plants, which ſprung from theſe feeds, he repeated the experiment,
impregnating their piſtilla with the farina of the nicotiana paniculata.
As the mule plants, which he thus produced, were prolific, he con-
tinued to impregnate them for many generations with the farina of
the nicotiana paniculata, and they became more and more like the
male parent, till he at length obtained fix plants in every reſpect per-
fectly fimilar to the nicotiana paniculata, and in no reſpect reſembling
their female parent the nicotiana ruſtica. Blumenback on Genera-
tion.
Mr. Graberg, Mr. Schreber, and Mr. Ramſtrom, ſeem of opinion,
that the internal ſtructure or parts of fructification in mule plants re-
ſemble the female parent ; but that the habit or external ſtructure re-
ſembles the male parent. See treatiſes under the above names in
Vol. VI. Amonit. Academic.
7. Something ſimilar to this ſeems to obtain in mixing the breeds
of the ſame ſpecies of animals, and in animal mules, which may be
worth the attention of the grazier. The mule produced from a horſe
and a fhe aſs reſembles the horſe externally with his ears, mane, and
but with the nature, or manners of an aſs. But the hinnus,
or creature produced from a male aſs and a mare, reſembles the father
externally in ftature, aſh-colour, and the black croſs on his ſhoulders,
but with the nature or manners of a horſe. The breed from Spaniſh
rams and Swediſh ewes reſembled the Spaniſh ſheep in wool, ſtature,
and external form; but was as hardy as the Swediſh Theep; and the
contrary occurred in the breeds which were produced from Swediſh
a
a
tail;
a
a
rams

ITS
Sect. VII. 2.8.
ORGANS OF
rams and Spaniſh ewes. The offspring from the male goat of An-
gora and the Swediſh female goat had long ſoft camel's hair ; but that
from the male Swediſh goat, and the female one of Angora, had no
improvement of their wool. An Engliſh ram without horns, and a
Swediſh horned ewe, produced ſheep without horns. Amen. Acad.
Vol. VI. p. 13.
8. From theſe circumſtances it appears, that not only new varie-
ties may be procured from the ſeminal offspring of plants; where
thoſe from the lateral offspring become diſeaſed by age, as the can-
kered apple-grafts, and perhaps the curled potatoes, and barren
Arawberries; but that more curious or uſeful fruits or flowers may
be obtained by ſhedding the farina of ſome valuable plant on the
ftigma of another variety of the ſame ſpecies, as of two different but
equally excellent apple-trees, or tulip-flowers, hyacinths, anemonies,
and geraniums. And thirdly, that mules may be produced by a mix-
ture of different fpecies of plants, and perhaps of different genera;
as of pines and melons; grapes and gooſeberries; oranges and apples ;
apricots and nectarines ; nuts and acorns; which may be afterwards
propagated by the lateral progeny, if not by the ſeminal one.
The facility of generating vegetable mules ſeems forcibly to have
ſtruck the great Linneus; who in the preface to his natural orders
of plants at the end of his Genera Plantarum thinks, that about ſixty
vegetables were at firſt created correſponding with his natural orders.
That a mixture of theſe orders amongſt themſelves produced the ge-
nera; that a mixture of the genera amongſt themſelves produced the
fpecies; and that a mixture of the ſpecies produced the varieties,
which he believes to accord with the general progreſs of nature
" from ſimpler things to the more compound.”'
In the ſame manner it may be ſuppoſed, that many of the preſent
ſpecies of animals were originally mules produced by a mixture of
animals of different genera ; and that all ſuch mules, as had perfect
ergans of reproduction, continued their ſpecies. But as theſe organs
feem
а
a

Sect. VII. 2. 8. REPRODUCTION.
119
feem to be the chef d'œuvre of nature, as above remarked, they often
become imperfect in the generation of mules, and the ſpecies then
becomes extinct; as it could not be propagated by ſexual generation,
it is poſſible, that many new kinds of mules, which might be uſeful
for labour, or by their milk or wool, or for food, might ſtill be pro-
duced by the method of Spallanzani; who diluted the ſeminal fluid
of a dog with much warm water, and by injecting it fecundated a
bitch, and produced puppies like the dog.
Thus new animal combinations might poſſibly be generated nume-
rous as the fabled monſters of antiquity; as between the ram and the
female goat; the ſtag and the cow; the horſe and the doe; the bull
and the mare; boar and bitch ; dog and fow. And ſecondly, as Spal-
lanzani diluted the ſeminal fluid of a male frog with water, and fe-
cundated ſome female ſpawn with it, and produced perfect tadpoles,
there is reaſon to conclude, that new combinations of fiſh might thus
be generated, and people our rivers with aquatic monſters. And laſtly,
that it is not impoſſible, as ſome philoſopher has already ſuppoſed, if
Spallanzani ſhould continue his experiments, that ſome beautiful
productions might be generated between the vegetable and animal
kingdoms, like the eaſtern fable of the roſe and nightingale, and
which might be propagated by lateral or paternal, though not by
ſexual or feminal generation.
The claſſic reader will. here be reminded of the metamorphoſes of
Ovid, of gods turned into bulls and ſwans, men into frogs and par-
tridges, ladies into trees and flowers, of ſphinxes, griffins, dragons,
mermaids, centaurs, and minataurs; Paſiphae and her bull; Leda and
her ſwan ; Arethuſa and her fiſh-god Alpheus, and conclude that
mules in early times were more frequent than at preſent, which oc-
caſioned the poets and the prieſts of antiquity to invent ſo many fa-
bulous monſters, and impoſe them on the credulity of mankind.
ITI, VEL

120
Sect. VII. 3. 1.
ORGANS OF
soilo
III.
VEGETABLE GENERATION.
1. The intelligent reader is become, I hope, by this time fo much
intereſted in the further inveſtigation of the circumſtances attending
the lateral and ſexual generation of vegetables, that he will not be
diſpleaſed with the continuance of the ſubject for a few more pages,
ſo agreeable from its novelty, and ſo important from its future ap-
plication to animal reproduction.
If a ſcion of a nonpareil apple be ingrafted on a crab-ſtock, and a
golden pippin be ingrafted on the nonpareil, what happens ? The
caudex of the bud of the golden pippin conſiſts of its proper abſorbent
vefſels, arteries, and veins, till it reaches down to the nonpareil-
ſtock; and then the continuation of its caudex downwards conſiſts of
veſſels ſimilar to thoſe of the nonpareil ; when its caudex deſcends
ſtill lower, it conſiſts of veſſels ſimilar to thoſe of the crab-ſtock.
The truth of this is ſhewn by two circumſtances; firſt, becauſe
the lower parts of this compound tree will occaſionally put forth buds
ſimilar to the original ſtock. And ſecondly, becauſe in ſome in-
grafted trees, where a quick-growing ſcion has been inſerted into a
ſtock of flower growth, as is often ſeen in old cherry-trees, the upper
part of the trunk of the tree has become of almoſt double the diameter
of the lower part; both which occurrences ſhew, that the lower
part of the trunk of the tree continues to be of the ſame kind, though
it muſt have been ſo repeatedly covered over with new circles of
wood, bark, and cuticle.
Now as the caudex of each bud, which paſſes the whole length of
the trunk of the tree, and forms a communication from the upper
part, or plumula, to the lower part, or radicle, muſt conſiſt in theſe
doubly ingrafted trees of three different kinds of caudexes, reſembling
thoſe of the different ſtocks or ſcions; we acquire a knowledge of
what may be termed a lateral or paternal mule, in contradiſtinction
a
a
5
to

Sect. VII. 3. 2.
121
REPRODUCTION.
to a ſexual mule. For as in theſe trees thus combined by ingraftment
every bud has the upper parts of its caudex that of a golden pippin,
the middle part of it that of a nonpareil, of the lower part of it that
of a crab; if theſe caudexes, which conſtitute the filaments of the
bark, could be ſeparated intire from the tree with their plumules and
radicles, they would exhibit ſo many lateral or paternal mules, con-
fiſting of the connected parts of their three parents ; the plumula be-
longing to the upper parent, and the radicle to the lower one, and the
triple caudex to them all.
A ſeparation of theſe buds from the parent plant is ſaid to have been
obſerved by Mr. Blumenback in the conferva fontinalis, a vegetable
which conſiſts of ſmall ſhort ſlender threads, which grow in our foun-
tains, and fix their roots in the mud. He obſerved by magnifying
glaſſes, that the extremities of the threads ſwell, and from ſmall tu-
bera, or heads, which gradually ſeparate from the parent threads, at-
tach themſelves to the ground, and become perfect vegetables; the
whole progreſs of their formation can be obſerved in forty-eight
hours. Obſervations on Plants, by Von Uſlar, Creech, Edinb.
2. The lateral propagation of the polypus found in our ditches in
July, but more particularly that of the hydra ſtentorea, is wonder-
fully analagous to the above idea of the lateral generation of vegeta-
bles. The hydra ſtentorea, according to the account of monſieur
Trembley, multiplies itſelf by ſplitting lengthwiſe; and in twenty-
four hours theſe diviſions, which adhere to a common pedicle, reſplit,
and form four diftinct animals. Theſe four in an equal time fplit
again, and thus double their number daily, till they acquire a figure
ſomewhat reſembling a noſegay. The young animals afterwards ſe-
parate from the parent, attach themſelves to aquatic plants, and give
riſe to new colonies,
Another curious animal fact is related by Blumenback in his treatiſe
on generation, concerning the freſh water polypus. He cut two of
them in half, which were of different colours, and applying the upper
R
part

122
Sect. VII 3. 3
ORGANS OF
part of one to the lower part of the other, by means of a glaſs-tube,
and retaining them thus for fome time in contact with each other,
the two divided extremities united, and became one animal.
The attentive reader has already anticipated me in applying theſe
wonderful modes of lateral animal reproduction and conjunction to
the lateral propagation and ingraftment of vegetables. The junction
of the head-part of one polypus to the tail-part of another is exactly
repreſented by the ingraftment of a ſcion on the ſtock of another
tree. The plumula, or apex of each bud, with the upper part of its
caudex, joins to the long caudex of the ſtock, which paſſing down
the trunk terminates in the radicles of it. And if this compound ve-
getable could be ſeparated longitudinally from the other long filaments
of the bark in its vicinity, like the fibres of the bark of the mulberry-
tree prepared at Otaheite, or as the bark of hemp and flax are pre-
pared in this country, as the young ones of the hydra ſtentorea ſepa-
rate from their parents, it might claim the name of a lateral or pater-
nal mule, as above mentioned.
3. It hence appears, that every new bud of a tree, where two ſcions
have been inſerted over each other on a ſtock, if it could be ſeparated
from the plume to the radicle, muſt confiſt of three different kinds
of caudex, and might therefore be called a triple lateral mule. And
that hence it follows, that every part of this new triple caudex,
muſt have been feparated or ſecreted laterally from the adjoining part
of the trunk of the tree; and that it could not be formed, as I for-
merly believed, from the roots of the plume of the bud deſcending
from the upper part of the caudex of it to the earth. A circum-
ſtance of great importance in the inveſtigation of the curious ſubject
of the lateral generation of vegetables, and of inſects.
One might hence ſuſpect, that if Blumenback had attended to the
propagation of the polypus, which he had compoſed of two half po-
lypi, that the young progeny might have poſſeſſed two colours re-
ſembling

SECT. VII. 3. 4, 5.
123
REPRODUCTION.
ſembling the compound parent, like the different caudexes of ingraft-
ed trees; an experiment well worthy repeated obſervation.
4. Another animal fact ought alſo to be here mentioned, that many
infects, as common earth-worms as well as the polypus, are ſaid to
poffefs ſo much life throughout a great part of their ſyſtem, that
they may be cut into two or more pieces without deſtroying them,
as each piece will acquire a new head, or a new tail, or both; and
the infect will thus become multiplied. How exactly this is re-
ſembled by the long caudex of the buds of trees, which poſſeſs ſuch
vegetable life from one extremity to the other, that when the head or
plume is lopped off, it can produce a new plume; and when the
lower part is cut off, it can produce new radicles; and may be thus
wonderfully multiplied.
5. Hence we acquire ſome new and important ideas concerning
the lateral generation of vegetables, and which may probably contri-
bute to elucidate their ſexual generation. Theſe are, firſt, that the
parts of the long caudex of each new bud of an ingrafted tree, and
conſequently of all trees, are ſeparated or ſecreted from the corre-
ſpondent or adjoining parts of the long caudex of the laſt year's bud,
which was its parent; and not that it conſiſts of the roots of each
new bud ſhot down from the plumula or apex of it, as I formerly
ſuppoſed; and that thoſe various molecules, or fibrils, ſecreted from
the caudex of the laſt year's buds, adjoin and grow together beneath
the cuticle of the trunk of the tree, the upper ones forming the plu-
mula of the new bud, which is its leaf or lungs, to acquire oxygen
from the atmoſphere ; and the lower ones forming the radicles of it,
which are abſorbent veſſels to acquire nutriment from the earth.
Secondly, that every part of the caudex of an ingrafted tree, and
conſequeñtly of all trees, can generate or produce a new bud, when
the upper part of it is ſtrangulated with a wire or cut off, or other-
wiſe when it is ſupplied more abundantly with nutriment, ventila-
tion, and light. And that each of theſe new buds thus produced
reſembles
R 2

124
ORGANS OF Sect. VII. 3. 6
3
.
6reſembles that part of the ſtock in compound trees, where it ariſes.
Thus in the triple tree above mentioned a bud from the upper part
of the long caudexes, which form the filaments of the bark, would
become a golden pippin branch; a bud from the middle part of them
would become a nonpareil, branch; and a bud from the lower part
a crab branch.
Thirdly, another wonderful property of this laterał mule progeny
of trees compounded by ingraftment conſiſts in this, that the new
mule may conſiſt of parts from three, or four, or many parents, when
fo
many different ſcions are ingrafted on each other; whence a queſ-
tion may ariſe, whether a mixture of two kinds of anther-duſt previ-
ous to its application to the ſtigma of flowers might not produce a
threefold mule, partaking of the likeneſs of both the males ?
6. On this nice ſubject of reproduction ſo far removed from com-
mon apprehenſion the patient reader will excuſe a more prolix inveſ-
tigation. The attraction of all matter to the centres of the planets, or
of the ſun, is termed gravitation ; that of particular bodies to each
other is generally called chemical affinity; to which the attractions
belonging to electricity and magnetiſm appear to be allied.
In theſe latter kinds of attraction two circumſtances ſeem to be
required ;. firſt, the power to attract poffeffed by one of the bodies,
and ſecondly, the aptitude to be attracted poffeffed by the other.
Thus when a magnet attracts iron, it may be ſaid to poffeſs a ſpecific
tendency to unite with the iron; and the iron may be ſaid to poſſeſs
a ſpecific aptitude to be united with the magnet. The former appears
to reſide in the magnet, becauſe it can be deprived of its attractive
power, which can alſo be reftored to it; and the iron appears to pof-
feſs a ſpecific aptitude to be united with the magnet, becauſe no
other metal will.approach it. In the ſame manner a rubbed ſtick of
ſealing-wax may be ſaid to poſſeſs a ſpecific tendency to unite with a
light ſtraw, but not with a glaſs bead. Here the ſtraw ſeems to
poffefs a ſpecific aptitude to unite with the rubbed ſealing-wax, becauſo
many

SECT. VII. 3.7.
125
REPRODUCTION.
many other bodies refuſe to do ſo, as glaſs, filk, air; and laſtly, the
ſpecific attraction of the rubbed ſealing-wax can be withdrawn or re-
ſtored; to which may be added, that ſome chemical combinations
may ariſe from the ſingle attraction of one body, and the aptitude to
be attracted of another; or they may be owing to reciprocal attrac-
tions of the two bodies, as in what is termed by the chemiſts double
affinity, which is known to be ſo powerful as to ſeparate thoſe bo-
dies, which are held together by the ſingle attraction probably of one
of them to the other, which other poſſeſſes only an aptitude to be at-
tracted by the former.
7. The above account of the tendencies to union by unorganized
or inanimate matter is not given as a philoſophical analogy, but to
facilitate our conception of the adjunctions or concretions obſervable
in organized or animated bodies, which conſtitute their forination,
their nutrition, and their growth. Theſe may be divided into two
kinds;
firſt the junction or union of animated bodies with inanimate
matter, as when fruit or fleſh is ſwallowed into the ſtomach, and be-
comes abſorbed by the lacteals; and the ſecond, where living parti-
cles coalefce or concrete together, as in the formation, nutrition, or
conjunction of the parts of living animals.
In reſpect to the former, the animal parts, as the noſtrils and palate,
poſſeſs an appetency, when ſtimulated by the ſcent and flavour of
agreeable food, to unite themſelves with it; and the inanimate ma-
terial pofſefſes an aptitude to be thus united with the animal organ.
The ſame occurs when the food is ſwallowed into the ſtomach; the
mouths of the lacteal veſſelsbeing agreeably ſtimulated poffefs an ap-
petency to abſorb the particles of the digeſting maſs, which is in a
ſituation of undergoing chemical changes, and pofſeffes at ſome pe-
riod of them an aptitude to be united with the mouths of the abſor-
bent lacteals.
But when thefe abforbed particles of inanimate matter have beea
circulated in the blood, they ſeem gradually to obtain a kind of vir
8
tality
33

126
Sect. VII. 3. S.
ORGANS OF
с
tality; whence Mr. John Hunter, and I believe ſome ancient philo-
ſophers, and the divine Moſes, aſſerted, that the blood is alive; that
is, that it pofſefſes ſome degree of organization, or other properties
different from thofe of inanimate matter, which are not producible
by any chemical proceſs, and which ceaſe to exiſt along with the life
of the animal. Hence for the purpoſe of nutrition there is reaſon to
ſuſpect, that two circumſtances are neceſſary, both dependent upon
life, and conſequent activity; theſe are firſt an appetency of the
fibrils of the fixed organization, which wants nutrition ; and ſe-
condly, a propenſity of the fluid molecules exiſting in the blood, or
ſecreted from it, to unite with the organ now ſtimulated into action.
So that nutrition may be ſaid to be affected by the embrace or cohe-
fion of the fibrils, which poffefs nutritive appetencies, with the
molecules, which poffefs nutritive propenſities.
8. If the philoſopher, who thinks on this ſubject, ſhould not be
inclined to believe that the whole of the blood is alive; he can not
eaſily deny life to that part of it which is ſecreted by the organs of
generation, and conveys vitality to the new embryon, which it
pro.
duces. Hence though in the proceſs of nutrition the activity of two
kinds of fibrils or molecules may be ſuſpected, yet in the proceſs of
the generation of a new vegetable or animal, there ſeems great reaſon
to believe, that both the combining and combined particles are en-
dued with vitality ; that is, with ſome degree of organization or other
properties not exiſting in inanimate matter, which we beg leave to
denominate fibrils with formative appetencies, and molecules with
formative propenſities, as the former may ſeem to poſſeſs a greater
degree of organization than the latter.
And thus it appears, that though nutrition may be conceived to be
produced by the animated fibrils of an organized part being ſtimu-
lated into action by inanimate molecules, which they then embrace,
and may thus be popularly compared to the ſimple attractions of
chemiſtry; yet that in the production of a new embryon, whe-
ther

Sect. VII. 3. 8. REPRODUCTION.
127
ther vegetable or animal, both the fibrils with formative appetencies,
and the molecules with formative propenfities, recriprocally ſtimulate
and embrace each other, and inſtantly coaleſce, and may thus popu-
farly be compared to the double affinities of chemiſtry. But there
are animal facts, which reſemble both theſe, and are thence more
philoſophically analogous to them; and theſe are the two great fup-
ports of animated nature, the paſſions of hunger and of love. In the
former the appetency reſides only in the ſtomach, or perhaps in the
cardia ventriculi, but the object conſiſts of inanimate matter ; in the
latter reciprocal appetencies and propenſities exiſt in the male and fe-
male, which mutually excite them to embrace each other. Two
other animal facts are equally analogous ; the thirſt, which reſides at
the upper end of the efophagus, and though it poffefles appetency it-
ſelf, its object is inanimate matter ; but in lacteſcent females, when
they give ſuck to their young, there exiſts a reciprocal appetency in
the mother to part with her milk, and in the young offspring to re-
ceive it.
This then finally I conceive to be the manner of the production of
the lateral progeny of vegetables. The long caudex of an exiſting
bud of a tree, which conſtitutes a ſingle filament of the preſent bark,
is furniſhed with glands numerous as the perſpirative or mucous
glands of animal bodies; and that theſe are of two kinds, the one ſe-
ereting from the vegetable blood the fibrils with formative appeten-
cies, correſpondent to the maſculine fecretion of animals; and the
other ſecreting from the vegetable blood the molecules with forma-
tive propenſities, correſpondent to the feminine ſecretion of animals
and then that both theſe kinds of formative particles are depoſited be-
neath the cuticle of the bark along the whole courſe of it, and nearly
at the ſame time by the ſympathy of the ſecreting organs, and in-
ftantly embrace and coaleſce, forming a new caudex along the fide of
its parent with vegetable life, and with the additional powers of nu-
trition, and of growth.
5
9. This

128
ORGANS OF Sect. VII. 3. 9, 10.
9. This then is the great ſecret of nature; more living particles
are produced by the powers of vitality in the fabrication of the vege-
table blood, than are neceſſary for nutrition or reſtoration of decom-
•poſing organs. Theſe are ſecreted, and detruded externally, and
produce by their combination a new vital organization beneath the
cuticles of trees over the old one. Theſe new combinations of vital
fibrils and molecules acquire new appetencies, or fabricate molecules
with new propenſities, and thus poſſeſs the power of forming the
leaf or lungs at one extremity of the new caudex; and the radicles,
or abſorbent veſſels at the other end; and ſome of them, as in the
central buds which terminate the branches, finally form the ſexual or-
gans of reproduction, which conſtitute the flower.
That new organizations of the growing ſyſtem acquire new ap-
petencies appears from the production of the paſſion for generation,
as ſoon as the adapted organs are complete; and from the deſire of
lacteſcent females to ſuckle their offspring, and alſo from the variation
of the palate, or deſire for particular kinds of food, as we advance in
life, as from milk to fleſh. Thus as a popular alluſion, and not as
a philoſophical analogy, we may again be allowed to apply to the
combinations of chemiſtry ; where two different kinds of particles
unite, as acids and alkalies, a third ſomething is produced, which
poſſeſſes attractions diſſimilar to thoſe of either of them; and that
new organizations form new molecules appears from the ſecretions
of the ſeminal and uterine glands, when they have acquired their
maturity; and from the breaſts of lacteſcent females.
10. In the lateral propagation of vegetable buds as the ſuperfluous
fibrils or molecules, which were fabricated in the blood, or detached
from living organs, and poſſeſs nutritive or formative appetencies and
propenſities, and which were more abundant than were required for
the nutrition of the parent vegetable bud, when it had obtained its
full growth, were ſecreted by innumerable glands on the various parts
of its ſurface beneath the general cuticle of the tree, and there em-
bracing

Sect. VII. 3. 11.
129
REPRODUCTION.
bracing and coalefcing, form a new embryon caudex, which gra-
dually produces a new plumula and radicles. And as the different
parts of the new caudex of a compound tree reſemble the parts of the
parent caudex, to which it adheres, it was thewn, beyond all doubt,
that different fibrils or molecules were detached from different parts
of the parent caudex to form the filial one.
So in the ſexual propagation of vegetables the ſuperfluous living
fibrils, or molecules, floating in the blood, appear to be ſecreted from
it by two kinds of glands only; thoſe which conſtitute the anthers,
and thoſe which conſtitute the pericarp of flowers. By the former I
ſuppoſe the fibrils, with formative appetencies and with nutritive
ap-
petencies, to be ſecreted ; and by the latter the molecules, with for-
mative and with nutritive propenſities. Afterwards that theſe fibrils
with formative and nutritive appetencies, become mixed in the peri-
carp or uterus of the flower, with the correſpondent molecules with
formative and nutritive propenſities; and that a new embryon is in-
ſtantly produced by their reciprocal embrace and coaleſcence. And
that parts of this new organization afterwards acquire new appe-
tencies, and form molecules with new propenſities, and thus gradually
produce other parts of the growing ſeed, which do not at firſt ap-
pear, as the plumula, radicles, cuticle, and the glands of reproduc-
tion in the pericarp and anthers, which correſpond in the animal
fetus to the lungs, inteſtines, cuticle, and the organs, which diſtin-
guiſh the ſexes.
11. From this new doctrine of a threefold vegetable mule by la-
teral propagation, as the new bud on the ſummit of a tree, which
has had two ſcions ingrafted on it one above another, in which it is
inconteſtibly ſhewn, that different fibrils, or molecules, are detached
from different parts of the parent caudex to form the filial one, which
adheres to it; and that it then acquires the power of producing new
radicles, or a new plumula; we may ſafely conclude, as it is dedu-
cible from the ſtrongeſt analogy, that in the production of ſexual
S
mules,

130
SECT. VII. 3. 12.
ORGANS OF
mules, whether vegetable or animal, ſome parts of the new embryoni
were produced by, or detached from, ſimilar parts of the parent,
which they reſemble. And that as theſe fibrils, or molecules, floated
in the circulating blood of their parents, they were collected fepa-
rately by appropriated glands of the male or female; and that finally,
on their mixture in the matrix the new embryon was immediately
generated, reſembling in ſome parts the form of the father, and in
other parts the form of the mother, according to the quantity or ac-
tivity of the fibrils or molecules at the time of their conjunction.
And laſtly, that various parts of the new organizations afterwards
acquired new appetencies, and formed molecules with new propen-
ſities, and thus gradually produced other parts of the growing fetus,
as the ſkin, nails, hair, and the organs which diſtinguiſh the fexes.
If the molecules fecreted by the female organ into the pericarp of
flowers, or into the owary of animals, were ſuppoſed to conſiſt of
only unorganized or inanimate particles ; and the fibrils ſecreted by
the male organ only to poſſeſs formative appetencies to ſelect and com-
bine with them; the new embryon muſt probably have always re-
ſembled the father, and no mules could have had exiſtence.
But by the theory above delivered it appears, that the new off-
ſpring, both in vegetable and animal reproduction, whether it be a
mule or not, muſt ſometimes more reſemble the male parent, and
ſometimes the female one, and ſometimes appear to be a combination
of them both, as the epigram of Martial :
Dum dubitat natura gravis puerum faceretne puellam,
Factus es, O pulcher, pene puella, puer.
12. The certain proof above given, that ſome parts of the triple
caudex of the new bud of a tree, which has been compounded by in-
graftment, are formed from ſimilar parts of the triple caudex of the
parent bud, carries us one ſtep further back into the myſterious pro-
ceſs

Sect. VII. 3. 12.
131
REPRODUCTION.
ceſs of reproduction, and ſomewhat countenances the ingenious con-
je&tures of monſieur Buffon. And the analogy here obſerved, that
as in chemical union there muſt be ſome particles of inanimate matter
with attractions, and others with aptitudes to be attracted; ſo in the
conjunctions of animated particles in the nutrition or formation of
organized beings, there muſt exiſt fibrils or molecules with forina-
tive or nutritive appetencies, and others with formative or nutritive
aptitudes or propenfities, one of which may be ſecreted by the male,
and the other by the female parent, may facilitate our reaſoning upon
this dark ſubject, which will be reſumed and enlarged upon in the
next edition of Zoonomia, in the ſection on generation,
S 2
2
SECT.

132
Sect. VIII. 1.
MUSCLES, NERVES, BRAIN.
SECT
VIII.
1. THE MUSCLES, NERVES, AND BRAIN OF VEGETABLES.
1. Vegetable muſcles evinced by their cloſing their corols, and calyxes, and moving their
leaves in conſequence of ſtimulus. Hence alſo vegetable nerves both of ſenſe and mo-
tion. When one part of a leaf of mimoſa is touched the whole leaf falls. Hence
alſo a vegetable brain or common fenforium. 2. Their irritability Mewn by the ab-
Sorption, and circulation of their fluids. By eleEtric ſhocks. By the aſcent of Jap-
juice. 3. Their ſenſibility fewn by the collaps of mimoſa. By cloſing their petals
from defeet of ſtimulus, as in darkneſs and cold. By the males and females bending
to each other. 4. Their volition mewn from hedyſarum gyrans. From polymorpha
marchantia. From tendrils of vines. From their ſleep. 5. Their affociations of
motion mewn by their cloſing their petals, performing abſorption and circulation of
fluids. Their acquired habits. Grains and roots from the ſouth vegetate fooner.
Apple-trees. Senſitive plant. Berberry. 6. Vegetables poſſeſs a ſenſe of heat,
of light, and of moiſture, and conſequently poſſeſs a brain or common ſenſorium.
7. They poſſeſs a ſenſe of touch and a common ſenſorium. 8. How do the anthers
and ſtigmas find each other? by a ſenſe of ſmell. Adultery of collinfonia. 9. From
their abſorptions, ſecretions, ſenſes, love and
ſeep, they muſt poſſess a brain. Does
this reſide in the pith of each individual bud ?
1. The various motions of peculiar parts of vegetables evince the
exiſtence of muſcles and nerves in thoſe parts, ſuch as the cloſing of
their petals, and calyxes, at the approach of night, or in cold or wet
weather; though the fibres and nerves, which conſtitute theſe muſcles,
are too fine for anatomical demonſtration.
Some vegetables fold the older leaves over the new buds at the ex-
tremity of their ſtalks during the night, as alfine, chickweed; others,
as the mimoſa, ſenſitive plant, fold the upper or poliſhed ſides of
their

Sect. VIII. 2. MUSCLES, NERVES, BRAIN.
133
their leaves together during their fleep. The hedyfarum gyrans
whirls its leaves in various directions, when the air is ſtill, by an ap-
parently voluntary effort, probably for the purpoſe of reſpiration.
The dionoa muſcipula, Venus's fly-trap, cloſes its leaves from the
ſtimulus of inſects, which crawl upon them, and pierces them with
its prickles. And the apocynum androſemifolium contracts its petals
or nectaries round the proboſcis of the flies, which ſtimulate it, and
holds them till they die, or till the ſleep of the plant releaſes them by
the relaxation of its muſcular action.
From theſe circumſtances it appears, that there are not only muf-
cles about the moving foot-ſtalks or claws of the leaves and petals
above mentioned; but that theſe muſcles muſt be endued with nerves
of ſenſe as well as of motion. Now, as when one part of a leaf of
mimoſa is touched, the whole leaf falls, it follows, that there muſt
be a common ſenſorium, or brain, where the nerves communicate,
belonging to this one leaf-bud. To evince this further another leaf-
let was ſlit with ſharp fciffars, and ſome ſeconds of time elapſed, be-
fore the plant ſeemed ſenſible of the injury; and then the whole plant
collapſed as far as the principal ſtem. Afterwards a ſmall drop of oil
of vitriol was put on the bud in the boſom of a leaf of another ſen-
fitive plant; and, after about half a minute, when the brain of this
bud could be ſuppoſed to be deſtroyed, the whole leaf fell, and roſe
If the individual buds of plants poſſeſs muſcles and nerves
with a brain, or common ſenſorium; the following queſtions conſe-
quently occur, and ſhould be anſwered in the affirmative. Have ve-
getable buds irritability ? have they ſenſation ? have they volition :
have they aſſociations of motion ? I am perſuaded they poſſeſs them
all, though in a much inferior degree even than the cold blooded
animals.
2. The irritability of vegetable fibres is demonſtrated by the ab-
ſorption and circulation of their fluids in their roots, leaves, and pe-
tals; which can not be explained by any mechanic law, and exactly
correſponds
a
no more.

134
MUSCLES, NERVES, BRAIN.
Sect. VII. 3.
correſponds with the abſorption of the aliment, and the circulation of
the blood in animals; which Phyſiologiſts have demonſtrated to de-
pend on the muſcular motions of the veſſels themſelves, which poſ-
ſeſs irritability, and are excited into action by the ſtimulus of the
fluids, which they acquire or contain.
The irritability of vegetable veſſels is ſhewn by a curious experi-
ment of Von Ular, who paſſed ſtrong electric ſhocks through a plant
of euphorbia, ſo as to deſtroy the life of the plant; and he then ob-
ſerved on cutting off a branch, that it did not bleed; though a ſimilar
branch cut off before the death of the plant effuſed much milky
juice; whence he juſtly concludes, that the electric percuſſion had
deſtroyed the irritability of the plant.
Mr. Cavallo afferts in his Treatiſe on Electricity, that he found by
repeated experiments, that the plant balſam (impatiens) was deſtroy-
ed by leſs quantities of electricity than any other vegetables, which
he ſubjected to it; and that on examining the plant afterwards no
injury on the external or internal parts of it could be diſcovered ;
whence it may be concluded that the irritability ſimply, and not the
organization of the plant, was deſtroyed by the unnatural quantity of
ſtimulus. He adds, that not only ſhocks from ſo ſmall a coated ſur-
face as fix or eight ſquare inches, but even ſtrong ſparks from a large
conductor deſtroyed theſe plants, which ſometimes recovered in a day
or two, but not frequently. See Sect. XIII. 3. and Sect. XIV. 2. 3.
of this work.
The aſcent of the fap-juice during the vernal months in the ex-
periments both of Hales and Walker, being retarded or quite ſtopped
during the cold parts of the day, and in the night, and on the north
ſide of the tree in cool days, when it continued to flow on the ſouth
fide, can only be aſcribed to the irritability of the vegetable veſſels
being decreaſed by the deficient ſtimulus of heat. See this ſubject
further treated of in Sect. XIV. 1. 10. of this work.
3. The fenfibility of fibres is diſtinguiſhed from their irritability
by
a

Secr. VIII. 3.
135
MUSCLES, NERVES, BRAIN.
a
by the pain or pleaſure, which precedes or attends any animal action;
and therefore ſuppoſes the exiſtence of a common ſenſorium; now
when one diviſion of a leaf of mimoſa is injured by a wound or touch,
in a ſhort time the whole leaf cloſes, which is owing to the actions
of the diſtant muſcles about the foot talks of the ſubdiviſions of the
leaf. Does not this prove, that there is a brain or common ſenſo-
rium, where the nerves communicate in ſome part of this bud or
leaf, as the injury of one diſtant part of it thus affects the whole ?
or in other words, that the diſagreeable ſenſation is propagated from
a part to the whole, and cauſes the actions of fome diſtant muſcles,
in the ſame manner as I draw away my hand when my finger is
hurt?
There are muſcles placed about the foot-ſtalks of the leaves or
leaflets of many plants, for the purpoſe of cloſing their upper ſurfaces
together, or of bending them down ſo as to ſhoot off the ſhowers or
dew-drops, as in fenfitive plant, mimoſa; kidney-bean, phaſeolus ;
and many trees. The claws of the petals, or of the diviſions of the
calyx of many flowers, are furniſhed in a ſimilar manner with muſ-
cles, which are exerted to open or cloſe the corol and calyx of the
flower, as in tragopogon, anemone. This action of opening and clof-
ing the leaves or flowers does not appear to be produced ſimply by ir-
ritation on the muſcles themſelves, but by the connexion of thoſe
muſcles with a ſenſitive ſenſorium, or brain, exiſting in each individual
bud or flower. iſt. Becauſe many flowers cloſe from defect of ſti-
mulus, not by the exceſs of it, as by darkneſs, which is the abſence
of the ſtimulus of light; or by cold, which is the abſence of the
ſtimulus of heat. Now the defect of heat, like the abſence of
food, or of drink, affects our ſenſes with pain, which had been pre-
viouſly accuſtomed to a greater quantity of them, and a cutaneous
ſhivering may be excited in conſequence of the pain ; but a muſcle
cannot be ſaid to be ſtimulated into action by a defect of ſtimulus,
though ſome modern writers on medicine have called cold a ſtimulus
animal fibres, which it always renders torpid or inactive; a theory
5
derived
a
a

136
MUSCLES, NERVES, BRAIN. Sect. VIII. 4.
derived from Galen, and which muſt have originated in his total ig,
norance of chemiſtry and natural philoſophy.
In ſome flowers the males bend into contact with the females, as
in ciſtus, kalmia, fritillaria perfica, lithrum falicaria ; in others the
female bends to the males, as in collinſonia, glorioſa, geniſta, epilo-
bium; which ſhews a fenfibility to the paſſion of reproduction. In
irritation the ſtimulated muſcles only are brought into action, with-
out being perceived by the other parts of the ſyſtem ; but in ſenſation
the whole ſyſtem is affected by means of the brain or common ſenſo
rium, and thence very diſtant muſcles are brought into action to ac-
quire an agreeable object, or to repel or withdraw from a diſagreeable
one. See Zoonomia, Vol. I. Sect. XIII. 2.
4. That plants pofſeſs in ſome degree the power of volition would
appear firſt from the hedyſarum gyrans, which moves its leaves in
circular directions when the air is too ſtill. Secondly, from the
marchantia polymorpha, in which fome yellow wool advances from
the flower-bearing anthers, while it drops its duſt like atoms. Mur-
ray's Syſtem of Vegetables. Thirdly, from the tendrils of vines, and
the ſtems of other climbing vegetables, which continue to move
round, till they find ſomething to adhere to, or till they have rolled
themſelves up in a ſpiral line like a cork-ſcrew. And laſtly, from
the efforts of almoſt all plants to turn the upper furface of their leaves,
or their flowers, to the light.
But there is an indubitable proof of plants poffefſing ſome degree
of voluntarity, and that is deduced from their ſleep. In animal bodies
ſleep conſiſts in a ſuſpenſion or temporary abolition of voluntary
power ; the organs of ſenfe being at the ſame time cloſed, or by ſome
other means rendered unfit for the perception of external bodies. Now
the ſleep of plants is proved by the hanging down or cloſing of the
leaves of many plants, and of ſhutting the petals and calyxes of many
flowers in the dark, and their again opening or expanding them in
the light, or at certain hours of the day.
5. In

Sect. VIII.
137
5, 6.
MUSCLES, NERVES, BRAIN.
5. In reſpect to vegetables acquiring aſſociations of motion, or ha-
bits of action, the former is ſeen in the abſorptions and circulations of
their fluids, and in the various movements above deſcribed ; which
whirl their leaves or tendrils, and cloſe or open their corols and ca-
lyxes, which could not be performed without the ſynchronous and
aſſociated actions of many muſcles; as in the abſorptions and circu-
lations of animal bodies, and the movements of their limbs.
Other acquired habits of vegetable actions appear from the grains
and roots brought from more ſouthern latitudes, which germinate
here ſooner than thoſe which are brought from more northern ones,
owing to their acquired habits. Fordyce on Agriculture. And from
the apple trees ſent from hence to New York, which bloſſomed for a
few years too early for the climate, and bore no fruit; but after-
wards learnt to accommodate themſelves to their new ſituation. Tra-
vels in New York by Profeffor Kalm.
The diviſions of the leaves of the fenfitive plant have been accuf-
tomed to contract at the ſame time from the abſence of light; hence
if by any other circumſtance, as a flight ſtroke or injury, one divi-
fion is irritated into contraction ; the neighbouring ones contract alſo,
from their motions being aſſociated with thoſe of the irritated part.
So the various ſtamina of the barberry have been accuſtomed to con-
tract together in the evening; and thence, if you ſtimulate one of
them with a pin, according to the experiment of Dr. Smith, they all
contract from their acquired aſſociations,
6. This leads us to a curious inquiry, whether vegetables poſſeſs
any organs of ſenſe ? Certain it is, that they poſſeſs a ſenſe of heat
and cold, another of moiſture and dryneſs, and another of light and
darkneſs; for they cloſe their petals occaſionally from the preſence
of cold, moiſture, or darkneſs. And it has been already ſhewn, that
theſe actions cannot be performed ſimply from irritation, becauſe cold
and darkneſs are defective quantities of our uſual ſtimuli; and that
on that account ſenſation or volition are employed; and in conſe-
T
quence

138
MUSCLES, NERVES, BRAIN. Sect. VIII. 7,8.
a
a
quence a ſenſorium or union of the nerves muft exiſt. So when we
go into the light, we contract the iris, not from any ſtimulus of the
light on the fine muſcles of the iris, but from its motions being aſ-
ſociated with the ſenſation of too much light on the retina, which
could not take place without a ſenſorium or center of union of the
nerves of the iris with thoſe of viſion.
7. Beſides theſe organs of fenfe, which diſtinguiſh cold, moiſture,
and darkneſs, the leaves of mimoſa, and of dionæa, and of droſera,
and the ftamens of many flowers, as of the barberry, and of the nu-
merous claſs of fyngeneſia, are ſenſible to mechanic impact; that is,
they poffefs a ſenſe of touch; and as many of their diftant muſcles are
in conſequence excited into action, this alſo evinces, that they poſſeſs
a common ſenſorium, by which this ſenſation is communicated to the
whole, and volition occaſionally exerted.
8. Laſtly, in many flowers the anthers when mature approach the
ftigma, in others the female organ approaches to the male. I aſk,
By what means are the anthers in many flowers, and ſtigmas in other
flowers, directed to find their paramours ? Is this curious kind of
ſtorge produced by mechanic attraction, or by the ſenſation of love?
The latter opinion is ſupported by the ſtrongeſt analogy, becauſe a
reproduction of the ſpecies is the conſequence; and then another or-
gan
of ſenſe muſt be wanted to direct theſe vegetable amourettes
to find each other; one probably analagous to our ſenſe of ſmell,
which in the anirnal world directs the new-born infant to its ſource
of nouriſhment; and in fome animals directs the male to the female;
and they may thus poſſeſs a faculty of perceiving as well as of pro-
ducing odours.
A moſt curious example of the exiftence of ſome kind of fenſe,
which may direct the piſtils, or female parts of the flowers of col-
linfonia, which way to bend for the purpofe of finding the mature
males, is related in Botanic Garden, Vol. I. Canto IV. 1. 460, where
ſome of the piſtils miſtake the males, or ſtamens, of the neighbouring
flowers

Sect. VIII. 9.
139
MUSCLES, NERVES, BRAIN.
a
a
flowers for their own huſbands; and bending into contact with them
become guilty of adultery. See Sect. VII. 2. 2. of this work.
9. Thus, beſides a kind of taſte or appetency at the extremities of
their roots, ſimilar to that of the extremities of our lacteal veſſels, for
the purpoſe of ſelecting their proper food; and beſides different kinds
of irritability or appetency reſiding in the various glands, which fepa-
rate honey, wax, reſin, and other juices from their blood; vegetable
life ſeems to poſſeſs an organ of ſenſe to diſtinguiſh the variations of
heat, another to diſtinguiſh the varying degrees of moiſture, another
of light, another of touch, and probably another analogous to our ſenſe
of ſmell. To theſe muſt be added the indubitable evidence of their
paſſion of love, and of their neceſſity to ſleep; and I think we may
truly conclude, that they are furniſhed with a brain or common ſen-
ſorium belonging to each bud.
But whether this brain, or common ſenſorium, reſides in the me-
dulla, or pith, which occupies the central parts of every bud and leaf,
like the ſpinal marrow of animals, has not yet been certainly deter-
mined. By this medulla is meant only the pith of each individual
bud, not that which is ſeen in the center of a tree, which, like the
wood which ſurrounds it, has long ceaſed to have vegetable life.
The pith, or medulla of each bud, is ſuppoſed by its elaſticity to
puſh out the central part of the bud; as the veſicular productions on
the inſide of young quills are ſuppoſed to puſh forwards their early
growth, and in ſome birds are ſaid by Mr. Hunter to receive air from
the lungs. It is more probable that this pith, or medulla oblongata
of plants, ſupplies the ſpirit of vegetation, ſince it exiſts in all buds
in their moſt early ſtate, and does not communicate from one bud to
another, and thus diſtinguiſh them from each other, and evinces
their individuality. See Sect. I, 8, and IX. 2. 4.
T 2
PHYTO-

1
oto
situps

PHYTOLOGIA.
PART THE SECOND.
ECONOMY
OF
VEGETATION.
SECT. IX.
THE GROWTH OF SEEDS, BUDS, AND BULBS,
4. Seeds
1. 1. SEEDS reſemble eggs.
2. The embryon is of different maturity. The leaves
viſible in ſome feeds. 3. Wby the plumula aſcends and the root deſcends. Is nou-
riſhed by the feed-lobes, by the fruit. Becomes a dwarf if deprived of them.
Melons and cucumbers are too luxuriant. Turnep-ſeed ſhould be new.
have hard fbells, have acrid rinds with bitter or narcotic juices, but pure ſtarch tilay
be procured from them. 5. Umbilical veſſels, and roots of ſeeds. Annual, biennial,
and perennial plants. Reſervoirs of nutriment in their roots. All plants are bi-
ennials. Bulbs and buds ſucceed each other many times before they flower.
6. Wheat. Stems and roots round the firſt joint. Has no neetary. Is greatly
increaſed by tranſplanting. II. 1. Buds are a viviparous progeny. Protected by
ſcales and varniſh. Grow by piping with more heat and moiſture as they exhale leſs.
Are individual, annual, or biennial plants. 2. Buds of herbs. Evergreens have
no bleeding ſeaſon. 3. Buds of deciduous trees are in different ſtates of maturity,
as in hepatica, daphne, ofmunda. Some buds are inviſible. 4. Importance of the
pith like the Spinal me rrow; it lines hollow ſtalks. 5. Reſervoir of nutriment for
buds. Their umbilical veſſels. 6. A bud contains many embryons. The firſt
leaf-buds often deſtroyed by inſeats. The flower-buds only injured by them. 7. Vi-
gorous branches produce leaf-buds, weak ones flower-buds. Why ſeedling apples
are long before they bear. Why pears bear only at their extremities. 8. New
buds may be made either leaf-buds by lopping a part of the branch, or flower-
buds by bending the branch down, or cutting a ring in the bark, or ſtrangulating
I

142
SECT. IX. I.I.
SEEDS, BUDS, BULBS.
it with a wire. Debarked oaks pullulate. Sap-juice in the alburnum. 9.
A
pauſe in vegetation about midſummer. Trees then ſecrete nutriment in their roots
and fep-wood for the new buds. Are then beſt tranſplanted without lopping their
branches. 10. Caudexes of the buds form the bark, whoſe veſſels inofculate. Heart-
wood dies. Sap-wood acts as umbilical veſſels, and afterwards as capillary tubes,
or as capillary fyphons. 11. Flower-buds periſh without increaſing the bark by
new caudexes. Are convertible into leaf-buds. Vegetable monſters. 12. Central
part of an adult bud. III. 1. Bulbs. Leaf-bulbs precede flower-bulbs in
the tulip as leaf-buds in apple-trees, as joints in the ſtalk of wheat. Solitary ge-
neration of infeéts. 2. Bulbs of onions. Orchis. Tulip. Hyacinth. Ranun-
culus. Iris. 3. Roots of potatoes. Wires of ſtrawberries. Seeds of orchis.
Flowers of potatoes. 4. Stem-bulbs on magical onions are ſimilar to root-bulbs.
5. Root-grafting. Root-inoculation. Root-propagation. Suckers of trees. Root-
buds of herbaceous plants. Internal parts of which decay. 6. Tuberous roots of
turnep and carrot are reſervoirs of nutriment for the ſucceeding flower-ſtem. No
flower-bud is ever produced from a ſeed without previous leaf-buds. Why ſeedling
apple-trees are ten or twelve years before they bear fruit. Magazines of aliment
in almoſt all roots. 7. Uſe of the horſe-hoe to accumulate earth round the wheat-
plants. Wbeat dropped on the ſoil ſhoots up but one ſtem. Covered with the ſoil
it ſhoots up many. And tranſplanted deeper in the ſoil many more. Potatoes, vines,
and figs, produce lateral roots from their joints. So does the bark if wounded cir-
cularly. Uſe of eating down forward wheat with ſheep.
I. 1. Having treated of the phyſiology, we now ſtep forwards to
conſider the economy of vegetation, as far as it may ſerve the pur-
poſes of agriculture and gardening.
After the production of the feed, or vegetable egg in the pericarp
of flowers, and its enſuing impregnation by the farina of the anthers
ſhed upon the ſtigma, a coagulated point appears on the ſeed-lobes
according to the obſervations of Spallanzani, like the cicatricula on
the yolk of the egg.
The ſeed continues to grow in the pericarp ſuſtained by adapted
fecretions from the vegetable blood, which is previouſly oxygenated in
8
the

SECT. IX. 1. 2, 3.
143
SEEDS, BUDS, BULBS.
the bractes or floral-leaves of many plants; in others the feed is it-
ſelf incloſed in an air-veſſel probably for that purpoſe, as in ſtaphylea,
bladder nut, and tagetes, African marygold. At the ſame time a re-
ſervoir of nutriment is ſecreted, and depoſited in the feed-lobes or co-
tyledons, which are ſingle ones in the ſeeds of palms, graſſes, and
lilies; though twofold in thoſe of moſt other herbs and trees; whence
the ſtricteſt analogy exiſts between ſeeds and eggs.
2. In ſome feeds, when they leave the vegetable uterus, this em-
bryon is much more mature than in others. In the feeds of the
nymphæa nelumbo the leaves of the future plant were ſeen ſo dif-
tinctly by Mr. Ferber, that he found out by them to what plant the
ſeeds belonged. The ſame in the feeds of the tulip-tree, lirioden-
dron tulipiferum. Amæn. Acad. V. VI. No. 120. And Mr. Baker
aſſerts, that on diffecting a ſeed of trembling graſs, he diſcovered by
the microſcope a perfect plant with roots fending forth two branches,
from each of which ſeveral leaves or blades of graſs proceeded. Mi-
croſc. Vol. I. p. 252. While in other feeds the corculum, or heart
only of the feed, is diſtinctly viſible, as in the kernel of the walnut,
and the feed of the garden-bean. So in the animal kingdom the young
of ſome birds are much more mature at their birth than thoſe of others.
The chickens of pheaſants, quails, and partridges, can uſe their eyes,
run after their mothers, and peck their food, almoſt as ſoon as they
leave their ſhell; but thoſe of the linnet, thruſh, and blackbird, con-
tinue many days totally blind, and can only open their callow mouths
for the offered morſel.
3. When the feed falls naturally upon the earth, or is buried arti-
ficially in ſhallow trenches beneath the ſoil, the firſt three things ne-
ceffary to its growth are heat, water, and air. Heat is the general
cauſe of Auidity, without which no motion can exiſt; water is the
menſtruum, in which the nutriment of vegetable and animal bodies
is conveyed to their various organs; and the oxygen of the atmo-
ſphere is believed to afford the principle of excitability fo perpetually
neceſſary

144
SECT. IX. 1. 3.
SEEDS, BUDS, BULBS.
neceſſary to all organic life; and which renders the living fibres both
of the vegetable and animal world obedient to the ſtimuli, which are
naturally applied to them.
Whence we may in ſome meaſure comprehend a difficult queſ-
tion; why the plume of a ſeed fowed upon, or in the earth, ſhould
aſcend, and the root deſcend, which has been aſcribed to a myſterious
inſtinct; the plumula is ſtimulated by the air into action, and elon-
gates itſelf, where it is thus moſt excited ; and the radicle is ftimu-
lated by moiſture, and elongates itſelf thus, where it is moſt excited,
whence one of them grows upwards in queſt of its adapted object,
and the other downward.
The firſt ſource of nutriment ſupplied to the ſeminal embryon, af-
ter it falls from the parent plant, exiſts in the ſeed-lobes, or cotyle-
dons, which either remain beneath the earth, and are permeated by
the umbilical veſſels of the embryon plant, which abſorb the muci-
laginous, farinaceous, or oily matter depoſited in them, as in the bean,
piſum; or the ſeed-lobes riſe up into the air along with the young
plant, as in the kidney-bean, phaſeolus, become ſeed-leaves, and ſerve
both as a nutritive and reſpiratory organ. Theſe cotyledons or ſeed-
lobes generally contain mucilage, as in quince-feed; or ſtarch, as in
wheat, or oil, as in line-feed. Some of theſe nutritive materials
are probably abſorbed unchanged, or diſſolved only by the moiſture
of the earth; others are converted into ſugar partly by a chemical
proceſs, and partly by the digeſtive powers of the young plant, as ap-
pears in the proceſs of germinating barley, and converting it into
malt; theſe reſervoirs of nutriment are hence perfectly analogous to
the white of the egg, a part of which is probably abſorbed unchanged
by the lymphatics of the young embryon, and a part of it converted
into a ſweet chyle for the nouriſhment of the chick, when it has
acquired a ftomach.
If the ſeed be deprived of theſe cotyledons, ſoon after the root ap-
pears, it will continue to grow, but with leſs vigour, and is ſaid to
duce
a
pro-

Sect. IX. 1. 3. SEEDS, BUDS, BULBS.
145
a
duce a dwarf plant from three to nine times lefs than the parent.
Hence the feeds of plants, which are liable to produce too vigorous
roots, and thence have not time to ripen their fruits in the ſhort fum-
mers of this climate, or which fill our hot-beds with too luxuriant fo-
liage, as melons, and cucumbers, ſhould in this climate be kept three
or four years; by which part of the mucilaginous, or farinaceous, or
oily matter of the cotyledons becomes injured or decayed, and the new
plant grows leſs luxuriantly.
Another ſource of nutriment for the ſeminal embryon of many
plants exiſts in the fruit, which envelopes the ſtone or feed-vefſel,
after the growing fetus has burſt its confinement, and ſo far re-
ſembles the yolk of the egg, which becomes a nutriment to the chick,
after it has conſumed the white, and eloped from its ſhell.
When mature fruit, as an apple or a cucumber, falls upon the
ground, it ſupplies, as it ripenis or decays, a ſecond ſource of nou-
riſhment, which enables the incloſed feeds to ſhoot their roots into
the earth, and to elevate their ſtems with greater vigour. Hence
fruits generally contain a faccharine matter, or juices capable of be-
ing converted into fugar, either by a ſpontaneous chemical proceſs, as
in baking four apples; or by a vegetable proceſs, as in thoſe four
pears, which continue to ripen for many months both before and af-
ter they are plucked from the tree, as long as life remains in them;
that is, till they ferment or putrify; and laſtly, by the digeſtive
power of the young embryon, as above mentioned.
If the feed be deprived of the fruit, it will indeed vegetate, but
with leſs vigour. Hence thoſe ſeeds which are liable to produce too
vigorous ſhoots for this climate, as the ſeeds of melons and cucum-
bers, ſhould be waſhed clean from their pulp, before they are hoard-
ed, and preſerved three or four years before they are ſown in hot
beds. But thoſe ſeeds, which are fown late in the ſeaſon for the pure
poſe of producing winter fodder, as the ſeeds of turneps, ſhould be
collected and preſerved with every poſſible advantage; and on this
U
account

146
SECT. IX. 1. 4,50
SEEDS, BUDS, BULBS.
account new feed is much to be preferred to that which has been
long kept.
4. Many ſeeds when mature are diſperſed far from the parent tree,
for the purpoſe of their growth, by various contrivances, as men-
tioned in Sect. VII. 2. 5. Some of theſe are ſurrounded with hard
ſhells, which are impenetrable by inſects, as they lie on the earth to
take root, as peaches, nectarines, nuts, cocoa-nuts. Other feeds are
furniſhed with an acrid covering to prevent the depredation of inſects,
as the peel of oranges and lemons, the outward hulk and inward rind
of walnuts, and of caſhew-nuts, and the ſkin of muſtard-feed, and
rape-feed; other ſeeds for the ſame purpoſe abound with bitter or
narcotic juices, as the horſe-cheſnut, acorn, apricot, cherry, many of
which ſupply materials to the ſhops of medicine, and may ſupply nu-
triment in times of ſcarcity; as the ſtarch, which they contain, may
be procured by grating them into cold water, and waſhing away the
mucilage, and the poiſonous material, which adheres to it, or which
is ſoluble in water.
5. The plumula of the feed, or embryon plant, abſorbs the nutri-
ment laid up for it in the ſeed-lobes by vefſels, which permeate them
for that purpoſe, and have been termed umbilical veſſels; and after-
wards ſhoots its roots down into the fruit, or into the earth, in ſearch
of other nouriſhment; and expands its leaves in the air as an organ of
;
refpiration.
Thoſe plants, which are uſually termed annuals, produce their
flowers and die in the ſame year in which their ſeeds are fown; as
barley, oats, and a variety of garden flowers. Theſe nevertheleſs in
accurate language ſhould be termed biennials, becauſe the ſeed in
this climate is produced in one ſummer ; and the embryon plant be-
comes mature in the next; as the feed is generally preſerved in our
granaries, or ſeed-boxes, and not committed to the ground till the en-
ſuing ſpring; for many of theſe vegetables are not natives of this
climate,
ފް

SECT. IX. 1. 5.
147
SEEDS, BUDS, BULBS.
climate, and would periſh if the ſeeds were ſown in autumn, when
it is naturally ſcattered on the earth.
Thoſe which are uſually termed biennial plants, differ from the
former, firſt in the time of ſowing the ſeed, which is generally in the
early autumn, as ſoon as it is ripe, as of turneps, carrots, wheat;
and thus theſe produce their flowers in the ſecond year after the feed
is ſown, which has given them the name of biennials. Many of theſe
plants, perhaps all of them, lay up a reſervoir of nutritious matter
during the ſummer or autumn in their roots. This nutriment is
fecreted from the vegetable blood, which is previouſly oxygenated
for that purpoſe in the large leaves, which generally ſurround the
caudex of the plant, as in turneps and carrots. Theſe leaves ſurvive
the winter in many plants, which the more ſucculent ſtems probably
would not; and the nutriment depoſited in the root is expended in
the growth of the ſtem and the production of feed in the enſuing
ſpring. As in theſe vegetables one of our ſummers is too ſhort for
their growth from the ſeed to the fructification; and it is for this
reſervoir of nutriment that theſe plants are generally cultivated.
But thoſe plants, which are termed perennial, when firſt raiſed
from ſeed, are many of them fome years before they produce flowers.
Some of them form bulbous roots, as the tulip, hyacinth, onion,
which are three or four years before they flower, during which time
I believe all the bulbs die annually, producing one larger than that of
the preceding year, and perhaps ſome ſmaller ones, all which an-
nually increaſe in ſize till they flower. The ſame occurs in potatoe-
roots raiſed from ſeed, which do not flower as I am informed till the
third year, and then only thoſe which ſeemed of ſtronger or for-
warder growth.
Other perennial plants have palmated or branching roots; in ſome
of theſe, as in ſeedling apple-trees, the flower is ſaid not to appear till
ten or twelve years after the feed is ſown; the buds nevertheleſs
annually dying and producing other buds over them, perhaps more
perfect
U 2

148
SECT.IX. 1.5.
SEEDS, BUDS, BULBS.
a
perfect ones, as they acquire after a few years the power of produc-
ing ſexual organs, and in conſequence a feminal progeny. In theſe
perennial herbaceous plants and trees a magazine of nutriment is pro-
vided in their roots or fap-wood, to ſupply the new buds, which are
to grow in the enſuing ſpring.
Whence it appears, that all the vegetables of this climate may be
termed biennial plants; as the ſeeds of ſome, and the buds or bulbs
of others, are produced in one fummer, and flouriſh and die in the
next; thoſe which are called annuals or biennials leaving behind them
a future progeny of ſeeds only; thoſe, which are termed perennial
herbaceous plants, leaving behind them the firſt year or two a pro-
,
geny of bulbs or root-buds only, and afterwards a progeny of ſeeds
alſo; while the perennial arboreſcent vegetables leave behind them a
progeny of buds only for ſeveral ſucceſſive years, and afterwards a
progeny of both buds and feeds.
Thus the bulb from a tulip-feed produces a more perfect bulb an-
nually, till it flowers, I believe, on the fifth year. It then produces
a flower, and alſo one perfect bulb, which flowers the next year ;
and ſome other lefs perfect bulbs, which are ſucceeded by more perfect
ones annually, till they alſo flower. Whence I conclude, that no
tulip bulb flowers till the fourth or fifth generation.
It is probable, that a ſimilar circumſtance occurs in other vegeta-
bles, as in apple-trees; and that the buds of theſe do not produce
ſexual organs, and a conſequent ſeminal progeny, till the twelfth or
fourteenth generation of the bud from the feed; each of thoſe buds
nevertheleſs producing one principal bud annually more perfect than
itſelf, and many lateral buds leſs perfect than itſelf; that is, at a greater
diſtance from that ſtate of maturity which enables it to form a flower.
This art of diſtinguiſhing the greater or leſs maturity of buds is a
matter of great importance in the management of fruit-trees, as in
many of them the central bud becomes a ſpur one year, and flowers
the
a

SECT. IX. 1. 6.
149
SEEDS, BUDS, BULBS.
a
a
the next; and the lateral buds one or two years afterwards, as will
be mentioned in Sect. XV. on the production of fruit.
6. In wheat there exiſts about the caudex a reſervoir of nutritious
juices depoſited in the autumn for the purpoſe of raiſing the ſtem
in the enſuing ſpring like that of turneps and carrots ; but which
is attended with other circumſtances peculiar I ſuppoſe to the graſſes,
and other plants, which poſſeſs only one cotyledon or feed-lobe. The
early leaf, which ſurrounds the firſt joint of the ſtem, withers, as the
ſpring advances; in which joint it had previouſly depoſited a faccha-
rine juice, and probably ſome new embryon buds were at the ſame
time generated in the caudex; for through this withered leaf, which
ſurrounds the firſt joint of the ſtem within the earth, a circular ſet
of new ſtems iſſue adhering to it, and a circle of roots below them ad-
hering to the caudex or baſe of it. Theſe new buds riſe into air, and
ſhoot their roots into the earth; and in this manner many ſtems are
produced in the ſpring from one ſeed fowed in the autumn preced-
ing; though in ſome kinds of wheat the whole proceſs of the ſeed
riſing from earth, and producing other ſtems round the principal one,
and of ripening its feeds, may be performed in one ſummer even in
this northern climate.
Another peculiarity attends the growth of wheat and other graſſes;
the leaf, which ſurrounds and ſtrengthens the ſtem by its foot-ſtalk,
depoſits at every lower joint a faccharine matter for the purpoſe of
nouriſhing the aſcending part of the young ſtem; and in the upper-
moſt joint, I ſuppoſe, - to ſerve inſtead of honey for the ſtamens and
ſtigmas, as their flowers have no viſible nectary; and as the ſcales
of the flower may with good reaſon be eſteemed a calyx rather than
a corol, according to the opinion of Mr. Milne; as theſe ſcales attend
the feed-veſſel to its maturity, which the corol does not. Milne's Bo-
tanical Dict. Art. Gramina.
Owing to this ſecretion of faccharine matter at the foot-ſtalk of
every leaf, and its collection round the joints of graffes, it happens
that
$

150
SECT. IX. 2. I.
SEEDS, BUDS, BULBS.
that when theſe joints are ſurrounded with moiſt earth, and are plac-
ed but a certain depth from the air, that new buds will put forth
round theſe joints, and ſtrike their roots into the ſoil. Whence the
agrarian huſbandman may derive great advantage from tranſplanting
his wheat, after it has produced a circle of new ſtems from the firſt
joint of the ſtraw; for if he then parts and replants them an inch or
two deeper in the ground, ſo as to cover the firſt joint of each of
theſe additional ſtems, he may multiply every one of them four or
ſix times, and thus obtain twenty or thirty ſtems from one original
ſeed. See No. III. 1. and 7. of this ſection.
II. 1. Other vegetable embryons are produced in the buds on the
ſtems or branches of trees, which may be termed the viviparous pro-
geny of plants, in contradiſtinction to thoſe from ſeeds, which
may
be termed their oviparous progeny. Theſe buds are either leaf-buds
or flower-buds, or both in one covering; the bud is termed hyber-
naculum, or winter-cradle, of the embryon ſhoot, and is covered with
ſcales, and often with a reſinous varniſh, as in tacamahacca, to pro-
tect it from the cold and moiſture of the enſuing winter, and from
the depredation of inſects.
Theſe by inoculation or ingrafting on other ſtems of trees, or by
being planted in the earth, become plants exactly ſimilar to their pa-
rents. A ſmall glaſs inverted over theſe buds, when ſet in the
earth, contributes to inſure their growth by preventing too great an
exhalation ; otherwiſe they are liable to perfpire more than they can
abſorb, before they have acquired roots; this the gardeners call pip-
ing a ſlip, or a cutting, of a plant. In this ſituation a greater heat
may be given them, as in hothouſes, without increaſing their quan-
tity of perſpiration, which ceaſes as ſoon as the air in the glaſs is fa-
turated with moiſture; and the increaſe of heat much contributes to
the protruſion of their roots and new buds, as they can at the ſame
time bear to be ſupplied with a greater quantity of moiſture.
Every bud of moſt of the deciduous trees of this climate may there-
a
;
8
fore

SECT. IX. 2. 2. SEEDS, BUDS, BULBS.
151
a
fore be conſidered as an individual biennial plant, as diſtinctly ſo as a
feed; that is, the bud like a feed is formed in one ſummer, grows to
maturity in the next, and then dies. In ſome trees nevertheleſs of
this climate, as the mock orange, philadelphus, acacia, viburnum;
and in the evergreen ſhrubs or trees, as holly, laurel, vinca, heath,
and rue; and in all thoſe herbs commonly called annuals; and in moſt
of the trees of warmer climates; the buds appear to be formed in
the vernal months, and to arrive at their maturity during the ſame
year; and may therefore properly be called annual plants.
2. The bud of theſe herbs, which are commonly called annuals,
riſes in the boſom of a leaf; and, as it adheres to its parent, requires
no female apparatus to nouriſh it, but gradually ſtrikes down roots
from its caudex into the ground, which caudex forms a part of the
bark of the increaſing plant. This occurs in thoſe herbaceous vege-
tables, which have juſt riſen from feeds; the buds of which are pro-
perly individual annual plants, which grow to maturity adhering to
the parent, and do not therefore reſemble a ſeed or egg, as there is
no reſervoir of nutriment laid up for them.
This circumſtance alſo happens, I ſuppoſe, to the evergreen ſhrubs
I
and trees of this climate, as to heath, rue, box, pine, laurel; for in
theſe vegetables, as the leaf does not die in the autumn, it continues
to oxygenate the blood, and to ſupply nouriſhment to the bud in its
bofom during the fine days of winter, and in the ſpring, and ſurvives
till near midſummer; that is, till the new bud has expanded a leaf of
its own. Whence I ſuppofe theſe evergreens lay up in ſummer no
ſtore of nutriment in their roots or alburnum for the ſuſtenance of
their enſuing vernal buds; and have thence probably no bleeding ſea-
;
ſon like deciduous trees.
But the embryon in a bud of a deciduous plant leaves in the ſpring
of the year its winter cradle, or hybernaculum, like the embryon ia
a ſeed, or a chick in the egg; and like theſe the young plants of
different vegetables have previouſly arrived at different ſtates of matu-
sity.
a
a

152
SECT. IX. 2. 2.
SEEDS, BUDS, BULBS.
rity. Thus Mr. Ferber aſſerts, that he was delighted in obſerving
in the buds of hepatica, and pedicularis hirſuta, yet lying in the earth,
and in the gems of the ſhrub daphne mezereon, and at the baſe of
oſmunda lunaria, a perfect plant of the future year diſcernible in all
its parts; thus alſo in horſe-cheſnut the leaves, and in cornel-tree the
flowers, are each diſtinctly viſible during the winter in their reſpec-
tive buds. Amen. Acad. Vol. VI. No. CXX. Milne's Dict. Art.
Gemma.
While in buds of many other trees, and probably in all the more
backward buds, which are formed late in the ſummer on the lower
parts of branches, and much deprived of light and air, the embryon
is not ſo forward as to be eaſily diſcernible; and in thoſe ſhrubs or
trees, which are deciduous in this climate, and yet have no apparent
buds in winter, as the philadelphus, mock orange, viburnum, and
many ſhrubs. I ſuſpect there is nevertheleſs an embryon ſecreted from
the blood at the foot-ſtalk of each leaf, though it is not ſo forward
as to protrude through the bark, and produce a prominent bud, or
hybernaculum. The ſame I ſuſpect to occur in reſpect to trees,
which loſe their leaves in winter, in warmer climates, in which
they are ſaid not to produce autumnal buds; as I can not conceive
by what means freſh leaf-buds can be generated in the ſpring, when
the leaves, which conſtitute the lungs of the mature living part of the
tree, are dead; and the whole of that mature living part, or laſt year's
bud, confequently dead along with them. But if the caudex of the
new bud be generated without the plumula, or viſible bud, it can cer-
tainly produce a plumula for itſelf in the enſuing ſpring, as is ſeen
by the production of new buds, when a branch is cut off, round the
remaining trunk, as is done frequently to the ſtems of willows.
In ſimilar manner the viviparous offspring of different animals arrive
at different ſtates of perfection before they are born, as calves and
foals can ſtand erect in an hour, and quickly learn to uſe their eyes,
and to run after their mothers; while the blind puppy, and kitten,
a
7
and

Sect. IX. 2. 4.
153
SEEDS, BUDS, BULBS.
a
a
3
and the downleſs rabbit, are long before they can leave the neſt which
the parent has provided for them.
4. The preſence of the pith or medulla is of great importance to
the growth of the new bud, as may be obſerved by gradually ſlicing
oot of a horſe-cheſnut in autumn, or in the early ſpring. The
rudiments of the ſeven ſeparate ribs of the late parent-leaf, and the
central pith of the bud in its boſom, are ſeen to ariſe or terminate
near the pith of the parent ſhoot, where the embryon plumula is
probably ſecreted by a gland at the bottom of the parent leaf-ſtalk,
finds there its firſt reception and nouriſhment, and is gradually pro-
truded and elongated by the pith, which exiſts in its center, as the
bud proceeds, and thus conſtitutes the aſcending caudex or uterus of
the new bud; which is reſembled by the wires of ſtrawberries, and
other creeping vegetables; whereas the deſcending caudexes of the
new buds, which form the filaments of the bark of trees, are ſecreted
from the various parts of the old bark in their vicinity; all which
probably occur at the ſame time by ſympathy, as ſhewn in Sect. VII.
The pith thus appears to be the firſt or moſt effential rudiment of
the new plant, like the brain or ſpinal marrow, medulla oblongata,
which is the firſt viſible part of the figure, I believe, of every animal
fetus, from the tadpole to mankind.
In thoſe plants which have hollow ſtems, this central cavity, though
not filled with the pith or medulla, appears to be lined with it; as in
picris and tragopogon ; in the former the ſtem is not only lined with
the pith, but wherever a new bud is generated on the ſummit of the
aſcending ſtem, or in the bofom of a leaf, a membranous diaphragm
divides the cavity, and is covered with this medullary ſubſtance,
which diviſion thus diſtinguiſhes one bud from another; and in flicing
away the part of the ſtem of tragopogon, where the new lateral bud
adheres, the medulla or pith in the center of the bud is ſeen to com
mence near that membrane which lines the ſtem, and to paſs through
the circle of arterial, venal, and abſorbent vefſels, which conſtitute
X
the

154
SECT. IX. 2. 5.
SEEDS, BUDS, BULBS.
66
the aſcending caudex, or uterus, of the new bud, while the deſcend-
ing caudex of it is ſecreted from the various parts of the older bark
in its vicinity.
Something ſimilar to this mode of the production of the buds of
trees had not eſcaped the ingenious Mr. Bradley, who aſſerts," that
buds have their firſt riſe in the pith ; they are there framed, and
furniſhed with every part of vegetation, and forced forwards to meet
the air through the tender bark, and would drop on the ground, if
they were not reſtrained by veſſels, which ſerve as roots to nouriſh
them; and thus as a feed takes root in the earth, a bud takes root in
the tree; but with this difference, that the feed has lobes to ſupply
it with nouriſhment, till it can ſelect juices from the earth ; but the
bud has no occaſion for lobes, becauſe it takes root immediately in the
body of the tree, where the proper juices are already prepared for it."
Diſcourſes on Growth of Plants, 1727, p. 56.
5. As the ſeed was nouriſhed in the pericarp by an adapted ſecre-
tion from the vegetable blood oxygenated in the bractes or floral-
leaves; and as a reſervoir of nutriment was alſo prepared for it after-
wards in the feed-lobes and fruit : fo the bud is at firſt nouriſhed in
the boſom of its parent-leaf by an adapted ſecretion from the vege-
table blood; and continues to be ſo nouriſhed in annual herbs and
evergreen trees, till it protrudes and expands its own leaf; but if it
be a bud of a deciduous plant, which muſt loſe its parent-leaf in
winter, a reſervoir of nutriment is prepared for it in the roots of
ſome plants, as in carrots, tnrneps, liquorice, fern ; and probably
both in the roots and alburnum, or fap-wood, of trees.
Thus in the ſpring the umbilical veſſels belonging to each indivi-
dual biennial plant, or bud of a tree, abſorb moiſture from the earth,
and propel it upwards through the roots and alburnum, where it is
mixed with a nutritious material, and carried upwards in ſome trees
with a power equal to the preſſure of the atmoſphere, as in the vine,
vitis;

Sect. IX. 2. 6.
155
SEEDS, BUDS, BULBS.
a
vitis; the birch, betula ; and the maple, acer; which at that ſeaſon
bleed at every wound, as treated of in Sect. III.
6. At this time the buds begin to ſwell, and to ſhoot roots down-
wards from their caudexes into the earth; the intertexture of theſe
caudexes conſtitutes a new bark over the old one, conſiſting of arte-
ries, veins, and abſorbents, as deſcribed in Sect. I. 3. Each bud then
alſo puts forth a leaf, which is a reſpiratory organ, and reſembles in
many reſpects the lungs of animals, as deſcribed in Sect. IV. but dif-
férs from them in this circumſtance, that the leaf requires light as
well as air for the purpoſe of perfect reſpiration, as will be treated of
in the Section on Light.
Each embryon of a leaf-bud is thus furniſhed with its proper rer-
piratory organ; and as many new embryons were generated during
the ſummer in each leaf-bud, they now pullulate in ſucceſſion ; each
of which has like the firſt its appropriate leaf, which, as they ſuc-
ceſſively advance, compoſe the annual ſhoots or ſprigs of trees; which
in ſome plants become of great length, as in vines, and willows, con-
ſiſting of twenty or thirty new leaves. Hence if the firſt ſet of
leaves be deſtroyed by vernal froſts, as frequently happens to aſh-
trees, fraxinus, and to the weeping willow, ſalix babylonica ; or by
the depredation of inſects, which often injures our fruit-trees; and
perpetually occurs in this climate to the ſpindle-tree, euonymus; and
in Italy to the white mulberry-tree, which has its firſt leaves plucked
off for the food of filk-worms, and to the tea-tree in China ; a ſecond
ſet of leaves ſucceeds, which belong to the ſecond embryons of the
ſame bud,
But when the bractes or floral-leaves are deſtroyed by inſects, as
ſometimes happens to currant-trees, and apple-trees; the fruit in the
pericap does not periſh, like the firſt embryon of the leaf-bud above
mentioned; becauſe it is ſtill ſupplied by the abſorbent ſyſtem of the
caudex and roots of the flower-bud, which compoſe a part of the bark,
and paſs into the ground; but the fruit becomes ſour and leſs per-
X 2
fect
;
n
a

156
SECT. IX. 2. 7.
SEEDS, BUDS, BULBS.
a
fect from the want of a due oxygenation of the juices, from which
it is ſecreted; though its glands may probably alſo receive fome
oxygenated blood by the inofculation of the veſſels of different buds,
whether flower-buds or leaf-buds, with each other in the bark, on
fuppoſition that they are not all of them totally deſtroyed.
7. In the axilla of each leaf is generally produced about midſum-
mer either a new leaf-bud or a flower-bud; if it be a leaf-bud, it
becomes a branch the next year, producing many other leaves, and
many other buds; if it be a flower-bud, the growth ceaſes, termi-
nating in the feed. During the greater vigour of the plant the leaf-
buds are ſolely or principally produced, as in young healthy trees;
but when the veſſels of the bark become further elongated, as the
plant grows taller, the nutritive juices are leſs copiouſly ſupplied, or
the buds are become more mature, and the production of flower-buds
ſucceeds as in Mr.Walker's experiments the ſap of the birch-tree in
the ſpring was two or three weeks later in aſcending to the top of a
high tree, than to the lower branches. Edinb. Tranſact. Vol. I.
Hence it happens, that the grafts from ſtrong ſeedling apple-trees
do not bear fruit, till they are twelve or twenty years old ; while the
grafts from old weak trees will bear copiouſly in two or three years,
and hence very vigorous trees, as pears, produce fruit only at their
extremities; but if you decorticate about an inch of a branch of a vi-
gorous pear-tree, and thus weaken it ; that branch will flower, and
bear fruit at every bud like trees of leſs vigour.
It ſhould be here obſerved, that the words ſtrength and weakneſs,
when applied to the growth of vegetables, are in reality metaphorical
terms; or expreſs the effect or confequence of their producing leaf-
buds or flower-buds, rather than the cauſe of it, whereas it is the fa-
cility with which the long caudexes of the new buds, which form
the new filaments of bark, can be generated, which increaſes the
number of leaf-buds, and gives the tree a luxuriant or vigorous ap-
pearance; and the difficulty of generating theſe new caudexes which
increaſes
a
a

SECT. IX. 2. 8. SEEDS, BUDS, BULBS.
157
a
1
increaſes the flower-buds, and thus gives a leſs vigorous appearance
to the tree.
The generation of buds ſeems to require a leſs perfect apparatus
than the generation of ſeeds; as that of buds always precedes that of
ſeeds, both in trees and herbs ; and becauſe the caterpillar is convert-
ed into a butterfly ſolely for the purpoſe of feminal propagation ;
whereas the polypus can only propagate laterally, or by buds. Hence
the age of the plant is another neceſſary circumſtance to the produc-
tion of flowers, fruit, and feeds, as appears in tulips, and hyacinths,
as well as in apple-trees and pear-trees.
8. About midſummer the new buds are formed; but it is believed
by ſome of the Linnean ſchool, that theſe buds may in their early
ftate be either converted into flower-buds or leaf-buds, according to
the vigour of the vegetating branch. Thus if the upper part of a
branch be cut away, the buds near the extremity of the remaining
ſtem, having a greater proportional ſupply of nutriment, and poſſeff-
ing a greater facility of producing their new caudexes along the bark,
will become leaf-buds; which might otherwiſe have been flower-
buds; and on the contrary, if a vigorous branch of a wall-tree,
which was expected to bear only leaf-buds, be bent down to the ho-
rizon or lower, it will bear flower-buds with weaker leaf-buds, as is
much exemplified by Mr. Hitt in his Treatiſe on Fruit Trees.
The theory of this curious vegetable fact has been eſteemed diffi-
cult, but receives great light from the foregoing account of the indi-
viduality of buds. Both the flower-buds and leaf-buds die in the au-
tumn; but the leaf- buds, as they advance, produce during the ſum-
mer other leaf-buds or flower-buds in the axilla of every leaf; which
new buds require new caudexes extending down the bark, and thus
thicken as well as elongate the branch; whereas the flower-buds
Thed their ſeed, when they periſh in the autumn, and thus require
no place on the bark for new caudexes. Hence when the ſummit of
a branch is lopped off, the buds near the extremity of the remaining
ftem
I

158
Sect. IX. 2. 8.
SEEDS, BUDS, BULBS.
C
a
ſtem produce new leaf-buds with greater facility, as there is more
room for their new caudexes to be generated along the deſcending
bark. But if a vigorous branch be bent down to the horizon, or be-
low it, the bark is compreſſed beneath the curve, and extended above
it, and thus the production of new caudexes along the bark is im-
peded, and in conſequence leſs leaf-buds and more flower-buds will
be generated, or the former converted into the latter ; which require
no new caudexes. And on this circumſtance principally depends the
management of wall-fruit trees, and of eſpalliers.
For the purpoſe of thus converting leaf-buds into flower-buds Mr.
Whitmill adviſed to bind ſome of the moſt vigorous ſhoots with ſtrong
wire, and even ſome of the large roots; and Mr.Warner cuts, what
he calls, a wild-worm about the body of the tree; or ſcores the bark
quite to the wood like a ſcrew with a ſharp knife. Bradley on Gar-
dening, Vol. II. p. 155. Mr. Fitzgerald produced flowers and fruit
on ſtandards and wall-trees by cutting off a cylinder of the bark, three
or four inches long, and replacing it with proper bandage, (Philof.
Tranf. Ann. 1761) as deſcribed in Sect. XV. 1. 3. of this work.
M. Buffon produced the ſame effect by a ſtraight bandage put round
a branch, Aet Paris, Ann. 1738; and concludes that an ingrafted
branch bears better from its veſſels being compreſſed by the callus pro-
duced, where the grafted fcion joins the ſtock.
It is cuſtomary to debark oak-trees in the ſpring, which are in-
tended to be felled in the enſuing autumn; becauſe the bark comes
off eaſier at this ſeaſon, and the ſap-wood, or alburnum, is believed
to become more durable, if the trees remain till the end of ſummer
from their expending their faccharine fap-juice in the enſuing fo-
liage, and thus being leſs liable to ferment and putrify. The trees
thus ſtripped of their bark put forth ſhoots as uſual with acorns on,
the fixth, ſeventh, and eighth joint, like vines ; but in the branches
I examined the joints of the debarked trees were much ſhorter than
thoſe of other oak-trees; the acorns were more numerous; and no
new

SECT. IX. 2.9.
159.
SEEDS, BUDS, BULBS.
a
new buds were produced above the joints which bore acorns. From
hence it appears that the branches of debarked oak-trees produce
fewer leaf-buds, and more flower-buds; which muſt be owing to
the impoſſibility of their producing new caudexes down the naked
branches and ſtem for the embryon progeny of leaf-buds.
The pullulation of leaves on debarked oaks demonſtrates, that the
reſervoirs of nutriment depoſited in the preceding ſummer for the uſe
of the vernal buds muſt be in this alburnum; and that it is this fac-
charine matter which induces the alburnum to ferment and rot ſooner
than the internal wood. Thus Dr.Walker found on nice inſpection
the ſap-juice to flow from the ligneous circles of the alburnum as
well as between them, when a freſh piece was cut off from a cica-
trized part, and alſo between the wood and the bark. Edinb.
Tranſact. Vol. I. He alſo obſerved that oak, aſh, elm, aſpen, hazel,
and hawthorn, do not bleed; and that the birch, plane, and maple
bleed the moſt, and that the grey willow, falix caprea, does not
bleed, but the fap-juice riſes viſibly between the wood and the bark,
ſo as to make the bark ſeparate eaſily from the wood. From all
theſe facts it may be inferred, that the ſaccharine matter, which is
diſſolved in the fap-juice, is depoſited in the autumn in the roots of
ſome trees, and in the alburnum of others, or in both; as manna is
found in the wood of the manna-aſh; and ſugar in the joints of many
graſſes and of the ſugar-cane, and in the roots of liquorice, beets, and
many other herbaceous vegetables.
9. About Midſummer, after the new buds appear in the boſom of
every leaf, many authors have remarked that there ſeems to be a kind
of pauſe in vegetation for about a fortnight, which they have aſcrib-
ed to different cauſes. At this time I ſuſpect the reſervoir of nou-
riſhment for the new buds is forming about the roots or in the albur-
num of the tree; and that the caudexes and umbilical veſſels of the
new buds are alſo at this time forming down the bark, and terminate
in thoſe nutritious reſervoirs in the roots or new alburnum like the
umbilical
a

160
Sect. IX. 2.9.
SEEDS, BUDS, BULBS.
umbilical veſſels called feminal roots, which are viſible in many
feeds.
That this ſyſtem of umbilical veſſels is poffefſed of a great power
of abſorption in the roots of trees is certain from the force, with which
the fap-juice was propelled upward from a vine-ſtump in Dr. Hales'
experiment. That the fap-juice thus propelled upwards nouriſhes or
expands the leaf of each new bud appears from the experiments of
Dr.Walker ; as the leaves began to unfold at the ſame height, as the
wounded wood began to bleed, and that theſe veſſels paſs through or
conſtitute the fap-wood is evinced by the growth of the buds on oak-
trees, after the bark is almoſt totally taken off.
The roots of trees are at this time protruded with greater vigour, as
obſerved by the ingenious Mr. Bradley, who on that account prefers
the midſummer ſeaſon for tranſplanting trees, if they are not to be
removed to any great diſtance; and adds, that the new ſhoots in the
following ſpring will put forth with much greater force, and the tree
will thence be almoſt a year forwarder in its growth, than if it re-
mains untranſplanted till the winter. Diſcourſes on Earth and Wa-
ter. This ſeems to be owing to the deſtruction of much of the nu-
tritious matter depoſited in the roots for the uſe of the new buds,
which is torn off in tranſplanting, and which can only be replaced
about Midſummer or foon after.
Mr. Bradley further adds, that when trees are thus tranſplanted
at Midſummer, no part of the top or branches, or foliage, ſhould at
that time be cut off; which well accords with the theory above de-
livered; as it is from the vegetable blood, which is oxygenated by
its expoſure to the air through the thin moiſt pellicle on the upper
ſmooth ſurfaces of theſe leaves, that the nutriment for the expan-
fion of the buds in the fucceeding ſpring is ſecreted or produced; and
hence if theſe leaves are prematurely deſtroyed, the vernal growth
of the buds muſt receive injury; as the reſervoir of future nutriment
for them will be leſs in quantity; but if ſome of the branches are
lopped

SECT. IX. 2. 10.
161
SEEDS, BUDS, BULBS.
lopped during the winter, the remainder will protrude more vigorous
ſhoots, as their ſhare of the reſerved nutriment will be greater.
10. The umbilical veſſels of the new buds of deciduous trees,
which are analogous to thoſe which permeate the lobes of the ſeed,
are extended downward in the bark about midſummer, and terminate
in certain reſervoirs of nutriment, which are at this time ſecreted from
the vegetable blood oxygenated in the leaves. This bark now con-
fiſts of an intertexture of the caudexes of the preſent leaves, which
were buds in the laſt ſummer, and are now adult vegetable beings;
and of the embryon caudexes of the new buds; and of the umbilical
vefſels of the new buds; it will become alburnum or ſap-wood dur-
ing the autumn or enſuing ſpring, and will be gradually covered over
with a new bark conſiſting of the mature caudexes of the new buds,
while that, which was the alburnum in the preceding ſpring, will
become a circle of lifeleſs timber, interior to the circle of alburnum.
The veſſels of this new bark, though they conſiſt of the caudexes
of the individual adult leaves, and the umbilical veſſels of the indi-
vidual young buds, evidently inofculate; becauſe, when ſome buds
are rubbed off or deſtroyed, thoſe in their vicinity grow with greater
vigour; as the daily experience of pruning all kinds of trees evinces,
The facility with which the ruptured veſſels of vegetables inofculate
into each other, or grow together, correſponds with that of animal
vefſels in their inflamed ftate. Thus a bud taken from one tree, and
inſerted into any part of the bark of another tree of the ſame genus,
or ingrafted on it, preſently receives nutriment, and grows to it by
the reciprocal inoſculation of the wounded veſſels, in the ſame man-
ner as a tranſplanted tooth; or as the fingers are liable to grow to-
gether after having been excoriated by a burn; or as the inflamed
lungs and pleura are liable to adhere, and intermix their blood-veſſels.
See Sect. III. 2. 7.
During the winter, when the leaves die and fall off, the arterial and
venous ſyſtems, which belonged to them, and which compoſed the
Y
greateft
a

162
SECT. IX. 2. 10.
SEEDS, BUDS, BULBS.
greateſt part of the bark, ſeem to loſe their vegetable life at the ſame
time, and to coaleſce, and form the alburnum, or ſap-wood ; but the
umbilical veſſels belonging to the new buds, which are intermixed
with this alburnum, remain alive; and at the returning ſpring act
with aſtoniſhing vigour; as deſcribed in Sect. III. 2. 2.
As the ſpring advances, the umbilical veſſels, after having drank up
the reſervoirs of nutriment, which were depoſited about the roots,
and having thus nouriſhed and expanded the new leaves, ceaſe to act;
and the alburnum gradually changes into hard wood, called the heart
of the tree; which no longer poſſeſſes vegetative life; and is now
only uſeful to elevate and ſuſtain aloft the ſwarm of biennial plants,
which cover it; and was probably originally produced for this pur-
poſe in the conteſt of all vegetables for light and air.
This inert or lifeleſs ſtate of the central parts of trees, called the
heart-wood, is evident from thoſe old oaks and willows, which have
loſt their internal hard wood, and are become quite hollow, conſiſt-
ing only of their bark and alburnum, and yet are furniſhed with
many healthy branches. But the umbilical veſſels of the alburnum
poſſeſs the properties of capillary tubes, or of a ſponge, after they
are extinct, and ceaſe to act as umbilical veſſels ; and thus may oc-
caſionally attract moiſture, or ſuffer it to paſs through them mecha-
nically ; whilſt the new bark, which conſiſts of an intertexture of the
caudexes of each bud with their radicles, may occaſionally abſorb this
moiſture from the capillary veſſels of the alburnum, which may be
compared to the upper ftratum of the foil attracting by capillary
power the moiſture from the ſoil immediately beneath it, which
may exhale into the atmoſphere, or be imbibed by the roots of ve-
getables by the ſuperior living power of their abſorbent mouths.
That the veſſels of the alburnum in their living ſtate poſſeſs the
property of conveying the fap-juice, which is propelled upwards in
the early ſpring by the abſorbent terminations of the roots, is viſible
in decorticated oaks; the branches of which expand their buds, like
I
thoſe

SECT. IX. 2. 10. SEEDS, BUDS, BULBS.
163
4
a
thoſe of the birch and vine in the bleeding ſeaſon. That the veſſels
of the alburnum in their living ſtate occaſionally act as capillary fy-
phons, through which the fap-juice is firſt puſhed upwards by the
abſorbent extremities of the roots, and afterwards returns downwards
partly by its gravitation in branches bent below the horizon, appears
from an experiment of Dr.Walker, mentioned in Sect. III. 2. 4.
Laſtly, that the veſſels of the alburnum after their vegetable life
is extinct, poſſeſs a power of capillary attraction of the fap-juice, or
of permitting it to paſs through them occaſionally, appears from the
following experiments. Firſt, a branch of a young apple-tree was
ſo cankered, that the bark for about an inch quite round it was to-
tally deſtroyed. To prevent the alburnum from becoming too dry
by exhalation, this decayed part was covered with thick white paint;
in a few days the painting was repeated, and this three or four times,
ſo as to produce a thick coat of paint over the decayed part, or naked
alburnum, extending to the aſcending and deſcending lips of the
wound; this was in ſpring, and the branch bloffomed and ripened
ſeveral apples.
In a garden in Lichfield about four years ago a complete cylinder
of bark about an inch long was cut from a branch of a pear-tree
nailed againſt a wall; the circumciſed part is now not more than half
the diameter of the ſame branch above and below it ; yet this branch
has been full of fruit every year fince, when the other branches of the
tree have borne only ſparingly. I lately obſerved, that the leaves of this
wounded branch were ſmaller and paler, and the fruit leſs in ſize,
and ripened a fortnight ſooner, than on the other parts of the tree.
Another branch of the ſame tree has a part of the bark taken off
about an inch long, but not quite all round it, with much the ſame
effect.
The exiſtence of capillary tubes in dead fap-wood is viſible in a
piece of dry cane, which permit water or finoke to paſs through
them; and in the exhauſted receiver of an air-pump both water and
quickſilver
Y 2

164
SECT. IX. 2. II.
SEEDS, BUDS, BULBS.
quickſilver may be made readily to paſs through pieces of the dry al-
burnum of wood by the preſſure of the atmofphere.
11. The flower-buds of many trees ariſe immediately from the laſt
year's terminal ſhoots, or ſpurs, either accompanied with leaf-buds,
or ſeparately, as in apple and pear-trees. Other flower-buds ariſe from
the ſhoots of the preſent year alternately with leaf-buds, as thoſe of
vines, and form the third or fourth buds of the new ſhoots. They
differ from leaf-buds in this circumſtance, that they periſh when their
ſeeds are ripe, without producing any addition or increaſe to the tree;
whereas when the leaf-buds periſh in the autumn, their caudexes, the
intertexture of which conſtitutes the bark of the tree, gradually be-
come converted into alburnum, or fap-wood; over which the new
leaf-buds ſhoot forth their caudexes and radicles, or inſert them into
it, and gradually fabricate the new bark and root-fibres.
It was before mentioned, that it is believed by ſome difciples of the
Linnean ſchool, that about Midſummer leaf-buds may be changed
into flower-buds, or flower-buds into leaf-buds; and that even after
the vegetable embryons are generated. And that this may be effect-
ed by weakening or ſtrengthening the growth of the laſt year's buds,
which ſecrete theſe new ones from the vegetable blood, and nouriſh
them in their infant ſtate. Thus if fome inches of the extremity of
a branch be lopped off at Midſummer, as is fometimes done by uvíkil-
ful gardeners, the remaining few buds will become more vigorous,
and conſequently produce leaf-buds inſtead of flower-buds; or per-
haps the embryons already formed may be converted from one kind
to the other. The contrary may occur, if a vigorous branch of a
wall-tree be bent down beneath the horizon, or ſo much as to im-
pede the generation of new caudexes; or if the leaf of the parent-bud
be taken off, ſoon after the plumula or apex of the new bud is ge-
nerated; and thus the new caudex along the bark may be prevent-
ed by deficiency of nutriment.
The probability of this idea of tranſmuting flower-buds and leaf-
buds

Sect. IX. 2. 12,
165
SEEDS, BUDS, BULBS.
a
buds into each other is confirmed by the curious converſion of the
parts of the flowers of ſome vegetable monſters into green leaves ; if
they be too well nouriſhed, after they are ſo far advanced as to be
unchangeable into leaf-buds. Thus in the plantago roſea, roſe-plan-
tain, the diviſions of the ſpike become wonderfully enlarged, and are
converted into leaves; the chaffy ſcales of the calyx in xeranthe-
mum, everlaſting, and in a ſpecies of dianthus, pink, and the glume
of ſome alpine graſſes, and the ſcales in the ament of the falix roſea,
roſe-willow, grow into leaves, and produce other kinds of vegetable
monſters.
Add to this, that the petals of the helleborus niger, or chriſtmas-
rofe, are beautifully white till the feed is impregnated ; and then
they change into green leaves, forming a calyx. And laſtly, in other
flowers a bud or bulb ſucceeds the impregnation inſtead of a ſeed, as
in polygonum viviparum, viviparous biftort; and in allium magi-
cum, magical onion ; the fame occurs in many of the alpine graſſes,
and in the feſtuca dumetorum, feſcue graſs; all which are in ſome
degree analogous to the ſuppoſed converſion of early flower-buds into
leaf-buds; for in theſe magical onions, and other bulbiferous flowers,
the bractes or floral-leaves, which at firſt ſecrete nouriſhment for the
pericarp and ſeeds of the plant, aſſume a new office, and ſecrete a
magazine of nouriſhment for the new bulb, as appears in the concen-
tric fleſhy membranes, which ſurround the new ſummit-bulbs of the
allium magicum, and the cloves of garlic.
12. The central part of an adult bud therefore conſiſts firſt
of a conjunction of the blood-veſſels from above and below, which
exiſts in the caudex of the bud between the beginning of the leaf-
veſſels and the beginning of the root-veſſels; the circulation reſem-
bling that of many inſects, of fiſh, and in the livers of quadrupeds,
as ſhewn in Sect. V. 2. Secondly, there is probably at the ſame place
a conjunction of the abſorbent veſſels correſpondent to the recepta-
culum chyli of animals. Thirdly, there exiſts in each bud an organ
of
3

166
SECT. IX. 3. In
SEEDS, BUDS, BULBS.
a
of reproduction, which in a leaf-bud produces the lateral or paternal
offspring, and in a flower-bud the ſeminal or amatorial one. Fourth-
ly, a center of nervous influence, as a brain, or ſpinal marrow, or
common ſenſorium, exiſts in each bud; and probably refides near this
junction of the blood-veſſels of the leaf and root, and of the abſorbent
fyftem, along with the organ of reproduction in the caudex gemmæ.
III. 1. THE BULBOUS ROOTS of ſome perennial herbaceous plants,
and the root-ſcions of other perennial herbaceous plants, are ſimilar
in this reſpect, which diſtinguiſhes them from buds; that they are
generated on the broad caudex of the plant within the ground, or in
contact with it, and immediately ſhoot down their new roots into
the earth. Whereas buds are formed above the ſoil on the long
caudexes, which conſtitute the filaments of the bark of trees, and
ſhoot down new roots into the earth from the lower end of theſe
elongated caudexes.
Bulbs have not improperly been called ſubterraneous buds; and like
them they may be divided into leaf-bulbs and flower-bulbs. When
a tulip-feed is lown, it produces a ſmall plant the firſt ſummer,
which in the autumn dies, and leaves in its place one or more bulbs.
Theſe are leaf-bulbs, which in the enſuing ſpring riſe into ſtronger
plants than thoſe of the firſt year, but no flowers are yet generated ;
in the autumn theſe periſh like the former, and leave in their places
other leaf-bulbs ſtronger, or more perfect, than their preceding pa-
rents. This fucceffion of leaf-bulbs continues for four or five years,
till at length the bulb acquires a greater perfection or maturity, neceſ-
ſary for feminal generation, and produces in its place a large flower-
bulb in the centre with ſeveral ſmall leaf-bulbs around it.
This ſucceſſive formation of leaf-bulbs in bulbous rooted plants
previous to the formation of a flower-bulb is curiouſly analogous to
the production of leaf-buds on many trees for ſeveral years before the
production of flower-buds; thus the apple-trees, pyrus malus, which
are raiſed from ſeeds, generate only leaf-buds for ten or twelve years,
and
a

SECT. IX. 3. 1,
,
SEEDS, BUDS, BULBS.
167
a
a
and afterwards annually generate both flower-buds and leaf-buds.
From whence it would ſeem, that the adherent lateral or paternal
progeny is the moſt ſimple, and eaſieſt, and conſequently the firſt
mode of reproduction ; and that the amatorial or ſeminal progeny is
on this account not generated till the maturer age or more perfect
ſtate of the parent-bud.
A ſtill more curious analogy to this circumſtance of a ſucceſſion of
leaf-buds and leaf-bulbs preceding the formation of flower-buds and
flower-bulbs exiſts in the growth of wheat, triticum, and other
graſſes; but with this difference, that a ſucceſſion of leaf-buds, as of
two, or three, or four, are produced in the ſame year previous to
the flower-bud. At the firſt joint of the ſtem of wheat, on or within
the ſurface of the earth, a leaf is produced; from which riſes the
principal or central bud, and around it many new buds, which ſtrike
their roots into the ſoil. After this central bud, and thoſe around it,
have ariſen fix or eight inches, a new leaf and a new leaf-bud riſes
on each of them, producing a ſecond joint of the ſtem ; and laſtly, a
flower-bud is generated at the ſummit, which are all evidently diſ-
tinct vegetable beings, as there is a diviſion acroſs the ſtem at each
joint, which ſhews there is no connexion of the pith, or brain, or
fpinal marrow, between the lower and upper joints, as mentioned in
Sect. I. 8.
That a new bud thus conſtitutes each joint of the ſtem of wheat,
and other graffes, is further evinced; firſt, by the exiſtence of a leaf
at each joint without a lateral bud in its axilla, as occurs in other ve-
getables. Secondly, becauſe for the nouriſhment of this new leaf-
bud a reſervoir of ſweet-juice is prepared in the new joint; as in the
bulbs of many plants. And thirdly, becauſe the lower leaf dies, and
the ſweet juice is abſorbed, as the upper leaf becomes, vegete. Hence:
we acquire the knowledge of the uſe of this reſervoir of ſugar in
the vegetable economy, which ſupplies ſo much agreeable and falu-
tary
a
a

168
SECT. IX. 3. 1.
SEEDS, BUDS, BULBS.
a
tary nouriſhment to mankind from the cultivation of the ſugar-cane.
See No. 1. 6. and No. 3. 7. of this section.
The analogy between the buds of plants and the adherent lateral
progeny of ſome inſects, as of the polypus, and tenia, or tape-worm,
and volvox, was mentioned in Sect. VII. 1.4. But the circumſtance
of the ſucceſſive production of leaf-buds and leaf-bulbs previous to the
production of flower-buds or flower-bulbs is wonderfully analogous
to the generation of the aphis, which riſing from an egg in the ſpring
after caſting its ſkin once or twice produces a living progeny without
amatorial copulation ; and this offspring produces others by this ſoli-
tary propagation till the tenth generation ; then a ſexual progeny of
males and females is produced, and eggs are laid in the autumn from
their amatorial intercourſe. Encycloped. Britan. Amanitat. Academ.
Vol. VII. by A.T. Bladh. See Sect. XIV. 3. 2. Thus this infect
from the egg requires to be reproduced many times by folitary pro-
pagation before it becomes ſufficiently perfect to generate a ſexual
offspring like the buds and bulbs from ſeeds above mentioned. And
it is probable, that the polypus of our ſtagnant waters, which pro-
duces a lateral offspring in the ſummer, I ſuppoſe by folitary propa-
gation, may produce males and females, and generate eggs in conſe-
quence in the autumn for their reproduction in the enſuing ſpring.
To this may be added the great change, which many inſects and
even larger animals undergo either in ſtrength or form, before they
acquire the power of ſeminal reproduction. As the filk-worm
changes into a butterfly apparently for the purpoſe of generation only,
as it then performs this office and dies. Other caterpillars change their
form likewiſe into butterflies, and at the ſame time change their kind
of food, which was the green foliage of vegetables before this tranſ-
formation; but now conſiſts ſolely of honey. And laſtly, the gnat
and muſqueto change at the ſame time both their forms, their food,
and their element; and thus acquire higher animation apparently for
the purpoſe of ſexual reproduction.
a
2. The

SECT. IX. 3. 2.
169
SEEDS, BUDS, BULBS.
2. The manner of the production of herbaceous plants from their
various perennial roots wants further inveſtigation, as their analogy
is not yet clearly aſcertained. I this autumn diffected two large roots
of the onion or leek kind, which were in full flower; the ſtem of
each of them was embraced by the cylindrical pedicles of fix or ſeven
concentric leaves; but the ſtem itſelf aroſe from the center between
three large new bulbs in one of them, and between two in the other.
All of which grew from the ſame caudex, but the central flower-
ſtem was wrapped at its bottom in one membrane only, which fe-
parated it from the new bulbs in its vicinity.
A large root of a young onion, which grew from ſeed ſown in the
ſpring, was at the ſame time diffected by ſtripping off the leaves, and
their fleſhy baſes, one after another, till two buds were viſible in the
center of the fleſhy baſes of the concentric leaves, which formed the
bulb. Theſe two bulbs were evidently formed and nouriſhed on the
caudex by the ſtem, and its fix or ſeven concentric cylindrical leaves;
and will, I ſuppoſe, ſeparate in the ſpring, as they riſe up, and pro-
duce each of them a flower with two or three new bulbs at the baſe
of it, as deſcribed in the above paragraph.
Or from the different ſize and apparent greater maturity of the
central bulb, and the ſecondary bulb being between the innermoſt
and the ſecond circular fleſhy membrane, I ſuppoſe in theſe roots of
onion, like the tulip-roots before ſpoken of, that the central bulb
alone may produce a flower in the next ſummer; and that the la-
teral bulb or bulbs will produce only ſtronger and more mature leaf-
bulbs, which will in the ſucceeding ſummer bear a flower or ſexual
progeny.
The caudex, or central part of the bulb, from which the root-
fibres deſcend, and the leaves afcend, lies above the knot in the orchis
morio; and the parent-root ſhrivels up and dies, as the young one in-
creaſes. The flower of this plant does not ripen its ſeeds in this
climate; it might be otherwiſe worth cultivation for the uſe of the
Z
new
a
a

170
SECT. IX. 3. 2.
SEEDS, BUDS, BULBS.
new roots; which when ſcalded and peeled, are ſaid to be the ſalep
of the ſhops. It is aſſerted by one of the Linnean ſchool in the
Amen. Academ. that if the new root be pinched off, the ſeeds on the
old one will ripen, and become prolific.
In the tulip the caudex lies below the bulb, from whence proceed
the fibrous roots and the new bulbs; the root after it has flowered
dies like the orchis root; for the ſtem of the laſt year's tulip lies on
the outſide, and not in the center of the new bulb. In the tulip-
root, diffected in the early ſpring, juſt before it begins to ſhoot, a per-
fect flower is feen in its center; and between the firſt and ſecond coat
the large next year's bulb is, I believe, produced; between the ſe-
cond and third coat, and between this and the fourth coat, and per-
haps further, other leſs and leſs bulbs are viſible, all adjoining to the
caudex at the bottom of the mother bulb; and which I am told, re-
quire as many years, before they will flower, as the number of the
coats with which they are covered, and that the ſame different ſtates
of maturity probably obtain in the buds round the ſhoots of many
fruit-trees, the central one of which will produce flowers the next
year as on the ſpurs of apple-trees; while thoſe beneath it require
more or fewer years, before they become ſufficiently mature to pro-
duce organs of ſexual generation; an important ſecret in the manage-
ment of fruit-trees.
The hyacinth-root differs from the tulip-root ; for, as I am inform-
ed, the ſtem of the laſt year's flower is always found in the center
of the root, as in the onions above deſcribed; and that the new off-
ſets ariſe from the caudex below this bulb, and not between
any
of
the concentric coats of it, except the two external ones. On this ac-
count the central part is liable by its decay to deſtroy the flower-bud,
if not taken out of the earth, when the leaves die; and hence ſome
;
floriſts believe, that theſe roots periſh naturally in five or ſeven years,
after they have flowered, but that the tulip-root never dies from
age.
113

Sect. IX.
3. 2.
SEEDS, BUDS, BULBS.
171
a
a
a
In a few roots of hyacinths, which I this day examined, Septem-
ber 1, the ſtem of one, which had apparently flowered in the fum-
mer, was perfectly decayed in the center of many new bulbs. In
another bulb of leſs fize and compact, which I ſuppoſed had not born
a flower, I found a central flower-bud incloſed in many concentric
fleſhy baſes of former leaves, like an onion in the autumn, which had
been ſown in the preceding ſpring. And concluded from hence, that
the hyacinth-root dies annually or biennially like the onion, leaving
behind it a ſucceſſion of leaf-bulbs or of flower-bulbs.
The caudex and claw-like roots of the ranunculus cultivated by
floriſts dies I believe annually, after having put forth a circle of new
claws from the upper part of it round the bottom of the periſhing
flower-ſtem. Hence the claws of the old root, which became ſhrivel-
led, as the flower advanced, in the autumn diſappear; and the de-
cayed part of the old caudex is ſeen beneath the new claw-like roots,
which I ſuppoſe has given occaſion to ſome inaccurate obſervers to
believe, that the old ſtem in this and ſome other perennial herbaceous
plants was drawn downwards by the new root fibres; while the bulbs
of the iris have been ſuppoſed to have been puſhed upwards, like the
lamb-like barometz, by the reſiſtance of the ſoil to the elongation of
the root-fibres; which laſt ſeems to be a much more probable idea
than the former.
From theſe obſervations it appears, that the concentric leaves,
which incircle the ſtems of bulb-rooted plants, are the lungs to the
caudex, as one or more leaves are to the bud of a tree; and that the
caudex with theſe leaves, and the root-fibres, conſtitute a vegetable
being; which produces a viviparous progeny of new leaf-bulbs, or a
ſeminiferous progeny in flower-bulbs, with a magazine of nutriment
in the fleſhy baſe of each leaf; and that the tulip produces only leaf-
bulbs for four or five years from the ſeed, and then but one flower-
bulb with many leaf-bulbs annually. But that the onion-kind, al-
lium, generates two or three flower-bulbs in the firſt fummer from
the
Z 2

172
SEEDS, BUDS, BULBS.
SECT. IX. 3. 3.
the feed; which produce flowers and other leaf-bulbs in the ſecond
ſummer from the feed. And laſtly, that it is probable, that all bul-
bous roots, like the buds of deciduous trees, and perhaps of evergreen
ones alſo, are properly ſpeaking biennial plants, as they riſe in one
ſummer and periſh in the next.
3. In tulip-roots, which have been planted too deep in the earth,
and in onion-roots, a vegetable cord, or proceſs, is fometimes feen
about an inch long to ariſe from the caudex beneath the baſes of the
cylindrical leaves, and to form a new bulb. Similar to this appears
the natural growth of the roots of potatoes; a ſpermatic cord ariſes
from the old root, after the leaves are expanded in the air, to oxy-
genate the vegetable blood, and a new tuberous or bulbous root is
thus generated.
This mode of producing diſtant roots is exactly reſembled above
ground by the wires of ſtrawberries; which may be called ſpermatic
cords, which depoſit a new vegetable being on the earth, and ſupport
it like a bud on a' tree, till it can ſtrike roots into the ſoil, and elevate
leaves into the air. The final cauſe of the length of theſe fubterra-
neous and aerial ſpermatic cords is evidently the deſign of placing
their roots at a convenient diſtance from their parent plants; that
they may not incommode each other, but may both of thein more rea-
dily acquire nutritious juices from the earth, and the ventilation and
ſunſhine of the atmoſphere.
Theſe embryon vegetables in the various bulbous and tuberous roots
are in very different ſtates of maturity, as in the buds of different
trees; thus in the potatoe the corculum or plumula of the new plant
only is viſible, ſurrounded with a farinaceous nutriment, as in many
feeds; whereas in the tulip and hyacinth the flower of the ſucceed-
ing year is diſcernible, as in the bud of the horſe-cheſnut.
As the ripening of the feed of ſome bulbous-rooted plants is for-
warded by deſtroying the new bulbs, as in orchis; and the flowering
bulbs of other plants are made ſtronger by raiſing them out of the
earth,
a

SECT. IX. 3. 4.
173
SEEDS, BUDS, BULBS.
earth, and taking away the leaf-bulbs, which ſurround them on the
ſame caudex; as in the cuſtomary management of tulip-roots, and
hyacinth-roots by the floriſts; I was led to ſuſpect, that pinching off
the flowers of potatoes two or three times might increaſe the ſize or
quantity of the roots; as the nouriſhment derived from the vegetable
blood to the flowers and ſeeds might thus be directed to enlarge the
roots, and thus lay up more nutriment for the future plants. This
idea I mentioned to an ingenious Lady, who acquainted me a few
months afterwards, that on a few roots lhe had made this experiment
with apparent advantage.
4. The bulbous and tuberous roots of plants are a lateral or pater-
nal progeny like the buds of trees, and therefore exactly reſemble the
parent plant, as mentioned in Sect. III. 2. 1. and on this account may
be liable to be affected by hereditary diſeaſes, and thus to become un-
healthy; whence the canker is ſuppoſed to ariſe in thoſe apple-trees,
which have for a century or two been propagated by grafting; and
the curled leaf in potatoes, which have been too long propagated by
their bulbs ; and the barrenneſs of hautbois ſtrawberries, which have
too long been propagated by wires; all which diſeaſes are believed not
to happen in theſe plants, if they have recently been raiſed from ſeed,
but want further obfervations to authenticate the facts.
But there exiſts a ſet of bulbs, which ſeem to be formed by amato-
rial or ſeminal generation, and not by the lateral or paternal gene-
ration, and would therefore ſeem to be a viviparous ſexual progeny.
Theſe are produced on the flower-ſtem in the place of ſeeds; and in
proceſs of time fall off, and take root in the earth, as is agreeably ſeen
in the polygonum viviparum, viviparous biſtort, and the magical onion,
allium magicum, and the leek, allium ſativum. A curious queſtion
here occurs, whether the plants from thefe bulbs are liable exactly to
reſemble their parents ? and whether they would be liable to heredi-
tary diſeaſes from a long cultivation of them in fucceffion, as is ſupe
poſed to happen to thoſe mentioned above ?
Though
a

174
SEEDS, BUDS, BULBS.
SECT. IX. 3. 50
Though a perfect flower precedes the product of ſome ſummit-
bulbs, as I believe in the lower part of the ſpike of the polygonum vi-
I
viparum ; yet I ſuſpect, that the ſummit-bulbs of allium magicum,
are exactly ſimilar to the bulbs, which are produced at their roots;
becauſe on cutting one of them horizontally into two hemiſpheres
this morning, September 10, I obſerved three young bulbs incloſed in
the concentric fleſhy membranes of the ſummit-bulb in the following
manner; five thick fleſhy concentric coats of the general ſummit-
bulb being taken away, there appeared one fingle naked ſmall bulb;
and on the fixth coat being removed, two other bulbs became viſible,
which were included in it. Whence it ſeems, that theſe ſtem-bulbs
are as forward as thoſe of the root, and probably are in every reſpect
ſimilar; and that the bractes or floral-leaves, which in feed-bear-
ing plants ſecrete or prepare a nouriſhment for the ſeed, and peri-
carp of the flower, acquire in theſe bulbiferous onions and leeks a
new office, and prepare a magazine of nouriſhment in the concentric
membranes, which ſurround their ſummit-bulbs; and theſe may be
eſteemed therefore a ſexual viviparous progeny of vegetables, as buds
are a lateral viviparous progeny.
5. The roots of trees ſo reſemble their branches, that ſubterrane-
ous buds are frequently produced upon them, which reſemble the
parent-tree. The bark of the root likewiſe ſo reſembles the bark of
the branches, that it is not uncommon to ingraft with ſucceſs on
roots taken out of the earth and replanted ; as the robinia on the root
of the acacia, and any other apples on the roots or the ſuckers of bur-
apples or of codlings; which may be done earlier in the vernal
months, as being leſs liable to injury from froſty nights; and it is
probable, that budding or inoculating may be performed in the ſame
manner on the roots at midſummer, as on the branches.
The roots of thoſe plants, which are otherwiſe not eaſily propa-
gated, will ſhoot up buds, if a part of them next to the plant be balf
cut through, or raiſed out of the ground, and expoſed to the air ; as
9
1
in

SECT. IX. 3. 5.
175
SEEDS, BUDS, BULBS.
a
;
in pyramidal campanula, and geranium lobatum ; and after a time the
root may be ſeparated from the ſtock, and many new plants may be
this way produced.
Theſe root-buds, or ſuckers, are generally produced near the trunk
of the tree, before the root deſcends much beneath the ſoil; but in
fome trees, as the eim, ulmus, and acer, maple, whoſe roots ſpread
far horizontally, and near the ſurface of the earth, they are generated
at a great diſtance from the parent tree; becauſe the new ſcion can
thus foon acquire the influence of the atmoſphere on its expanding
foliage. Theſe root-ſcions from apple-trees are frequently uſed in ve-
getable nurſeries for the purpoſe of ingrafting upon, and are termed
paradice-ſtocks by ſome gardeners; but are not liable to the canker
like the grafts from thoſe old apple-trees, which have been in faſhion
above a century; as theſe root-ſcions reſemble the trunk of the tree,
which produces them, not the ingrafted head of it; and thus may not
have been many years from the ſtate of a ſeedling vegetable.
Similar to theſe root-ſcions of trees it is probable, that the root-
buds of perennial herbaceous plants are produced; which have diva-
ricated, or fibrous-roots, and whoſe fummits periſh in the winter.
For many years the root thickens by an annual new bark being in-
duced over the old one, exactly as in the trunks and roots of trees.
As theſe roots increaſe in ſize, the central part, I ſuppoſe, changes
like the internal wood of a tree, and ceaſes to poſſeſs vegetable life;
and in proceſs of time is liable to decay. On this account theſe pe-
rennial roots are not ſo valuable for the purpoſes of medicine or diet,
or mechanic arts, either before or after they have paſſed a determinate
age; as the bark of the root changes annually into a kind of albur-
num, and then into a kind of wood, and laſtly, is liable to decay, as
occurs in the roots of rheum palmatum, when they are ſeven or
more years old. See Sect. XVII. 2. I. This decay of the central part
of the root, which happens annually to ſome plants, and is ſurrounded
with new buds and their root-fibres, exhibits the appearance of the
lower

176
Sect. IX. 3.6
SEEDS, BUDS, BULBS.
--
lower end of the root having been chopped, or bitten off, to ſome fan-
ciful botaniſts; as in plantago major, and valerian ; and has hence
given to ſcabioſa ſucciſa the name of devil's-bit, morſus diaboli.
6. The bulbs already mentioned, as thoſe of tulips, hyacinths, and
onions, are properly the winter-cradles, or hybernacula, of the young
plants, whether in their leaf-bulb or flower-bulb ftate; and are fur-
niſhed with a magazine or reſervoir of nouriſhment for the growing
embryons, as appears in the ſquil, ſcilla maritima, which vegetates
from this ſource of nutriment in the druggiſts ſhops. But there are
other roots termed tuberous roots, as of turnep and carrot, which
conſiſt ſolely of a large reſervoir of nutriment for the growth and
nouriſhment of the riſing ſtem and future ſeeds; whether theſe are
produced in the ſame year, as occurs, when the ſeeds are fown early
in the fpring; or when their vegetation is ſtopped by the cold of
winter, and proceeds again in the enſuing ſpring; as generally occurs
to our turneps, the roots of which I am well informed may be much
enlarged by tranſplantation. See Sect. XII. 6.
In theſe plants the leaves, by expoſing the vegetable blood to the
influence of the air, prepare it for the ſecretion of nutriment in their
knobby roots ; in the ſame manner as nouriſhment is produced and
reſerved in the concentric fleſhy baſes of the leaves of onions; and in
theſe plants, as in the onion kind, the leaves, which ſurround the
baſe of the new ſtems, wither and die; as the new buds, or bulbs,
put forth leaves of their own for the purpoſe of oxygenating their
blood. Thus it appears, that the ſtem and flower of the onion, or
carrot, or turnep, is a new plant, not ariſing immediately from the
.
ſeed which was ſown, but from the leaf-root or leaf-knob, if it may
be ſo called, which preceded the production of the flower-bud, or
flower-ſtem, exactly as the flower or ear of wheat, which was ſhewn
in Sect. IX. 3. 1, to have three or four ſucceſſive leaf-buds preceding
the flower-bud.
From theſe obſervations may we conclude, that no flower-bud or
flower-

Sect. IX. 3.6.
177
SEEDS, BUDS, BULBS.
flower-bulb is ever produced from a ſeed, without the previous in-
terpoſition of one or more leaf-buds or leaf-bulbs ? and that thoſe
flower-buds or flower-bulbs are either produced in one generation af.
ter fowing the ſeed, as the flower-bulbs of onions, which are gene-
rated and nouriſhed at the baſes of the concentric cylindrical leaves of
the preceding leaf-plant, which aroſe from the ſeed; or as the ſtems
and flower-buds of the carrot and turnep, which are generated and
nouriſhed at the baſe of the concentric leaves of the preceding leaf-
plant. Or ſecondly, that they are produced in one fummer, though
after ſeveral generations from the ſeed; as the three or four joints of
the ſtem of wheat, and other graſſes, which are generated and nou.
riſhed in ſucceſſion in the bofoms of four or five cylindrical leaves,
one at each joint; which alſo probably obtains in all other vegeta-
bles, which are ſupported by hollow ſtems divided by joints, and
furniſhed with leaves at theſe ſtem-joints with or without branches,
as tragopogon or picris. In theſe plants, where there are no branches,
there is ſimply a new central bud; and two or more lateral new buds
beſide the central one, where there are branches.
Or laſtly, where the leaf-buds or leaf-bulbs, which are produced
from feeds, ſucceed each other for ſome years, before they arrive at
fufficient maturity to produce ſexual organs, or generate a flower,
as in the bulbs of tulips, and hyacinths, and the buds of trees.
Whence we at length acquire a diſtinct idea, why ſeedling apple-trees
are ten or twelve years before they bear fruit; though the buds or
ſhoots taken from a tree, which already has born fruit, and ingraft-
ed even on a young ſeedling-tree, ſhall produce flowers in the firſt or
ſecond year; as theſe buds have already acquired that ſtate of per-
fection or maturity, which is neceſſary to the production of ſexual or
feminal generation : and as it therefore poffefſes the age of puberty,
or the maturity of the tree; we may ſuſpect, that it will ſooner
acquire the hereditary diſeaſes conſequent to too long unmixed fuc-
Аа
ceffive

178
SECT. IX. 3. 7.
SEEDS, BUDS, BULBS.
ceſſive generations, a piece of very important knowledge to the
planters of orchards; which they owe to the obſervation of Mr.
Knight, as mentioned in Sect. VII. 1. 3.
Hence in many plants produced from feeds, perhaps in all, one or
more leaf-buds precede the flower-bud; and I ſuppoſe generally, if
not always, a magazine of aliment is formed at the baſes of the leaves,
or in the roots, for the nutriment of the ſucceeding leaf-bud or
flower-bud, of which it is the parent.
Thus in the carrot and turnep the firſt leaves conſtitute the lungs
of the new vegetable being, which generates the ſucceeding flower-
ſtem, and ſecretes or depoſits for it a magazine of aliment, which
forms the tuberous root : and then this firſt plant from the ſeed and
its leaves or lungs periſh; and the root gradually ſhrivels up, as it is
abſorbed by the new flower-ſtem. In many plants theſe firſt or root-
leaves differ in form from thoſe of the ſucceeding ſtem, as in palmated
rhubarb, and in campanula rotundifolia, which is ſo called from the
round form of the leaves of this firſt leaf-bud, or root-plant, which
precedes the flower-ſtem.
7. One great advantage of Mr. Tull's horſe-hoeing huſbandry, in
which the earth near the rows of wheat is alternately turned from
and to them during the vernal months, has been ſuppoſed to ariſe
from ſome fibres of the roots being thus cut off, and new ſtems ſhoot-
ing up at the ends of thoſe which remain ; but the real cauſe of the
production of the new ſtems is from the accumulation of earth above
the firſt joint of the young wheat-plant ; from which the new buds
ſpring out, generated and nouriſhed by the caudex of the leaf, which
ſurrounds that joint, and which afterwards withers; this important
circumſtance is ſhewn by the annexed delineation of a tranſplanted
wheat-plant.
The plant of wheat was taken from a corn-field in the ſpring,
and then conſiſted firſt of the root immediately proceeding from the
feed

SECT. IX. 3: 7.
179
SEEDS, BUDS, BULBS.
a
ſeed a, which has been called the ſeminal root; and ſecondly, of the
,
root, which was then near the ſurface of the ground b, which has
been called the coronal root, was furniſhed with a ſtem and leaf, c, d,
and with a ſecondary ſtem, or root-ſcion, e, f. This wheat-plant
conſiſting of only two ſtems was replanted in my garden, and pur-
poſely buried ſo deep as to cover the two or three firſt joints of both
the ſtems beneath the ſoil ; that is as high as the letter f, where the
ſecondary ſtem was purpoſely cut off.
On taking up this plant with ſome others on September 24, it had
aſſumed the form here delineated. The primary ſtem,c,g, had ſhot
out no new roots from the joint g, which I ſuppoſe to have hap-
pened from its being too far advanced when replanted; as many
other ſtems of other wheat-plants, which had not been obtruncated,
had nevertheleſs put forth one or more lateral ſtems or root-ſcions at
the ſecond or third joints, which on tranſplantation had been covered
with the ſoil.
But the obtruncated ſtem, e, f, had generated a new root-ſcion
at h, like the firſt ſhoot from the feed at a; which had produced
other new ſtems, as it approached nearer the ſurface of the earth at
i; and as theſe advanced into the air, and formed their leaves, other
new root-ſcions were generated at k and l. Whence it appears, that
by decapitation, and a deeper immerſion in the ground, a ſecondary
ſtem in this plant became multiplied into five; all which produced
perfect ears of corn ; and in other roots, which I had planted in a
ſimilar manner, the increaſe was much greater : and eſpecially where
one or more of the primary or ſecondary ſtems had been decapi-
tated.
If a grain of wheat be dropped on the ſurface of the earth, and ſuf-
fered to ſhoot down its roots, and to raiſe its ſtem, which is the
proceſs of nature, I ſuppoſe but one ſtem would be produced; as the
firſt knot or joint of it would not be covered with earth, and could
A a 2
not

180
. IX. 3. 7.
SEEDS, BUDS, BULBS.
SECTSect
9
not therefore ſhoot down new roots; which are neceſſary in theſe
plants to the production of new ſtems, which are not branches but
ſuckers or root-fcions.
But if the grain be buried an inch deep in the earth, a ſhoot riſes
from the roots, which iſſue from the ſeed, which is an elongation of
the caudex, and puts forth a leaf in contact with the ſurface of the
earth; this leaf and ſtem conſtitute the primary plant, and generate
new buds, which put forth new roots deſcending into the earth;
and thus three or four or more fuckers, or new plants, ariſe round the
original one, which was contained in the feed : hence the appearance
of two roots, which ſome authors have named the ſeminal and co-
ronal roots. The ingenious Mr.Tull ſeems himſelf to have been
aware of this circumſtance, as he ſays in his Huſbandry, “ Late
planted wheat ſends out no root above the grain before ſpring, but is
nouriſhed all winter by a ſingle thread proceeding from the grain up
to the ſurface."
This explains the prodigious multiplication of the ſtems of wheat,
which may be produced by tranſplanting it three or four times in the
fummer, autumn, and enſuing ſpring; for if it be ſo managed, that
a ſecond joint of each young ſtem be buried in the ſoil, or brought
even into contact with it, ſo that new roots may ſtrike down into the
earth; the caudex of the leaf, which ſurrounds this joint, will gene-
rate many new buds, which will thus become ſuckers, or root-ſcions,
and rival their parent; and may be again tranſplanted or earthed up
three or four times with wonderful increaſe. Mr. Charles Miller of
Cambridge fowed ſome wheat on the ſecond of June 1766, and on
the eighth of Auguſt one plant was taken up and ſeparated into
eighteen parts and replanted; theſe plants were again taken up and
divided between the middle of September and the middle of Octo-
ber, and again planted ſeparately to ſtand the winter, and this ſecond
diviſion produced fixty-ſeven plants. They were again taken up, and
divided between the middle of March and the middle of April, and
8
produced

Sect. IX. 3. 7.
181
SEEDS, BUDS, BULBS.
1
manner ;
produced five hundred plants. The number of ears thus produced
from one grain of wheat was 21109, which meaſured three pecks
and three quarters of corn, weighed forty-ſeven pounds ſeven ounces,
and were eſtimated at 576840 grains ! Philof. Tranſ. Vol. LVIII.
p. 203. See Sect. XII. 6.
Nor is this unſupported by the analogy of other vegetables, in
which new roots are liable to ſhoot in great abundance from their
joints either alone or along with new buds, if a proper degree of
moiſture is preſented to them. Thus if the ſtem of a potatoe be laid
down upon the earth, and covered with ſoil over the firſt joint, a new
ſeries of roots will be protruded from that joint ; and afterwards ano-
ther ſeries of roots from the ſecond joint, if managed in the ſame
and it is aſſerted that this will occur even if the potatoe
ſtems are taken out of the ground, when they are fix or eight inches
high, and deprived of all their young roots, and tranſplanted, ſo as
to cover one or two joints, and that a great crop has been thus pro-
duced.
The rapid growth of fome graffes, and of fome ſpecies of the con-
volvulus, and of colt’s-foot, is well known, and very troubleſome in
many ſituations. Of theſe very minute parts of the jointed root,
when cut from the parent, elongate themſelves, and ſhoot up new
plants. From the very numerous diviſions of the wheat-root de-
ſcribed by Mr. Miller, it may be ſuſpected that ſomething ſimilar to
this muſt have happened, which further obſervations muſt deter-
mine.
Vines alſo are thus liable to ſhoot out roots at their joints, and
fig-trees, when covered only with a ſhred of cloth in nailing them
to a wall, if it be accidentally kept moiſt. And there is an apple-
tree, which is called a burr-apple, becauſe it puts out roundiſh pro-
tuberances or excreſcences of the bark like a burr, which if the
branch be bent down, or even torn off, and ſet in the moiſt earth,
will

182
Sect. IX. 3.7
SEEDS, BUDS, BULBS.
a
a
will immediately ſtrike out roots, as I am told, and become a tree
ſimilar to the parent.
In the ſame manner I have been informed that if a circular ring
of the bark be cut off from many trees and ſhrubs, which are other-
wiſe difficult to propagate, and earth be put round the branch thus
decorticated a few inches above and below the wounded part, by
means of a garden-pot previouſly broken longitudinally, and bound
together round the branch, that roots will ſhoot from the upper lip
of the wound; and in a little time the branch may be ſafely cut off
below the garden-pot, and planted with ſucceſs.
When a few inches of the end of a branch are cut off in the ſpring,
as is common in pruning wall-trees, new buds are produced near the
extremity, which remains; or thoſe, which did exiſt, grow with
greater vigour ; as they obtain ſome of that nouriſhment, which
ſhould have ſupported the buds, which were cut off. The ſame oc-
curs in reſpect to the fuckers or root-ſcions of thoſe trees, which
produce them, as of elm-trees, and of ſome apple-trees; if many of
the branches be cut away, the fuckers or root-ſcions become more
numerous, or more vigorous.
This explains the uſe of a practice among many farmers of eating
down a forward crop of wheat in the ſpring with ſheep. In this
caſe the central or upright ſtem of the wheat is decapitated, and
many lateral ones, or root-fcions, as above deſcribed, become gene-
rated, or grow with greater vigour ; acquiring additional nouriſh-
ment from the joint, which was to have been expended in the growth
of the central ſtem; and which appears ſo diſtinctly in the preceding
figure of a tranſplanted wheat-plant, which nevertheleſs in crops,
which are not too forward, may be very injurious, as ſpoken of in
Sect. XVI. 2. 3.
Thus the figure above alluded to explains four important circum-
ſtances in the cultivation of grains, that of earthing up the rows in
7
ſpring

PLATE IV.
no

PLATE IV.
Repreſents a tranſplanted root of wheat deſcribed in Sect. IX. 3.7. a the ſeminal
root, b the coronal root, a b the elongated caudex, cg the firſt ſtem, c d the firſt leaf,
ef a ſecondary ſtem. All theſe exiſted before tranſplantation. The ſecondary ftem
was then cut off at f, and the plant was buried in the ſoil as deep as the letter f, where
it was cut off. Afterwards the ftem, which was lopped, had put forth a new caudex
or root-ſcion at b; which had produced three new ſtems at i; and other new ones, as it
approached nearer the ſurface, at k and I. "As theſe leaves advanced into the air, the
latter new ſtems were produced by the caudexes of them.

Plate IV.
bhu
Sect. IX. 3.7
k
h
g
d
6
a
London, Publishel Jan '14.800,by J. Johnson, S'Paul's Church Yard.


SECT. IX. 3. 7.
183
SEEDS, BUDS, BULBS.
ſpring by Mr. Tull's horſe-hoe; that of eating down the firſt ſtems
of forward crops by ſheep; that of tranſplanting the roots deeper
in the ſoil; and that of ſowing the ſeed an inch or two beneath the
ſurface. For an account of the drill huſbandry now practiſed by
Mr. Coke of Holkham in Norfolk, ſee Sect. XVI. 2. 2.
SECT.

284
SECT. X.
MANURE S.
SECT. X.
MANURES, OR THE FOOD OF PLANTS.
1. 1. The CHYLE of all animals is ſimilar. It conſiſts of water, ſugar, mucilage,
oil, with carbon, phoſphorus, and calcareous earth. The SAP-JUICE of vege-
tables conſiſts of water, ſugar, mucilage, with carbon, phosphorus, and calcare-
ous earth.
2. Food of young animals, of adult animals. Power of digeſtion.
Produɛtion of ſugar by digeſtion. 3. Food of young vegetables. Production of
ſugar by germination. 4. Food of adult plants from the ſpontaneous decompoſition
of vegetable and animal bodies, or from water and air alone. They poſſeſs low heat
and cold blood like winter-ſleeping animals. Diſtinction between animals and vege-
tables. II. 1. AIR. Oxygen in air, in water, united with heat, and light.
2. Forms all acids. 3. Metallic oxydes. 4. The baſes of all acids are inſoluble
in water. 5. Carbonic acid gas from fermentation. In its fluid ſtate. 6. Aque-
ous acid. 7. Oxygen in vegetable perſpiration. 8. Plants Sprinkled with oxy-
genated water. Oxygen gas applied near their roots. 9. Azote or nitrogen is
found in vegetables. Produces nitre and ammoniac. III. 1. WATER. Its large
quantity in plants. 2. Uſe of their great perſpiration. 3. Water becomes decom-
poſed in plants, and is hyper-oxygenated. 4. Gives lubricity, fluidity, and ſolu-
tion. 5. Irrigation of the ſoil brings other manures 6. Penetrability of the foil
from irrigation. Sow and reap early in wet foils. 7. Hafty Showers are injuri-
ous. Hills ſhould be ploughed horizontally Uſe of ridges and furrows. Surface
of air greater. 8. Evaporation produces cold. Uſes of coping-ſtones on fruit-walls.
9. ProduEtion of foliage requires more moiſture than that of ſeeds. Froſt in Scot-
land ripens the corn. 10. Lime and dung-bills attract water. Steam uſed in
bot-bouſes. Much water in the atmosphere. IV. 1. CARBON is an univerſal
material in the atmoſphere. 2. In limeſtone. 3. In black earth, moraſſes, loam.
.
Carbon combines with putrid exhalations. 4. United with oxygen is ſoluble in
water. Lime combines with water. Emits beat. Is broken into powder by ſteam.
Sbould be ſlaked before it is uſed in agriculture. Better Naked with hot water.
Attraet's

Secr. X.
MANURES.
18;
Attraets the carbonic acid, and in conſequence the water, of the atmoſphere. 5. Cor-
bonic acid fubfides on the earth in the air. 6. United with calcareous earth is
ſoluble in water, and abſorbed by vegetables. 7. An experiment in which carbon
and lime form an hepar, and thus become ſoluble in water. 8. Vegetable roots ab-
forb carbonic acid from limeſtone in its fluid, not its gaſeous ſtate. 9. Carbon
exiſts in ſugar and mucilage, which are abſorbed undecompounded. V. PHOSPH0-
RUS is a ſimple ſubſtance. Appears in rotten wood. In putreſcent fleſh and fiſh.
2. Exiſts in all vegetable and animal matter, as ſeen in Homberg's pyrophorus, and
in Kunkel's phosphorus. 3. And in all calcareous earth, as in oyſter-ſhells, lime-
ſtone, gypſum, fluor. 4. Hence the uſe of calcareous earth in agriculture. 5. Shells
become limeſtone by attrating carbonic acid from the air. Mountains of calcareous
phoſphorus. Limeſtone ſhould be burnt in cloſe veſſels. 6. The hardneſs of bones
owing to phoſphoric acid, and perhaps of ligneous fibres. VI. 1. Lime witho
carbon may make an hepar carbonis ſoluble in water. 2. Unites with carbonic
acid, and renders it ſoluble in its fluid not its gaſſeous ſtate. Water from Springs
is preferable to that from rivers for flooding lands. 3. Lime unites with phof-
phorus, and renders it ſoluble in water. Unites alſo with phosphoric acid. Whence
crab-fifh renew their ſhells, and ſnails repair and enlarge theirs. 4. Lime unites
with oil and mucilage, and may thence become nutritious. It decompoſes ſoap, and
conſtitutes a part of animals and vegetables. 5. Lime deſtroys the coheſion of dead
vegetables. Of recent oxes by combuſtion. Attracts moiſture from the air and
earth. Makes clay leſs adheſive. Unites with acids of vitriol and of nitre. Kills
inſects. 6. One limeſtone twenty miles long and ten broad. Lime not of uſe on
wet land, nor always on all calcareous ſoils. 7. Lime both forwards the ripening
and meliorates and increaſes wheat and graſs by ſupplying nutriment. 8. Gypſum,
fluor, bone aſhes. Breedon lime is half magneſia. VII. 1. CLAY is too adhe-
five. Becomes more ſolid by frot. 2. Efferveſces in the air. Acquires oxygen.
So iron, manganeſe, zinc. Raddle uſed as manure.
3. Granite acquires oxygen.
Granites and dry clay have a ſmell when breathed on. Marl crumbles in the air.
Burnt clay acquires oxygen and burnt lead. 4. Burnt clay promotes the genera-
tion of nitre. Uſe of paring and burning. 5. Burnt clay decompoſes marine ſalt.
Uſe of ſea-Salt in manure. 6. Would phosphat of lime combine with clay, or bone-
aſhes? 7. Coheſion of clay overcome by air. By roots of ſtrong plants. By car-
bonic acid from leaves in the ſhade. By dunghill water. By lime. 8. Aluminous
clays how to correct. By wood-afbes, ſoap-fuds, lime, magneſia. VIII. 1. Spon-
Bb
TANEOUS

186
SECT. X. I.I.
MANURE S.
TANEOUS MANURES.
Saccharine fermentation is a chemical proceſs. Exiſts
beneath the ſoil. 2. Vinous fermentation. Carbon and oxygen in a fluid ſtate.
Heat of bark-beds. Hay-ſtacks take fire. 3. Putrefaction decompoſes water.
4. Produces nitre, whoſe looſe oxygen promotes vegetation. 5. Sow foon after the
plough. IX. CHEMICAL MANURES. 1. Sugar and mucilage abſorbed unde-
compoſed. 2. Heat deſtroys life in feeds, fruits, roots. Potatoes dried on a malt-
kiln. Cooked in ſteam hotter than boiling water. Papin's digeſter. 4. Tritura-
tion of wood, ſtraw, hay, for food in times of ſcarcity; of bones, chalk, bricks,
ochres, calamy for manures. X. INSECT-MANURE. Cultivated countries in-
creaſe in fertility. Some have decreaſed. Calcareous ſtrata from ſhells. Thoſe
above them from vegetables and animals. The former can live on air and water,
not the latter.
2. Crops ploughed in for manure. 3. Infeits increaſe manure.
Water from dunghills. 4.. Fiſh. XI. PRESERVATION OF MANURES. Rains
waſ manure into the ſea. Snow floods leſs injurious. Hills ſhould be ploughed.
horizontally. 2. Common fhores. 3. Burial grounds. 4. Wood-fuel. 5. Fer-
mentation requires air, water, heat. Manure hould be turned over and mixed
with lime. 6. Pig-troughs, ſoap-fuds. 7. Weeds, leaves, water-plants. 8. Peat.
XII. APPLICATION OF MANURES. 1. In powder for top-drefing. In ſtraw
for clay-fields. 2. In fields when the corn is fowed. On graſs-lands in the ſpring,
not in the autumn. 3. Cover dung-heaps with foil. Gather cow-dung from the
graſs. 4. What mesures are most nutritive. Fleſh, horn, woollen rags, meal,
ſugar, oil.
1. 1. The various ſubſtances, which conſtitute animal bodies, or
which are found in the cavities of them, are compoſed from ſimpler
elements by the proceſſes of digeſtion, and fanguification, and ſecre-
tion; for it is well known, that even milk, wbich ſo much reſembles
the chyle of animals, is not abſorbed by the lacteals without its being
previouſly coagulated, and again diſſolved in the ſtomach by the
power of digeſtion.
Hence it happens, that the chyle of all animals, and from every
kind of food which they take into their ſtomachs, is very fimilar ; and
like milk conſiſts of water, ſugar, mucilage, and oil; the laſt of
which

Sect. X. 1.2.
187
MANURE S.
which not being ſoluble in water, but only miſcible with it, gives
it its opaque white colour.
But though the chyle from different kinds of aliment is ſo ſimilar,
and all the various conſtituent parts of animal bodies are ulti-
mately produced from the chyle by fanguification and ſecretion, yet
it happens, that ſome kinds of aliment poſſeſs a greater quantity of
theſe particles, which make chyle, than other kinds of aliment.
Such materials for inſtance as already contain much ſugar, mucilage,
and oil, as the fleſh of dead animals, or the fruits and feeds of
vege-
tables.
Beſides the water, ſugar, mucilage, and oil, which exiſt in chyle,
there may be other materials, which are inviſible from their perfect
folution in water, either alone or when converted into acids by the
addition of oxygen; as carbon, phoſphorus, calcareous earth, marine
and ammoniacal ſalts; though it is more probable, that the two laſt
are formed and ſecreted by animal proceſſes, as well as ſelected by
their abſorbent roots, as they are more compounded bodies than the
former.
Similar to this chyle of animals the fap-juice, which is abſorbed
from the earth by the roots of plants, conſtitutes their nouriſhment,
and confifts of water, ſugar, and mucilage, with other tranſparent
ſolutions, as of carbon, phoſphorus, and calcareous earth. And though
it has been proved by the experiments of ſome philoſophers, that ve-
getables can extract or compofe all theſe ſubſtances from air and
water alone ; yet fome materials contribute more to the production of
this vegetable chyle or fap-juice than others, ſuch as the recrements
of dead vegetable and animal ſubſtances.
2. If any one ſhould aſk, what is the food of animals? I ſhould
anſwer, that in the moſt early ſtate of animal life the embryon lives
on a mucilaginous fluid, with which it is ſurrounded, whether in the
egg or womb: that in its infant ſtate the young animal is fuſtained
by milk, which its ſtomach converts into chyle.
B b 2
Ina
;

188
Sect. X. 1. 2.
MANURES.
In their adult ſtate animals are ſuſtained by other vegetable or ani-
mal ſubſtances taken into their ſtomachs, which are there converted
into chyle partly by a chemical, and partly by an animal proceſs; as by
a mixture of gaſtric juice with water and heat, ſome of theſe recre-
ments of organic nature are decompoſed, either into their fimpler
component parts, or ſometimes even into their elements; while other
parts of them are only rendered ſoluble or miſcible with water; and
are then drank up by the abſorbents of the ſtomach and inteſtines.
In this proceſs of digeſtion much ſugar is produced, which is pro-
bably immediately ſelected and drank up by the numerous mouths of
the lacteals, or lymphatics; to which it is preſented by the vermi-
cular or periſtaltic motions of the ſtomach and inteſtines. And as this
ready ſelection and abſorption of the ſugar, as ſoon as it is formed,
prevents it from paſſing into the vinous or acetous fermentation ; it
is probable that from the want of ſuch a means of ſeparating ſac-
charine matter, as ſoon as it is formed, chemiſtry has not yet been
able to produce ſugar from its elements without the aſſiſtance of ani-
mal digeſtion, or vegetable germination; as further ſpoken of in
No. 8. 1. of this ſection.
In this proceſs of digeſtion, I believe, a great part of the water,
ſugar, mucilage, and oil, which exiſt in vegetable and animal re-
crements, are not decompoſed into their elements, but abſorbed by
being ſoluble or miſcible with water; the carbon, and the phof-
phorus, and the hydrogen, are alſo I ſuppoſe diſſolved in the other
fluids by means of oxygen, and form a part of the chyle, without
their being converted into gaſſes; for when this happens to any ex-
ceſs in reſpect to carbon, it eſcapes from the ſtomach in eructations;
and the ſame occurs to the inflammable air or hydrogen, if a part of
the water becomes decompoſed in the inteſtines; which, if it be not
abforbed by its folution in other fluids, but acquires a gaffeous ſtate,
is liable to eſcape below; though both theſe gaffes ſeem occaſionally
3
to

Sect. X. 1. 3, 4.
189
MANURE S.
to revert to a fluid ſtate from their aerial one in the ſtomach or ine
teſtines, and to be then abſorbable by the lacteals or lymphatics.
3. What then is the food of vegetables ? the embryon plant in the
feed or fruit is ſurrounded with faccharine, mucilaginous, and oily
materials, like the animal fetus in the egg or uterus, which it ab-
forbs, and converts into nutriment; while the embryon buds of de-
ciduous trees, which is another infantine ſtate of vegetables, are ſup-
plied with a faccharine and mucilaginous juice prepared for them at
the time of their production, and depoſited in the roots or fap-wood
of their parent-trees; as in the vine, maple, and birch ; which fac-
charine matter is foluble and miſcible with the water of the ſurround-
ing earth in the ſubſequent ſpring, and is forcibly abſorbed by their
root-veffels, and expands their naſcent foliage.
In their infantine ſtate therefore there is a wonderful analogy be-
tween plants and animals; and it is particularly curious to obſerve
in the proceſs of converting barley into malt by the germination of
the ſeed, that the meal of the barley is in part converted into ſugar
by the digeſtion of the young plant exactly as in the animal ſtomach.
The wonderful effect of vegetable digeſtion in producing ſugаr may
be deduced from the great product of the fugar-cane, and of the
maple-tree in America, mentioned in Sect. III. 2. 3. and the won-
derful effect of animal digeſtion in producing ſugar appears in patients,
who labour under diabetes. A man in the Infirmary of Stafford, who
drank daily an immoderate quantity of beer, and who eat above twice
the quantity of food that thoſe in health conſume, voided ſixteen or
eighteen pounds of water daily, from each pound of which above an
ounce of coarſe ſugar was extracted by evaporation. Zoonomia, Vol. I.
Sect. XXIX. 4. 9.
. . 9
4. We now come to conſider the food of adult plants ;, and in this
conſiſts the great and eſſential difference between the nutritive pro-
ceſſes of animals and vegetables. The former are poſſeſſed of a ſto-
mach, by which they can in a few hours decompoſe the tender parts
of
a

190
MANURE S.
SECT. X. 1. 46
a
of vegetable and animal ſubſtances by a chemical proceſs within them-
ſelves, conducted in the heat of ninety-eight degrees, with a due
quantity of water, and a perpetual agitation of the ingredients; which
both mixes them, and applies them to the mouths of the abſorbent
veſſels, which ſurround them. Whereas a vegetable being having
no ftomach is neceſſitated to wait for the ſpontaneous decompoſition
of animal or vegetable recrements; which is indeed continually go-
ing on in thoſe foils, and climates, and in thoſe feaſons of the year,
which are moſt friendly to vegetation ; but is in other ſituations, and
in other ſeaſons, a ſlow proceſs in a degree of heat often as low as
forty of Farenheit, (in which the reindeer moſs, moſchus rangiferinus,
vegetates beneath the ſnow in Siberia,) and often without an adapted
quantity of water to give a due fluidity, or any mechanical locomo-
tion to preſent them to the abſorbent mouths of their roots; or in ſtill
worſe ſituations adult vegetables are neceſſitated ſtill more ſlowly to
acquire or produce their nutritive juices from the ſimpler elements of
air and water, with perhaps the ſolutions of carbonic acid and cal-
careous earth, and perhaps of ſome other matters, with which one or
more of them abound.
But M. Haſſenfratz found, that the vegetation of thoſe plants was
imperfect, which had not been ſuffered to grow in contact with the
earth; as they never arrived at ſuch maturity as to produce fruit;
and were found on analyſis to contain a lefs portion of carbon, than
other plants of the ſame kind. The experiments were tried on hya-
cinths, kidney-beans, and creſſes.
Hence the other great difference, which exiſts between theſe two
extenſive kingdoms of nature, is, that the larger and warmer blooded
animals certainly, and I ſuppoſe all the tribes of inſects, and of colder
blooded creatures alſo, can not exiſt long on air and water alone, ex-
cept in their ſtate of hibernal torpor. The neareſt approach to this is
however ſeen in ſome fevers, where water alone has been taken for
a week or two, and yet the patient has recovered ; and there is a well
atteſted
a

SECT. X. 2. 1.
191
MANURES.
a
atteſted account of a numerous caravan, which having loſt their rout,
or their proviſions, are affirmed to have lived ſome weeks on gum
arabic and water alone.
Vegetables on the contrary, as above mentioned, can exiſt, though
in a feebler ſtate, on water and air alone, with the carbonic acid,
and perhaps other inviſible ſolvends, which thoſe elements unavoid-
ably contain. This I ſuppoſe to be owing to the low degree of heat,
which they produce internally, and to the flow circulation of their
blood; from both which circumſtances leſs nutriment is expended,
as by animals which ſleep in winter.
For the purpoſe of ſupplying adult vegetables with nouriſhment,
we ſhould firſt confider what kinds of matter are moſt prevalent or
moſt neceſſary in their compofition. Secondly, what of theſe ſub-
ftances they can abſorb without previous decompoſition. Laſtly, how
to expedite the decompoſition of vegetable and animal ſubſtances on
or in the ſoil, like the digeſtive proceſſes in the ſtomachs of animals;
we may thus become acquainted with the fources and the manage-
ment of manures.
II. AIR.
1. Oxygen combined with heat conſtitutes that part of the atmo-
ſphere, which is perpetually neceſſary to animal and vegetable reſpi-
ration ; an
and a greater part of that water, which forms a principal
portion of their organization; a few words may be therefore premif-
ed on theſe moſt important diſcoveries of modern chemiſtry.
This vital air, called oxygen gas, conſtitutes twenty-ſeven hun-
dredth parts of the atmoſphere; it is indiſpenſably neceſſary to the
exiſtence of life, and of combuſtion, and forms the principal part of
all acids; whence its name. The other ſeventy-three hundredth
parts of the atmoſphere conſiſt of azote, which takes its name from
its inutility to life in animal reſpiration ; it is alſo called nitrogen,
becauſe it conſtitutes the baſis of nitre.
Oxygen
I

192
MANURE S.
Sect. X. 2. 2, 3.
Oxygen gas conſiſts of oxygen and heat; and when it unites with
ſuch bodies, as are capable of uniting with it, the heat is ſet at liberty,
as in reſpiration and in combuſtion; in both which proceſſes an acid
is produced by the combination of oxygen with ſome inflammable
baſe. Hence vital air conſiſts of oxygen diſſolved in the fluid matter
of heat; but there is alſo another fluid, which ſeems to be combined
with this ſolution of oxygen in heat, and that is light. For when
oxygen becomes combined with charcoal, or with ſulphur, or with
phoſphorus, both heat or light are ſet at liberty from theſe new com-
binations of oxygen ; which thus produce the carbonic, ſulphuric,
and phoſphoric acids.
When theſe new combinations of oxygen are performed very
ſlowly, the light is ſometimes not viſible, as in the heating of a dung-
hill; in which proceſs the oxygen in the cells or cavities of the hot-
bed unites flowly with the carbon and phoſphorus of the decompoſ-
ing vegetable and animal matters; but though much heat is given
out, no light is ſeen. While on the contrary from rotten wood alone,
or putreſcent fiſh, when expoſed to the atmoſphere, much light is
emitted, but not much ſenſible heat, owing perhaps ſimply to the
combuſtion of the phoſphorus, which they contain.
2. The products of theſe combinations of oxygen with other bodies
may all of them be termed acids; though in ſome the heat or light
ſet at liberty converts theſe acid productions into gaſſes, as oxygen
and charcoal form carbonic acid gas; and in others it converts the
new product into ſteam, which is condenſible by cold, as the ful-
phuric acid from the combination of oxygen and fulphur; and the
phoſphoric acid from oxygen and phoſphorus.
3. Other combinations of oxygen with heavier ſubſtances are pro-
duced in the atmoſphere without the ſeparation of either ſenſible
heat, or viſible light; as the union of oxygen with metallic bodies,
as with that of manganeſe, with zinc, lead, iron, as in common ore
of manganeſe, in lapis calaminaris, white calciform lead-ore, and the
8
red

SECT. X. 2. 4.
193
MANURE S.
a
red ochre of iron; which have not obtained the name of acids, but
are termed oxydes of thoſe minerals.
4. Now it happens, that none of theſe baſes, which can combine
with oxygen alone, are ſoluble in water, and therefore can not be
imbibed by the abſorbent veſſels of vegetable roots, until they become
acids; and are perhaps then all of them in greater or leſs quantities
ſoluble in water; and are thence capable of being drank up by the ab-
ſorbent veſſels of vegetable roots, and conſtitute a part of the food of
plants.
5. When vegetable ſubſtances are decompoſed by fermentation,
there is a quick union of oxygen and carbon ; and this carbonic acid
gas, called formerly fixed air, riſes up in vapour, and flies away.
But where this proceſs goes on more ſlowly, as in a dung-hill lately
turned over, or in black garden mould lately turned over, and thus
expoſed to the air ; much of which remains in the cells or cavities
of the hot bed, or border ; this carbonic acid is ſlowly produced, and is
abſorbed by vegetable roots, I ſuppoſe in its fluid ſtate, or diſſolved
in water, before it acquires ſo much heat as to riſe in the atmoſphere
in the form of gas.
This carbonic gas in its fluid ſtate, or diſſolved in water, not in its
aerial or gaſſeous ſtate, is the principal food of plants; as appears,
becauſe their ſolid fibres conſiſt principally of carbon, and their fluids
of water.
6. Next to carbonic acid the aqueous acid, if it may be ſo called, or
water, ſeems to afford the principal food of vegetables; as water con-
ſiſts of oxygen and hydrogen, it is properly an acid, like all other com-
binations of oxygen ; and when abſorbed by vegetable roots becomes
in part decompoſed in the circulation or ſecretion of their juices;
the oxygen diſappears, or contributes to form the vegetable acids;
and the hydrogen produces ammonia by its union with azote; which
may contribute to vegetable nutriment by its mixture with oils, and
thus producing ſoaps, which become diffuſible in water; and alſo by
Сс
decompoſing

194
Sect. X. 2.7.
MANURE S.
a
decompoſing inſoluble ſaline earths, as gypſum, or metallic falts, as
vitriol of iron, and thus producing more ſoluble or innocuous ſalts.
And which laſtly forms a part of the various vegetable productions of
ſugar, honey, wax, reſin, and other ſecretions.
7. There is a curious evolution of oxygen attends the perſpiration
of the leaves of plants, which is not known to attend that of animal
lungs; and that is, that when vegetable leaves are expoſed to the
ſun's light, they ſeem to give up oxygen gas ; but in the dark they
give up carbonic acid gas, like the breath of animals. It is probable that
animal lungs might do the fame, if they were expoſed to the light;
as perhaps might be ſubjected to experiment in the gills of fiſh, or
by breathing through a tube into water in the ſunſhine.
In reſpiration as well as in combuſtion ſome light may poſſibly be
given out as well as ſome heat from the combination of oxygen with
ſome phlogiſtic baſe, as carbon or phoſphorus; whence the produc-
tion of carbonic and phoſphoric acids in both animal and vegetable
reſpiration. In moſt animals this quantity of light is probably too
ſmall to be perceived, if their bodies were tranſparent; but in the
glow-worm of this country, and in the more luminous fire-flies of
the tropical climates, I ſuſpect the light to be emitted from their
lungs in the act of reſpiration, which is a ſlow combuſtion.
8. Beſides the uſe of oxygen in the reſpiration of vegetables,
when applied to their leaves, as it is mixed in the atmoſphere; it is
believed by many to contribute much to their growth and nouriſh-
ment in its combined ſtate, when abſorbed by their roots; and that
by the decompoſition of water in the vegetable ſyſtem, when the hy-
drogen unites with carbon and produces oil, the oxygen becomes ſu-
perfluous, and is in part exhaled, as further ſpoken of in Sect. XIII.
Hence alſo ſome calciform ores, or metallic oxydes, as raddle,
and calamine, and burnt clay, are ſuppoſed to be uſeful as manures,
becauſe they contain much oxygen, as mentioned in No. 7. 1. of
this Section
Mr.
a
I. 22.

SECT. X. 2.9.
195
MANURE S.
Mr. Humboldt afferts, that on putting creffes, lepidium ſativum,
into oxygenated muriatic acid gas mixed with water, they produced
germs in ſix hours; while thoſe in common water were thirty-fix
hours before they produced germs. Jacquin at Vienna put many old
ſeeds, which had been in vain tried if they would vegetate, into ſuch
a ſolution of oxygenated muriatic acid, and found great numbers of
them quickly to vegetate. Journal de Phyſique, 1798. See Sect. XIV.
2. 5.
In the experiments of fir Francis Ford many plants, which were
ſprinkled with water previouſly impregnated with oxygen gas, are
ſaid to have grown more vigorouſly, and to have diſplayed more
beautiful tints, than thoſe nouriſhed with common water. Other ex-
periments are ſaid to have been made by inverting bottles filled with
oxygen gas, and burying their open mouths beneath the ſoil near
the roots of vegetables, which are ſaid to have grown more healthy
and beautiful, as the oxygen became abſorbed, and was ſucceeded by
air like the common atmoſphere. Philof. Magaz. 1798, p. 224. Fur-
ther experiments are required on this ſubject, ſince the fluids of ve-
getables would in general appear to be hyperoxygenated from the
oxygen emitted from the perſpiration of their leaves in the ſunſhine,
and which is believed to ariſe from the decompoſition of water in
their arteries or glands.
9. We now come to the other ingredient, which conſtitutes a
much greater part of the atmoſphere than the oxygen, and this is
the azote, or nitrogen ; which alſo ſeems much to contribute to the
food or ſuſtenance of vegetables ; for though azote, or nitrogen, en-
ters into animal bodies in much greater quantities perhaps than into
vegetables, ſo as to conſtitute according to ſome chemical philofo-
phers the principal difference between theſe two great claſſes of or-
ganized nature; yet it enters alſo into the vegetable ſyſtem, and is
given out by their putrefa&tion ; and alſo when lime is applied to moiſt
;
vegetables it diſengages from them both hydrogen and azote forming
Сс2
volatile

196
SECT. X. 3. I.
MANURE S.
volatile alkali, as aſſerted in the ingenious work of Lord Dundonald
on the Connection of Agriculture with Chemiſtry.
The azote of the atmoſphere, when air is confined in the inter-
ſtices of the ſoil newly turned over by the plough or ſpade, contributes
to the production of the nitrous acid by its union with the
oxygen
of
the atmoſphere, with which it was before only diffuſed, or with the
much greater ſource of oxygen from the decompoſing water of the
ſoil. At the ſame time another part of the abundant azote combines
with the hydrogen of the decompofing water of the ſoil, and produces
ammonia or volatile alkali; which contributes to the growth of ve-
getables many ways, as already deſcribed in No. 2. 6. of this Sec-
tion.
III.
WA T E R.
1. The neceſſity of much water in the progreſs of vegetation ap-
pears from the great quantity, which exiſts naturally in all parts of
plants; inſomuch that many roots, as ſquill and rhubarb, are known
to loſe about fix parts out of ſeven of their original weight ſimply by
drying them before the fire ; which quantity of moiſture nevertheleſs
does not exhale in the common heat of the atmoſphere during the
life of the root; as is ſeen in the growth of ſquills in the ſhops of the
druggiſts, and of onions on the floors of our ſtore-rooms.
2. A ſecond neceſſity of much water in the economy of vegetation
may be deduced from the great perſpiration of plants, which appears
from the experiments of Hales and others; who like Sanctorius have
eſtimated the quantity of their perſpiration from their daily loſs of
weight; which however is not an accurate concluſion either in re-
ſpect to plants or animals, as they both abſorb moiſture from the at-
moſphere, as well as perſpire it.
This great perſpiration of vegetables, like that from the ſkin and
lungs of animals, does not appear to conſiſt of excrementitious mat-
ter, becauſe it has in general no putreſcent ſmell or taſte; but ſeems
to

SECT. X. 3. 3.
197
MANURE S.
to be ſecreted firſt for the purpoſe of keeping the external ſurface of
the leaves from becoming dry, which would prevent the oxygen of
the atmoſphere from entering into the vegetable blood through them;
ſince according to the experiments of Dr. Prieſtley on animal mem-
branes the oxygen will only paſs through them, when they are moiſt.
A ſecond uſe of this great perſpiration is to keep the bark ſupple by
its moiſture, and thus to prevent its being cracked by the motion of
the branches in the wind. And though a great part of this perſpi-
rable matter is probably abſorbed, as on the ſkins of animals; yet as
it exiſts on ſo large a ſurface of leaves and twigs, much of it muſt
neceffarily evaporate on dry and windy days.
3. One of the great diſcoveries of modern chemiſtry is the decom-
poſition of water, which is thewn both by analyſis and ſyntheſis to
conſiſt of eighty-five hundredth parts of oxygen, and fifteen of hy-
drogen. Hence a third great uſe of water in the vegetable economy
is probably owing to its ready decompoſition by their organs of di-
geftion, fanguification, and fecretion. This is evinced firſt by the
great quantity of hydrogen, which exiſts in the compoſition of many
of their inflammable parts. And ſecondly, from the curious circum-
ſtance, which was firſt diſcovered by the ingenious Dr. Prieſtley, that
the water, which they perſpire, is hyperoxygenated ; and in conſe-
quence always ready to part with its ſuperabundance of oxygen, when
expoſed to the ſun's light; from whence it may be concluded, that
part of the hydrogen, which was previouſly an ingredient of this wa-
ter, had been ſeparated from it, and uſed in the vegetable economy,
as is further treated of in Section XIII. 1. 2.
Add to this, that from the decompoſition of water, when confined
in contact with air beneath the ſoil, the nitrous acid ſeems to be pro-
duced and ammonia, both which are believed uſeful to vegetation, as
mentioned in No. 2. 6. of this Section,
4. Beſides the peculiar uſes of a great quantity of water, as above
deſcribed, the more common uſes of it both to vegetable and animal
life,

198
SECT. X. 3. 5.
MANURE S.
life, along with the matter of heat, are to produce or preſerve a due
ſuppleneſs or lubricity of the ſolids, and a due degree of fluidity of
the liquids, which they contain or circulate. And laſtly, for the pur-
poſe of diffolving or diffuſing in it other ſolid or fluid ſubſtances, and
thus rendering them capable of abſorption, circulation, and ſecre-
tion.
5. The due irrigation of the ſoil is much attended to in drier and
warmer countries, as in Italy, Egypt, and ſome parts of China ;
where numerous canals, and aqueducts, have been dug through hills,
and carried over vallies, for the purpoſe of watering the ſoil; and
even in this colder and moiſter climate the practice of flooding land
is coming daily into greater repute. For this occaſional ſuffufion of
water over land not only ſupplies ſimple moiſture for the purpoſes
above mentioned in the drier parts of the ſeaſons, but brings along
with it calcareous earth and azotic air from the neighbouring ſprings,
or other manures from the rivers. Calcareous earth may be detected
in the water of all thoſe ſprings which paſs under or over ſtrata of
marle or limeſtone, by dropping into them a ſolution of ſalt of tartar;
or of ſugar of lead in water, or of ſoap in ſpirits of wine; and a por-
tion of azotic gas was diſcovered in Bath-water by Dr. Prieſtley, and
in Buxton-water by Dr. Pierſon. See Section XI. 3. 1. Dr. Home
thinks he diſcovered nitrat of lime in hard water, and found by his
experiments that it promoted the growth of plants in a much greater
degree than ſoft water.
6. Another demand for water in agriculture is to give a due penc-
trability to the ſoil, which otherwiſe in moſt ſituations becomes ſo
hard as to ſtop the elongation of the tender roots of plants; but the
coheſion of the ſoil may nevertheleſs be too much diminiſhed by great
and perpetual moiſture, ſo as not to give ſufficient firmneſs to the
roots of trees. And beſides this too much as well as too little water
may be ſupplied to the generality of vegetables, which grow upon
the land ; though there are aquatic and amphibious plants as well as
3
aquatic

SECT. X. 3. 7.
199
MANURE S.
aquatic and amphibious animals, and which differ from each other as
fiſh and feals from quadrupeds.
Where land abounds too much with moiſture, the art of making
ſubterraneous or ſuperficial drains deſcribed in Sect. XI. 1. muſt be
had recourſe to. But where theſe are not executed, in lands not very
moiſt it is thought advantageous to fow the crops early before the wet
ſeaſon, fince corn will bear much more moiſture after it has ſhot from
the ſeed, than the feed will bear; as the feed is leſs tenacious of life,
and in conſequence more liable to putrify. The crops ſhould like-
wiſe be ſown or planted thinner, and be reaped early in the ſeaſon, as
the excluſion of the air by thick foliage, and the greater dampneſs of
the autumn, are liable to generate mildew in moiſt ſituations. Per-
haps it ſhould be added, that ſowing early, and the conſequent reap-
ing early, has ſo many advantages in all ſeaſons on all lands, that it
may in general be univerſally recommended; and that in wet lands
it might be very advantageous to cultivate crops by tranſplantation
in the vernal months, having previouſly fowed the ſeed in drier or
warmer ſituations. See Sect. XVI. 8. 1.
7. Another injury in this climate occaſioned by too great a quan-
tity of water ariſes from hafty ſhowers; which waſh off much of
the decompoſing animal and vegetable recrements, which are ſoluble
or diffuſible in water, and carry them down the rivers into the ſea.
From the ſides of hills this damage is accompliſhed by ſmall ſhowers,
on which account all floping grounds when applied to agriculture
ſhould be ploughed horizontally, as by the ridges and furrows thus
produced the ſmaller ſhowers of rain will not paſs ſo haſtily off, as
when they are ploughed vertically.
A queſtion here occurs, whether it be advantageous to plough level
plains into ridges and furrows ? the Chineſe are ſaid never to divide
their fields into ridges and furrows, but to plant their grain on an
even ſurface. Embaffy to China by ſir G. Staunton, Vol. III. p. 197,
8vo. edit. Some think it an error to ſuppoſe, that any increaſe of
crop

200
Sect. X. 3. 8.
MANURES.
crop can be thus obtained, as no more plants can riſe perpendicularly
from the ground; but in the ripening of grain the ſurface of air to
which the ears are expoſed is alſo to be conſidered ; which correſ-
ponds with the ſurface of the ground, and is increaſed by its being
laid in hill and dale. But there is a ſerious objection to this mode of
ploughing in moiſt ſituations without ſufficient declivity, as the corn
in the furrows appears weak and backward owing to the rain lying
on it too long; and alſo to the beſt part of ſhallow ſoils being fre-
quently taken from them to conſtruct the ridges. See Sect. XVI.
2. 2.
8. Add to this, that the evaporation of moiſture from the ſurface
of the earth produces ſo much cold as to injure thoſe terreſtrial plants,
which are too long covered with it. On this account thoſe parts of
wall-trees, which are ſheltered from the deſcending dews by a coping
ftone on the wall, are not ſo liable to be injured by froſty nights on
two accounts; both as they are not made colder by the evaporation
of the dew, and alſo have leſs water to be congealed in their veſſels,
and by its expanſion to burſt them.
9. Laſtly, the foliage on buds of plants, which conſtitute one part
of their progeny, requires more moiſture for its vigorous growth, than
their flowers or organs of ſexual generation. Hence in warm coun-
tries the rice-grounds are flooded only till the ſeaſon of flowering
commences, and are laid dry again for the purpoſe of maturating the
ſeed; and in our climate continued rains are liable not only to waſh
off the farina from the burſting anthers, and thus prevent the im-
pregnation of the piſtillum, but alſo to delay the ripening of the fruit
or ſeeds from the want of a due evaporation of their perſpirable mat-
ter, as well as from the leſs ſolar light in cloudy ſeaſons; whence in
the north of Scotland the oats are ſaid ſeldom to ripen till the froſt
commences with the dry ſeaſon, which accompanies it.
10. There are methods of procuring or preſerving the falutary
moiſture of the ſoil beſides thoſe of canals and aqueducts, which
ſhould
a

SECT. X. 4. 1.
201
MANURE S.
ſhould be here mentioned. Theſe are by uſing as manures ſuch ſub-
ſtances as perpetually attract moiſture from the lower part of the ſoil,
or from the atmoſphere; as quick-lime, and vegetable and animal
recrements in the act of putrefaction.
In hot-houſes fome have already employed ſteam as a means both
of giving warmth and moniture to the included plants, or to the ſoil
in which they grow; and a great variety of forcing pumps have been
conſtructed for the purpoſe of moiſtening the foliage of wall-trees;
but there is a hope from the preſent great progreſs of chemical re-
ſearch, that a means may ſometime be diſovered of precipitating the
water of the atmoſphere, which the ingenious bithop Watſon thinks
always exiſts in it in ſuch quantity as, if it was ſuddenly precipitated,
might again deluge the world.
IV.
CARBON.
1. When animal and vegetable bodies are burnt without the acceſs
of air, that is, when their volatile parts are ſublimed; there remains
a great quantity of charcoal, a much greater in vegetable bodies than
in animal ones ; this is termed carbon by the French ſchool, when
it is quite pure; and is now known to be one of the moſt univerſal
materials of nature. And as vegetable bodies contain ſo much of it
in their compoſition, they may be ſuppoſed to abſorb it intire, where
they grow vigorouſly; eſpecially as it is a ſimple material; but they
may poſſibly form it alſo occaſionally from water and air within
their own veſſels, when they are ſecluded from acceſs to it exter-
nally.
The whole atmoſphere contains always a quantity of it in the form
of carbonic acid, or fixed air ; as is known by the ſcum, which pre-
fently becomes viſible on lime-water, when expoſed to the air ; and
which conſiſts of a reunion of the lime with carbonic acid, which
may therefore be ſaid to encompaſs the earth.
Dd
The
a

202
SECT. X. 4. 2.
MANURE S.
3
a
The fimplicity of carbon, as an elementary ſubſtance, was diſputed
by Dr. Auſtin, who believed he had decompounded it. But Mr.
Henry, by accurately repeating his experiments, has ſhewn the fal-
lacy or inconclufiveneſs of them. Philof. Tranfaét. 1797.
2. Another great reſervoir of carbon exiſts in limeſtone in the form
of carbonic acid ; which when a ſtronger acid is poured on the cal-
careous earth becomes a gas, acquiring its neceſſary addition of heat
from that, which is given out in the combination of the ſtronger acid
with the lime. It alſo acquires its neceſſary heat, when limeſtone is
burnt, from the conſuming fuel, riſes in the form of gas, and is diſ-
ſipated in the air; and probably ſoon ſettles on the earth, as it cools,
as it is ten times heavier than the common atmoſphere.
3. But the great ſource of carbon exiſts in the black earth, which
has lately been left by the decompoſition of vegetable and animal bo-
dies; and is then in a ſtate fit to combine with azote or nitrogen,
ac
and with oxygen, when expoſed to thoſe two gaſſes, as they exiſt
in the atmoſphere; and is thus adapted either to promote the gene-
ration of nitrous acid, or to form carbonic acid, and thus to aſſiſt
vegetation
Moraſſes conſiſt principally of the carbonic recrements of vegeta-
ble matters, which are gradually decompoſed in great length of time
into clay, with argillaceous ſand, ſuch as is found over coal-beds, and
ſome calcareous earth, as in marl; and laſtly, with ſome iron, and
foffile coal. Theſe by elutriation are ſeparated from each other, and
form the ſtrata of coal countries. In other places they remain in-
termixed, as they were probably produced from the decompoſition of
vegetables and terreſtrial animals; and form what in books of prac-
tical agriculture is called a loamy ſoil, conſiſting of carbonic matter,
fand, and clay, with a portion of iron.
It has always been obſerved, that this black garden mould, or earth
produced from the recrements of vegetables, is capable of abſorbing a
much greater quantity of putrid effluvia than either air or water, and
6
probably
-

Sect. X. 4.4.
203
MANURE S.
a
a
a
probably of combining with its ammonia, and producing a kind of he-
par carbonis, and thus facilitating vegetation. The practice of bu-
rying dead bodies ſo few feet below the ſurface is a proof of this; a
the putrid exhalations from the carcaſs are retained, and do not pene-
trate to the ſurface. On the ſame account the air over new plough-
ed fields has long been eſteemed falutary to invalids, or convalef-
cents, as it probably purifies the ſupernatent atmoſphere. But it was
not till lately known that carbon, or charcoal, abſorbs with ſuch
great avidity all putrid exhalations; if it has been recently burnt,
and has not been already ſaturated with them, in ſomuch that putrid
fleſh is ſaid to be much ſweetened by being covered a few inches with
the powder of charcoal ; or even by being buried for a time in black
garden mould; as putrid exhalations conſiſt chiefly of ammonia, hy-
drogen, and carbonic acid, and are the immediate products of the
diffolution of animal or vegetable bodies, they are believed much to
contribute to vegetation ; as whatever materials have conſtituted an
organic body, may again after a certain degree of diffolution form a
part of another organic body. The hydrogen and azote produce am-
monia, which combining with carbon may form an hepar carbonis,
and by thus rendering carbon foluble in water may much contri-
bute to the growth of vegetables.
It has been ſaid, that forne moraffes have prevented the animal bo-
dies, which have been buried in them, from putrefaction; which may
in part have been owing to the great attraction of the carbon of the
moraſs to putrid effluvia, and in part perhaps to the vitriolic acid,
which ſome moraffes are ſaid to contain.
4. Here occurs an important queſtion, by what other means is
this ſolid carbon rendered fluid, ſo as to be capable of entering the
fine mouths of vegetable abſorbents? The carbon, which exiſts in
the atmoſphere, and in limeſtone, is united with oxygen, and thence
becomes ſoluble or diffuſible in water; and may thus be abſorbed by
the living action of vegetable veſſels; or may be again combined by
D d 2
chemical
DICT

204
Sect. X. 4. 4.
MANURE S.
a
chemical attraction with the lime, which has been deprived of it by
calcination.
When mild calcareous earth, as limeſtone, chalk, marble, has been
deprived of its water and of its carbonic acid by calcipation, it be-
comes lime. Afterwards when it is cold, if water be ſprinkled on
it, a conſiderable heat is inſtantly perceived; which is preſſed out
by the combination of a part of the water with the lime; as all bo-
dies, when they change from a fluid ſtate to a ſolid one, give out
the heat, which before kept them fluid. At the ſame time another
part of the water, which was added, is raiſed into ſteam by the great
heat given out as above mentioned; and the expanſion of this ſteam
breaks the lime into fine powder, which otherwiſe retains the form
of the lumps of limeſtone before calcination. But if too great a quan-
tity of cold water be ſuddenly added, no ſteam is raiſed; and the
lump of lime retains its form ; whence it happens, that ſome kinds
of lime fall into finer powder, and are ſaid to make better mortar, if
ſlaked with boiling water than with cold.
On this account the lime, which is deſigned to be fpread on land,
ſhould previouſly be laid on a heap, and either ſuffered to become moiſt
by the water of the atmoſphere, or flaked by a proper quantity of
water ; otherwiſe if it be ſpread on wet ground, or when ſo ſpread
is expoſed to much rain, the heat generated will be difſipated with-
out breaking the lumps of lime into powder; which will then gra-
dually harden again into limeſtone, diſappoint the expectation of the
agricultor, and afflict him with the loſs of much labour and ex-
pence.
When the powder of flaked lime mixed with ſand and water is
ſpread on a wall, that part of the water which is not neceſſary for its
imperfect cryftallization, evaporates into the air ; and the lime then
gradually attracts the carbonic acid, which is diffuſed in the atmo-
ſphere; but as I ſuppoſe this carbonic acid is diffolved in the water,
I
which is alſo diffuſed in the atmoſphere; the lime is perpetually
-moiſtened

Sect. X. 4. 5.
205
MANURE S.
moiſtened by this new acquiſition of water from the air ; as that,
which before adhered to it, and had parted with its carbonic acid, eva-
porates. On which account new built walls are months, and even
years, in drying, as they continue to attract water along with the
carbonic acid from the air, which ſtands upon them in drops, till the
lime regains its original quantity of carbonic acid, and again hardens
into ſtone, or forms a ſpar by its more perfect or leſs diſturbed cryſ-
tallization.
5. The earth I ſuppoſe acquires carbon, both in a manner ſimilar
to the above by its attracting either the carbonic acid, or the water
in which it is diffuſed, from the atmoſphere; and alſo by the ſpecific
gravity of carbonic acid gas being ten times greater than that of
common air; whence there muſt be conſtantly a great ſediment of
it on the ſurface of the earth; which in its ſtate of ſolution in
oxygen
and water may be readily drank up by the roots of vegetables.
6. Another means by which vegetables acquire carbon in great
quantity may be from limeſtone diffolved in water; which though a
flow proceſs occurs in innumerable ſprings of water, which paſs
through the calcareous or marly ſtrata of the earth; as thoſe of Mat-
lock and Briſtol in paſſing through limeſtone; and thoſe about Derby
in paſſing through marl ; and is brought to the roots of vegetables by
the ſhowers, which fall on foils, where marl, chalk, limeſtone, mar-
ble, alabaſter, fluor, exiſt; which includes almoſt the whole of this
iſland. By this ſolution of mild calcareous earth in water not only
the carbon in the form of carbonic acid not yet made into gas, but
the lime alſo, with which it is united, becomes abforbed into the ve-
getable ſyſtem, and thus contributes to the nutriment of plants both
as ſo much calcareous earth, and as ſo much carbon.
7. Another mode by which vegetables acquire carbon, may be by
the union of this ſimple ſubſtance, with which all garden-mould
abounds, with pure calcareous earth into a kind of hepar, analogous
to the hepar of ſulphur made with lime, which abounds in ſome mi-
neral
a

206
SECT. X. 4. 8.
MANURE S.
neral waters. And this I ſuppoſe to be the great uſe of lime in agri-
culture.
For the purpoſe of aſcertaining the probability of this mode of ſo-
lution of carbon I made the following experiment. About two
ounces of lime in powder were mixed with about as much charcoal
in powder, put into a crucible, and covered with an inch or two of
ſiliceous ſand. The crucible was kept red hot for an hour or longer,
and then ſuffered to cool. On the next day water was poured on the
lime and charcoal, which then ſtood a day or two in an open cup,
and acquired a calcareous ſcum on its ſurface. And though it had
not much taſte, except of the cauſticity of the lime, yet on dropping
one drop of marine acid into a tea-ſpoonful of the clear ſolution a
ſtrong ſmell like that of hepar ſulphuris was perceived, or like that
of Harrogate water; which evinced, that the carbon was thus ren-
dered foluble in water.
Perhaps the fulphureous ſmell of Harrogate and Kedleſton waters,
and other ſimilar ſprings, may be owing to the union of the alkali
of decompoſing marine falt with the carbon of the earth, they run
through ? and this kind of water might thus poſſibly be uſed as a
profitable manure
8. Another mode by which vegetable roots acquire carbon, I ſuf-
pect to be by their difuniting carbonic acid from limeſtone in its fluid
not its gaſſeous ſtate; which the limeſtone again attracts from the
atmoſphere and conſolidates, or from other matters included in the
foil. Firſt, becauſe lime is believed by ſome agricultors, who much
employ it, to do more ſervice in the ſecond year than in the firſt;
that is in its mild ſtate, when it abounds with carbonic acid, than in
its cauſtic ſtate, when it is deprived of it.
Secondly, that the uſe of burning lime ſeems hence to be fimply
to reduce it to an impalpable powder, almoſt approaching to fluidity;
which muſt facilitate the application of the innumerable extremities
of vegetable fibres to this uncalculable increaſe of its ſurface; which
may

SECT. X. 5. I.
207
MANURES.
may thence acquire by their abſorbent power the carbonic acid from
theſe minute particles of lime, as faſt as they can recover it by che-
mical attraction from the air, or water, or from other inanimate
ſubſtances in their vicinity.
Thirdly, the hyper-oxygenation of the perſpirable matter of plants,
which thence gives up oxygen gas in the ſunſhine, would induce us
to believe, that a great part of the carbon, which furniſhes ſo prin-
cipal a part of vegetable nutriment, was received by their roots in the
form of carbonic acid; and that it becomes in part decompoſed in
their circulation, giving up its oxygen; which thus abounds in the
ſecreted fluids of vegetables from this ſource, as well as from decom-
poſed water.
9. Another way by which carbon is received into the vegetable
ſyſtem is by its exiſtence in ſugar and in mucilage ; both which are
taken up undecompounded, as appears by their preſence in the vernal
ſap-juice, which is obtained from the maple and the birch; which
like the chyle of animals, is abforbed in its undecompounded ſtate.
V.
PHOSPHORUS.
1. Another material which exiſts, I believe, univerſally in vegeta-
bles, and has not yet been ſufficiently attended to, is phoſphorus.
This like the carbon, nitrogen, hydrogen, and ſulphur, is probably
a ſimple ſubſtance; as our preſent chemiſtry has not yet certainly
analyſed any of them; and therefore I ſuppoſe it is taken up intire
by the abſorbent veſſels of vegetables, when it can be met with in a
ſtate of ſolution ; though it may alſo be occaſionally formed and ſe-
creted by them; and may hence be regiſtered among the articles of
their food or ſuſtenance,
When wood is decompoſed by putrefaction in a certain degree of
warmth and moiſture, it is often ſeen to emit much light in dark
evenings, when recently broken and expoſed to the oxygen of the
atmoſphere,

208
.
MANURE S.
.
Sect. X. 5.2a
atmoſphere, ſo as to alarm benighted paſſengers; which is undoubt-
edly owing to the phoſphorus, which it contains, and which is at this
time converted into phoſphoric acid. Such a light frequently is ſeen
on putreſcent veal, when kept in a certain degree of warmth and
moiſture; and on the ſea-weed placed on the oyſters packed in bar-
rels, and ſent into the country; and in the ſtreets of Edinburgh,
where the heads of the fiſh called whitings or haddies are frequently
thrown out by the people, I have on a dark night eaſily seen the hour
by holding one of them to my watch.
2. The exiſtence of phoſphorus in vegetables was detected by
Margraaf; who found, that many vegetable matters, particularly fa-
rinaceous grains, contain enough of the phoſphoric acid to produce
phoſphorus, when they are expoſed to great heat in cloſe veſſels.
Macquer's Chemical Dictionary tranſlated by Mr. Keir, Vol. II.
p. 535, Art. Phoſphorus. Phoſphorus has been detected in gum
arabic, ſugar, honey, flour, and in every kind of vegetable or ani-
mal ſubſtance by the proceſs of making the phoſphorus of Homberg.
And the exiſtence of phoſphorus in greater quantity in all the parts
and recrements of animals, as in their fleſh, dung, urine, and bone-
alhes, and moſt copiouſly in the two latter, is evinced in the fabrica-
tion of Kunkel's phoſphorus. Whence its univerſal exiſtence is dif-
covered in theſe two great kingdoms of nature. See the above Dict.
Art. Pyrophorus.
The moft eaſy proceſs for producing Homberg's phoſphorus con-
fifts in mixing three parts of alum with one of ſugar, which are to be
expoſed to a great heat in a covered crucible, till a bluiſh flame has
appeared for ſome time. It muſt then be ſuffered to cool a little, and
be put into a dry hot bottle, and cloſely ſtopped from the air. A
drachm of this powder will afterwards, when poured from the bottle
into the open air on paper, quickly kindle, become red like burning
coals, and burn the paper, which it lies upon.
Hence we may conclude, that vegetable bodies, as well as animal
ones,
a

SECT. X. 5. 3.
MANURE S.
209
ones, contain acid of phoſphorus ; and that in this experiment the
acid of the alum takes the fixed alkaline falt from the vegetable
aſhes, and the calcareous earth, if ſuch there be, and that the car-
bon unites with the oxygen of the phoſphoric acid; and the vege-
table phoſphorus is left mingled with the earth of alum; exactly in
the ſame manner as the animal phoſphorus is obtained from the aſhes
of bones, or the ſalt of urine, by calcining them in cloſe veſſels with
charcoal.
3. An important queſtion now occurs ; if this ſimple material of
phoſphorus be not generally made in the veſſels of vegetables, whence
do they acquire it? They may probably obtain it in conſiderable
quantity from the recrements of decaying vegetable and animal bo-
dies; as it appears in rotten wood, and in putrefying fiſh, and exiſts
in ſuch large quantities in bone-alhes, and in the falt of urine. But
I ſuppoſe there is another great ſource of phoſphorus, I mean in cal-
careous earth, which alſo has been of animal origin in the early ages
of the world.
If an oyſter-ſhell be calcined for about half an hour in a common
fire, and is then kept from the air in a cold place; when it is after-
wards expoſed for a while to the ſunſhine, and brought into a dark
room, it will appear luminous like the calcined Bolognian ſtone; which
is owing to the phoſphoric acid thus deprived of its oxygen by the
carbon of the fire-coals, and intermingled with the pure calcareous
earth or lime of the ſhell; and which again combining with the oxy-
gen of the air, both light and heat are emitted in the reproduction of
phoſphoric acid. See Wilſon ori Phoſphori, Dodſley, London, 1795.
The Bolognian ſtone is a ſelenite or gypſum, which conſiſts of
vitriolic acid and calcareous earth, and I ſuppoſe of acid of phoſpho-
rus; ſince on mixing the powder of this ſtone with gum arabic, and
calcining it ſome time, a kind of phoſphorus is produced fimilar to the
above, owing I ſuppoſe to the carbon of the fire coals, or of the gum
arabic, carrying off the oxygen from the phoſphoric acid ; which pre-
Еe
viouſly
a

210
MANURES.
Secr. X, 5. 4.
viouſly exiſted both in the calcareous earth of the ſelenite, and in the
aſhes of the gum arabic.
Mr. Canton, in the Philoſ. Tranſact. Vol. LVIII. p. 337, pub-
liſhed his making a pyrophorus by calcining oyſter-ſhells, and then
mixing them reduced to powder with ſulphur, and recalcining them
in cloſe veſſels. This pow.der after being expoſed to light, or heated
by other means, became luminous in the dark for many minutes. By
this proceſs the acid of phoſphorus exiſting in the animal ſhell had
been decompoſed by the red hot ſulphur having robbed it of its oxy-
gen; and thus the phoſphorus remained united with the calcareous
earth.
M. Du Fay, in a memoir publiſhed in the year 1730, aſſerts from
experiments, that all calcareous ſtones, whether they contain vitri-
olic acid or not, are capable of becoming luminous by calcination ;
with this difference only, that the pure calcareous ſtones require a
ſtronger or repeated calcination; whereas thoſe, which contain an acid,
as ſelenites, or gypſum, become phoſphoric by flighter calcination.
M. Margraaf alſo aſſerts, that all kinds of calcareous ſtones may by
calcination be rendered phoſphoric; but thinks, that the pure ones
ſhould be previouſly ſaturated with an acid. Keir's Dict. Art. Phof-
phorus. And laſtly, ſome kinds of fluor, which is known to confift
of calcareous earth and the fluor-acid, emit phoſphoric light on being
heated ſlowly, but looſe it, when much ignited. (Kirwan's Minera-
logy.) This material might probably as well as gypſum become ufe-
ful in agriculture.
4. Theſe experiments, which ſhew that all common calcareous
ſtones, which contain only carbonic acid, were rendered phoſphoric
by calcination ; but that thoſe which did contain a fixed acid, as gyp-
ſum, and fluor, were rendered phoſphoric with leſs difficulty, acquaint
us firſt with perhaps one very important uſe of lime in agriculture.
Secondly, with that alſo of gypſum, or alabaſter, which has lately
been uſed in America and in Germany without previous calcination;
but
;

SECT. X. 5. 5.
2.12
MANURES.
but which might probably be more ſucceſsful after calcination. And
thirdly, with the probable uſe of fluor ſpar in its recent or calcined
ftate. As there is reaſon to believe, that the vegetable ſyſtem may
abſorb phoſphorus from any of theſe materials; which phoſphorus
may originally have been of animal origin, as well as that which ex-
iſts in feces and urine. And laſtly, the uſe of recent ſhells or bones
ground into powder, or of bone-aſhes, ſpread on land may be deduc-
ed; as they conſiſt almoſt entirely of phoſphorus and calcareous
earth.
5. In the converſion of ſhells into limeſtone there ſeems to have
been either ſimply an additional quantity of carbonic acid attracted
from the air or from water during the proceſſion of ages, and added
to the calcareous earth, or alſo a diminution of the phoſphoric acid.
But an union of phoſphoric acid only with lime has lately been found
tocompoſe whole mountains in Spain,which is mentioned by Fourcroy,
and is now termed phoſphate of lime, reſembling bone-alhes. And
M. Brumaire lately received from Spain a yellowiſh tranſlucent ſtone,
called chryſolite by the jewellers, which he found to contain nearly
equal parts of phoſphoric acid and calcareous earth, and to be a ſpar
or cryſtallization of the phoſphate of lime. And as the limeſtone
at Breedon has lately been diſcovered to contain equal parts of mag-
neſia and lime, we may hope by greater attention to diſcover a moun-
tain of phoſphate of lime in our own country. See Nicholſon's Jour-
nal 1798, p. 414.
From hence it would appear, that the immenſe quantities of Time-
ſtone in the world, which was originally formed from the ſhells of
fubmarine animals, has during the long lapſe of time loft more or leſs
of its original phoſphoric acid, and acquired more or leſs carbonic
acid. The carbon diſſolved in the atmoſphere or in the ocean having
thus ſlowly decompoſed the phoſphoric acid in the elaboratory of na-
ture without great heat, as it does in our crucibles in a ſhort time
by the aſſiſtance of great heat.
E e2
It

2 1 2
MANURE S.
Sect X. 5.5:
E
It is probable that much phoſphorus may be conſumed in our inar-
tificial mode of burning lime, which might be preſerved by calcining
limeſtone in cloſe veſſels, and thus detaching the carbonic acid with-
out admitting the aerial oxygen to the phoſphorus; but the advan-
tage to agriculture of ſuch a proceſs can only be determined by expe-
riment.
There are many inſtances given by Mr. Anderſon, and by Lord
Kaims, of ſoils which are ſaid to have been for ages uncommonly
fertile without addition of manures or culture. Theſe are plains near
the ſhore in the county of Caithneſs, and in the Hebrides, and are
ſaid to conſiſt almoſt entirely of ſhells broken into very ſmall parti-
cles, without almoſt any mixture of other foil. See Encyclop. Britan.
Art. Agricult. Now the ſoil of an extenſive country called Lincoln
Heath I obſerved ſome years ago to conſiſt in a great degree of pow-
dered limeſtone, which like the Ketton limeſtone appeared in ſmall
rounded particles, which I ſuppoſe had in temote times been diffolv-
ed in water, and again precipitated; which ſhews a probable differ-
ence between this lime and recent ſhells in reſpect to their antiquity,
and conſequently that the former muſt contain much of the original
phoſphoric acid, and the latter only carbonic acid. And as Lincoln
Heath was then eſteemed a very unproductive foil, there is reaſon to
infer that the phoſphoric acid in recent ſhells is of greatly more fer-
vice to agriculture than the carbonic acid of alluvial limeſtone, or
than calcined lime alone.
Hence it is probable, that a greater quantity of phoſphoric acid
may
exiſt in ſome marles than in others, as well as in ſome limeſtones;
thus the appearance of recent ſhells exiſts in the lime near Loughbo-
rough in Leiceſterſhire, in the road to Nottingham, and in ſome
marles called ſhell-marle; which muſt therefore probably contain
much more phoſphoric acid, ſo as almoſt to reſemble the bones of
animals; and may thus be more friendly to vegetation. A piece of
land is mentioned by Mr. Anderſon, that, after a thick coat of marle
8
laid

Sect. X. 6.1.
213
MANURES.
laid on it, bore crops for thirty years without additional improve-
ment, and I think it was called ſhell-marle. See Encyclop. Britan.
Agricult.
6. A medical philoſopher, M. Bonhomme, has endeavoured to
ſhew, that the hardneſs of animal bones depends on the quantity of
phoſphoric acid united to calcareous earth, which they contain ; and
that the rickets, a diſeaſe in which the bones become too ſoft, is ſolely
owing to the want of it, or to the exiſtence of the vegetable acid
inſtead of it. Annales de Chemie, Vol. XVII. May we not con,
clude, that the preſence of phoſphoric acid in the vegetable ſyſtem
muſt be of importance; becauſe it ſo univerſally exiſts in them, and
may probably give firmneſs to liqueous as well as to oſſeous fibres ?
To which may be added, that M. Fourcroy believes, that the aſhes
of burnt vegetables, which have been ſuppoſed to conſiſt of earth or
clay, when the fixed alkali is waſhed from them, are principally cal-
careous phoſphorus, like thoſe of animal bones. The fame is afferted
by Lord Dundonald in his Connection of Agriculture and Chemiſtry,
p 25, who calls the inſoluble part of vegetable aſhes a phoſphat of
lime. This ſubject is worthy further inveſtigation.
VI.
LIME.
Many of the principal uſes of calcareous earth in promoting the
growth of vegetables have been already mentioned in this ſection,
which we ſhall recapitulate with additions.
1. One great uſe of calcareous earth I ſuſpect to conſiſt in its unit-
ing with the carbon of the ſoil in its pure or cauſtic ſtate, or with that
of vegetable or animal recrements during ſome part of the proceſs of
putrefaction ; and thus rendering it ſoluble in water by forming an
hepar carbonis, ſomewhat like an hepar ſulphuris produced by lime
and fulphur, as mentioned in No. 4, 7. of this Sect. ; by which pro-
ceſs

214
Secr. X. 6. 2.
MANURES.
ceſs I ſuppoſe the carbon is rendered capable of being abſorbed by the
lacteal veſſels of vegetable roots.
The black liquor, which flows from dunghills, is probably a fluid
of this kind; but I mean to ſpeak hypothetically, as I have not veri-
fied it by experiment; and the carbon may be ſimply ſupported in
the water by mucilage, like the coffee drank at our tea-tables; or
may be converted into an hepar carbonis by its union with the fixed
alkali of decaying vegetable matter, or by the volatile alkali, which
accompanies fome ſtages of putrefaction. See No. 10. 3. of this Sec-
tion.
2. A ſecond mode of its ſerving the purpoſes of vegetation I believe
to be by its union with carbonic acid, and rendering it thus ſoluble
in water in its fluid ſtate inſtead of its being expanded into a gas;
and that thus a great quantity of carbon may be drank up by vegeta-
ble abſorbent veffels.
In the practice newly introduced of watering lands by deriving
ſtreams over them for many weeks together, I am informed that wa-
ter from ſprings is generally more effectual in promoting vegetation
than that from rivers; which though it may irr part be owing to
the azotic gas, or nitrogen, contained in ſome ſprings, as thoſe of
Buxton and of Bath, according to the analyſis of Dr. Prieſtley, and
of Dr. Pearſon ; yet I ſuppoſe it to be principally owing to the cal-
I
careous earth, which abounds in all ſprings, which paſs over marly
foils, or through calcareous ftrata ; and which does not exiſt in rivers,
as the falts waſhed into rivers from the ſoil all ſeem to decompoſe
each other, except the marine ſalt, and ſome magneſian falt, which
are carried down into the ocean. The calcareous earth likewiſe,
which is waſhed into rivers, enters into new combinations, as into
gypſum, or perhaps into filiceous ſand, and ſubſides. Theſe ſolutions
of calcareous earth in thoſe waters, which are termed hard waters,
and which incruſt the ſides of our tea-kettles, may poſſibly alſo con-
tribute

Sect. X. 6. 36
215
MANURE S.
tribute to the nutriment of animals, as mentioned in Zoonomia,
Part III. Article 1. 2. 4. 2.
3. A third mode, by which lime promotes vegetation, I ſuppoſe
may be aſcribed to its containing phoſphorus; which by its union
with it may be converted into an hepar, and thus rendered ſoluble
in water, without its becoming an acid by the addition of oxygen.
Phoſphorus is probably as neceſſary an ingredient in vegetable as in
animal bodies; which appears by the phoſphoric light viſible on rot-
ten wood during ſome ſtages of putrefaction ; in which I ſuppoſe the
phoſphorus is ſet at liberty from the calcareous earth, or from the
fixed alkali, or from the carbon of the decompoſing wood, and ac-
quires oxygen from the atmoſphere; and both warmth and light are
emitted during their union. But phoſphorus may perhaps more fre-
quently exiſt in the form of phoſphoric acid in vegetables, and may
thus be readily united with their calcareous earth, as mentioned in
No. 5. 6. of this Section, and may be ſeparated from its acid by the
carbon of the vegetable during calcination, and alſo during putrefac-
tion, which may be conſidered as a ſlow combuſtion.
The exiſtence of a ſolution of phoſphoric acid and calcareous earth
in the veſſels of animals is proved by the annual renovation of the
ſhells of crab-fiſh, and by the fabrication of the egg-ſhells in female
birds; and is occaſionally ſecreted, where it cements the wounds made
on ſnail-ſhells; or where it joins the preſent year's growth of a ſnail-
ſhell to the part, where a membranous cover had been attached for
the protection of the animal during its ſtate of hibernation. And
laſtly, it is evident from the growth of the bones of quadrupeds, and
from the depoſition of callus to join them where they have been
broken.
4. Lime in its pure ſtate is ſoluble in about 600 times its weight of
water; and by a greater quantity of carbonic acid than is neceſſary
for its cryſtallization, it is ſoluble in water in much greater quan-
tities, as appears by the calcareous depoſition of the water at Mat-
lock;

216
Sect. X. 6.5.
MANURES.
a
lock; and may I ſuppoſe fupply a nutritious ſubſtance by uniting with
mucilage or oil, either in the earth at the roots of vegetables, or on
the ſurface of the ſoil, which may be gradually waſhed down to
them.
If a ſolution of ſoap be poured into lime-water, the oil of the ſoap
combines with the calcareous earth, and the cauſtic alkali is ſet at li-
berty, according to the experiments of Mr. Bertholet; (ſee Nichol-
ſon's Journal, Vol. I. p. 170,) who concludes, that oil has a ſtronger
affinity to calcareous earth than it has to fixed alkali. At the ſame
time it appeared, that a ſolution of the mild or efferveſcent fixed al-
kali poured on this calcareous ſoap would decompoſe it by twofold
elective attraction; as the carbonic acid of the mild fixed alkali unites
with the calcareous earth of the calcareous ſoap, and the oil unites
with the pure or cauſtic alkali.
Many arguments may be adduced to ſhew, that calcareous earth
either alone, or in ſome of the ſtates of combination above mention-
ed, may contribute to the nouriſhment both of animals and vegeta-
bles. Firſt, becauſe calcareous earth conſtitutes a conſiderable part
of them, and muſt therefore either be received from without, or
formed by them, or both. Secondly, becauſe from the analogy of all
organic life, whatever has compoſed a part of a vegetable or animal,
may again after its chemical ſolution become a part of another vege-
table or animal; ſuch is the general tranſmigration of matter!
5. There are other uſes of lime in agriculture, which may not be
aſcribed to it as a nutritive food for vegetables, but from its produc-
ing ſome chemical or mechanical effects upon the ſoil, or upon other
manures, with which it is mixed; as firſt, from its deſtroying in a
ſhort time the coheſion of dead vegetable fibres, and thus reducing
them to earth; which otherwiſe is effected by a ſlow proceſs, either
by the conſumption of infects, or by a gradual putrefaction. This
is ſaid to be performed both by mild and by cauſtic calcareous earth,
as in the experiments both of Pringle and Macbride. It is ſaid that
unburnt

SECT. X. 6.5.
217
MÀ NUR E S.
unburnt calcareous earth forwards the putreſaction of a mixture of
animal and vegetable matter. But that pure lime, though it ſeemed
to prevent putrefaction, deſtroyed or diffolved the texture of the feſh.
Thus I am informed, that a mixture of lime with oak-bark, after
the tanner has extracted from it whatever is ſoluble in water, will in
two or three months reduce it to a fine black earth; which if only
laid in heaps, would require as many years to effect by its own ſpon-
taneous fermentation or putrefaction. This effect of lime muſt be
particularly advantageous to newly encloſed commons when firſt
broken up.
a
Mr. Davis, in the papers of the Society of Arts, Vol. XVI. p. 122,
aſſerts, that on a common, which had been previouſly covered with
heath, but was otherwiſe very barren, the effect of lime was very
advantageous for about ten years, during which time the vegetable
roots might be ſuppoſed to have been diſſolved and expended ; but
that a ſecond liming he obſerved produced no good effect. It is
pro-
bable the good effect might not be ſo great, but I ſhould doubt the
circumſtance of its producing no good effect at all.
Mr. Browne of Derby has alſo an ingenious paper in the tranfac-
tions of the Society of Arts, in which he aſſerts, that recent vegeta-
bles, as clover, laid on heaps and ſtratified with freſh lime, are quickly
decompoſed, even in a few days. The heat occaſioned by the moiſ-
ture of the vegetables uniting with the lime I ſuppoſe quickens the
fermentation of the vegetable juices, and produces charcoal in con-
fequence of combuſtion, fimilar to that frequently produced in new
hayſtacks, which if air be admitted burſt into flame.
Secondly, lime for many months continues to attract moiſture from
the air or earth; which it deprives I ſuppoſe of carbonic acid, and
then ſuffers it to exhale again, as is ſeen on the plaſtered walls of
new houſes. On this account it muſt be advantageous when mixed
with dry or ſandy ſoils, as it attracts moiſture from the air above, ou
Ff
a
the

218
Sect. X. 6.6.
MANURES.
the earth beneath ; and thiş moiſture is then abſorbed by the lym-
phatics of the roots of vegetables.
Thirdly, by mixing lime with clays it is believed to make them
leſs coheſive; and thus to admit of their being more eaſily penetrated
by vegetable fibres.
Fourthly, a mixture of lime with clay deſtroys its fuperabundancy
of acid, if ſuch exiſts; and by uniting with it converts it into gypſum,
or alabaſter.
Fifthly, when lime is mixed with a compoſt of foil and manure,
which is in the ſtate of generating nitrous acid, it arreſts the acid as
it forms, and produces a calcareous nitre, and thus prevents both
its exhalation and its eafy elutriation.
And laſtly, freſh lime deſtroys worms, fnails, and other inſects,
with which it happens to come in contact, and with which almoſt
every ſoil abounds,
6. The various properties of lime above deſcribed account for the
great uſes of it on almoſt all lands; except perhaps ſome of thoſe
which already abound with calcareous earth.
On riding from Beckingham to Sleaford, and from thence to Lin-
coln, I was informed by three or four farmers, that lime had been
tried, but was believed to be of no ſervice in that country. Nor
was I ſurpriſed at this obſervation, as I had ſeen fragments of allu-
vial limeſtone thrown out of every ditch on the road, which was of a
looſe texture, conſiſting of calcareous ſand, like the Ketton limeſtone,
rounded by friction, before it was conſolidated into a maſs, the up-
per ſurface of which was broken into fragments, when it was raiſed:
from the ſea by ſubterraneous fires, or by its cooling from a hot ſtate:
or its drying from a moiſt one.
Thus, as I had ridden over one ſingle alluvial limeſtone above ten
miles broad and above twenty long, the broken furface of which
appeared in the bottom of almoſt every ditch, I concluded, that the
ſoil muſt be calcareous earth mixed only with ſome animal and ve-
getable
a
a

Sect. X. 6. 6.
219
MANURE S.
a
getable recrements, and that an addition of pure lime could probably
not be of much advantage to the vegetables it ſupported. And the
ſame I ſuppoſe muſt occur in thoſe ſituations, where the ſurface of the
ſoil conſiſts almoſt totally of chalk, which is another kind of alluvial
limeſtone; that is, which has been diffolved in water in the early
ages of the world, and again depoſited.
Yet even in ſome foils, which abound in calcareous earth, lime is
eſteemed to be of ſervice; which may be owing both to its cauſtic
quality, and to its being ſo finely pulverized. For a part of the wa-
ter, which combines with it after calcination, gives out ſo much heat
as to convert another part of it into ſteam ; which breaks the cal-
cined lime-lumps into a moft fubtile and impalpable powder, ap-
proaching even to fluidity, as mentioned in No. 4. 4. of this section.
In the pariſh of Hartington in Derbyſhire there is a ſtratum of
hard limeſtone, or marble, as I am informed, immediately beneath a
Thallow foil, and which in many places peeps through it; yet on
ſome of this land an ingenious active agricultor has laid lime on the
graſs in great quantity with prodigious advantage; and that he con-
tinues annually to improve by this means a conſiderable extent of
land.
The difference between the hard limeſtone of this part of Derby-
ſhire, and the ſoft ſand-formed limeſtone about Lincoln Heath and
Sleaford, may render the incumbent foil to be more or leſs mixed
with calcareous earth; or they may abound more or leſs with phof-
phoric acid, as mentioned in No. 5. 5. of this section. But it may
have happened, that ſome prejudices of the farmers, who gave me the
information, might have led them to condemn the uſe of lime about
Sleaford and Lincoln ; and I ſhould again recommend it to their fe-
rious attention.
Another improper ſituation for the uſe of lime is ſaid to be on thoſe
lands, which are too wet, and which therefore ſhould be previouſly
drained; otherwiſe the lime is ſaid to coaleſce into a kind of mortar,
Ff2
and

220
SECT. X. 6.7.
MANURE S.
and become ſo hard, that the tender plumula of growing ſeeds, or
the fine extremities of their roots, can not eaſily penetrate it. This
may occur more certainly in that kind of lime, which contains man-
ganeſe, and is therefore capable of ſetting under water, as, I ſuppoſe,
the barrow lime of Leiceſterſhire, and agnes lime near Aſhbourn in
Derbyſhire.
7. The great and general advantage of lime in all ſoils and all
fituations, except ſome of thoſe which are already replete with cal-.
careous earth, or are too moiſt, can only be underſtood from the idea
already mentioned of its ſupplying actual nutrition to vegetables; and
this ſeems more probable, as it contributes ſo much to the meliora-
tion of the crops, as well as to their increaſe in quantity. Wheat
from land well lined is believed by farmers, millers, and bakers, to
be, as they ſuppoſe, thinner ſkinned; that is, it turns out more and
better flour ; which I ſuppoſe is owing to its containing more ſtarch
and leſs mucilage.
Hence we perceive another very important uſe of lime in cultiva-
tion of land may be owing to its forwarding the converſion of mu-
cilage into ftarch, that is to its forwarding the ripening of the feed;
which is a matter of great conſequence in this climate of ſhort and
cold ſummers. See Sect. VI. 3. and XVI. 3.
In reſpect to graſs-ground I am informed, that if a ſpadeful of lime
be thrown on a tuſſock, which horſes or cattle have refuſed to eat for
years, they will for many ſucceeding ſeaſons eat it quite cloſe to the
ground; which is owing, I ſuſpect, to the graſs containing more
ſugar in its joints; or to the leſs acidity of all its juices.
8. There are not only ſome other bodies, which poffefs a calca-
reous baſe, beſides the common limeſtone, as gypſum, fluor, bone-
aſhes, and perhaps vegetable aſhes; but there are others which are:
occaſionally united with carbonic acid, and may be detached from it
by calcination, as the aerated barytes and magneſia. The laſt in its
calcined ſtate may poſſibly be as uſeful in agriculture as the lime of
calcareous
a

Sect. X. 7. I.
221
MANURES.
a
calcareous earth, with which I believe it is frequently mixed. For
Mr. Tennant aſſured me a few days ago, that he had analyſed the
limeſtone of Breedon in Leiceſterſhire, and found it to contain nearly
as much magneſia as calcareous earth, beſides fome manganeſe; which
is nevertheleſs a lime much eſteemed in this country both for archi-
tecture and agriculture. As magneſia exiſts in ſea-water, and in ſalt
fprings, it may render theſe waters uſeful as a manure as well as the
marine falt, which they contain. As fteatites or ſoap-ſtone conſiſts.
principally of magneſia, perhaps this limeſtone of Breedon may be
worth the attention of the porcelain manufactory.
This magneſian lime of Breedon is further worthy attention in the
cultivation of land, and particularly where a foil abounds with vitriol
of iron, or where it abounds with gypſum, as about Chelafton on the
banks of the Derwent, and from Nottingham to Newark on the
banks of the Trent, as the magneſian earth would unite with the vi-
triolic acid, and leave an ochre of iron in one caſe, and lime in the
other; at the ſame time a ſoluble falt, called Epſom ſalt, would be
formed, which, according to the experiments of Dr. Home, promotes
rapid vegetation. To ſow a few pecks of gypſum reduced to powder
on graſs land, as is done in America ; and then to ſow upon this
twice or thrice as much Breedon lime, might be an experiment which
might be advantageous in the part of Derbyſhire next to Leiceſter-
ſhire, where both of them are to be obtained at no great expence.
a
a
a
VII. CLAY, METALLIC OXYDES, NITRE, SEA-SALT..
1. The too great adheſion of the particles of argillaceous earth or
clay renders it in its pure ſtate unfit for vegetation ; as the tender
fibrils of roots can with difficulty penetrate it, whence it becomes
much improved for the purpoſes of agriculture, when it is mixed with:
calcareous earth and with ſiliceous fand, as in marle.
It is commonly believed that lumps of clay become meliorated by
being

222
Sect. X. 7. 2.
MANURE S.
а
being expoſed to froſt in its moiſt ſtate, which by expanding the wa-
ter, which it contains, by converting it into ice is ſuppoſed to leave
the particles of the clay further from each other. This however
ſeems in general to be a miſtaken idea, ſince if the act of freezing
be not very ſuddenly performed, a contrary effect ſeems to occur, as
noticed by Mr. Kirwan ; who obſerves, " that clay in its uſual ſtate
of dryneſs can abſorb two and a half times its weight of water with-
out ſuffering any to drop out, and retains it in the open air more per-
tinaciouſly than other earths; but that in a freezing cold clay con-
tracts more than other earths ſqueezing out its water, and thus part-
ing with more of it than other earths.” Mineralogy, Vol. I. p. 9.
This curious circumſtance, that water, as it cryſtallizes, detrudes
the clay, which is diffuſed in it, correſponds with other facts of con-
gelation. Thus when wine, or vinegar, or common ſalt and water, or
a ſolution of blue vitriol in water, are expoſed to froſty air ; the al-
cohol, the acetous acid, the marine ſalt, and the calx of copper, are
all of them detruded from the aqueous cryſtals, and retreat to the
central part of the fluid, or to that laſt frozen, or into numerous
cells ſurrounded with partitions of ice, as I have frequently obſerved ;
whence it appears, that wet clay is in general rendered more folid
and tenacious by being frozen, as well as when it is dried, and its
moiſture exhaled by too warm a fun; and by both thoſe circum-
cumſtances becomes leſs adapted to the purpoſes of agriculture.
2. In moſt clays a kind of efferveſcence occurs, after they are
turned over, and thrown on heaps, and thus acquire air into their in-
teſtines, which renders them much fitter for the purpoſes of vitrifica-
tion; and thus forwards the proceſſes of the brick-kiln and pottery.
This greater facility to vitrify is probably effected by the union of
oxygen with the iron, which moſt clays contain ; as oxydes of lead
and manganeſe are uſed in the more perfect vitrifications.
The calciform ores, or oxydes, of iron, manganeſe, and zinc, are
frequently found near the ſurface of the earth, where they have been
united
I

SECT. X.7.2.
223
MANURE S.
united with oxygen by the paſſing currents of the atmoſphere; and
have been ſuppoſed to have originated from the decompoſition of ve-
getables and animal bodies, as mentioned in Botanic Garden, Vol. I.
additional note 18. Iron has been detected in all vegetable and animal
matters, manganeſe in fome of them; and, if we poſſeſſed a teſt for
diſcovering ſuch minute particles of zinc, as the magnet diſcovers of
iron, it is probable, that zinc alſo would be detected in the vegetables,
which grow over its beds.
As ſome philoſophers have lately contended for the great utility of
oxygen in vegetation, as Humboldt and Von Ular; who affirm from
their experiments, that hyper-oxygenated muriatic acid uſed in ſmall
quantities promotes both the growth and irritability of plants; there
is reaſon to ſuſpect, that the calciform ores of iron, manganeſe, and
zinc, as well as minium, and other calces or oxydes of metals made
by fire, and even burnt clays, when ſtrewed on the ground, may
contribute to vegetation by their parting with their abundant oxygen
in a fluid, not in a gaffeous form ; which uniting with carbon, or
phoſphorus, or nitrogen, without emitting perceptible heat or light,
might ſupply nutritious fluids to the roots of vegetables ; further ex-
periments are wanted on this ſubject. But I am well informed, that a
red ocher of iron, called raddle, has been uſed on ſome lands with ad-
vantage in the north of Staffordſhire; and ſhould recommend a trial
of manganeſe in thoſe countries, where it abounds, as near Kingſbury,
and near Atherſtone in Warwickſhire ; and a trial of lapis calaminaris,
where it abounds, as near Matlock in Derbyſhire; and even of the
calciform ore of lead, which is found in Angleſey, and on the top of
ſome other lead mines.
M. Humbold aſſerts, that he mixed many ſeeds into a kind of paſte:
with the black oxyde of manganeſe, and poured over it the muriatic
acid diluted with water, in the proportion of about fix of water to
one of acid; and that much oxygen was thus diſengaged, and occaſion --
ed:
a
a
a

224
SECT. X. 7. 3.
MANURE S.
ed quick vegetation. Journal de Phyſique, 1798. See No. 2. 3. of
this Section.
3. When clays are turned up with the ſpade, as is uſual in prepar-
ing them for the brick kiln, a kind of efferveſcence occurs, as men-
tioned above; which is probably owing to the eſcape of the azote of
the air impriſoned in the interſtices, as the oxygen unites with ſome
metallic particles in the clay; or to ſteam raiſed from the water in
the clay by the heat ſet at liberty from the combination of the oxy-
gen and the iron. This union of oxygen with iron is curiouſly al.
moſt viſible in many granates or porphyries; which I have ſeen
thinly ſcattered in large nodules near Cannock in Staffordſhire, in the
road from Lichfield to Shrewſbury; and on breaking them have ob-
ſerved no appearance of iron on the newly divided ſurfaces; but which
in a few days acquired an ochery appearance on them, which pene-
trated nearly half an inch. This can not but be aſcribed to the oxygen
of the atmoſphere having united with the iron in theſe ſtones, which
by their ſmell, when breathed upon, contain indurated clay, and hav-
ing converted into an oxyde either the clay itſelf, or ſome metallic
particles included in it.
There is nevertheleſs an exhalation from clay, and perhaps from
moſt ſoils, when they have been previouſly dried, and then ſprinkled
with water, as after a ſhower in ſummer, which has been ſuppoſed
to be falubrious to invalids and convaleſcents. This remarkably oc-
curs, when dry clay is breathed upon even in its moſt indurated ſtate,
as in granites and porphyries, by which criterion theſe ſtones are im-
mediately diſtinguiſhed from the filiceous and calcareous ones. This
I imagine is produced by the heat ſet at liberty by the combination
of dry clay and water, like that produced in ſo much greater degree
by the combination of lime and water; and that this heat raiſes a part
of the acquired moiſture into ſteam, in which are diffolved the odor-
ous particles; both which probably cauſe the quick vegetation on
clayey ſoils after the ſhowers in ſummer.
When
a

SECT. X. 7.4.
225
MANURE S.
When marl, which conſiſts of clay, calcareous earth, and ſand,
which are frequently coloured red by iron, or blue probably by man-
ganeſe, is expoſed in ſmall lumps to the atmoſphere; it is liable to
crumble into powder, which I ſuppoſe to ariſe from a ſimilar circum-
ſtance; that the oxygen of the atmoſphere uniting with the clay, or
the metallic particles it poffefſes, lets at liberty the ſame gas, or ſteam,
which is ſeen to riſe from clay, when thrown on heaps for the brick
kiln or pottery; which breaks the lumps into powder, as the lumps
of lime are broken into powder by the ſteam, which is generated
when water is thrown on them, by the heat fet at liberty by the
combination of the lime and water.
This union of oxygen with the clay, or with the metallic particles
mingled with it, I ſuppoſe to be much facilitated by expoſing it to a
red heat, as in burning bricks; while a greater heat may unite ſo
much oxygen with it as to turn it into glaſs. Exactly ſuch a pro-
ceſs occurs in the production of minium ; a certain quantity of heat
with the contact of air combines ſo much oxygen with the melted
lead, as to form an oxyde ; a greater quantity of heat converts it into
glaſs.
4. When clay is united with fo much oxygen by fire as to form a
foft or imperfect brick, it poffefſes the power of promoting the ge-
neration of the nitrous acid in certain ſituations; which is frequently
ſeen like an effloreſcence on mouldering walls, having become by
the addition of lime a calcareous nitre. The uſe of theſe ſoft bricks in
the production of nitre is well known in Paris, where the rubbiſh of
old houſes is regularly purchaſed for that purpoſe; which before the
revolution was a royal manufacture.
As theſe ſoft effloreſcent bricks from old houſes are known power-
fully to promote vegetation, when pulverized and mixed with the
foil ; at the ſame time that they are capable of producing the nitrous
I imagine, that the uſe of paring and burning the turf of ſome
newly encloſed commons depends on this circumſtance. That is,
that
acid;
GS

226
Sect. X. 7.6.
MANURES.
a
that the heat emitted from the burning vegetable fibres unites oxygen
with the clay; which latter forms more than half of the ſlices of
turf, as they are dug from the ground. In other refpects the paring
and burning of graſs grounds would certainly be a waſteful proce-
dure ; as much carbon is converted into carbonic acid, and diſperſed
along with the uninflamed ſmoke or foot, and nothing left but the
vegetable alhes. From theſe confiderations it would probably be
worthy experiment in farms, where coal and clay abound, to burn
the latter to a certain degree; which might ſupply an exhauſtleſs
ſource of profitable manure.
5. I have ſuſpected alſo, that this calcined clay, as it exiſts in ſoft
bricks, has a power of decompoſing marine ſalt, as I once obſerved
in a cellar, where beef had been long falted on one ſide of a nine-inch
wall, the wooden falting-tub for which was attached to it; that a
great effloreſcence appeared on the other ſide of the wall, which I
believed to be foſfile alkali or natron. If this idea be juſt, the ſoft
bricks from old buildings, or clays ſo far purpoſely burnt, may in
this manner be ſerviceable to vegetation, by ſeparating the foſſile al-
kali from the ſea-falt, which is waſhed from decompofing animal and
vegetable ſubſtances; which by converting carbon into an hepar car-
bonis, as lime is ſuppoſed to do in No. 6. 1. of this Section, might
render it ſoluble in water, and capable of being abſorbed by the
lymphatic veſſels of the roots of plants.
If clay calcined to a certain degree, and thus united with oxygen,
poſſeſſes the power of decompoſing marine ſalt, there is reaſon to
believe, when it is more flowly united with oxygen by its expoſure
to the atmoſphere by the ſpade or plough, that it may poſſeſs the
ſame property; and that this may have given riſe to the very con-
tradictory reports concerning the uſe of fea-falt in agriculture; as it
may probably be of great advantage to clayey foils, but perhaps
not ſo to other foils. See Sect. XIV. 2.8.
6. Another faline body, which readily unites with argillaceous
earth

SECT. X. 7.7.
227
MANURES.
a
earth in the fire, is ſalt of urine, commonly called microcoſmic ſalt,
which acts as a flux diffolving clay with conſiderable efferveſcence.
Kirwan's Mineralogy, Vol. I. p. 9. This microcoſmic ſalt conſiſts of
phoſphoric acid united with an ammonical, or with a calcareous baſe;
and muſt in the latter caſe reſemble the phoſphat of lime, of which
there are whole mountains diſcovered in Spain, as mentioned in No.
5. 5. of this Section ; and of which many may probably be diſcovered
in our own country. Now as the ſame combinations of matter,
which are quickly formed by the heat of the chemiſt's furnaces, are
often performed, though more ſlowly, in the elaboratory of nature;
it is probable, that if this calcareous phoſphorus could be procured in
this country, reduced to powder, and ſpread on our clay lands, that
it might more than any other calcareous matter render them friendly
to vegetation, like the aſhes of burnt bones; which experiment alone
can determine.
7. As clay is leſs adapted to the growth of the roots of plants by
the too great coheſion of its particles, this may be in ſome degree
corrected by frequently expoſing it to air impriſoned in its inter-
ſtices, as by turning it over by the plough or ſpade. Another me-
thod is by planting on it ſuch vegetables firſt as are known to grow
well in clay, as beans, and as their roots are afterwards left in the
clay, they not only thus form tubes in it, ſo as to render the maſs
leſs coheſive; but add to it ſo much carbon, and thus rather enrich
than impoveriſh it. Add to this that the lower leaves of the denſe fo-
liage of theſe vigorous vegetables are believed to give out much car-
bonic acid by their reſpiration in the ſhade ſimilar to the reſpiration
of animals; which perpetually finking down upon the ſurface of the
foil is believed to ſupply it with carbon ; and thus alſo to render it
more nutritive to other vegetables, which may afterwards grow upon
it.
Lord Kaimes, who allows that clay, if it be moiſtened after it has
been pulverized, becomes on drying as indurated and coheſive as
Gg 2
before,

228
SECT. X. S.
MANURES.
before, aſſerts, that this does not happen, if it be moiſtened with the
fluid, which eſcapes from dunghills; which may be owing both to
the carbon, and to the fixed vegetable alkali, which that fluid con-
tains. And alſo adds, that lime will prevent the coheſion or indura-
tion of clay, and therefore greatly improves argillaceous foils for all
the purpoſes of agriculture.
8. When clay abounds with vitriolic acid ſo as to be converted
into alum, it becomes very unfriendly to vegetation. In this ſtate it
is believed much to counteract the proceſs of putrefaction in animal
bodies, as is ſaid to have happened in ſome burying grounds. This
it may effect by uniting with the ammonia generated by putrefaction
the moment it is formed, or by preventing its production ; as when
the falt of Neville Holt water in Leiceſterſhire, which I ſuppoſe is
alum, is mixed with very putrid blood, as I once witneſſed, the pu-
trid ſcent was inſtantly deſtroyed, as I ſuppoſe the argillaceous earth
was precipitated.
Where this acid or aluminous clay abounds, it is believed to check
the vegetation of trees as well as of herbaceous plants by eroding the
fine extremities of their roots, as mentioned in Sect. II. g. which is
perhaps beſt to be remedied in gardens by wood-aſhes or ſoap-fuds,
and in larger fields by mixing lime, or chalk in powder, or the
ſweepings from roads, which are repaired by limeſtone, with theſe
aluminous clays. Or laſtly, where it can be procured, by mixing
with them ſuch lime as that of Breedon in Leiceſterſhire, which con-
fifts of equal parts of magneſia and calcareous earth, which would
thus fabricate what has been termed Epſom ſalt, which is ſaid to be
friendly to vegetation.
VIII.
MANURES BY SPONTANEOUS DECOMPOSITION.
We ſhall now conſider more generally the decompoſition of organ-
ized matter, which vegetable and animal bodies ſpontaneouſly un-
dergo,

Secr. X. 8. 1.
MANURE S.
229
:
dergo, when they ceaſe to live. The proceſſes of this decompoſition
have commonly been divided into the vinous, acetous, and putrefac-
tive fermentations; which have been ſuppoſed uniformly to ſucceed
each other. But it is more probable, that different kiads or parts of
dead organized matter may be ſubject to many different kinds of
chemical changes, and that theſe may vary with the degrees of heat,
and the quantity of water, and of air, with which they are ſur-
rounded.
1. In the ſtomachs of animals a ſaccharine proceſs precedes the
vinous fermentation; which laſt only occurs, when the animal power
of digeſtion or abſorption is for a time ſuſpended. A fimilar proceſs
occurs in the germination of vegetable roots, whereby meal is con-
verted into ſugar, as in the malt-houſe; and in the gradual ripening
of apples and pears, after they are plucked from the tree; but all
theſe may be ſaid to be ſtill alive ; and this change of meal or of
mucilage into ſugаr may thus be eſteemed a vegetable rather than a
chemical proceſs.
The art of cookery, by expoſing vegetable and animal ſubſtances
to heat, has contributed to increaſe the quantity of the food of man-
kind by converting the acerb juices of ſome fruits into fugar, as in the
baking of unripe pears, and the bruiſing of unripe apples; in both
which ſituations the life of the vegetable is deſtroyed, and the con-
verſion of the harſh juice into a ſweet one muſt be performed by a
chemical proceſs; and not by a vegetable one only, as the germina-
tion of barley in making malt has generally been ſuppoſed.
Some large round auſtere pears were yeſterday, November 20,
fhewn me after having been nine hours in the oven behind a kitchen
fire covered ſome inches with water in a ſteam-pot. On taſting
them they were ſweet, and ſoft, and appeared to have had at leaſt
the heat of boiling water. They were replaced in the oven, and
kept in it twelve hours longer; and then became nearly as ſweet as
fyrup or treacle; which might in part have been occafioned by the
evaporation
I

230
Sect. X. 8. 1.
MANURE S.
a
evaporation of half the water. From this curious circumſtance there
ſeems reaſon to conclude, that in a degree of heat about that of boil-
ing water the faccharine proceſs may ſucceed ; and at the ſame time
that the proceſs of fermentation may be prevented from exiſting;
which I hope may induce ſome chemical philoſopher to inveſtigate
by experiments this curious and important ſubject.
Some circumſtances, which ſeem to injure the life of ſeveral fruits,
ſeem to forward the faccharine proceſs of their juices. Thus if ſome
kinds of pears are gathered a week before they would ripen on the
tree, and are laid on a heap and covered, their juice becomes ſweet
many days ſooner. The taking off a circular piece of the bark from
a branch of a pear-tree cauſes the fruit of that branch to ripen ſooner
by a fortnight, as I have more than once obſerved. The wounds
made in apples by inſects occafion thoſe apples to ripen ſooner ; ca-
prification, or the piercing of figs, in the iſland of Malta, is ſaid to
ripen them ſooner; and I am well informed, that when bunches of
grapes in this country have acquired their expected ſize, that if the
ſtalk of each bunch be cut half through, they will ſooner ripen.
The germinating barley in the malt-houſe I believe acquires not
half its ſweetneſs, till the life of the feed is deſtroyed ; and the fac-
charine proceſs then continued or advanced by the heat in drying it;
though I have lately been informed that ſome grains of malt will ve-
getate after having been dried in the uſual manner, which however
may have been owing to their not having been previouſly ſuffered
perfectly to germinate. Thus in animal digeſtion the ſugar produc-
ed in the ſtomach is abſorbed by the lacteals, as faſt as it is made ;
otherwiſe it ferments and produces flatulency; ſo in the germination
of barley in the malt-houſe ſo long as the new plant lives, the ſugar
I ſuppoſe is abſorbed, as faſt as it is made; but that which we uſe
in making beer is the ſugar produced by a chemical proceſs after
the death of the young plant, or which is made more expeditiouſly
than the plant can abſorb it.
It

Secr. X. 8. 2.
MANURE S.
231
It is probably this faccharide proceſs, which obtains in new hay-
ſtacks too haſtily; and which by immediately running into fermen-
tation produces ſo much heat as to ſet them on fire. The greateſt
part of the grain, or feeds, or roots, uſed in the diſtilleries, as wheat,
canary ſeed, potatoes, are not I believe previouſly ſubjected to ger-
mination ; but are in part by a chemical proceſs converted into ſugar,
and immediately fubjected to vinous fermentation. And it is proba-
ble, a proceſs may ſometime be diſcovered of producing ſugar from
ftarch or meal; and of ſeparating it from them for domeſtic pur-
poſes by alcohol ; which diffolves ſugar but not mucilage; or by
other means.
This then may be termed the faccharine fermentation, and may
exiſt I ſuppoſe beneath or upon the earth in the beginning of ſome
fpontaneous vegetable decompoſitions, previous to the vinous fer-
mentation ; and may ſupply thus a very nutritive material to vege-
tation; fimilar to that which the embryon plants in the ſeeds of many
fruit-trées acquire from their fruits; and to that, which the em-
bryons in many farinaceous feeds acquire from the ſpontaneous
change of the meal in their cotyledons; though perhaps in leſs quan-
tity and purity.
2. A ſecondary proceſs to this I ſuppoſe to be the vinous fermen-
tation, in which much carbon becomes united to oxygen; and
pro-
bably at the very inſtant of their combination, while they are yet in
the form of a liquid, and not of a gas, they become abſorbed by the
roots of plants. The heat, which is perceived in the hotbeds, which
are uſed for the growth of cucumbers and melons, is produced by
this union of oxygen and carbon, or by the generation of ſome other
acids, as of phoſphorus, or nitre.
That this heat is owing to the atmoſpheric air combining with
fome inflammable baſe, and producing acidity of ſome kind, appears
from the following experiment. A few years ago a gardener told
me that a hot-bed, which he had made of tanner's bark with ſome
horſe

232
SECT. X. 8. 3.
MANURE S.
a
a
horſe dung and ſtraw, was become too cold for the growth of his
pots of cucumbers. He was deſired ſimply to turn over the bed,
and ſhake every part of it in the air with his fork, as he lightly re-
placed it. This was complied with, and in a few days I obſerved by
touching a ſtick, which had for ſome hours been inſerted into it, that
it had acquired the uſual heat of a hot-bed.
This addition of heat was doubtleſs acquired from the air, which
was recently included in the interſtices of the bed by its being turned
over, broken into ſmall pieces, and expoſed to the atmoſphere;
whence new acids ſeem to have been generated, and carbon, and per-
.
haps phoſphorus and nitrogen, rendered ſoluble in water, Great heat
is produced from the union of oxygen with thoſe baſes of acidity,
which in large ſtacks of new hay is often known to excite real
combuſtion ; the violent fermentation of which may be partly owing
to the ſugar, which is depoſited in the joints of graſs before the ſeeds
are ripe for their nouriſhment, and partly to a chemical production
of ſugar, as above deſcribed.
3. In the putrefactive proceſs carbon is not only converted into
carbonic acid, as above related; but there appears to be a decom-,
poſition of water, as is known by the ſmell of hydrogen ; and it is
probable, this inflammable body may unite with carbon, as in hy-
drocarbonate gas, and thus render them both ſoluble in water, and
abſorbable by the veſſels of vegetable roots, without their paſſing into
an acid or gaffeous form, and may much contribute to the nutriment
of vegetables.
4. There alſo appears at the end of the putrefactive proceſs to be
a junction of azote with oxygen producing the acid of nitre, which
probably may contribute much to promote vegetation. This appears
from the mode of procuring that acid in France and Pruſſia, and
which might be ſucceſsfully practiſed under every ſhed in our own
farm-yards ; as it conſiſts in a due mixture of vegetable and animal
recrements with foil, frequently turned over to expoſe it.to the air,
a
a
while

SECT. X. 9. 1.
233
MANURE S.
while it is defended by a ſhed from the ſunſhine and rain; which is
thus at the ſame time adapted to produce the quickeſt vegetation,
and to generate the nitrous acid,
The oxygen, which compofes nitrous acid, is believed to adhere
more weakly to its baſe the azote, than in the compoſition of other
acids. On this account it fo readily explodes by its junction with
carbon in a given degree of heat. This looſe adherence of the oxygen
in nitrous acid, like that of hyper-oxygenated marine acid, and of
the oxygen in the ore of manganeſe, and of ſome other metallic
oxydes, may adapt them to promote vegetation by their more readily
parting with this material ſo eſſential in the compoſition of plants.
5. From the above obſervations it appears, that when the ſoil is
turned over by the ſpade or plough, and thus acquires atmoſpheric
air in its interſtices, and in conſequence becomes warm by the pro-
duction of new acids, that the ſeeds or plants ſhould be inſerted as
ſoon as convenient, for the purpoſe of their receiving the moſt fa-
lutary effect of thoſe operations. Nor ſhould this be obſerved only
in black garden mould, or well manured glebes, where carbon or
phoſphorus may be ſuppoſed to abound, and a proper diſpoſition for
the production of the nitrous acid, but in thoſe clays alſo which are
pure enough for the brick-kiln or the pottery.
IX.
MANURES BY CHEMICAL DECOMPOSITION.
The uſe of fire and water contributes to increaſe the nouriſhment
of mankind by rendering many vegetable materials innocuous, and
others digeſtable in the animal ſtomach ; and ſeems particularly effi-
cacious in promoting the faccharine proceſs, and in producing muci-
lage from griſtles, horn, hair, and perhaps even from bones by means
of Papin's digefter. Whether this art could be advantageouſly uſed
for the purpoſe of rendering manures capable of being abſorbed by
Hh
vegetable

234
MANURE S.
SECT. X. 9.21
vegetable roots in a ſtate of lefs decompoſition, than by the flow pro-
ceſs of putrefaction, is a queſtion of curioſity and utility.
Sugar and mucilage are certainly abſorbed by vegetables without
their being reſolved into the elements, from which they were com-
poſed; as appears in the fap-juice which flows from the wounds of
birch and maple trees in the vernal months; which I am informed
will paſs into fermentation and produce wine; a proceſs which ſome
modern chemiſt affirms cannot be effected by ſugar alone without
the addition of mucilage. The abſorption of mucilage ſeems to oc-
cur in the germination of many feeds, as of barley; a part of the meal
of the cotyledon is evidently converted into ſugar, but another part
of it is probably abſorbed in the form of mucilage; ſome of which
oozes on breaking the plumula ; and in the growth of thoſe ſeeds,
which contain oil, as in almond, hemp, rape, and line-ſeed, it is
probable, a part of the undecompoſed oil may be abſorbed by the um-
bilical veſſels of the embryons in thoſe ſeeds.
It hence ſeems credible, that by the uſe of heat and water the art of
cookery might furniſh mucilage, ſugar, and oil, from vegetable or
animal materials; which might be converted into ſap-juice or chyle,
without their being previouſly reduced into their elements; and
might thus facilitate the more luxuriant growth of plants, as they
contribute more to fatten animals, than materials of leſs combina-
tion.
2. To this might be added, that the putrefactive proceſs may be
forwarded by heat in ſome materials by deſtroying the life of the ma-
terial; as in roaſting apples and pears, and in killing the roots of po-
tatoes, or the feeds of corn. Thus Mr. D-, a friend of mine,
had twenty ſtrikes of potatoes, which he wiſhed to dry on a malt-
kiln, hoping to render them more like the meal of wheat, and better
to preſerve them during the ſummer-months. Whether they were
ſufficiently dried he did not attend to; but they were carried into a
granary, and laid on heaps; and in a week or two became ſo putrid,
that

SECT. X. 9. 2.
MANURES.
23
that the ſmell was inſufferable, his ſwine refuſed to eat them, and
he was obliged to add them to the manure of the dunghill.
That potatoes, which have undergone a certain degree of heat,
contribute more to fatten all kinds of animals, ariſes from the acri-
mony of their rinds being deſtroyed, and from their auſtere juices be-
ing converted into mucilage, and perhaps a part of their mucilage
into ſtarch, and are hence ready for the faccharine and oily proceſſes
of animal digeſtion. A very convenient method of expoſing them
to ſteam is deſcribed in a late ingenious publication of the Agricul-
tural Society. A ſmall boiler is ſet in brick work under a ſhed, ſo
that the flame of wood or coal may paſs ſpirally round it. It ſhould
be covered with a double lid of tin or wood to prevent much heat
from eſcaping; and may have a ſand-joint to keep the ſteam in, or a
little moiſt clay, or even a wet flannel put circularly round the cover
may anſwer this purpoſe.
Near this furnace is to be fixed a large barrel on one of its ends,
with a cover on the other end; which may be occaſionally opened
to admit potatoes, and cloſed again ſo as to confine the ſteam, which
is to be derived into it from the boiler by a double pipe one within
the other, of tin or wood, about two inches in diameter. By theſe
means a large quantity of potatoes may be rendered much more nu-
tritive to animals, and I ſuppoſe to vegetables (if they were uſed as
manure), as they may thus probably be abſorbed by their lacteals or
lymphatics without being ſo much decompoſed as by the putrefactive
proceſs; and thus produce nutriment in leſs time, and by leſs labour
of digeſtion.
If the ſteam could be made hotter than boiling water, which it pof-
fibly may in the veſſel above deſcribed, if the water in it riſes but a
few inches, and the ſteam after it is produced, is heated above 212
degrees by the ſides of the boiler above the water, round which the
flame plays fpirally, the ſteam thus made hotter might probably
render the potatoes more mucilaginous or more ſtarchy.
H h 2
3. A

236
MANURES.
SECT. X. 9:4
a
3. A ſtill more effectual method of diffolving hard vegetable and
animal ſubſtances, and rendering them nutritive, might be by digeſt-
ing them for ſome time in water raiſed to a much greater heat than
that of boiling. This is to be done in a cloſe vefſel, called Papin's
digefter ; in which it is ſaid, that the confined water may be made
red hot; and will then diffolve hair, horns, hoofs, bones, tortoiſe-
ſhell, and all animal, and perhaps many vegetable matters; which
;
might thus facilitate their decompoſition for the purpoſes of manures,
or for the nutriment of many animals; and might even contribute to
the food of mankind in times of ſcarcity. This veſſel ſhould be made
of iron, and ſhould have an oval opening at top, with an oval lid of
iron larger than the aperture. This lid ſhould be ſlipped in endways,
when the veſſel is filled, and then turned, and raiſed by a ſcrew above
it into contact with the under edges of the aperture. There ſhould
alſo be a ſmall tube or hole covered with a weighted valve to pre-
vent the danger of burſting the digefter.
4. Other materials might be rendered more eaſily digeſtible, and
thence more nutritive to animals, and perhaps to plants, by mechanic
trituration as well as by cookery; if the labour and expence were
not too great ; as the grinding of graſſes, ſtraws, and farinaceous ſeeds
into powder between mill-ſtones; which have been called the arti-
ficial teeth of ſociety. It is probable, that ſome foft kinds of wood
ground into powder, and eſpecially when they have undergone a kind
of fermentation, and become of looſer texture, or boiled to deſtroy
their acrimony, might be rendered uſeful food for ſwine or horſes,
and even for mankind in times of famine.
Nor is it improbable, that hay, which has been kept in ſtacks, fo
as to undergo the faccharine proceſs, may be ſo managed by grinding
and by fermentation with yeaſt like bread, as to ſerve in part for the
fuftenance of mankind in times of great ſcarcity. Dr. Prieſtley
gave to a cow for ſome time a ſtrong infuſion of hay in large quantity
for her drink, and found, that the produced during this treatment
a
above

Sect. X. 9.4.
237
MANURE S.
a
a
a
above double the quantity of milk. Hence if bread cannot be made
from ground hay, there is great reaſon to ſuſpect, that a nutritive be-
verage may be thus prepared either in its ſaccharine ſtate, or fer-
mented into a kind of beer.
It may be here obſerved, that it is believed by ſome, that feeding
horſes with ground corn, as with the flour of beans or oats, does not
ſtrengthen them nearly ſo much as by giving them the fame quantity
of oats or beans whole. Parkinſon, Exper. Farmer, Vol. I. p. 227.
It is aſſerted alſo that ſoup, with the fleſh-meat boiled down into a fluid
maſs, will give much leſs ſtrength to a man, than he would acquire
by eating the ſolid meat, of which the ſoup was made. The reaſon of
both theſe ſeems to ariſe from the ſaliva being well mixed with the
maſticated food, and in greater quantity; which therefore becomes
more animalized aliment, than that diſſolved in water alone, and is
more eaſily converted into nutriment.
In times of great ſcarcity there are other vegetables, which though
not in common uſe, would moſt probably afford wholeſome nouriſh-
ment, either by boiling them, or drying and grinding them, or by
both thoſe proceſſes in ſucceſſion. Of theſe are perhaps the tops and
the bark of all thoſe vegetables which are armed with thorns or
prickles, as gooſeberry-trees, holly, gorſe, and perhaps hawthorn.
The inner bark of the elm-tree makes a kind of gruel. And the roots
of fern, and probably very many other roots, as of graſs and of clover,
taken up in winter, might yield nouriſhment either by boiling or
baking, and ſeparating the fibres from the pulp by beating them; or
by getting only the ſtarch from thoſe which poſſeſs an acrid mucia
lage, as the white briony.
The grinding of bones to powder has already been applied to agri-
culture, and the chopping of woollen rags; and I ſuppoſe the tritu-
ration of alabaſter, and of chalk, and of ſoft bricks, and probably of
iron ochres, manganeſe, and calamy, might well repay the labour ;
after
a

238
MANURES.
Secr.X. 1o. I.
after a few experiments had been inſtituted to determine the quan-
tity, which ſhould be ſtrewed on different foils.
X. MANURES BY INSECT PROPAGATION,
a
1. That the continual growth and decay of animal and vegetable
nature increaſes the quantity of ſuch matter, as is fit for the repro-
duction of organized bodies, is evinced by the increaſing fertility of
cultivated countries; fince even in theſe a great quantity of the an-
nual recrements of decompoſed animals and vegetables are waſhed by
rains from the ſoil, and carried down the rivers into the ocean; and
in
many ſituations of ſoil in Africa and America, which have been
but lately cultivated, there exiſts a wonderful fertility from the aggre-
gate remains of vegetable and animal bodies; which have for un-
counted ages ariſen and periſhed there ; and which have either left
moraſſes, where they could not part with their ſuperabundant wa-
ter; or a fertile earth, ſuch as in our gardens and church-yards,
where the declination of the ground was more favourable.
Some countries on the contrary once highly cultivated and very
populous are in proceſs of time become deferts of ſand; as many
parts of Syria, and the diſtricts about Palmira, and Balbec. This has
probably been owing to the want of the neceſſary moiſture in thoſe
warm and fandy regions; which was formerly ſupplied by artificial
derivations of water ; but which ceaſed, after their inhabitants were
deſtroyed by war and tyranny; and fecondly to the rapid ſtreams oc-
caſionally poured over them by the monſoon floods ; fimilar to thoſe
which impoveriſh Abyſſinia and Nubia, while they fertilize the flat
and fhowerlefs provinces of Egypt.
We might add, that all calcareous ſtrata are now believed to have
been produced by fhells depoſited by aquatic animals in the early ages
of the world, and that the materials, which conſtitute the ſtrata above
4
them,

Sect.X. IO: 2.
MANURE S.
239
them, have afterwards been formed by the recrements of terreſtrial
animal and vegetable bodies. Whence it may be concluded, that ve-
getables and animals during their growth increaſe the quantity of
matter fit for the more nutritive food of organized bodies, or of that
which is leſs decompounded; while they muſt at the ſame time occa-
fionally form or elaborate a part of the materials, of which they confift,
from the fimple elements of hydrogen, nitrogen, carbon, phoſphorus,
fulphur, and oxygen; into which modern chemiftry has reſolved
them by analyfis.
And laſtly, that vegetables can acquire nutrition from water and
air alone with the carbonic acid, which floats in them, appears by
the experiments of thoſe philoſophers, who have nicely encloſed the
roots of ſome plants in pots, and moiſtened them with diſtilled wa-
ter; and from hence we learn an eſſential diſtinction between vege-
table and animal nature; the former can elaborate the two univerſal
elements of water and air into nutritive juices, whereas the latter is
neceſſitated to ſeek more compound nutriment, and to live upon the
vegetables, which have produced it.
2. One method therefore of increaſing manures may be by repeat-
edly propagating and deſtroying vegetable crops ; as by raiſing thoſe
of quick growth, and ploughing them again into the ſoil during their
faccharine and mucilaginous ſtate, before they ripen their feeds ; as of
vetches, and buck-wheat; vicia and polygonum; and thus produce
ing a ſucceſſion of crops by the partial decompoſition of the preced-
ing ones. And it is probable that this proceſs might be much im-
proved by ſtrewing lime over the recent vegetables, at the time of
ploughing them in, as is ſhewn in No. 6.5. of this Section.
3. Another mode by which vegetable matter may be decompoſed
in the fummer months, and at the ſame time the quantity of manure
increaſed, is by the depredation of infects, as is ſeen in wood, which
is ſo far decompoſing as to become tender, and is then conſumed by
various kinds of inſects, whether it be buried beneath the ſoil, or ex-
poſed

240
MANURES.
Sect. X. 10.4.
a
poſed to the air. And I ſuſpect, that the excrement and the bodies
.
of ſuch inſects would ſupply more nutriment to vegetable roots, than
if the vegetable recrements were left to their ſpontaneous or chemi-
cal diſſolution ; as I ſuppoſe the bitter excrementitious powder in a
filbert, and the well fed maggot, before it erodes its way out, would
fertilize more barren foil than an emulſion of the kernel.
An ingenious obſerver of nature conveyed water on a dunghill in
the ſummer months in ſuch quantity, as to make a kind of ſemi-
Auid chaos, for the purpoſe of animating the whole maſs. It be-
came full of inſects, and was uſed in the autumn as manure, and he
believed with much greater powers, than it would have otherwiſe
poffefTed.
Hence in the ſummer months a manure-heap may be advantage-
ouſly ſupplied with water for the purpoſe of encouraging the propa-
gation and nouriſhment of myriads of inſects; but in the winter ſea-
ſon it ſhould not be expoſed to much moiſture; or that which drains
from it ſhould be derived ſpontaneouſly on lower grounds, or con-
veyed to higher ones by pumps or water carts; as it probably con-
ſiſts of a ſolution of carbon by means of vegetable alkali; or of a mix-
ture of it in water by mucilage; and is thought to fertilize the
ground more than the other parts of the manure heap. In the tran-
factions of ſome provincial Society there is an account of much fixed
vegetable alkali having been obtained from the evaporation of the wa-
ter, which oozed from dunghills; and M. Rouelle has obſerved, that
fixed alkali diſſolves a conſiderable quantity of charcoal by fuſion.
Fourcroy's Elem. of Chemiſt. Vol. IV. p. 125.
4. Another great ſource of infect-manure may be obtained from
the myriads of ſmall fiſh, by thoſe who live near the ocean ; which by
mixing them with ſoil ſo as to make what is termed a compoſt, will
much add to the fertility of the land, on which it is afterwards ſpread,
more ſo perhaps than any other material except the fleſh of land-ani-
mals. In China it is ſaid that the ſpawn of fiſh in the proper ſeaſon
;
is

Sect. X. 11. 1.
241
MANURES.
brought to market, and purchaſed for the purpoſe of peopling the
floods on their rice grounds with fiſh, part of which becomes large
enough to be fried and eaten by the land cultivator ; and the reſt
ſerves the purpoſe of fertilizing the ſoil, when the floods are drawn
off, by their death and conſequent decompoſition.
XI.
PRESERVATION OF MANURES.
a
1. The fertility of all countries depends on the ſaving and uſing
thoſe kinds of matter, which are fit for the reproduction of organiz-
ed bodies. There is a proverb in China, that for this purpoſe a wiſe
man ſaves even the parings of his nails, and the clippings of his hair.
One great waſte of manure in this country, and in moſt others,
is from the frequent rains waſhing down the diffuſible and ſoluble
parts of the ſoil into the muddy rivers ; ſo that every flood from
ſudden ſhowers carries into the ſea many thouſand pounds worth of
the matter of fertility; and thus diminiſhes ſo much the food of ter-
reſtrial animals, however it may add to the ſuſtenance of marine
ones. The Delta of Egypt, and a diſtrict in South America near
the foot of the Andes mentioned by Ulloa, are ſaid by the ſituation
of the ſurrounding country to be free from rain, though they have
frequent dews; and to this circumſtance they may in part owe their
increaſing fertility
In this country the ſnow-floods, which occur after a continued
froſt, are leſs injurious than thoſe from rains; as the ſtreams of wa-
ter from the upper ſurface of the diſſolving ice flows over the under
ſurface of it not yet diſſolved ; and the ſoil is not agitated as in rain
by the percuſſion of the deſcending drops; inſomuch that in ſnow-
foods the rivers are ſcarcely muddy; whence theſe floods may be
readily diſtinguiſhed from land-floods by the eye, and are much leſs
injurious.
Great attention ſhould therefore be ſhewn to the preventing ſmall
li
ſhowers

242
Sect. X. 11. 2.
MANURE S.
a
ſhowers from waſhing away the foluble parts of good foil. For this
purpoſe all hills ſhould be ploughed horizontally, and not in aſcend.
ing and deſcending furrows. Deſcending plains of graſs-ground might
alſo be laid with horizontal ridges and depreſſions; by which ma-
nagement ſhowers will lie a few hours in the horizontal furrows or
depreſſions, and either exhale or ſoak into the ground; and in very wet
ſeaſons theſe may eaſily by the ſpade be opened into each other, if the
water is found to lie too long upon them, ſo as to produce too much
cold by its evaporation, or too great ſoftneſs by its abſorption into
the ſoil.
2. Secondly, the manures of towns and cities, which are all now
left buried in deep wells, or carried away by ſoughs into the rivers,
ſhould be removed by a police, which is ſaid to exiſt in China ; and
carried out of towns at ſtated intervals of time for the purpoſes of
agriculture; which might be performed in the night, as is done in
Edinburgh ; or by means of large baſons or reſervoirs at the extre-
mities of the common ſhores, or foughs for the reception of the ma-
nure, before it is waſhed into rivers. See Embaſſy to China by fir
G. Staunton, Vol. III. p. 308, 8vo. edit.
It has been believed by ſome writers in the American Medical Re-
poſitory, that the peftilential fever, which has of late infeſted that
country, was in part produced or propagated by the filth of the ſtreets
of New York. Dr. S. L. Mitchill adds to his chemical remarks on
manures, - it muſt be welcome intelligence, that the collected
maſs of nuiſance, which we are now with ſuch happy ſucceſs en-
gaged in removing from the city of New York, is convertible by the
powers of vegetation from poiſon to wholeſome articles of food; and
thus the purity and healthineſs of the towns may contribute to the
thriftineſs and wealth of the ſurrounding country.” Medical Journal,
No.I.
3. Thirdly, there ſhould be no burial places in churches or in
church-yards, where the monuments of departed finners ſhoulder
God's

Sect. X. 11. 4.
243
MANURE S.
a
God's altar, pollute his holy places with dead men's bones, and
pro-
duce by putrid exhalations contagious diſeaſes among thoſe who fre-
quent his worſhip. But proper burial grounds ſhould be conſecrated
out of towns, and divided into two compartments, the earth from one
of which, ſaturated with animal decompoſition, ſhould be taken away
once in ten or twenty years, for the purpoſes of agriculture; and
ſand or clay, or leſs fertile foil, brought into its place.
A great riſe of the ſoil, from the remains of the bodies entombed
in it, is ſeen round the churches of almoſt all populous towns; fo
as to have rendered it neceffary to deſcend by ſeveral ſteps into thoſe
churches, which were originally built ſo as to require ſteps to aſcend
into them; as may frequently be ſeen by the baſe of the architec-
ture. Nor would the removal of this earth, if the few bones, which
might be found, were again buried for a further decompoſition, be
likely to ſhock the relations of the deceaſed ; as the ſuperſtition con-
cerning the earth, from which we roſe, and into which we return,
has gradually vaniſhed before the light of reaſon; as occurred about
thirty years ago in removing much rich earth from the cloſe of the
cathedral at Lichfield, and more lately in changing a burying ground
at Shrewſbury; both which were executed without ſuperſtitious
terror, or popular commotion.
4. Fourthly, a great waſte of the materials of fertility occurs in all
countries, and cannot eaſily be avoided, in the conſumption by fire
of ſo much wood inſtead of coal. Whence the mucilage, and other
nutritious juices, which exiſt in the fire-wood, are decompoſed into
their elements; and the carbon united with oxygen is diffuſed in the
atmoſphere, and in part carried by the winds into the ſurrounding
ocean; inſtead of the manures occaſioned by the flow decompoſition
of it upon or beneath the ſoil, or by the depredation of inſects;
which might ſupply leſs decompoſed nutriment to the abſorbent roots
of plants.
This may be more eaſy to conceive, if we compare the little vege-
I i 2
table

244
SECT. X. 11. 5.
MANURES.
table nutriment, which could be derived from the ſmall quantity of
aſhes left from a cart-load of burnt-ſtraw, with that which would
ariſe from the ſame quantity of ſtraw mixed with ſome animal re-
crements, and made into a manure heap. A ſtill greater diminution
of uſeful manure would be made by burning ſhavings or rafpings of
horn, or woollen rags, or hair, or fleſh; as a nutritive mucilage
would be thus decompoſed into its elements, which might otherwiſe
have been gradually diſſolved beneath the ſoil, and abſorbed by the
roots of vegetabies nearly in an unaltered ſtate ; as jellies and mu-
cilage are known to be drank up by the lacteals of animals; and,
when drank in too great abundance, to appear almoſt unchanged in
their urine.
It muſt hence appear, that the numerous fires of a great city, if
ſupplied with wood inſtead of coals, as in Paris, muſt very much im-
poveriſh a great part of the country which ſupplies it; not only in
the neceſſity of uſing large tracts of land for the growth of fire-wood,
but alſo becauſe ſo ſmall a part of it returns as manure. There is a
provident adage of general benevolence, “ Burn nothing which any
animal will eat;" that is, “ Burn nothing which may nouriſh ani-
mals by its digeſtion in their ſtomachs.” May not the ſame bene.
volent idea be extended to the vegetable world, and ſay, “ Burn no-
thing which may nouriſh vegetables by its flow decompoſition be-
neath the ſoil, which conſtitutes their ſtomachs.”
5.
It
may be a matter of uſe as well as of curioſity to aſcertain the
ſituations and circumſtances moſt favourable for promoting the ſpon-
taneous decompoſition of vegetable ſubſtances; which may conſiſt
perhaps in the due quantity of air, water, and heat, with a ſufficient
proportion of animal ſubſtances, and finally an admixture of lime to-
ward the end of the proceſs.
1. In a cellar covered with an arch of bricks, and cloſed with a
very ſtrong door, I once obſerved, that a deal ſhelf two inches in
thickneſs was decayed, ſo as to fall down with ſome wine bottles on
9
it,

Sect. X. 11. 50
245
MANURE S.
it, in about four years. This ſudden decay I believed to have been
owing to the unchanging moiſture of the board, and at the ſame
time to its expoſure to unchanged air without the power of much ex-
halation; by which a ſlow fermentation was induced, and a conſe-
quent flow putrefaction, unchecked by the extremes either of heat
or cold.
a
For the ſame reaſon I ſuppoſe the wooden ſupporters of bridges
decay firſt juſt above the ſurface of the water; and pieces of timber
buried but a few inches under ground, which are there expoſed to
the influence both of water and air, go quicker into fermentation,
and conſequent putrefaction, than thoſe pieces of timber, which are
many feet buried beneath the ſoil, or immerſed deep in water; which
in that ſituation continue unchanged for ages. The ſame ſeems to
occur in the vinous fermentation, which is inſtantly checked, if not
totally ſtopped, by bunging the barrel, or corking the bottle, which
contains it, and thus precluding the acceſs of atmoſpheric air.
2. From hence it may be concluded, firſt, that the vegetable and
animal ſubſtances, which we wilh ſoon to become decompoſed by
the fermentative and putrefactive proceſſes, ſhould be expoſed to an
uniform moiſture, though not covered deep with water ; as is gene-
rally practiſed in the firſt part of the preparation of hemp or flax,
which is deſigned to diffolve the mucilage, and the cellular mem-
brane of thoſe vegetables, without injuring the ligneous fibres. And
that they ſhould be ſo far accumulated as not too much to exhale;
yet not to lie in ſuch large heaps, as entirely to preclude the acceſs
of air from the interior parts of them.
The manures of great farms ſhould therefore be occaſionally re-
moved from the fold-yards, or large reſervoirs of it, and laid in ſmall
heaps not only to increaſe its ſurface expoſed to the external atmo-
ſphere, for the purpoſe of exciting greater fermentation, which is a
flow combuſtion; but alſo that air may be impriſoned in the interſtices
of theſe manure-heaps, as mentioned in No. 8. 2. of this section.
It

246
SECT. X. 11. 5.
MANURES.
It ſhould then be uſed on or in the ſoil, as it afterward loſes much
of its nutritive qualities by evaporation, or finking into the ground,
or draining away.
3. A due degree of heat is neceſſary for the commencement of
fermentation and putrefaction, as both vegetable and animal materials,
as fruit or fleſh, may be preſerved for years if kept in an ice-houſe
below the freezing point of 32. And alſo, I am told, if they could
be kept in an uniform degree of heat above the boiling point of 212.
After the commencement of either of theſe proceſſes a quantity of
heat is evolved from the combination of the oxygen and carbon,
which contributes to forward the proceſſes by promoting the union
of the next particles of oxygen and carbon ; which may thence be
compared to a flow combuſtion, or to a gradual exploſion of gun-
powder.
This heat therefore ſhould be managed with ſome addreſs, as a
great quantity of it would calcine or evaporate too much of the ma-
terials, and leave the remainder a leſs profitable maſs; as happens, I
am informed, to ſome parts of thoſe heaps of manure, which are
uſed in the manufactory of white lead; while on the contrary, when
the heat is too ſmall, as in ſevere froſt, theſe proceſſes of decompo-
ſition will not commence, or may be ſtopped in their progreſs. In
the former caſe, where the heat is too great, it may be checked by
covering the whole manure-heap with foil and turf, and thus pre-
venting the acceſs of air. And when the heat is too ſmall, as in
old hot beds, it may be renewed or promoted by turning the heap
over with the ſpade, and thus confining a new quantity of air in its
interſtices. On theſe accounts it appears, that in the vernal and au-
tumnal months theſe proceſſes muſt ſucceed better than in the win-
ter or the ſummer ones.
4. Toward the end of the putrefactive proceſs the materials ſhould
be repeatedly turned over with the ſpade, not only for the purpoſe of
ſimply expoſing their interior parts to the atmoſphere, but alſo of in-
7
cluding
a

SECT. X. 11. 6.
247
MANURES,
cluding air in the interſtices; as the union of carbon with oxygen,
and probably of azote with hydrogen, ſeems thus to be occaſioned ;
by which the three laſt of theſe elements may change from a gaffe-
ous ſtate into a fluid one, and thus become abſorbed by vegetable
roots.
Laſtly, I conclude that in general the manure heap before ſtables,
or in the fold-yard, ſhould be placed on a gently riſing eminence, with
a baſon beneath it, that the ſuperfluous water, which would other-
wiſe prevent the fermentation of the ſtraw, may drain off and be
there received ; and that into this baſon, as often as a fluid appears in
it, fome earth, or weeds, or leaves, or faw-duft, or other vegeta-
ble or animal recrements ſhould be thrown; the fermentation and
putrefaction of which will be thus forwarded, and the carbonic drain-
ing from the manure-heap will not be loft.
5. The admixture of lime with this carbonic foil is found by daily
experience to produce the moſt fertile compoſitions for the growth
of vegetables, and for the production of nitre. The great uſe of ni-
trous acid in vegetation has long been acknowledged, and that of
hyper-oxygenated marine acid appears probable from recent experi-
ments; and would ſeem to be occaſioned by the more looſe adheſion
of the oxygen in thoſe acids to their reſpective baſes; which may
therefore in its fluid ſtate be more readily abſorbed by vegetable roots.
One uſe therefore of the admixture of lime in ſuch a compoſt of foil
and manure is to arreſt the nitrous acid, as it is formed, and by mak-
ing a calcareous nitre, prevent its exhalation, or its eaſy elutriation
from the other materials.
6. A principal circumſtance for the quicker and more perfect de-
compoſition of vegetable recrements is a due quantity of animal mat-
ter, and their being properly mixed together; as appears from the
early experiments of fir John Pringle and Macbride, and by daily ex-
perience. There is nevertheleſs great neglect in this reſpect in all
thoſe rm-yards, where the ſwine have their food in fixed ſtone-
troughs,
a

248
Secr. X. 11.7
MANURE S.
troughs, from which the refuſe is occaſionally waſhed or ſwept.
Whereas if wooden moveable ſwine-troughs were always placed on
the ſummit of the heaps of dry ſtraw, the quantity of their ſwill,
conſiſting of broth, whey, and other vegetable and animal matter,
which theſe animals waſte in their contention for it, would generate
early putrefactive proceſſes; beſides their mixing the ſubſtances well
together with their feet, and adding to it their urine and ordure.
Beſides this inattention to the manure-heap in many houſes the
waſhings of boilers, and milk-pans, and diſhes, as well as the ſoap-
ſuds, which are all of them manures of the moſt productive kind,
are thrown into the common ſewer, inſtead of being derived or car-
ried to the garden or the ſtraw-yard.
7. Another inattention to the production of manures concerns the
heaps of common weeds, and of dock-roots, and of cabbage-ſtalks,
and the roots of twitch-grafs; which improvident farmers and gar-
deners frequently throw into the high roads, or conſume with fire;
and which if laid on heaps, and occaſionally turned over, and co-
vered with foil, will quickly die, and paſs into ſpeedy fermentation
from the ſugar and mucilage, which they contain ; and if to theſe a
portion of lime be added, I am informed by one who made the expe-
riment, that the whole was decompoſed in a ſhort time, and manure
of the beſt kind was the product.
The ſame ſhould be practiſed with the leaves which fall in autumn
on graſs land, eſpecially from thoſe orchards, or hedges, or from
gooſeberry-trees, which have been infeſted with caterpillars; ſince I
am told the eggs of a future race of theſe inſects are frequently de-
poſited on the leaves, and hatched on or beneath the ſoil in the en-
ſuing ſpring. Theſe therefore ſhould be removed from the roots of
ſuch trees, and converted into manure by the proceſs above men-
tioned.
Along with the weeds and leaves above mentioned I ſhould ſtrongly
recommend to the induſtrious agriculfor to collect the water-plants
a
which

Sect. X. 12.
249
MANURES.
which grow in great abundance in lakes and rivers, for the purpoſe
of manure; which at preſent are employed to no advantage. Theſe
might be moved twice a year, as it is probable that theſe vegetables
in their younger ſtate, as the typha, or cat’s-tail; the butomus, or
flowering-ruſh ; nymphæa and aliſma, as well as many other aquatic
plants, would give better manure, or ſooner become ſufficiently de-
compoſed, during their more faccharine and mucilaginous ſtate, than
when they have acquired more fibrous leaves, and more woody
ſtems.
By thus expoſing the roots and tops of weeds to fermentation,
their feeds would alſo be deſtroyed as well as the vegetative power
of their roots; and on this account the hay-feeds collected from
ſtacks, which have fermented too violently, ſo as to become black by
this flow combuſtion, are frequently ſo much injured as not to vege-
tate, to the great diſappointment of the ſower, a circumſtance which
alſo ſometimes occurs in ſtacks of wheat, as mentioned in Sect.
XVI. 7. 1.
8. Laſtly, peat, ſo well underſtood and ſo ſtrongly recommended
by Lord Dundonald, is too much neglected in agriculture. The peat
or turf, which conſtitutes the ſolid parts of moraſſes, as it conſiſts
of vegetable fibres in different ſtates of decompoſition, may be laid
on clayey or ſandy ſoils with the greateſt advantage; and ought to be
conſidered as an ineſtimable treaſure to the farms in its vicinity. Or
it may previouſly be laid on heaps, and thus mixed with air and
drained from water for further decompoſition, with or without the
addition of lime.
XII.
APPLICATION OF MANURES.
Two queſtions of importance here preſent themſelves. As the
ſpontaneous or chemical changes of manure-heaps in farm-yards gra-
dually progrede from the faccharine and mucilaginous commence-
Kk
ment

MANURE S.
Sect. X. 12. 1.
250
ment through a great variety of other fermentations; which can
only be named from the principal material, which each of them pro-
duces, as carbonic acid, alcohol, vinegar, volatile alkali, hydrogen,
nitrous acid, and finally carbonic earth. At what era or ſtage of
this decompoſition of vegetable and animal ſubſtances can they be
moſt advantageouſly applied to the purpoſes of agriculture ? and ſe-
condly, at what time of the year?
1. In reſpect to the era of the progreſs of the decompoſition in
manure-heaps, in which they may be moſt advantageouſly applied in
agriculture, the particular purpoſe of that application muſt be attend-
ed to. Where they are deſigned to be ſpread on the ſurface of graſs
lands, as a top-dreſſing, the accumulations of vegetable and animal re-
crements ſhould be permitted to go through the various ſpontaneous
proceſſes of decompoſition, which begin with the faccharine and mu-
cilaginous ſtate, and end with the production of carbonic earth, with
many kinds of intermediate fermentations, if they may be ſo called,
which accompany or ſucceed each other, and which I believe to be
more in number than have had names applied to them.
But that leſs of the fertilizing materials, whether of foluble ſo-
lids, or of fluids, or of gaffes, may be loſt in theſe ſeries of fermenta-
tions; it is a very advantageous management to cover them with
foil, when the firſt fermentation is advanced, as is known by the pro-
duction of conſiderable heat; or when the putrefactive one has com-
menced, which is known by the ſmell of volatile alkali, or of hydro-
gen. By this method the too great rapidity of theſe fermentations
is checked, and the fluid part of the manure is retained by the addi-
tion of the ſoil below, and the gaſſeous part by that above; and if to
this be afterwards added a proportion of lime, which by uniting with
the nitrous acid may retain it from exhalation or from alluviation,
every thing is preſerved that art can accompliſh.
Where manure-heaps are to be ploughed into clayey foils, which
are liable to become too folid and impenetrable to the root-fibres of
feeds,

Sect.X. 12. 2.
251
MANURE S.
ſeeds, as of wheat; or where knobby or bulbous roots are to be in-
ſerted to produce other knobs or bulbs beneath the ſoil, as potatoes ;
it is probably more advantageous to bury the manure in a leſs de-
compoſed ſtate, while ſome of the ſtraw retains its form; as ſuch
parts by their flower decompoſition will longer prevent the ſuper-in-
cumbent foil from becoming too ſolid; and though they will in this
ſituation require ſome time before they will be perfectly decompoſ-
ed, and reduced to the black carbonic earth; yet they will in the
end totally decay, and give the ſame quantity of nutriment to the
roots, though it may be more gradually applied.
2. In reſpect to the time of year thoſe manures, which are to be
ploughed or dug into the ground, ſhould be uſed immediately before
ſowing the ſeeds or ſetting the roots, which they are deſigned to nur-
ture; becauſe the atmoſpheric air, which is buried along with the
manure in the interſtices of the earth, and which for many weeks,
or even months, renders the ſoil looſe, and eaſily impreſſed by the
foot on walking on it, gradually evolves by its union with carbon a
genial heat very friendly to vegetation in this climate, as well as the
immediate production of much fluid carbonic acid, and probably of a
fluid mixture of nitrogen with hydrogen, which are believed to ſup-
ply much nutriment to plants.
But thoſe manures, which are deſigned to be ſpread on the ſurface
of graſs-land, which is called the top-dreſſing, are beſt applied, I
ſuſpect, in the early ſpring; and ſhould be diſperſed over the ſoil al-
moſt in a ſtate of powder, or in lumps of very looſe coheſion; as at
this time the vernal ſhowers waſh them into the ſoil; and they are
applied to the roots of the graſs, before their eſſential parts are dimi-
niſhed by winter rains or by ſummer exhalation. There are ſome in
Derbyſhire, who ſpread manure even on the meadows, which are an-
nually overflowed by the Trent or Derwent, at the end of ſummer,
or as ſoon as the graſs is mowed and removed; which appears to be
in improvident management, ſince the aftermath, or autumnal graſs,
Kk 2
is

252
MANURE S.
SECT. X. 12. 3.
a
is thus rendered unpalatable to the cattle; and the winter rains, or
the vernal floods, which generally occur with the return of the
fouth-weſt winds, after the ſeaſon of froſt ceaſes, muſt waſh away
a great part of it.
In reſpect to the moſt economical manner of uſing manures in
agriculture Mr. Parkinſon aſſerts, that one great advantage of the
drill-huſbandry conſiſts in putting the manure into drills, which he
directs to be made at two feet diſtance from each other. He fows
wheat, beans, peas, cabbages, on this manure, and affirms, that four
loads of manure on an acre in this kind of huſbandry is equal to
fixteen loads in the uſual way of ſpreading it over the whole of the
field. Experienced Farmer, Vol. I. p. 32.
3. A third queſtion here preſents itſelf, if the recrements of ve-
getable and animal bodies buried a few inches beneath the ſoil un-
dergo the fame decompoſition, as when laid on heaps in farm-yards.
And though this is accompliſhed more ſlowly, yet it is attended with
leſs loſs of carbonic acid, and of volatile alkali, and of hyrogen, and
of the fluid matter of heat ; all which are emitted in great quantity
during the rapid fermentations of large heaps of manure, and are
waſted in the atmoſphere, or on unprolific ground; would it not
in general be more economical to bury ſuch vegetable and animal
matters beneath the foil without a previous fermentation and putre-
faction ?
In anſwer to this it muſt be obſerved, that in fome caſes the uſe
of recent vegetables ploughed into the earth is found of advantage,
as in fandy ſoils buck-wheat, or vetches, are fown, and the crop
ploughed in, before it ripens its ſeeds. In this circumſtance the re-
cent crop is buried in its ſaccharine and mucilaginous ſtate, which
muſt undergo indeed a flower fermentation, without being mixed
with animal ſubſtances, but no part of the organic matter, nor of the
fluid heat, is loſt to the purpoſes of new organization.
So in the cultivation of clayey lands, whoſe tenacity is too great;
;
OE

SECT. X. 12. 3.
253
MANURE S.
or where knobby roots, as potatoes, are to be inſerted for the produc-
tion of other knobby roots beneath the ſoil ; long muck, as it is call-
ed, or ſuch which is only ſo far decompoſed as to diſſolve the mu-
cilage or more tender veſſels or membranes, but in which the form
of the fibrous or ligneous parts of the ſtraw remains, is recommend-
ed above; and may in theſe ſituations perhaps be ploughed into the
ground even in their moſt early ſtate, when rejected from the ſtable
or cowhouſe, before the commencement of their ſpontaneous diffo-
lution.
So alſo in gardens, which are already fertile, and do not want the
immediate aſſiſtance of mature manure, it may be more economical
to bury the weeds, as the ground is dug, than to convey them to
a manure-heap, and replace them after a twelvemonth's decompo-
ſition.
But where a luxuriant crop is immediately wanted, a manure-heap
towards the end of the putrefactive proceſs by being recently in-
terred in the ſoil, which is immediately to be ſown or planted, has
,
this great advantage; that the carbonic acid is preſently formed by
the mixture of atmoſpheric air with the carbon of the manure;
which exiſts therefore in its fluid, not its gaſſeous ſtate, and is thence
more readily abſorbed. Secondly, ammoniac is produced, and nitre,
and hydrogen probably is mixed with nitrogen ; and theſe alſo, I ſup-
poſe, exiſt at firſt in their fluid, not in their gaſſeous ſtate. And
thirdly, from theſe combinations a genial degree of heat is evolved,
which ſo much affiſts the vernal growth of vegetation.
And where manure is to be uſed as a top-dreſſing, it is neceſſary,
that it ſhould be in a ſtate of powder, or in ſmall lumps of looſe
coheſion, as mentioned above; that it may be eaſily waſhed by rains
to the roots of the graſs, or that the young ſtems of graſs may rea-
dily ſhoot themſelves through it; whence mature heaps of manure
are for this purpoſe neceſſary; and on this account any adheſive ma-
nure,

254
Sect. X. 12.4.
MANURE S.
;
nure, as cow-dung itſelf, ſhould be weekly gathered from graſs-
ground, where cattle are nouriſhed, and laid on heaps with foil, or
ſtraw, or weeds, to ferment or putrefy ; till it becomes leſs tenacious,
and can be profitably replaced in the enſuing ſpring.
Finally, I ſuſpect the moſt economical method of diſpoſing of the
ſtraw, and dung from the farm-yard would be, as ſoon as a dark co-
loured water drains from the heap, by which much loſs is ſuſtained,
to carry the refuſe of the ſtable and cow-houſe, as frequently as con-
venient, to the ground, where it is deſigned to be employed; and
there to mix it with earth in heaps of proper ſize, and to cover them
likewiſe with foil; and by theſe means I ſuppoſe the whole proceſs
of decompoſition may be carried on with very little loſs; and by the
addition of a greater or leſs quantity of ſoil that the era of complete
or moſt profitable decompoſition of the compoſt may be managed, ſo
fo
as to coincide nearly with the time it may be wanted.
4. Fourthly, it may be aſked, what kinds of manure contribute
moſt to the luxuriant growth of vegetables ? In anſwer to this it
may be ſaid, that as plants are inferior animals, and are furniſhed
with abſorbent veſſels in their roots correſpondent to the lacteals in
the ſtomach ; that the ſame organic matters, which by their quick
ſolution in the ſtomach ſupply the nutritive chyle to animals, will
by their flow ſolution in or near the ſurface of the earth ſupply the
nutritive fap-juice to vegetables. Hence all kinds of animal and
vegetable ſubſtances, which will undergo a digeſtive proceſs, or ſpon-
taneous ſolution, as the fleſh, fat, ſkin, and bones, of animals; with
their ſecretions of bile, ſaliva, mucus; and their excretions of urine,
and ordure; and alſo the fruit, meal, oil, leaves, wood, of vegetables,
when properly decompoſed on or beneath the ſoil, ſupply the moſt
nutritive food to plants.
Secondly, the chyle of all animals is ſimilar to the ſap-juice of all
vegetables in this circumſtance, that they both contain mucilage and
7
ſugar,
V

Sect. X. 12. 4.
255
MANURES,
ſugar, and feem only to differ in this reſpect, that the chyle of ani-
mals alſo contains oil, which being mixed with the mucilage gives
it its whiteneſs like milk. Hence thoſe matters muſt ſupply nutri-
ment moſt expeditiouſly to vegetables, which contain mucilage and
ſugar, or produce them with the leaſt decompofition, as the jellies
from the ſhavings of horns, from hair, woollen rags, and the fac-
charine matter of ſweet fruits, roots, kernels, feeds; and in the
ſame manner theſe things with the addition of oil are moſt expedi-
tiouſly nutritive to animals.
Thirdly, ſuch materials as contain in ſolution thoſe ſimple ſub-
ſtances, which conſtitute a great part of vegetable bodies, as carbon,
which is found in moſt earths; and oxygen, hydrogen, and nitro-
gen, which are found in water and in air; and from hence we may
conclude, that whatever material has conſtituted a part of living or -
ganic bodies, may again conſtitute a part of them; and that with
more expedition, if they can be uſed without being decompofed into
their primary elements.
Mr. Bewley, the Norfolk philoſopher, ſaid to a friend, who was
riding by his ſide, that when he wanted a whip, he habitually looked
for a dead ſtick in the hedge, unwilling to pluck off a leafy branch,
and deſtroy ſo many living buds. He might have added, that to
burn a hair or a ſtraw unneceſſarily diminiſhes the ſum of matter fit
for quick nutrition by decompoſing it nearly into its elements, and
ſhould therefore give ſome compunctions to a mind of univerſal ſym-
pathy
It would ſeem therefore, that long roots fixed into the earth, and
leaves innumerable waving in the air, were neceſſary for the decom-
poſition and new combinations of water and air, and the converſion
of them into ſaccharine and mucilaginous matter ; which would
have been not only cumbrous but totally incompatible with the lo-
comotions of animal bodies ; for how could a man or quadruped
have
a
a
m

256
SECT. X. 12. 4.
MANURE S.
have carried on his head or back a foreft of leaves, or have trailed
after him long branching lacteals terminating on the ſurface of the
earth ? Animals therefore ſubſiſt on vegetables; that is, they take
the matter ſo far prepared, and poſſeſs organs to prepare it further
for the purpoſes of greater ſenſibility, and of higher animation.
j
-
SECT.

Secr. XI. 1.2.
257
DRAINING AND WATERING.
SECT. XI.
OF DRAINING AND WATERING LANDS.
I. 1. Moraſſes are in high or low ſituations. 2. Springs riſe from the ſummits of
mountains, paſs between the ſtrata. 3. Strata of the earth about Derby, and
at Lichfield, and the ſprings. 4. Plains formed in vallies. 5. Wall-Springs in-
tercepted by ditches, funk perpendicular to the ſides of the hills. 6. By boring
boles at the bottom of ſuch ditches. 7. Uſe of ditches, where the wall-Springs can-
not be intercepted. 8. Holes through clay into a ſand-ſtone beneath. 9. Deep
Springs riſe higheſt, when bored into. 10. Many Springs may be raiſed higher than
their ſources.
11. Enlarging the bottom of wells increaſes the water in them.
12. Springs diſcovered on one ſide only of ſome mountains. Diſcovered by even-
ing miſts. By morning rime. By aquatic plants. Warm Springs. II. I. Draining
moraſſes, where there is no fall. 2. In the craters of ancient volcanoes. 3. In
countries of marble, granite, or quartz. 4. Fens below the level of the ſea. Should
be ſurrounded with dikes. 5. Uſes of aquatic plants. III. 1. Of flooding lands.
2. Ice preſerves the graſs beneath. The French bored holes in the ice. 3. Ad-
vantages of flooding recapitulated. It deſtroys ruſhes. Saves manure. 4. Cau-
4
tions to be obſerved. Flooding not injurious to health. Vicinity of running water
wholeſome. 5. Flooding lands might be performed to a great extent. By rivers,
Springs, land-floods, and machinery. Hiero's fountain Horizontal wind-mill,
and centrifugal pump.
1. 1. The great quantity of water required for healthy vegetation
is treated of in Sect. X. 3. I. But as all extremes are injurious, too
much water becomes pernicious to all except aquatic plants. Whence
the neceſſity of draining thoſe lands, which too much abound with
moiſture; the art of which is better underſtood, ſince the knowledge
LI
of

258
DRAINING? Sect. XI. 1. 2.
-
of geology has been ſtudied, and in ſome meaſure diffuſed amongſt the
people.
Lands in reſpect to the method of draining them may be divided
into two fituations; thoſe which lie ſo high, that the water can de-
ſcend from them, if it be properly collected and conducted; and
thoſe which lie ſo low as to command no fall, ſome of which are
even below the level of the ſea.
2. In regard to the former it generally happens, that the waters from
the ſprings beneath the ſoil have not a free paffage to the rivers in
their vicinity; the nature of ſprings ſhould therefore be previouſly
underſtood. Many modern philoſophers have endeavoured to ſhew,
that all the continents and iſlands of the world, as well as the hills,
which emboſs their ſurfaces, have been raiſed out of the primeval
ocean by ſubterraneous fires. This appears from the quantity of ſea-
Thells, which form innumerable mountains; and from the fifiures in
the rocks, of which they conft; the quantity of volcanic produc-
tions all over the world; and the numerous remains of craters of vol-
canoes in mountainous countries.
Hence the ſtrata, which compoſe the ſides of mountains, lie flant-
ing downwards; and one or two or more of the external ſtrata not
reaching to the ſummit, when the mountain was raiſed up, the ſe-
cond or third ſtratum, or a more inferior one, is there expofed to
day. This may be well repreſented by forcibly thruſting a very blunt
inſtrument through ſome folds of paper, a bur will be raiſed with the
lowermoſt leaf ftanding higheſt in the center of it. Or if at the ori-
ginal elevation of an extenſive mountain the loweſt ſtratum ſhould
not at firſt ſtand higher in the center of the ſummit, it would in
time become ſo by ſome of the upper ftrata of the mountain being
gradually waſhed away by rains into the valleys or rivers, On this
uppermoſt ftratum, which is colder, as it is more elevated, the dews
are condenſed in large quantities; and ſliding down paſs under the
firſt, or ſecond, or third ftratum, which compoſe the ſides of the
bill;

SECT. XI. 1.3.
259
AND WATERING.
hill; and either form a moraſs below, or a weeping rock by oozing
out in numerous places; or many of theſe leſs currents meeting to-
gether burſt out in a more copious rill.
The immediate cauſe of ſprings conſiſts therefore in the conden-
ſation of the atmoſpheric moiſture, during the night principally, by
the greater coldneſs of the ſummits of hills, which is explained in de-
tail in the Botanic Garden, Vol. I. additional note 26. The water
'
thus condenſed on the ſummits of hills deſcends between the ſtrata
of the incumbent ſoil, ſometimes for many miles together ; but ge-
nerally from the neareſt eminences into the adjoining vallies.
3. Thus there is a ſtratum of marl, which I have obſerved on the
ſurface of the lands about Derby, which extends many miles in moſt
directions. This ftratum of marl is of various thickneſs from 10 to
150 feet, and beneath it lies a ſtratum of ſand, which is alſo of vari-
ous thickneſs from a few inches to fix or eight feet, and of various
degrees of induration ; and beneath this lies another ſtratum of marl
to an unknown depth. On the top of Radborne common, about five
miles north-weſt from Derby, the ſandy ſtratum is quite looſe, and
riſes above the ſtratum of marl, which is deficient at the ſummit of
the hill. Three or four ſtrong ſprings of water burſt out on the ſides
of this hill, which thus originate from the moiſture of the atmo-
ſphere condenſed on the cold ſummit, and pafling through the fandy
ftratum between the two ſtrata of marl.
In the road to Duffield, about two miles north of Derby, the
ſand-ſtratum is cemented into ftone, as well as in ſome ſituations
near Radborne-common above mentioned. This ſtratum of fand-
ſtone is ſome feet in thickneſs, and lies four or five yards deep, be-
neath the upper ſtratum of marl, dividing it from the lower one.
At Normanton, about two miles ſouth from Derby, the ſand- ftra-
tum conſiſts of a looſe ſand, fo white and pure, that I imagine it
might be uſed in the manufacture of flint-glaſs, and lies about twelve
feet deep, beneath the upper ſtratum of marl, dividing it from the
L 12
under
a

260
SECT. XI. 1. 2
DRAINING
under one. In the town of Derby on boring with deſign to ſink a
well, after having paſſed about thirteen yards through marl, fome
fand was brought up by the auger, and water followed, as related in
the Philoſ. Tranſact. Vol. LXXV.
The dews therefore, which are perpetually condenſing on the ſum-
mits of theſe hills, deſcend beneath the upper and under ſtrata of
mar), through the thin ſtratum of ſand, which divides them, and
form St. Alkmund's well, and many other ſprings in the vicinity of
Derby; and probably all thoſe which ſupply the wells within the
town.
a
a
But there is a ſituation, where the manner of the production of
ſprings is moſt agreeably viſible; it is about a mile from the city of
Lichfield, near the cold bath erected by fir John Floyer, in a beauti-
ful piece of ground, which was formerly Dr. Darwin's botanic
garden.
In this place a grotto about ſix yards wide and ten long has been
excavated on the fide of a hill conſiſting of filiceous fand-ſtone with
this peculiar circumſtance; that the upper ſtratum of the fand-rock,
which is there about five feet thick, is divided from the lower ſtra-
tum of it by a ſheet of clay not more than three or four inches in
thickneſs ; on the upper ſurface of this ſheet of clay, between the
lips of theſe rocks, a perpetual dribbling of water oozes quite round
the grotto, like a ſhower from a weeping rock. Such fheets of wa-
ter having been often obſerved to ſlide between the ſtrata of the
earth almoſt horizontally, like the horizontal joints of a ſtone-wall,
have, I ſuppoſe, given the name of wall-ſprings to them, to diſtin-
guiſh them from pipe-ſprings, or ſuch as burſt out in a fingle rill.
Thus this thin ſheet of clay prevents the water from finking into
the lower ftratum of ſand-ſtone ; and produces other copious fprings,
which are collected at about half a mile's diſtance, and conveyed by
leaden pipes to the cathedral cloſe of Lichfield, which is thus fup-
plied with water of uncommon purity, which contains no calcare-
a
a
OUS

Sect. XI. 1.4.
261
AND WATERING,
ous earth, owing to its paſſing through filiceous ſand over a ſtratum
of clay, and which would be a treaſure to the paper-mill or the
bleach-yard.
4. One other circumſtance in the preſent conformation of the earth
is neceſſary to be mentioned; which is, that at the time when the
mountains were raiſed all over the world by deep volcanoes, or by
central fires, ſome parts of the ſummits of many of them, and of
their ſteeper fides, rolled down again into the new formed vallies,
And ſecondly, that fince that remote time the recrements of vegeta-
ble and animal bodies have continually been waſhed down from the
eminences by ſhowers, and have contributed gradually to accumu-
late in the vallies, and to form the plains, which exiſt on the ſides of
rivers. This appears from the tin ores found in the vallies in Corn-
wall in loote pieces ſimilar to thoſe in the proximate mountains; and
from the black carbonic ſoil, or moraſs-turf, found in moſt vallies.
5. From thele clear ideas of the ſtrata of the earth, and of the
ſtreams of water, which flide between them, and form what are
ter ned wall-ſprings, it is eaſy to conceive, that the beſt method of
preventing the vallies at the bottom of hills from being too moiſt
muſt be by cutting a long horizontal ditch into the ſide of the mount-
tain to intercept the water, juſt before the level land of the valley
commences; and thus to carry away the water before it comes upon
the plain beneath.
For this purpoſe at the foot of the hill where the plain, which is
too moiſt, commences, fome auger-holes ſhould be bored to find the
depth of the ſprings, that is to find the thickness of the upper ftra-
tum of the foil. If this be only four or fix feet, an horizontal ditch
ſhould be cut along the bottom of the mountain to intercept the wa-
ter; which muſt en be carried away by one or more other ditches
opening into this, and conducting the water fo colle&ted into the
neighbouring rivulet.
As the ſtrata, between which the water defcends in forming theſe
1prings,

262
Sect. XI. 1. 6.
DRAINING
ſprings, have generally the ſame inclination as the ſurface of the hill,
or nearly fo; it follows, that the holes ſhould be bored, and the ditch
cut, not vertically downwards, as is the common practice, but per-
pendicular to the ſurface of the mountain ; as by that means the ſe-
cond ftratum will ſooner be arrived at; as ſhewn in Plate V. at the
end of this Section.
6. But if on cutting a ditch five or ſix feet along the bottom of the
hill perpendicular to the riſing plain, which forms the ſide of it, the
upper ſtratum be not cut through; and in conſequence no water
oozes into the bottom of the ditch ; it is then proper to bore other
holes at the bottom of this ditch ſome yards deeper, or till water riſes
up through them into the ditch, if it can be ſo diſcovered. Where
this ſucceeds, many holes ſhould be bored, and the water received
into the ditches, and conducted into the adjacent river ; for the wa-
ter will then riſe into the bottom of this ditch fix feet below the wet
ſurface of the valley, and thus flow away, rather than riſe up from
the lower wall-ſprings, or apertures of the ſtratum, through the in-
cumbent foil to the ſurface of the valley, which is ſo many
feet
higher. This well underſtood is the great ſecret for draining thoſe
grounds, where the ſprings can not be cut into fimply by a ditch.
This method has been ſome years practiſed with ſucceſs by Mr.
Elkington, but was previouſly uſed and explained by Mr. Ander
fon, as he aſſerts in his introduction to Vol. III. of his Eſſays on
Agriculture, who ſunk a hole into the earth at the bottom of a ditch
in the year 1964, and the water roſe fix feet above the ſurface of
the ground, and has continued to flow with leſs violence ever ſince
that time.
It ſhould here be noticed, that where the water riſes with great
force through holes thus bored into a deep ftratum, it is liable to
bring up along with it much fand, fo as ſometimes to obſtruct its
paffage; which fand in this caſe muſt frequently be removed for a
few days by the reapplication of the auger. Of this a remarkable in-
8
ſtance

Secr. XI. 1. 7.
AND WATERING.
263
a
ſtance is publiſhed in a late volume of the Phil. Tranſ. by Mr. Wul-
liamy, who funk a well 236 feet deep and four feet wide; and, on
then boring a few feet lower with a five-inch borer, ſo much fand
aroſe with a violent ſtream of water, as to fill up the whole well;
which was repeatedly cleared away by buckets in its fluid ftate, and
at laſt the water ran over the ſurface to the amount of forty-ſix gal--
lons in a minute.
The manner of making theſe ditches narrower, as they deſcend,
by ſpades of an adapted breadth ; and of making the loweſt part nara
rower than any other part, ſo that the thoulders or edges of it may
ſupport ſtones, or faggots, to cover the whole at a ſmall expence
without obſtructing the currents of water, are obvious to the work-
men. In many ſituations hollow bricks, or ridge-tiles, or old pieces
of plaſter-floors, may be worth the aditional expence of providing
them.
7.
There may nevertheleſs be found ſituations, where the firſt ftrae
tumn of earth may be too thick to be eaſily penetrated; or where the
water, condenſed from the atmoſphere on the ſummits of the hills,
may ſlide between the fecond and third, or between the third and
fourth ftrata, which form the fides of thoſe hills, owing to a deficien-
cy of ſo many of the ſtrata at the ſummits of them; and hence that
it
may lie too deep to be eaſily arreſted by a ditch, or by boring, and
yet by its being dammed up by the materials, which form the level
plain of the valley, may riſe up through thoſe materials to the fur-
face, and form boggy or moraffy ground.
In theſe ſituations the common unſkilful method of draining may
be uſefully employed; which conſiſts in cutting many ditches four
or fix feet deep acroſs the bog or morafs ; and covering them, fo that
the water may have no obſtruction in paſſing along them; which
may thus, as it riſes from below, be in part collected and conveyed
away ; though leſs advantageouſly than where the ſprings can be in-
tercepted.
Another

264
Sect. XI. 1. 8.
DRAINING
a
a
a
a
Another method of draining moiſt meadows has been by making
or opening drains almoſt annually by a large plough with two con-
verging coulters, and other adapted parts, for the purpoſe of cutting
both the ſides of a ditch at the ſame time, and turning out the inter-
vening turf and ſoil. Theſe large ploughs have been kept in ſome
pariſhes, and drawn over moiſt commons by twelve or twenty horſes,
to form parallel ditches.
Mr. Adam Scott has invented for the ſame purpoſe what he terms
a mole-plough, which conliſts of a coulter fifteen inches long, and
two and a half wide, to cut the ſward ; and behind this an horizontal
cone of caſt iron twenty inches long, and two and a half diameter at
the baſe, to the middle of which is fixed an upright bar two feet long,
and three inches and a half broad, with a ſharp edge. As this caſt
iron cone is drawn along ſix or eight inches beneath the turf in moiſt
Jands, either in the ſpring or autumn, in many parallel lines, the
water for a conſiderable time is conveyed away, and no injury done
to the ſurface; which thus ſeems to be an uſeful machine, and may
be well managed, I am informed, by fix or eight horſes. In very
moiſt lands, or at very moiſt ſeaſons, if more horſes be uſed, their feet
will not fink ſo deep into the turf, as each horſe will draw leſs; or
a contrivance of adding broader ſhoes of wood to the horſes like the
ſnow-ſhoes of higher latitudes, might anſwer this purpoſe. See Tran-
fact. of Society of Arts, Vol. XV.
8. There are nevertheleſs ſome ſituations, where the water is con-
veyed beneath the firſt ftratum on a thin bed of clay over a porus
fand-ſtone beneath it; as in the grotto at Lichfield above deſcribed.
In theſe ſituations by boring many auger-holes, or by ſinking wells,
through the ſtratum of clay the water will penetrate the fand-ſtone
beneath it; and either paſs away by the poroſity of this kind of ſtone,
or by the cracks or joints which are always found in it; of which
the horizontal joints were formed at the time of the production or
accumulation of the fand beneath the ſea, which was then formed in
horizontal

SECT. XI. 1.96
265
AND WATERING.
horizontal ſtrata ; but the vertical cracks were made at the time of its
elevation by ſubterraneous fires. In theſe vertical fiſſures the ores of
lead, ponderous earth, and calcareous ſpars, are found in the lime-
ftone rocks of Derbyſhire; and thoſe of tin, and quartz, in the gra-
nite rocks of Cornwall.
9. The knowledge of this part of geology concerning the forma-
tion of ſprings may be employed for many uſeful purpoſes ; thus
where the wall-ſprings, or water-conducting ſtrata, lie ſo deep as not
to be acceſſible at a ſmall expence; they generally exiſt between the
ſecond and third, or between the third and fourth ſtrata ; which riſe
into day higher on the ſummits of the adjacent mountains than the
firſt ſtratum ; and hence, when they are bored into, the water will
riſe higher, than when it is found beneath the firſt ſtratum only;
which generally becomes deficient on lower parts of the adjacent
eininences of the country.
Thus where water, deſcending in high columns between the
ſtrata of mountains, is dammed up below by the materials, which
fill up the vallies'; if a hole be bored in the valley deep through the
incumbent foil and ſtrata, it frequently riſes much above the ſource
of the new aperture, and ſometimes above the ſurface of the ground.
In finking the king's well at Sheerneſs the water roſe 300 feet above
its fource in the well, as related in Phtoof. Tranſact. Vol. LXXIV.
And at Hartford in Connecticut there is a well, which was dug fe-
venty feet before water was found; and then on boring an auger
hole through a rock the water roſe fo faſt, as to make it difficult to
keep it dry by pumps, till the hole could be blown larger by gun-
powder; which was no ſooner accompliſhed, than it filled, and run
over, and has been a brook for near a century. Travels through
America, Lond. 1789. Lane.
In the town of Richmond in Surry, and at Inſlip near Preſton, in
Lancaſhire, I am informed, that it is uſual to bore for water to a cer-
tain depth ; and that when it is found in both thoſe places, it riſes
fo
a
a
Mim

266
Sect. XI. 1. 10.
DRAINING
fo high as to flow over the ſurface. And there is reaſon to conclude,
that if fimilar experiments were made in many other places, ſuch ar-
tificial ſprings might be produced at ſmall expence, both for the com-
mon purpoſes of life, and for the great improvement of lands by
watering them.
10. Another deduction, which may be made from this knowledge
of geology, is, that many ſprings of water, which lie too low for
ſerving a houſe, or ſtreet, (or town, or for watering higher grounds
for the purpoſes of agriculture or gardening, may in many ſituations
be dammed up many feet with little or no loſs. Thus when the new
bridge was building at Dublin, Mr. G. Semple found a ſpring in the
bed of the river, where he meant to lay the foundation of a pier;
which by fixing iron pipes into it he raiſed many feet; and in bor-
ing a hole near the Derwent in Derby about fifteen yards deep, the
water roſe above the furface of the ground, and has continued to flow
now for above twelve years in rather an increaſing quantity. From
having obſerved a valley north-weſt of St.Alkmund's well near Derby,
at the head of which that ſpring of water once probably exiſted, and
by its current formed the valley, (which current in after times found
its way out in its preſent lower ſituation), I ſuſpect, that St. Alk-
mond's well might by building round it be raiſed high enough to
ſupply many ſtreets in Derhy with ſpring water, which are now only.
fupplied with river water.
11. A third deduction from the knowledge of this geology con-
cerning the production of ſprings teaches, that by enlarging the bot-
tom of a well, where the water oozes from between the ſurrounding
ſtrata in too ſcanty a ſupply, a proportionally greater quantity of wa-
ter may be procured. The hole near the river Derwent in Derby
above mentioned, is about an inch and a half in diameter, and was
bored about fifteen yards deep through the uppermoſt ſtratum of marl
into the ſand beneath it, and ſupplies Dr. Darwin's houſe with two
or three hogſheads of water a day. And Mr. Strutt near St. Pe-
ter's
a

SECT. XI. 1. 12.
267
AND WATERING.
W
ter's Bridge has funk a well for the uſe of his ſteam-engine about
200 yards from the former, which paſſes through the fame upper
ſtratum of marl, and is three feet in diameter at the bottom, and ſup-
plies, when required, a hundred hogſheads in a day.
12. The knowledge of this part of geology leads to another uſe-
ful purpoſe, the diſcovery of ſprings ; concerning which fome have
pretended to poffefs ſecret or myſtical intelligence both in England
and in France. When the eminences of a country were raiſed out
of the primeval ocean by ſubterraneous fires, ſome of them were
raiſed nearly equally on all ſides, like the limeſtone mountain at
Breedon in Leiceſterſhire; in which the central ſtratum may be ſeen
to ſtand nearly erect or vertical, and thoſe on all ſides at conſiderable
inclination. Other mountains were abruptly broken off on one ſide
only from the adjoining earth, like thoſe which form the high torr at
Matlock; which riſe with one of their fides perpendicular as a wall
by the Derwent ſide; ſo that the ſtrata of the former of theſe moun-
tains may be repreſented, as before mentioned, by the bur, which
would be made on ſome folds of paper, if a very hard blunt inſtru-
ment was thruſt through them; and the latter by raiſing up one
edge of ſuch folds of paper, ſo as to incline the whole of it at ſome
angle with the horizon.
As the ſprings conſiſt of the water, which ſlides between theſe
inclined ſtrata ; it is evident, that in fome eminences of ground they
are only to be met with on one ſide of the mountain ; and in other
eminences of ground on all ſides of it. In ſearching for ſprings there-
fore attention ſhould be given to the inclination of the ſtrata of that
part of the country, which may be often ſeen in marl-pits, gravel-
pits, or in hollow lanes. But they may in general be found above
any moiſt or moraffy plain or valley; the moiſture of which ſhews,
that ſprings exiſt in the ſtrata on that ſide of the mountain.
A fecond obſervation for the purpoſe of detecting ſprings may be
made on miſty evenings; as thoſe parts of the ground, where the
mift
M m 2

268
Secr. XI. I. 12.
DRAINING
even-
miſt commences, are moiſter than thoſe in their vicinity on the ſame
level; and in conſequence may generally, if they are not bollow
bafons, poffefs ſprings nearer the ſurface; for theſe moiſter parts of
the ground, having evaporated more during the day, are become
colder on their ſurfaces than the drier ground in their vicinity; and
in miſty evenings, which are at the ſame time calm, the ſtationary
air over theſe moiſt parts of the ground is alſo more loaded with the
evaporated moiſture ; and on both theſe accounts theſe moiſter fitua-
tions are liable to ſhew a condenſation of aerial vapour ſooner than
other places on the ſame level.
As mountains are colder in proportion to their height, which is
explained in Botanic Garden, Vol. I. additional note 26, the
ing miſt ſometimes commences ſooner on them than in the valleys;
but is ſeen earlier in theſe ſituations over the moifter places, if they
are on the ſame level with the drier ones, exactly as on the plains
or valleys; and may therefore indicate the exiſtence of ſprings, un-
leſs theſe moiſter places conſiſt of hollow baſons containing water,
which if not attended to may in all ſituations deceive the obſerver.
Another obſervation for detecting ſprings may be made in rimy
mornings; for as moiſt earth is a better conductor of heat than dry
earth, the rime will ſooner melt on thoſe parts of the ſoil, which are
kept moiſt by ſprings under it than on other parts; as the common
heat of the earth, which is 48 in this country, will ſooner be con-
ducted upwards in moiſt places to diſſolve the rime on the ſurface.
On this account the rime is frequently ſeen on froſty mornings,
when the heat of the air is not much above 32, to lie an hour longer
on dry cakes of cow-dung, or on bridges, or planks of wood, than
on the common moiſt ground; as the latter much better conducts
the common heat of the earth to the incumbent rime, which is in
contact with it.
But as the heat of the common ſprings in this country is 48, where
they exiſt, the rime is ſooner diffolved, than on the ſtagnant moiſ-
ture

SECT. XI. 2. 1. AND WATERING.
269
ture of bogs or moraſſes. And as the ſprings about Buxton and Mat-
lock, and at Bath and Briſtol, are ſo much warmer than common
ſprings; it is highly probable, that where theſe waters approach the
ſurface of the ſoil, they muſt much fooner diſſolve the rime on froſty
mornings; which may probably be obſerved in ſituations much higher
than their preſent apparent ſources; as they ſlide down between the
interior ſtrata of thoſe hills, beneath the ſummit of which they are
condenſed from the ſteam of water boiling at great depths in the
earth; which riſes up through thoſe perpendicular clefts of the rocks,
which were formed at their original elevation, as explained in Bo--
tanic Garden, Vol. II. note on fucus; and in Pilkington's View of
Derbyſhire, V. I. p. 256.
In the winter months the riſe of ſprings may be detected in moiſt
ditches by the preſence of aquatic plants, as of water-creſs, water-
parſnip, brook-lime; as in thoſe ditches, which become dry in the
ſummer, theſe plants do not exiſt; and when thoſe ditches with
fprings in them are nearly dry, it may be diſcovered which way the
current has formerly deſcended by the direction of the points of the
leaves of the aquatic plants as certainly as by a level; an obſervation
which I learnt from Mr. Brindley, the great canal-conductor of Stafa
fordſhire.
Finally, theſe arts of detecting the ſituation of ſprings may be ad-
vantageous to the attentive agricultor both for the purpoſes of drain-
ing thoſe lands, which too much abound with water, and for the
purpoſe of watering thoſe, which are too dry, and which lie beneath
the level of the ſprings, or to which the water may be raiſed by
wind-mills or water-engines to be explained hereafter.
II. 1. In reſpect to draining thoſe plains or moraſſes where no fall
can be had, the water may in many ſituations be caught by cutting a
long horizontal ditch into the adjoining mountain perpendicular to
the inclined plane, which conſtitutes the ſide of the mountain, above
the level of the moraſs, ſo as to intercept all the wall-ſprings; and
may
s

270
Secr. XI. 2.2,
DRAINING
may then be conveyed away in wooden troughs or hollow bricks
above the ſurface; and if ſome water ſtill finds its way into the mo-
raſs, this leſs quantity may be conducted to one extremity of the
ground in open drains or covered foughs, and raiſed by an horizontal
windmill and centrifugal pump, as deſcribed at the end of this Sec-
tion ; and thus the moraſs may be converted into foil of the moſt
productive kind.
2. There may be other ſituations, as in the Peak of Derbyſhire,
where pools of water, or moraſſes, are collected on the hollow ſum-
mits of hills; which have been the craters of volcanoes in the prime-
val ages of the world, as Elden-hole near Caſtleton, which ſeems to
have been the ſhaft of ſuch a volcano. In many of theſe baſons on
the ſummits of hills there ſtill exiſt what are called “ Swallows,”
"
or cavities; where the water ſinks into the earth, as it collects, to
paſs to ſome diſtant valley, as Elden-hole above mentioned, and as in
the channels of the rivers Hamps and Manifold, between Aſhbourn
and Leek. In others, as at the ſummit of a ſteep promontory called
Axedge, near Buxton, and about Broke-houſe,are unfathomed moraſſes,
which are ſaid in ſome places not to bear a ſheep to paſs over them ;
and that on the more tenacious parts of them it is neceſſary for the
adventurer to ſtep from tafſock to tafſock, or to carry a long pole ho-
rizontally in his hand, like thoſe who ſkaite upon ſuſpected ice, to
prevent his finking over head, if he ſhould chance to fink at all.
It is probable, that by linking a well, or boring a hole, where
ſuch moraſſes or lakes now exiſt, into the obſtructed ſhaft of the an-
cient volcano, the water might be let off from thoſe eminent mo-
raiſes at leſs expence, than by excavating a paſſage for it ſome miles
in a country of marble.
3. It is poſſible there may be ſituations in high countries of mar-
ble, or granite, or quartz, where the difficulty and expence of
vating the ground may be too great, as above; in which a fyphon
might be contrived for the purpoſe of raiſing the water from a mo-
8
raſs
exca.

Sect. XI. 2.4.
AND WATERING.
270
W
a
raſs or lake, and conveying it away. Such an inſtrument might be
conſtructed of bored Riga deals; but as air is liable to collect in the
ſummit of a fyphon from the water, which paſſes through it, it
would be neceſſary to fix at the ſummit an air-vefſel with an air-
pump at the top of it; which might be moved by a very ſmall horis
zontal windmill fail, to be deſcribed at the end of this Section, or
occaſionally by the hand of a labourer for a few minutes perhaps
once or twice a day.
4. The draining of thoſe large plains, which lie beneath the level
of the ſea, is a ſubject, which belongs to the public, rather than to
the individual farmer ; and is practifed near Linn on the river Cam
by locks to keep out the tide, and by windmills to lift or forward
the otherwiſe ſtagnate water in the fen-dikes. Theſe windmills have
vertical fails of the common kind, which move a vertical water-
wheel, by which the water is raiſed a foot or two ; but it is probable-
even this might be done better by the horizontal ſail and centrifugal
pump to be deſcribed at the end of this Section, as being a fimpler
machine, and requiring no attention to turn it to the wind.
It might be a noble work, worthy the attention of a government,
that wiſhed to increaſe the quantity of nutriment, and conſequent
population and happineſs of the country, to employ proper engineers
with a number of labourers to environ with ditches every moraffy
diſtrict of whatever extent, which lies beneath the level of the tides,
as the fens of Lincolnſhire and Cambridgeſhire. Theſe ditches ſhould
be cut at the feet of the adjacent riſing grounds, or of eminences ſur-
rounded with fens, like iſlands in a lake, ſo as to intercept the wall-
ſprings and land-floods, and convey the water thus collected above
the level of the moraſs into the ocean.
But this, I fear, is an effort not to be expected in the preſent times,
when the encloſure of foreſts and large commons is prevented by the
intereſt of individuals, or by the difficulty of procuring expenſive acts
of parliament for every minute diſtrict, inſtead of including them in
a general
e

272
DRAINING
Sect. XI. 2. 5.
a general act, fo meritoriouſly contended for by fir John Sinclair,
then Preſident of the Agricultural Society,
5. Where finally the draining of marſhy grounds can not be effect-
ed at a reſponſible expence, ſome plants may perhaps be cultivated
with profit to the cultivator ; as in ſome ſituations the feſtica fluitans,
floating feſcue, callitriche, ſtar-graſs; or in others the orchis for the
purpoſe of making ſaloop by drying the peeled roots in an oven.
This might be better worth notice, if the ſeed could be ripened in
this climate for its eaſier propagation, which probably may be accom-
pliſhed either by cutting away the new root, as is affirmed in the
Amenitates Academicæ; or by planting them in a garden-pot ſo as
to confine the roots in reſpect to ſpace, which is ſaid in the ſame
work to ripen the ſeeds of convallaria, lily of the valley; and laſtly
by cultivating a few on a hot-bed or in a green-houſe.
In other ſituations the menyanthes, bog-bean, would flouriſh abun-
dantly, and might become a ſubſtitute for hops in the brewery, and
be equally wholeſome and palatable. It is indeed much to be la-
mented, that we have no grain ſimilar to rice, that will grow in wa-
tery grounds in this cold climate, nor any eſculent roots or foliage
except the water-creſs. There is reaſon to believe nevertheleſs, that
the roots of nymphæa, water-lily, or of butomus, flowering-ruſh,
may be eſculent by ſimple boiling; or that a wholefone ſtarch might
be obtained from them; or laſtly, that they might be fermentable
into ardent ſpirit, like the roots of potatoes, or into vinegar.
The nymphæa nelumbo is much cultivated in China in their
ſwampy grounds, and in their lakes. The feed is like an acorn, and
of a taſte more delicate than that of almonds. The roots are fliced and
ſerved with ice in ſummer at their tables; and are preſerved in ſalt
and vinegar for the winter. Embaſſy to China by ſir G. Staunton,
Vol. III. p. 214, 8vo. ed. The nymphæa alba of our country pro-
duces a root of three or four inches in diameter. See Sect. XVII.
2. 3; and though the feed is very ſmall, and perhaps does not per-
fectly
a
a

Secr. XI. 3. 1.
273
AND WATERING.
fe&tly ripen, I have obſerved it to be agreeable to the palate both in
its recent ſtate, and when dry.
If theſe ſhould not ſucceed, other quick-growing plants might be
cultivated for manures, as typha, cat’s-tail, caltha, and others; which
ſhould be mowed twice a year, while they are young, and in conſe-
quence abound with faccharine and mucilaginous matter ready to paſs
into fermentation.
III. 1. The advantages reſulting from occaſionally covering lands
with water have long been experienced in warmer countries, as in
Egypt, Italy, and many parts of China; and have of late years been
introduced into our own more northern climates. The great import-
ance of much water to the progreſs of vegetation has already been
ſpoken of in Section X. 3. And in the warm climates above men-
tioned, it is particularly uſeful in the cultivation of rice for the pur-
poſe perhaps of ſimply moiſtening the ground.
But the advantages of flooding meadow-lands in this country may
be divided principally into three kinds, one of which conſiſts in fim-
ply moiſtening them, which ſeems to be the principal uſe of water-
ing lands in warm countries, where the water is derived to them al-
moſt every evening from reſervoirs above them, or from water-
wheels worked by aſſes, and which is ſometimes done in the gardens
of this country by watering pans and human labour.
The ſecond and greater advantage of flooding lands in this cli-
mate conſiſts in deriving much water over them from rivers or from
ſtrong ſprings, and by thus ſupplying them with the muddy ſedi-
ment brought down by rivers, after ſudden rains, or with the cal-
careous earth diſſolved in inany ſprings. All thoſe ſprings, which
paſs through marl, or chalk, or other limeſtone, are replete with
calcareous earth; which they hold in ſolution, as thoſe about Derby
and about Matlock, which earth they depoſit on ſtanding on the
foil, or in ſlowly trickling over it. See Sect. X. 6. 2. And river
water
Nn

274
DRAINING
Sect. XI. 3. 1.
e
water in rainy ſeaſons is loaded with diffuſed as well as with diffolved
materials from the neighbouring country.
Both theſe therefore are of great ſervice in flooding meadow-lands,
and perhaps almoſt all other lands. But thoſe ſprings, which paſs
only through filiceous ſandſtone, as thoſe at Lichfield in Staffordſhire,
have no calcareous earth diffolved in them, as I have found by expe-
riment; and the water of moſt rivers, when they are not ſwelled by
rain, are alſo too pure for this purpoſe ; as they have depoſited al-
ready in their courſe the calcareous earth, which might abound in
the ſprings, which feed them; as I have obſerved by experiments on
the water of the Derwent at Derby, which though it runs for many
miles about Matlock through a bed of limeſtone, yet when clear of
mud from rains, it contains no calcareous earth, as it paſſes by
Derby, though the fprings in the vicinity are replete with it. Nei-
ther of theſe fources of water can therefore do much ſervice for this
ſecond deſign of depoſiting limeſtone, or mud.
The third advantage of flooding lands in this climate is for the
purpoſe of defending them from the cold of the winter or vernal
months. For this advantage the water from ſtrong ſprings, which
are always at 48 degrees of Farenheit in this country, is preferable
to river water, where it can be had in ſufficient quantity; ſince the
water of rivers is of the ſame degree of cold as the atmoſphere, till
the thermometer finks to 32. But both of them, when they form a
ſheet of thin ice, as they cover a meadow, defend the roots of the
graſs from ſeverer degrees of cold; which are thus preſerved, and
thoſe of ſome graſſes are believed even to vegetate beneath the ice, as
the rein-deer moſs in Siberia vegetates beneath the ſnow in a degree
of heat about 40, which is the mediumn between that of the under
ſurface of the thawing ſnow, which is 32 ; and that of the common
heat of the interior parts of the earth, which is 48 ; and thus the
rops of graſs in this cold climate may be wonderfully forwarded ; ſo
as

SECT. XI. 3. 2.
275
AND WATERING.
as almoſt to double the product of the year, if well managed and
carefully attended to.
The method of forming the channels to convey the water confifts
in carrying the firſt or principal aqueduct along the higheſt part of
the meadow, and deriving others on the ſummits of the lands; if the
meadow has formerly been ploughed into ridges and furrows, theſe
again are to be divaricated ſo as to paſs into the furrows; all theſe
branches of the ſtream are again to be collected from the furrows,
and diſcharged at the loweſt part of the ſurface.
Something ſimilar to this muſt be managed on more level grounds,
ſo as to conduct the water over the whole meadow, and alſo to carry
it off, that it may not ftagnate ; but that a moving ſheet of water
about an inch in depth may continually flow over the whole for the
purpoſe of depoſiting the materials diſſolved or diffuſed in it. The
conſtruction and width of theſe channels, with many uſeful obſerva-
tions, are ſhewn in a pamphlet of Mr. T. Wright, on “ the Art of
Floating Land in Glouceſterſhire." Scatcherd. London.
2. Mr.Wright in the treatiſe above mentioned adviſes, that the
aftermath of graſs land ſhould be eaten off bare by the beginning of
November, and that the channels for conducting the water to and
from the meadows ſhould be then cleanſed and repaired; and that
the water ſhould be ſuffered to flow over the meadow for three
weeks; and that then the land ought to be expoſed to the air for a
few days; fince ſome of the graſſes, and thoſe of the moſt nutritive
kinds, he believes will not much longer exiſt under water. By this
early preparation, he adds, that advantage is taken of the autumnal
floods, which bring along with them a greater quantity of putref-
cent matter than thoſe of winter.
In the months of December and January Mr. Wright adds, that the
chief care of the floater conſiſts in keeping the land ſheltered by the
water from the ſeverity of froſty nights; but adviſes through the
whole of theſe months every ten or fourteen days to expoſe the land
Nn 2
to

276
SECT. XI. 3. 20
DRAINING
3
to the air by laying it as dry as poſſible for a few days; and always to
diſcontinue the flooding, when the land is covered with a ſheet of
ice.
In the month of February greater attention is required ; if the wa-
ter be ſuffered to flow over the meadow for the ſpace of many days
without intermiſſion, a white fcum is generated, and the graſs is
,
much injured. And he juftly obſerves that, if you now take off the
water, and expoſe the land in its wet ſtate to a ſevere froſty night, a
great part of the graſs will be cut off.
Mr. Wright adds, that in Glouceſterſhire two methods of avoiding
theſe injuries are practiſed: one is to take off the water by day to pre-
vent the production of the ſcum, and to turn it over again at night
to guard againſt the froſt. The other is to take off the water early
in the morning; and, if the day be dry, to ſuffer it to remain off a
few days and nights; for if the land experiences only one drying day,
the froſt at night will do little injury. But the former of theſe
prac-
tices, where it can be eaſily done, he thinks preferable to the latter.
In the beginning of March the graſs on well-flooded meadows will
generally be fo forward, as to afford abundant paſturage, and the wa-
ter ſhould be taken off for about a week, that the land may become
dry and firm; and the cattle ſhould for the firſt week be allowed a
little hay in the evening, if the weather be cold and rainy.
In the month of April the graſs may be eaten off quite ſhort and
cloſe, but not later ; ſince if you treſpaſs but one week in the month
of May, the crop of hay, which is to ſucceed, will be much impair-
ed; and the graſs will become ſoft and woolly, and the hay have the
appearance of lattermath hay, and be leſs valuable.
At the beginning of the month of May the water is again thrown
over the meadows for a few days; which fimply by moiſtening the
fand will in moſt ſeaſons, Mr.Wright obſerves, enſure a crop of hay
of one ton and a half on an acre in the courſe of fix or ſeven
weeks.
The

SECT. X. 3. 2.
279
AND WATERING.
The water is ſometimes again uſed, when the hay is carried off,
but may render the lattermath, he thinks, unwholeſome to ſheep.
But this is particularly ſerviceable, when the water is rendered tur-
bid by ſuddens rains. Some have taken off two hay-crops in one year,
but this Mr.Wright thinks is imprudent in this climate ; which how-
ever I ſuppoſe might be accompliſhed, where the firſt growth is not
eaten in April, and where much turbid river water or calcareous
fpring water can be uſed between them.
Mr. Wright further obſerves, that the hay on theſe flooded mea-
dows is little inferior to upland hay, if it be cut at its proper age;
but that ſome avaricious farmers have permitted it to remain uncut
till it produces three tons on an acre, and that then it will become
long and coarſe, and little better than ſtraw. But that when it is cut
in June, and has been flooded well with muddy water in the winter,
that it becomes little inferior to the beſt upland hay.
The hay, I ſhould ſuppoſe, which is cut before the graſs is in full
flower, while the faccharine juice ftill remains in part at the joints
of the flower-ſtems, muſt contain the moſt nutritious matter; which
is afterwards abſorbed as the flower expands, and as the feed ripens,
and forms the meal or ſtarch of the feed-lobe, and is ſhed upon
the
ground, or conſumed by birds, and the graſs-ſtems and their leaves
become ſimply like the ſtraw of ripened corn.
This will appear of more importance to any one, who attends to
the difference of the pods or huſks of peas, or of kidney-beans, dur-
ing the early ſtate of the encloſed ſeeds, and again after the ſeeds be-
come ripe. The pod or capſule is at firſt ſweet and mucilaginous, ſo
as to ſupply an agreeable and nutritive food, the latter of which, and
ſometimes the former, are eaten at our tables; afterwards as the ſeeds,
;
which are attached alternately to each ſide of the capſule, drink up
by their vegetable life after impregnation the ſaccharine and mucila-
ginous matters there purpoſely depoſited for them; the capſule itſelf
becomes

278
.
DRAINING
Sect. XI. 3.3
SECT
It may
a
becomes a mere fibrous membrane not better than the ſtraw of ripe
grains above mentioned.
be here repeated, that one great uſe in this country of flood-
ing graſs-grounds in winter, and in early ſpring, ſo as to let a thin
ſheet of water perpetually flow flowly over them, is, that it will in
froſty nights, when the cold is not much below the freezing point,
produce a thin ſheet of ice, and thus prevent the cold from affecting
the roots of the graſs beneath it; which may thus be two or three
weeks forwarder than on other lands; for ice is ſo bad a conductor of
heat, that water is not readily frozen beneath it; and eſpecially if it
ſtands hollow, ſo as to encloſe a ſtratum of air between itſelf and the
water beneath,
This ſeems to have been attended to by the philoſophers in the
French army, when they paſſed over ice to ſubdue Holland ; fearing
leaſt the ice ſhould be too weak for the paſſage of their troops and
artillery, they bored many holes through it every night; and then
by preſſure on its ſurface the water was made to riſe through theſe
holes, ſo as to ſtand an inch above the ſurface; which being thus
expoſed to the cold air of the night, became frozen before morning;
and thus in a few nights thickened and ſtrengthened the ice ten times
more than would have been done naturally by the flower freezing
beneath it.
3. To recapitulate the advantages of flooding, firſt, not only the
common meadow grounds are enriched, but moraſfy ones are confo-
lidated, by the mud brought over them from river water ; or the cal-
careous ſediment, and azotic or nitrogen air, from moſt ſpring wa-
ters, during thoſe ſeaſons when graſs does not naturally make much
progreſs in its growth. 2. They are defended from froſt by the flow-
ing water, or by the ice, when it is frozen; and thus a much for-
warder crop of graſs is produced, as may frequently be ſeen over
pieces of ground naturally moiſt; which look green in the ſpring,
ſome
a

SECT. XI. 3. 4.
279
AND WATERING.
a
a
a
a
fome weeks before that on drier land in their vicinity. 3. The ground
is rendered more eafily penetrable by the roots of graſs, both by its
being kept fofter, and alſo from its being ſeldomer frozen below the
ſurface in the vernal months. 4. This early crop may be eaten off
by cattle or ſheep, and a new flooding for a ſhort time will forward
the growth of it ſo as to produce a good crop of hay. 5. After the
hay is removed another flooding for a ſhort time enſures a luxuriant
growth of autumnal graſs, or aftermath.
The difficulty of getting moiſt lands free from ruſhes is ſaid to be
readily overcome by flooding them, and that eſpecially after previ-
ouſly mowing them, as their ſpongy pith will then abſorb ſo much
water, as to cauſe them to putrify by its ftagnation ; or if this be
done in autumn or ſpring, and a froſt fupervenes, the water in their
pith by expanding, as it becomes ice, burſts and deſtroys their organic
ſtructure.
The following conclufion is copied from Parkinfon's Experienced
Farmer. “Upon the whole, artificial watering of meadows is a moſt
profitable improvement; it robs no dunghill, but raiſes one for the
benefit of other lands; for if a farmer can water ten acres of land,
cut the graſs and uſe it either in ſtall or fold-feeding, he might keep
perhaps forty beaſts; and by working the manure made by them into
a compoſt, and applying that compoſt to other lands, he might either
have a great deal more hay for the winter, or feed more cattle in the
fummer." Vol. II.
4. Two or three obſervations of importance ſhould be here inſert-
ed. 1. That in flooding lands for a conſiderable time, the water ſhould
only trickle over them from the canal, which leads it along the more
elevated parts, and not ſtand on it like a fiſh-pond; as in the latter
caſe the graſs roots will periſh in a few weeks in the early ſpring, to
the great injury of the farmer, an example of which on ſeveral acres
I once witneſſed.
As ſoon as any materials thus begin to putrefy beneath the water,
a
p. 68.
a
І
a ſcum

280
Secr. X1. 3. 46
DRAINING
a fcum of white froth ariſes owing to the air ſet at liberty by putre-
faction ; which is ſuppoſed by ſome to injure the graſs, whereas it is a
conſequence rather than a cauſe of injury, and ſhews, that the water
has ſtagnated too long; and ſhould either be immediately drawn off,
or ſupplied by a running ſtream ; but the former ſhould probably be
preferred : if the ſtems of graſs are ſo tall as to riſe above the running
water, it is probable, that their death and putrefaction do not ſo ſocn
occur.
Secondly. It is obſerved by gardeners, that in dry ſeaſons, if you
begin to water any kinds of plants, you muſt continue to repeat it ;
otherwiſe that they are ſooner injured by dry weather, than thoſe
which have not been watered. This fact alſo I think I have obſerved,
and it may depend on the circumſtance of the roots of annual vege-
tables ſhooting themſelves lower down in dry ſeaſons in ſearch of
moiſture; but if this be given them in the commencement of their
growth, they then ſhoot their roots more horizontally, and are after-
wards in conſequence ſooner deſtroyed by the ſubſequent dry wea-
ther.
Thirdly. Much cold water given ſuddenly to plants, which were
nearly periſhing with heat and dryneſs, will I believe ſometimes in-
jure or deſtroy them, as I ſaw occur this year, 1798, in June to ſome
rows of garden beans; which after being flooded for one night wi-
thered, and in part died, on the following day, which was probably
cauſed, not by the exceſs of water, as plants of this genus would ſeem
to bear much moiſture from an experiment of Lord Kaimes, who
ſays in the Gentleman Farmer, that he planted a pea on ſome cot-
ton-wool ſpread on water in a phial, and that it ſprung up, and ſhot
roots through the cotton-wool into the water, and produced large
pods full of ripe ſeeds. The death of theſe beans was more probably
occaſioned by the torpor of the ſyſtem induced by cold, as occurs to
thoſe who have injudiciouſly drank much cold water, or plunged into
a cold bath, when they have been previouſly much weakened by the
unneceſſary

SECT. XI. 3. 281
3
5.
AND WATERING.
unneceſſary activity of the ſyſtem occafioned by continued heat, or
great exerciſe. See Sect. XIV. 1. I.
Nor is there reaſon to ſuppoſe that to whatever extent this mode of
cultivation of graſs could be carried in this country, that any injurious
effects in reſpect to the health of the inhabitants could be produced ;
as this mode of flooding is not by ſtagnant water, as in rice grounds ;
which D. A. J. Cavanilles, who has lately publiſhed a work on the
cultivation of rice in the kingdom of Valencia, believes to be injurious
to the health of the inhabitants. Magaz. Encyclop. T. 3.
In theſe cold climates the vicinity of running ſtreams may per-
haps be rather ſalubrious than the contrary; as the air is cooled in hot
weather, and warmed in cold weather, by its contact with their
ever-changing ſurfaces, till they become frozen. I at this moment
recollect many, who lived to an healthy old age in the valley of the
Trent near the very edge of the water, whoſe names I could repeat.
But ſtagnate waters, from which putrid exhalations ariſe, produce
agues in cold countries, as in the fens of Lincolnſhire; and putrid fe-
vers in hot ones; from which our armies ſuffered ſo much at St.
Lucia both in the preſent and the laſt war.
5. This practice of flooding is capable of being extended to a won-
derful degree in this country, not only by uſing the natural falls of
brooks and ſprings, and by occaſionally damming them up to ſupply
higher ſituations; and by effectually ſpreading the land-floods from
accidental ſhowers over the inferior lands to a great extent. And
laſtly, the water, which is now dammed up to ſupply the numerous
mills, might be diffuſed in rills over a thouſand meadows, or part of
it be raiſed by pumps to higher grounds; and thus fertilize and en-
rich the country; while the grinding of corn, ſpinning of cotton, roll-
ing iron bars, and other mechanic purpoſes, might be effected by
wind-mills, or ſteam-engines, in almoſt every part of the iſland.
For this purpoſe likewiſe the new method of raiſing water by the
vis inertiæ or acquired momentum of moving ſtreams might be well
applied,
Oo

282
Sect. XI. 3. 6.
DRAINING, &c.
applied, which was formerly uſed by Mr. Whitehurſt of Derby on
ſmall ſcale at Oulton in Cheſhire, as deſcribed with a plate of the
machine, to which an air-vefſel is ingeniouſly added, in the Philoſo-
phical Tranſactions for the year 1775, Vol. LXV. p. 277, and which
is now adapted to variety of ingenious machinery by M. Boulton,
Eſq. of Soho near Birmingham; and is well explained with two
prints in the Repertory of Arts and Manufactures, No. LI.
6. The following water machine, which is on the principle of
Hiero's fountain, is deſigned to raiſe part of the water of a ſpring, or
ſmall brook, where ſome feet of fall may be acquired, to a greater
height for the purpoſe of watering higher levels of ground; and the
horizontal windmill with centrifugal pump is deſigned for the ſame
purpoſe, where no fall can be acquired. We ſhall then perhaps have
ſatiated ſome of our readers with this ſubject of watering lands, and
may conclude with the ſhepherds in Virgil's Eclogue,
Claudite jam rivos, Pueri, fat prata biberunt.
SECT

PLA TE V.

PLATE V.
Repreſents the ſtrata of a hill. a b is the upper ſtratum, ſuppoſe of marle ; c d is the
ab
ſecond ſtratum, ſuppoſe of ſand; e f repreſents the accumulated earth in the valley.
It is deſigned to ſhew, that in boring holes through the upper ſtratum to find that
beneath it, they ſhould be formed perpendicular to the ſide of the mountain, and not
perpendicular to the horizon, as is the common practice, as by thoſe means the
hole
уу
is much ſhorter than the hole * *. As explained in Sect. XI. 1. 5.

Sect. XI. 1.
Plate V.
d
b
f
N
a


PLATE
VI.

PL A TE VI.
Is a ſection of a machine fimilar to Hiero's fountain, but deſigned to raiſe water to a great
perpendicular height, where there is the convenience of a ſmall fall.
a
a b the ſtream of water, b c c the height of the fall of it, ſuppoſe ten feet, de two vef-
ſels of lead or iron containing, ſuppoſe, four gallons each, f g hikl are veſſels of lead con-
taining, fuppoſe, two quarts each, op two cocks, each of which paſſes through two pipes
opening one and cloſing the other, qr a water balance moving on its centre s and turning
the two cocks o and p, alternately, t u and wx two air-pipes of lead one quarter or half
an inch diameter within, yz, yz, yz, water-pipes one inch diameter.
e
The pipe bcc is always full from the ſtream ab, the finall ciſterns gil, and the large
8
one d, are ſuppoſed to have been previouſly full of water, then admit water by turning
the cock o through the pipe ce into the large ciſtern e. This water will preſs the air,
which was in this ciftern e up the air-pipe w x, and will force the water from the ſmall
*
ciſterns gilinto the ciſterns h k and great C. At the ſame time by opening B, the water
and condenſed air, which previouſly exiſted in the large ciſtern d, and the ſmall ones fhk,
is diſcharged at B. After a time the water balance ars cloſes the cocks now open, and
opens their antagoniſts, and the ciſterns f h k are emptied in their turn by the force of
the condenſed air from the ciſtern d, as the water enters into it from the pipe b c.
a

Plate VI.
Sect. XI. 3.6.
C
Z
y
k
u
X
i
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London, Published Jan 24,800iby J.Johnson, S. Pauls Church Yard.


PLATE
VII.

PLATE
VII.
a
Is a ſection of a machine for raiſing water a few feet high by the power of the wind for
the purpoſe of draining moraſſes, or of watering lands on a higher level.
a
It conſiſts of a windmill fail placed horizontally like that of a ſmoak-jack, ſurrounded
by an octagon tower; the diverging rays of this tower, a b, ab, may conſiſt of two-inch
deals only, if on a ſmall ſcale, or of brick-work if on a larger one. Theſe upright pil-
lars are connected together by oblique horizontal boards as ſhewn at A B, by which boards
placed horizontally from pillar to pillar, in reſpect to their length, but at an angle of
about 45 degrees in reſpect to their breadth, ſo as to form a complete octagon including
the horizontal windmill fail near the top of it; the wind as it ſtrikes againſt any
of them,
from whatever quarter it comes, is bent upwards and then ſtrikes againſt the horizontal
wind-fail. Theſe horizontal boards, which form the ſides of the octagon, may either be
fixed in their ſituations, or be made to turn upon an axis a little below their centres of
gravity, ſo as to cloſe themſelves on that ſide of the octagon tower moſt diſtant from the
wind.
a
It may be ſuppoſed that the wind thus reflected would loſe conſiderably of its power be-
fore it ſtrikes on the wind-fail, but on fixing a model of ſuch a machine on the arm of a
long whirling lever, with proper machinery to count the revolution of the wind fail, when
thus included in a tower and moving horizontally; and then when moved vertically as it
was whirled on the arm of the lever with the fame velocity, it was found on many trials
by Mr. Edgeworth of Edgeworth Town in Ireland, and by myſelf, that the wind by being
thus reverted upwards by a fixed planed board did not ſeem to loſe any of its power. And
as the height of the tower may be made twice as great as the diameter of the fail, there is
reaſon to conclude that the power of this horizontal wind-fail may be conſiderably greater,
than if the fame fail was placed nearly vertically oppofed to the wind in the uſual man-
.
ner.
At the bottom of the ſhaft of the wind-fail is placed a centrifugal pump with two arms
at CD, which has been deſcribed in mechanical authors. It conſiſts fimply of an upright
bored trunk, or cylinder of lead, with two oppoſite arms with an adapted valve at the bot-
tom to prevent the return of the water, and a valve at the extremity of each arm to pre-
vent any ingreſs of air above the current of the water as it flows out.
а
a
€ ccc is a circular trough to receive the ſtreams of water from C and D, to convey
thein where required.

Plate VII.
Sect. XI. 3
LIW
D
C
a
b
b
с
a
!b
1
1
1
с
с
a
с
a


SECT. XII. 1.
283
AERATION, &c.
SECT. XII.
AERATION AND PULVERIZATION OF THE SOIL.
1. Soils contain inflammable matters and water. Air conſiſts of oxygen, nitrogen, and
beat. Produces carbonic, nitrous, and phoſphoric acids, and volatile alkali with
water when buried in the ſoil. Heat and light given out from the union of carbon
and
oxygen in a letter-wafer. Sow and ſet foon after the plough or Spade. 2. Pe-
netrability of the
ſoil increaſed, and mixture of its ingredients. Retains the rains.
Enlarges the ſurface. 3. Uſes of fallowing. Turnips ſaid not to impoveriſh the
ſoil, why. 4. Fallowing injurious to rich lands, why. 5. The great advan-
tages of Tull's drill huſbandry. Prefers horſe-hoeing to hand-boeing. An im-
proved drill machine. 6. Advantages of tranſplanting wheat. 7. Of barrowing
wheat in Spring. 8. Rolling wheat in ſpring.
As almoſt all ſoils not only contain carbon, and other inflammable
materials, which are capable of uniting with oxygen, and thus pro-
ducing the carbonic and other acids; but alſo contain water, which
by its decompoſition, when in contact with confined air, produces
ammonia or volatile alkali by the union of its hydrogen with azote;
and nitre by the union of its abundant oxygen with another part of
the abundant azote or nitrogen of the atmoſpheric air ; there is rea-
ſon to conclude, that the great uſe of turning over the ſoil with the
plough or ſpade depends principally in the production of theſe effects
by the confinement of both the oxygen and the azote or nitrogen of
the air in the interſtices of the ſoil; and on this account we have en-
titled this ſection the aeration of the ſoil rather than the oxygenation
of
O. 2

284
Sect. XII. I.
AERATION AND
of it, as the latter belongs to the reſpiration rather than to the nutri-
tion of vegetables.
When atmoſpheric air is impriſoned in the cavities of the ſoil by
turning over its ſurface, which muſt be in greater quantity, when
the ſoil is reduced into the very ſmall fragments, which has been
called pulverization; and when it is the leaſt preſſed down by animals
trampling on it, it more readily unites, I believe, with the materials
above mentioned than in its free ſtate; which is probably effected by
double or triple chemical affinities.
For this atmoſpheric air conſiſts of oxygen, azote, and the fluid
matter of heat; now if the heat, which occaſions the oxygen and
azote of the atmoſphere to exiſt uncombined in the form of gaſſes,
be attracted from them by any other material, as they are confined
in the cavities of the ſoil, they may by their nearer approach to each
other combine into nitrous acid; or the oxygen may in its fluid ſtate,
not in its aerial one, more readily unite with carbon; and form a
fluid, not an aerial, carbonic acid ; which we believe to be of fo
much conſequence in the growth of plants, as fhewn in Sect. X. 4.
Add to this, that if any putrefactive proceſs be proceeding, where
atmoſpheric air is thus impriſoned in the cavities of the ſoil, and by
the loſs of its heat is converted from a gas to a fluid ; that the azote
may unite with the hydrogen of the decompoſing water, or contri-
bute to decompoſe it ; and thus to form volatile alkali, which like
the nitrous acid, may either during the proceſs of its formation, or af-
ter it is formed, be of effectual ſervice to vegetation, at the ſame time
the oxygen given out from the decompoſing water may contribute
like that of the atmoſphere to produce carbonic, nitrous, or phoſpho-
ric acids ; and thus to render carbon, phoſphorus, and the baſis of
nitre, capable of being abſorbed by vegetable lacteals.
Where atmoſpheric air is confined along with water, I well re-
member from experiments I made long ago, by inverting a bottle fill-
ed with air in a jar of water, that the bulk of the air was in ſome
days

Sect. XII. 2.
285
PULVERIZATION.
days ſo much diminiſhed as to occupy only half the bottle, which
probably occurs from the decompoſition of both the water and air ;
and the production of ammonia and nitrous acid, both which are be-
lieved to be ſo ſerviceable to vegetation, as mentioned in Sect. X.
2.9.
That the heat of the atmoſpheric air is given out, when oxygen
unites with carbon, is ſhewn by the heat of hot-beds; and of fer-
menting faccharine and mucilaginous fluids, as in the production of
ardent ſpirit ; and may be beautifully ſeen in the combination of oxy-
gen with carbon in the burning of one of thoſe common letter-wa-
fers, which conſiſt of the mucilage of flour, and red lead or mi-
nium ; not one of thoſe, which are called Iriſh wafers, and which are
coloured with vermilion. If one of theſe minium wafers be made
to blaze in the flame of a candle, the oxygen contained in the mi-
nium unites with the carbon of the flour, and gives out a very lumin-
ous fpark, and conſequent great heat, and at the ſame inſtant a ſmall
globule of melted lead drops down, and may be agreeably ſeen, if re-
ceived on a ſheet of white paper held under it. It is alſo probable,
that heat is emitted during the production of nitrous and of phoſ-
phoric acids.
From theſe obſervations it appears, that feeds ſhould be fown, and
roots planted, foon after the ſoil is turned over; while the produc-
tion of the carbonic, nitrous, and phoſphoric acids, and of volatile al-
kali, and perhaps many other proceſſes, are proceeding, rather than
after they are completed; and alſo while the fluid element of heat is
paſſing from its combined ſtate, and permeating the ſoil, which in this
cold climate in the vernal months muſt be highly conducive to vege-
tation.
2. By thus turning over the ſoil with the plough or ſpade the pe-
netrability of it by the roots of plants is alſo much facilitated ; and
for this purpoſe, as well as for the admixture of atmoſpheric air, it
can ſcarcely be reduced into too fine molecules, or a kind of wet pow-
der;

286
Sect. XII. 3.
AERATION AND
3. 6.
der; for the moiſture of ſoil is as neceſſary for its being permeated
by the young roots of plants, as its ſmall coheſion, as mentioned in
Sect. X. 3:
Secondly, a more intimate mixture of the various ingredients,
which moſt ſoils pofſefs, as carbon, calcareous, argillaceous, filiceous,
and magneſian earths, with various metallic oxydes, as thoſe of iron,
and ſometimes of manganeſe, and calamy, all which by frequent
turning over the ſoil with the plough or ſpade, become mixed ſo as
to act on each other or on the roots of vegetables in every minute part
of the ſoil.com
And thirdly, the vernal rains are retained by their finking more
readily into the pores and cells of land recently turned over, and
which ſtill poſſeſſes an uneven ſurface. Beſides a greater ſurface of it
being continually expoſed to the paſſing air, and to the heavier im-
purities, which it perpetually contains, as carbonic acid, foot, odours
of many kinds.
bas
3. A recapitulation of theſe circumſtances leads us to the know-
ledge of the uſe of fallowing lands, by repeatedly turning them over
much carbonic acid is produced in its fluid ftate; and perhaps ſome
of the nitrous and phoſphoric acids; theſe may remain united with
the vegetable recrements, or with volatile alkali, or with calcareous
earth. 2. The parts of the ſoil may become better mixed together,
and thus either chemically affect each other to their mutual meliora-
tion ; or they may more uniformly ſupply nutriment to the roots,
which penetrate it. 3. The foil may become broken into a moiſt
powder, and may thus be more eaſily permeated, and ſupply a greater
ſurface of its cavities for the vegetable abſorbents to apply themſelves
to. 4. Unprofitable plants, or weeds, not being permitted to grow on
it, or their being perpetually ploughed under the ſoil in their early
growth, much vegetable nutriment will be reſerved by not being ex-
pended; or it will be increaſed by the faccharine and mucilaginous
matter of the young plants, which are thus buried in it.
a
It

Scer. XII. 4.
PULVERIZATION.
287
It ſhould be added, that ſome plants are ſaid not to impoveriſh
the ground, on which they have grown during their herbaceous ſtate,
before the ſeed-ſtems have ariſen ; as turnips, when drawn up and
carried away to feed cattle or ſheep on other grounds. This has been
aſcribed by ſome authors to the ſoil having been ſhaded by their thick
foliage, and thus not having ſuffered ſo much by evaporation. Some
have aſcribed this ſuppoſed melioration of the ſoil to its having been
ſcreened or overſhadowed by the thicker foliage of ſuch crops; and
that as the putrefactive proceſs of vegetable recrements proceeds beſt
in damp and confined air, as wood decays ſooneſt in cellars, they ſup-
poſe the foil may thus become improved. But Mr. Tull ſeems either
to doubt the fact, or to attribute it to the ground, where ſuch plants
are cultivated, being uſually once or twice hoed; and thus in effect to
have been followed by the repeated aeration and pulverization of the
foil, and the deſtruction of innumerable weeds.
If nevertheleſs the fact be true, not only all the circumſtances above
mentioned may contribute to produce it, but alſo, as it appears by the
experiments of Prieſtley and Ingenhouſe, that though the perſpirable
matter of vegetable leaves gives out oxygen in the ſunſhine, yet that
it gives out carbonic acid in the ſhade; which even in its aerial or
gaſſeous form is much heavier than common air, and will therefore
fubfide on the earth in the ſhade of this perfpiring foliage, and con-
tribute to enrich the ſoil by the hourly addition of carbon.
4. Nevertheleſs where the foil is already replete with manures,
and theſe proceſſes productive of carbonic, nitrous, and phoſphoric
acids, and of volatile alkali, are going on in proper abundance; ſuch
ſoils muſt be injured by being too frequently turned over in ſummer
fallowing; and thus by expoſing too great a ſurface, and that too fre-
quently, to the air, the ſunſhine, and the rain ; by which much of
the fluid carbonic acid will be converted into aerial carbonic acid, and
eſcape, as well as the phoſphorus and the ingredients in their ſtate pre-
vious to the production of nitrous acid, and of the volatile alkali. On
6
this

288
Sect. XII. S.
AERATION AND
this account in the manufacture of nitre in France, Spain, and
Pruſſia, it is directed to cover the compoſt of ſoil and animal recre-
ments with a ſhed to prevent too great exhalation and ablution.
Hence though a ſummer fallow may be of advantage to a poor ſoil,
which has nothing to loſe ; it muſt be diſadvantageous to a rich one,
which has nothing to gain.
Lord Dundonald in his work on the Connection of Agriculture
and Chemiſtry ingenioufly ſuppoſes, that foils become injured,
when much expoſed to the air by fallowing, from the carbon or
other inflammable matters uniting with oxygen; and that then be-
ing again combined with other materials, they become inſoluble, pro-
ducing limeſtone, calcareous nitre, and phoſphat of lime. But there
is another injury to foil by frequent fallowing, which I ſuſpect to be
more extenſive, from the eſcape of carbonic acid, or of nitrous acid,
or of ammonia, into the atmoſphere in the form of gas, as above
mentioned ; or their being waſhed away by rains.
5. Hence the great advantages of Mr.Tull's ingenious diſcovery of
the drill huſbandry are eaſily underſtood, 1. By fowing the wheat in
rows, ſcattered by a drill-plough at regular diſtances, and buried at a
regular depth, the grain is neither crowded, nor too thinly diſperſed.
2. Nor are the roots buried either too deep in the ſoil, or too ſhal-
low. 3. By turning the ſoil firſt from the rows in the ſpring for a
week or two, and then turning it up againſt the rows, the ſoil be-
comes newly aerated with all the good effects in conſequence. 4. It
becomes more penetrable by the ſuperficial roots of the corn.
raiſing it to the ſecond joint of the corn-ſtems, four or fix new roots
with new ſtems will ſhoot out, generated by the caudex of the fe-
cond leaf of the corn-ſtem; which is now within the ſoil, or in
contact with it, as explained in Sect. IX. 3. I. and 7. XVI. 2. 2.
Thus Mr. Tull's method of heaping foil againſt wheat-plants up
to the ſecond joint anſwers in ſome degree the ſame purpoſe, as
tranſplanting the roots, and ſetting them deeper in the ſoil with
much
a
5. By

Sect. XII. 5.
PULVERIZATION.
289
a
much leſs expence of labour. But for the more perfect pulveriza-
tion of the ſoil, and the more complete aeration of it, he inſiſts much
on the preference of horſe-hocing to hand-hoeing; as the former
paſſes deeper into the ſoil, and thus expoſes a greater quantity of it
to the air ; and eſpecially of that part of it, which before lay too
much beneath the ſurface to be previouſly much affected by the in-
cumbent atmoſphere. But the great objection to the uſe of the
horſe-hoe is, that the alternate rows of corn muſt be placed at too
great a diſtance, as will be again ſpoken of in Sect. XVI. 2. 2.
To the many advantages of the drill huſbandry above recited Mr.
Tull adds, that " where the ſpring-turnips are uſed too late in the
year, there is not time to bring the land into tilth for barley, and
there is a loſs of the barley crop in conſequence; which he ſays is
entirely remedied by the drilling method; for by that the land may
be almoſt as well tilled before the turnips are eaten or taken off, as it
can afterwards.” Huſbandry, Chap. VIII. p. 89.
So many great advantages ſeem to accrue from Mr. Tull's method
of drill-fowing and horſe-hoeing, that a curious queſtion offers itſelf,
Why it has not been more generally adopted ? Firſt, I ſuppoſe, be-
cauſe it is difficult to teach any thing new to adult ignorance, ſo that
the maſter muſt for ſome time attend the proceſs with his own eye.
Secondly, I believe the axle-tree of Mr.Tull's fowing machine did not
accurately emit the proper quantity of ſeed from the hopper, and was
liable to bruife and deſtroy ſome of it in its paſſage. And thirdly,
that the improved drill machine of Mr. Cook’s patent is too expen-
five for the purchaſe of ſmall farmers, who fear that it may not an-
fwer the expected advantages.
I have therefore given a print at the end of this work of a machine
conſtructed on a cheaper plan, which is ſimply an improvement of that
deſcribed in Mr. Tull's book, by enlarging that part of the axle-tree
which delivers the grain, into a cylinder of ſome inches diameter
with
a
PP

AERATION AND
Secr. XII. 6.
290
with excavations in the rim; which rim riſes above the ſurface of
the corn in the feed-box, and lets drop again into the ſeed-box, what-
ever grains fill the holes above the level of the rim, as that ſide of the
cylinder aſcends. Whence the quantity delivered is uniform, and no
grains are in the way to be bruiſed or injured, as explained at large
along with the print; and the whole machine is ſimple, and of
ſmall expence.
6. The moſt effectual method of obtaining the great combined ad-
vantages of aeration and pulverization of the ſoil is by tranſplanting
the roots of wheat, and parting them, as already ſpoken of in Sect. IX.
3. 7. By taking up the roots and replanting them in foil lately turn-
ed over, and conſequently expoſed to the air, which is now confined
in its interſtices, all the advantages already mentioned are effectually
received, from the new made fluid, carbonic, nitrous, and phoſphoric
acids, and from the ammonia, and other unnamed combinations. Se-
condly, all the advantages ariſing from the eaſy penetrability of the
looſe foil by the root-fibres, which are believed by Mr. Tull to put out
more radicles with abſorbent mouths at every part, where they are
diffevered, like a bruſh or pencil of hairs. Thirdly, by parting the
root-ſcions from each other they acquire greater ſpace of air for their
reſpiring leaves, and of ſoil for their abſorbent roots. Whereas when
too many ſtems ariſe from one root, or many ſeeds are fown near
together, a tuffock is produced in a conical form riſing higheſt in
the center ; which ſeems to be occaſioned by the conteſt of the ſtems
for air and light; their roots alſo muſt deſcend lower in their conteſt
for moiſture, and for other advantages of the ſoil ; whence many of
theſe crowded ſtems become barren, producing no ears, or ill-corned
ones.
Another benefit from tranſplanting corn is owing to the quicker
tendency to fructification, and conſequent ſooner ripening of the
grain. Thus tranſplanted garden beans and tranſplanted brocoli
flower ſooner, and I ſuppoſe produce leſs ſtems or ſtraw, as men-
tioned

Secr. XII. 6.
291
PULVERIZATION.
tioned in Sect. XVI. 1. 2. I am alſo well informed by the Rev. Mr.
Pole of Radborne, that the roots of thoſe turnips, which were drawn
out of the ground and tranſplanted, became conſiderably larger than
thoſe, which were only hoed in the common manner; which I fup-
poſe to have been owing to many of the extremities of the roots hav-
ing been torn off in drawing them out of the ground; and that thence
the tendency to ſhoot up the new central ſtem is delayed, and the re-
ſervoir of nouriſhment accumulated in the tuberous root is thus in-
creaſed in quantity, as ſeveral of theſe turnips weighed ten and eleven
pounds; and hence probably the tranſplanting turnips by means of
a cylindrical ſpade deſcribed in Vol. IV. of the Bath Society, which
tears the roots leſs, might not have been ſo advantageous. Something
fimilar occurs in tranſplanting fruit-trees. See Sect. XV. 2. 4.
But the great advantage of tranſplanting wheat above the drill-
huſbandry conſiſts in being able at the ſame time to divide the root-
fcions from each other; and thus not only to prevent their crowd-
ing each other, but alſo wonderfully to increaſe the product from a
fingle grain, with many other advantages mentioned by Mr. Bogle
in the works of the Bath Society, Vol. III. p. 494.
Another great advantage of tranſplanting wheat conſiſts in this, that
it may be fowed in a garden, one acre of which will produce ſets for
one hundred acres, if they be divided and planted at nine inches diſ-
tance from each other; and as they are not to be tranſplanted till the
ſpring, wheat may be thus cultivated in moiſter ſituations than would
otherwiſe be friendly to its growth.
And that a clean crop may be certainly thus procured; becauſe if
the land be ploughed immediately before the plants are ſet out, the
corn will ſpring much quicker from the plants, than the weeds from
their feeds; and the corn will thence bear down the growth of the
weeds.
For many other particulars the reader is referred to the ingenious
paper of Mr. Bogle above mentioned, who thinks the tranſplanting
P p 2
might
a

292
SECT. XII. 7.
AERATION AND
might be done by boys and girls at a ſmall expence; I ſhall only
add, that rape-feed, which is generally fown in Auguſt, and not reaped
till the Auguſt following, might be profitably tranſplanted, as well as
peas and beans. And laſtly, that it is probable, that ſome means of
making the holes to receive the plants might be much expedited by
a broad wheel to be drawn by a man or horſe with prominent pegs
on its periphery two inches tall, and nine inches aſunder.
7. Another means of aeration and of pulverization has been uſed
in reſpect to wheat crops by many with advantage, and that is by
drawing a lightiſh harrow over a wheat-crop in the ſpring, which,
where a crop is thin, is particularly recommended; and may alſo be
of ſervice where it is too thick.
The harrow by breaking the clods, and by turning up the ſoil againſt
the ſtems of many plants, earths them deeper as in hoeing; and thus
by burying the ſecond joint occaſions it to tiller, or ſhoot out new
root-fcions; at the ſame time the earth is expoſed to the air, and
many weeds are rooted up and covered, and ſome roots of the corn.
The drawing a ſharp harrow over a field of wheat in the ſpring
muſt cut or tear many of the roots of thoſe ſtems, which it comes
near, which according to Mr. Tull's theory would ſhoot out many
new radicles, or pencils of fine roots, and thus acquire more nouriſh-
ment. But I ſuſpect that tearing of many of the root-fibres prevents
the too luxuriant growth of the ſtem and leaves, and thence ſooner
produces the fructification, as in tranſplanting. At the ſame time the
earth being looſened becomes more penetrable to the remaining roots,
as well as more nutritive from its aeration.
Others have even ploughed a field at this ſeaſon with good effect,
as Mr. Bogle afſerts; but both of them appear to be only inferior
kinds of drill huſbandry, and the former may ſo far be of conſider-
able utility.
8. Another method of aerating and pulverizing the ſoil of a wheat
field in ſpring is by rolling it, which may be done before or after the
4
uſe

Sect. XII. 8.
293
PULVERIZATION.
uſe of the harrow, or without it. As the ſurface of a wheat field is
generally left rough with clods or eminences, the preſſure of a hea-
vyiſh roller will not only pulverize theſe, and thus expoſe their inte-
rior ſurface to the air, and raiſe the ſoil round the wheat-ſtems above
the ſecond joint, and thus induce them to ſhoot out new root-ſcions,
or tiller ; but will alſo preſs down the wheat roots into the ſoil, and
thus alſo promote the growth of new ſtems, as mentioned in Sect.
XVI. 2. 5. if it be performed, when the ground is neither too wet
nor too dry for ſuch an operation.
SECT.

294
Secr. XHI.
LIGHT, HEAT,
SECT XIII.
OF LIGHT, HEAT, ELECTRICITY.
I. 1. Light and heat are different fluids. Light does not heat tranſparent bodies.
A glaſs fire-ſcreen, combines with opake bodies, and heat is detruded. 2. Light
«combines with ſolid oxygen, and with heat converts it into gas. Perſpiration of
plants is decompoſed by light. The hydrogen retained gives the green colour. Wa-
ter byper-oxygenated. Oxygenated marine acid. Colourleſs nitrous acid. A branch
immerſed in carbonic acid and water. 3. Etiolation of vegetables. Bleaching ow-
ing to oxygen. Colour of plants to hydrogen, and the yellow tan of the ſkin. Pure
air from dew. Perſpiration of plants oxygenated. Light tans living bodies, and
bleaches dead ones, both vegetable and animal. 4. Use of light in vegetable reſpi-
ration. Plants do not reſpire in the night. Truffles and fungi live without light.
5. Spring water frequently oxygenated. Air liberated by points. 6. Plants re-
quire oxygen. Fallacy of contrary experiments. II. 1. HEAT univerſal. Counter-
afts gravitation. Is the cauſe of fluidity, and of aeriform ſtate. Particles of mat-
ter do not touch. Heat becomes combined. Is ſet at liberty in produktion of acids.
.
In freezing water. 2. Froſt deſtroys fluidity. Ice expands. Separates compound
fluids from each other, and burſts the veſſels of plants. Not of evergreens. Rime
froſts and black froſts. Low ſituations not proper for gardens. Uſe of coping ſtones
on fruit- walls. Rows of young peas from S. E. to S.W. Bend fig-trees on the
ground. Froſt erroneouſly believed to meliorate the ſoil, and to be wholeſome. Clay
rendered denſer by froft. Snow protećis plants. Animals covered with ſnow are
not wet or ſtarved. Lichen rangiferinus. 3. Cold deſtroys vegetable irritability.
Heat is a ſtimulus. Acquired habits of plants. 4. Cold produced by evaporation.
Plants not to be watered in the funſhine. III. 1. FLCTRICITY conſiſts of two
fluids. Forwards the growth of plants whether poſitive or negative. Lightning
deſtroys them.
2. It aſlifts the decompoſition of water in vegetables. 3. Clouds
6

Sect. XIII. I. I.
295
ELECTRICITY.
are generally eleEtriſed plus. Experiment on vapour. Rain from hydrogen and
oxygen. Thunder ſhowers. 4. EleEtric points to colle&t dew, and promote ve-
getation. Electric clock.
1. 1. PHILOSOPHERS are not yet agreed, whether light and heat be the
fame fluid under different modifications, or two different fluids, which
exiſt frequently together. The latter opinion ſeems to be more pro-
bable from the circumſtances related below, and alſo from the ana-
logy of other aqueous, aerial, or ethereal fluids, which appear to con-
ſift of two other fluids combined or diffuſed with each other. Thus
water conſiſts of oxygen and hydrogen combined together. Atmo-
ſpheric air of oxygen and nitrogen diffuſed together. Electricity pro-
bably conſiſts of two fluids, which may be termed vitreous and re-
finous electricity. Magnetiſm alſo probably conſiſts of two fluids,
which conſtitute northern and ſouthern polarity. The power of at-
traction ſeems to conſiſt of gravitation and of chemical affinity. And
laſtly, the element of fire conſiſts I ſuppoſe of light and heat.
The diffimilarity of light and heat is evinced by this ſimple cir-
cumſtance; that as light gives no heat to tranſparent bodies, which
the emanations from a fire do, there is reaſon to believe them to be
different fluids. Thus when ſmoke is blown near the focus of a large
burning glaſs, it does not aſcend; which ſhews, that the air is not
heated and rarified by it ; though it would burn or vitrify in an in-
ftant any opake body, which might be oppoſed to it; but the ema-
rations of heat from a fire ſoon rarify and warm the air in its vicinity,
cauſing it to aſcend, as may be ſeen by a ſpiral card-vann placed over
a chimney-piece, and which is agreeably ſeen in the uſe of the new
glaſs fire-ſcreens of Pariſian invention, which placed before a parlour
fire permit the rays of light to paſs, but intercept the emanations of
fluid heat.
Whence it would ſeem, that light does not itſelf communicate heat
to opake bodies, when it falls on them; but combines with them,
and
a
w

296
LIGHT, HEAT, Sect, XIII. I. 2.
a
and by that union heat is detruded or given out; which heat may
produce inflammation of the material, if it be of an inflammable na-
ture, by uniting it with the oxygen of the atmoſphere ; and thus
producing an eduction of more heat from the oxygen, and greater in-
flammation of the burning body.
2. Another eſſential difference between light and heat conſiſts in
the particular attraction of the former to oxygen; inſomuch that by
their union the combined or ſolid oxygen becomes changed into an
aerial, or gaffeous ſtate ; as conſtantly occurs, when the ſun ſhines
on the hyper-oxygenated water, which is perſpired or exhaled from
plants, as mentioned in Botanic Garden, Vol. I. Cant. IV. 1. 25. But
as an addition of heat ſeems neceſſary to the converſion of a ſolid or
fluid body into an aerial or gaffeous one, I ſuppoſe the ſun's light at
the ſame time by combining alſo with the water ſets at liberty ſome
latent heat from it, which gives wings to the oxygen.
The water perſpired by plants, when expoſed to the ſunſhine, is
believed to be decompoſed, as it eſcapes from the fine extremities of
the exhalent or perſpirative veſſels of plants; and that the hydrogen
is reabſorbed by the mouths of thoſe veſſels, as explained in Botanic
Garden, Vol. I. note 34. That this happens to a certain degree is
evinced hy etiolated or blanched vegetable leaves becoming green,
when expoſed to the ſunſhine in a few days; which is, I believe,
produced by their retaining the hydrogen of the water they perfpire,
as it is decompoſed by the ſun's light.
But it is alſo probable, that the perſpired fluid of plants is previ-
oufly hyper-oxygenated in the vegetable circulation. Firſt, becauſe
there is never perceived any ſmell of hydrogen to attend this proceſs
of liberating oxygen by the ſun's light. And ſecondly, becauſe the fol-
lowing productions of oxygen gas by the ſun's light are ſimilar phe-
nomena ; though I ſuppoſe the points or hairs on vegetable leaves may
contribute to the eſcape of the oxygen, as explained in Botanic Gar-
den, Vol. I. note 10.
Sir

SECT. XIII. 1. 2.
297
ELECTRICITY.
Sir Benj.Thompſon, now Count Rumford, in a paper publiſhed in
Philof. Tranſact. Vol. LXXVII. put thirty grains of raw ſilk previ-
ouſly waſhed into ſome ſpring water, and expoſing it ſome hours to
the ſunſhine obtained from it very pure vital air, or oxygen gas. In
that experiment the ſpring.water ſeems to have been in a ſtate of hy-
per-oxygenation, and the points or fine edges of the raw filk to have
affifted its liberation from the water in the ſunſhine, as explained in
Botanic Garden, Vol. II. note on fucus. 2. The hyper-oxygenated
marine acid is known very haſtily to part with its ſuperabundant
oxygen in the ſunſhine. 3. Mr. Scheele inverted a glaſs vefſel filled
with colourleſs nitrous acid into another glaſs-veſſel containing the
ſame acid; and on expoſing them to the ſun's light, the inverted glaſs
became partly filled with pure air, and the acid at the ſame time be-
came coloured. Crell's Annal. 1786.
As water contains 85 hundredth parts of oxygen to 15 of hydro-
gen, it may become much oxygenated occaſionally by a ſmall loſs of
hydrogen in the vegetable ſyſtem; or by the carbonic acid being de-
compoſed in plants by the ſecretion of carbon, which conſtitutes fo
great a part of them; and that on both of theſe accounts they may
yield oxygen gas, when expoſed to the ſun's light, as appears from the
following experiment related from Von Uſar by G. Schmeiſſer. Ob-
ſervat. on Plants. Creech, Edinburgh, p. 92.
If two branches of a plant are immerſed, one in common water, and
the other in water impregnated with carbonic acid, we then find,
that the branch immerſed in the latter yields a much greater quan-
tity of oxygenous gas in the ſunſhine than the other. The difference
in ſome experiments has been found in the proportion of 264 to 1.
But the proportions vary when different plants are ſubjected to trial.
Thus the carbonic acid, with which the water is impregnated, is de-
compoſed by the branch, the carbon apparently enters into the con-
ftitution of the plant, while the oxygen is fet at liberty, and eſcapes
in
Q9

298
SECT. XIII. 1. 3
LIGHT, HEAT,
a
in the form of gas in the ſunſhine; but not in the night, as then the
carbon is perſpired along with it.
3. A third circumſtance, in which the effects of light differ eſſen-
tially from thoſe of heat, appears in the blanching or etiolation of ve-
getables; under whatever temperature of heat a plant is kept, it be-
comes white, if the light be excluded from it, and is ſo far diſeaſed,
as mentioned in Sect. XIV. 2.4. Whence all vegetables turn towards
the window, if confined in a room, and in denſe woods grow taller,
than in open grounds, for the purpoſe of acquiring acceſs to this ne-
ceſſary fluid. On this ſubject many experiments are related by M.
Senebier on vegetables confined in a dark cavern.
From the experiment laſt related of the nitrous acid becoming co-
loured, when the ſuperabundant oxygen was volatilized by the ſun's
light, or attracted from it; and from the experiments of bleaching
cotton by the hyper-oxygenated marine acid, where the union of
oxygen with the colouring matter ſeems to deſtroy the latter by
forming a new acid, which is colourleſs, it appears, that the abſence
of oxygen occaſions the colour of vegetable bodies, probably by the
accumulation of hydrogen ; and that on this account, when they are
ſecluded from the light, they become white, or blanched, or etiolat-
ed, by their not being in a ſituation to part with ſo much oxygen,
as when they are expoſed to the light.
Hence plants growing in the ſhade are white, and become green
by being expoſed to the ſun's light; for their natural colour being
blue, the addition of hydrogen adds yellow to this blue, and tans them
green.
I ſuppoſe a ſimilar circumſtance takes place in animal bodies; their
perſpirable matter is probably hyper-oxygenated; and, as it eſcapes
in the ſunſhine, loſes its ſuperabundant oxygen; and by the hydro-
gen being retained the ſkin becomes tanned yellow. Though this
muſt occur in leſs quantity in animals, as they perfpire fo much leſs
than
a

SECT. XIII. 1. 3.
ELECTRICITY.
299
a
than vegetables; and the greateſt part of their perſpired matter, which
exhales from the lungs, is not expoſed to the ſun's light. In proof
of this it muſt be obſerved, that both vegetable and animal ſubſtances
become bleached white by the ſun-beams and water, when they are
dead, as cabbage-ſtalks, bones, ivory, tallow, bees-wax, linen and cotton
cloth; and hence, I ſuppoſe, the copper coloured natives of ſunny
countries might become etiolated, or blanched, by being kept from
their infancy in the dark, or removed for a few generations to more
northern climates.
It is probable, that on a funny morning much pure air becomes
ſeparated from the dew by means of the points of vegetables, on
which it adheres, and much inflammable air imbibed by the vegeta-
ble, or combined with it; and, by the ſun's light thus decompoſing
water, the effects of it in bleaching linen ſeem to depend ; the
water is decompoſed by the light at the ends or points of the cotton
or thread; and the vital air unites with the phlogiſtic or colouring
matters of the cloth; and produces a new acid, which is either itſelf
colourleſs, or waſhes out; at the ſame time the hydrogen or inflam-
mable part of the water eſcapes. Hence there ſeems a reaſon, why
cotton bleaches ſo much fooner than linen ; viz. becauſe its fibres are
three or four times ſhorter, and therefore protrude ſo many more
points; which ſeem to facilitate the liberation of the vital air from
the inflammable part of the water.
A fun-flower three feet and a half high, according to the experi-
ment of Dr. Hales, perſpired two pints in one day, (vegetable ſtatics)
which is many times as much in proportion to its ſurface, as is per-
ſpired from the ſurface and lungs of animal bodies; it follows, that
the vital air, liberated from the ſurface of plants by the ſunſhine, muſt
much exceed the quantity of it abſorbed by their reſpiration; and
that hence they improve the air, in which they live, during the light
part of the day; and thus blanched vegetables will ſooner, become
tanned
a
Qq2

300
Secr. XIII. 1.4.
LIGHT, HEAT,
a
tanned into green by the ſun's light, than etiolated animal bodies will
become tanned yellow by the ſame means.
Laflly. This retention of the hydrogen on the ſkins of vegetables
and animals, when their perſpirable matter is decompoſed by the ſun's
light, and by which the former becomes green, and the latter yel-
low, is evidently owing to the power of life; becauſe when either
of them are dead, the action of the ſunſhine on the water ſprinkled
on them again blanches them, or bleaches them white.
It is hence evident, that the curious diſcovery of Dr. Prieſtley, that
his green vegetable matter, and other aquatic plants, gave out vital
air, when the ſun ſhone upon them; and the leaves of other plants
did the ſame when immerſed in water, as obſerved by Mr. Ingen-
houz, refer to the perfpiration of vegetables, not to their reſpiration.
Be ſe Dr. Prieſtley obſerved the pure air to come from both ſides
of the leaves, and even from the ſtalks of a water-flag, whereas one
ſide of the leaf only ſerves the office of lungs, and certainly not the
ſtalks. Exper. on Air, Vol. III. And thus in reſpect to the circum-
ſtance, in which plants and animals ſeemed the fartheſt removed from
each other, I mean in their ſuppoſed mode of reſpiration, by which
one was believed to purify the air, which the other had injured, they
ſeem to differ only in degree; and the analogy between them re-
mains unbroken.
4. The conteſt for light, as well as for air, which is ſo viſible in
the growth of vegetables, as deſcribed in Botanic Garden, Vol. II.
note on cuſcuta, fhews the former to be of great conſequence to their
exiſtence as well as the latter. Thus many flowers follow the ſun
during the courſe of the day by the nutation of the ſtalks, not by
the rotation of them, as obferved in the fun-flower by Dr. Hales;
and the leaves of all plants endeavour to turn their upper furface to
the light, which is their reſpiratory organ, or lungs, as ſhewn in
Sect. IV.
The

SECT. XIII. 1.5.
301
ELECTRICITY.
The great uſe of all plants turning their upper ſurfaces of their
leaves to the light is thus intelligible ; the water perſpired from thoſe
furfaces is hyper-oxygenated ; and, as it eſcapes from the ſharp edges
of the mouths of the perſpiring veſſels, when acted upon by the ſun's
light, gives out oxygen ; which oxygen, thus liberated from the per-
fpired water, and added to that of the common atmoſphere, preſents
to the reſpiratory terminations of the pulmonary arteries on the upper
furfaces of leaves an atmoſphere more replete with vital air.
This neceſſity of light to the reſpiration of vegetables is ſo great,
that there is reaſon to believe, that many plants do not reſpire during
the night, but exiſt in a torpid ſtate like winter ſleeping inſects.
Thus the mimoſa, fenfible plant, and many others, cloſe the upper
furfaces of their oppoſite leaves together during the night, and thus
preclude them both from the air and light. And the internal ſur-
faces of innumerable flowers, which are their reſpiratory organs, are
cloſed during the night, and thus unexpoſed both to light and air.
The fungi nevertheleſs, which are termed vegetables, becauſe
they are fixed to the earth, or to the ſtones, or trees, or timber,
where they are found, can exiſt without light or much air ;: as ap-
pears in the truffle, which never appears above ground; and by other
fungi, which grow in dark cellars; and in efculent muſhrooms,
which are cultivated beneath beds of ſtraw. From this circumſtance
of their exiſting without light, and from their ſmell of volatile al-
kali, like burnt feathers, when they are burnt, and from their taſte
when cooked and eaten, they ſeem to approximate to the animal
kingdom.
5. Laſtly. It may nevertheleſs be ſuſpected, that in many of the
experiments of Dr. Prieſtley and Dr. Ingenhouz, the production of
vital air might be ſimply owing to the action of the ſun's light on
the water, in which the vegetables were immerſed, like that from
the filk in the experiment of Count Rumford; and that the fine
points, or ſharp edges of thoſe bodies, contributed only to facilitate
the

302
SECT. XIII. 1. 16.
LIGHT, HEAT,
;
the liberation of it, when expoſed to the ſunſhine, which thus diſ-
oxygenate the water by their united effect.
This appears on immerſing a dry hairy leaf in water freſh from a
pump, innumerable globules like quickſilver appear on almoſt every
point ; for the extremities of theſe points attract the particles of wa-
ter leſs forcibly, than thoſe particles attract each other; hence the
contained air, whoſe elaſticity was but juſt balanced by the attractive
power of the ſurrounding particles of water to each other, finds at
the point of each fibre a place, where the reſiſtance to its expanſion
is leſs ; and in conſequence it there expands, and becomes a bubble of
air. It is eaſy to foreſee, that the rays of the ſunſhine, by being re-
fracted and in part reflected by the two ſurfaces of theſe minute air-
bubbles, muſt impart to them much more heat than to the tranſpa-
rent water; and thus facilitate their aſcent by further expanding
them; and that the points of vegetables attract the particles of water
leſs, than they attract each other, is ſeen by the ſpherical form of
dew-drops on the points of graſs.
6. It may be added in this place, that there may alſo be a fallacy
in the ſuppoſed reſults of thoſe experiments, where plants have been
confined in hydrogen or azote mixed with atmoſpheric air ; and have
been believed to have vegetated more vigorouſly, and to have me-
liorated the air. In theſe experiments I ſuſpect, that the impure part
of the air was attracted by the water, and taken up by the abſorbents
of the roots of the plants from the water, rather than by the abſorbents
of their leaves or ſtems in the air; and that the melioration of the air
was occaſioned, as above deſcribed, by the action of the light on the
water perſpired from the ſurface of the plant, or liberated by its
points from the water, with which part of it was covered. This is
rendered more probable, becauſe plants and feeds in the experiments
of others ceaſed to vegetate in thoſe gaſſes, which were totally de-
prived of oxygen, as in M. Scheele's experiments on the growth of
feeds.
II. 1. The

SECT. XIII. 2. 1.
303
ELECTRICITY.
II. 1. The Auid matter of heat is one of the moſt extenſive ele-
ments in nature, perhaps next to that of gravitation; all other bodies
are immerſed in it, and are preſerved in their preſent ſtate of folidity
or fluidity by the different attraction of their particles to the matter
of heat, which thus counteracts the powers of gravitation, and of
chemical affinity, which would otherwiſe compreſs them into one
folid chaotic maſs!
Since all known bodies are contractible into leſs ſpace by depriving
them of ſome portion of their heat; and as there is no part of nature
totally deprived of heat; there is reaſon to believe, that the particles
of bodies do not touch, but are held towards each other by their ſelf-
attraction, or recede from each other by their attraction to the maſs
of heat, which ſurrounds them; and thus exiſt in an equilibrium be-
tween thefe two powers.
If more of the matter of heat be applied to them, they recede far-
ther from each other, and become fluid ; if ſtill more be applied, they
take an aerial form, and are termed gafſes; and it is probable, that
the ethereal fluid of electricity may alſo be diffuſed with heat, as well
as the ethereal fluid of light.
Thus when water is heated to a certain degree, it would inſtantly
aſſume the form of ſteam, but for the preſſure of the atmoſphere;
which prevents this change from taking place ſo eaſily; the ſame is
true of quickſilver, diamonds, and of perhaps all other bodies in na-
ture; they would firſt become fluid, and then aeriform, by appro-
priated degrees of heat. On the contrary, this elaſtic matter of heat,
termed Calorique in the new nomenclature of the French academi-
cians, is liable to become conſolidated itſelf in its combinations with
ſome bodies, as certainly in nitre, and probably in combuſtible bodies,
as ſulphur and charcoal.
This combined heat is univerſally ſet at liberty in the production
of acids by the union of oxygen with all inflammable bodies, as ſhewn
in Sect. XII. 1. It is alſo taken from ſome bodies by the vicinity of
6
very

30.4
LIGHT, HEAT,
Secr. XIII. 2. 2.
very cold ones, as water when frozen loſes ſuddenly a part of its
combined heat, at the moment it becomes ice.
2. It is evident, that without fluidity the blood or juices can not
circulate in animal or in vegetable veſſels; whence ſo great a dimi-
nution of heat as to produce froſt on this account would deſtroy them
if long continued ; at the ſame time too great a deduction of heat is
known to deſtroy the irritability of animal as well as of vegetable
fibres, and muſt on this account alſo prevent the circulation of their
fluids, and occafion the mortification of parts of them, or the death
of the whole. But when fluids are converted into ice, the bulk of
them is enlarged to a conſiderable degree, and that with ſuch vio-
lence as to burſt iron veſſels, as bombs, which are filled with water.
Whence in this manner alſo froſt deſtroys thoſe parts of vegetables,
which are moſt ſucculent; as the early ſhoots of aſh trees, and other
young plants, are frequently deſtroyed in the beginning of May by a
froſty night.
The veſſels of theſe ſucculent parts of plants are diſtended and
burſt by the expanſion of their frozen fluids; while the drier or more
reſinous vegetables, as pines, yews, laurels, and other evergreens, are
leſs liable to injury from cold. The trees in valleys are on this ac-
count more liable to injury by the vernal froſts, than thoſe on emi-
nences; becauſe their early ſucculent ſhoots appear ſooner in the
year.
Another method, by which the act of freezing may deſtroy vege-
table life, may be by ſeparating ſome part of their fluids from other
parts of them. Thus when wine, or vinegar, or ſalt and water, or
clay diffuſed in water, and perhaps milk, are frozen; the watery
part, as it congeals, protrudes from its forming cryſtals the ſpirit, the
acid, the ſalt, the clay, and probably the opake particles of the milk;
and by a ſimilar proceſs on vegetable and perhaps on animal fluids,
when expoſed to great cold, they may be rendered unfit for future
circulation or life. See Sect. XV. 4. 1.
The

Sect. XIII. 2. 2.
305
ELECTRICITY.
The expanſion of ice nevertheleſs well accounts for the greater
miſchief which is ſometimes done by vernal froſt, when preceded by
much rain, or miſt, or dew, as by hoar-froſt, than by the dry froſts
without rime, called black froſts; as the vegetable veſſels are then
fuller of fluids. But when miſt or dew attends a froſty night, but
has not preceded it, I ſuppoſe a hoar froſt may be leſs injurious than
a black froſt; as the caſe of ice on the buds of trees, or on young
grafs, being inſtantly produced, covers them with a bad conductor
of heat, and prevents them from being expoſed to fo great cold, as
in the continuance of a black froſt without hoar or rime. See Sect.
XV. 3. 5.
a
a
Mr. Laurence, in a letter to Mr. Bradley, complains, that the dale-
miſt attended with a froſt on May-day had deſtroyed all his tender
fruits; though there was a ſharper froſt the night before without a
miſt, that did him no injury; and adds, that a garden not a ſtone's
throw from his own on a higher ſituation, being above the dale-miſt,
had received no damage. Bradley, V. II. p. 232. From this inſtruc-
tive fact it appears, that very low ſituations even in this cold climate
are not proper for the purpoſes of a garden. And on the contrary,
very high ſituations are equally improper on account of their greater
cold, and the conſequent backwardneſs of their vegetable products.
See Sect. XV. 3. 5.
Hence fruit trees againſt a wall, which are covered with coping
ſtones projecting fix inches over them, are leſs injured by the vernal
froſts; becauſe their being thus ſheltered from the deſcending night-
dews has prevented them from being moiſt at the time, they were
frozen ; which circumſtance has given riſe to a vulgar error amongſt
gardeners, who ſuppoſe froſt to deſcend.
Hence as the freezing winds of this country are from the north-
eaſt, a gardener ſhould extend his rows of young peas and beans from
the ſouth-eaſt to the north-weſt, and raiſe a mound of earth behind
them, and might ſhelter them occaſionally with ſtraw, placed on the
ground
a
Rr

306
Sect. XIII, 2. 2.
LIGHT, HEAT,
ground behind the young plants, and ſupported a few inches over
them in front by poles placed horizontally over the rows; remem-
bering the old proverb,
The wind from north-eaſt
Deſtroys man and beaſt;
The wind from ſouth-weſt
Is always the beſt.
The immediate cauſe of the coldneſs of the N. E. winds is, that
they conſiſt of regions of air brought from the north over evaporat-
ing ice, and gain an apparent eaſterly direction, becauſe they arrive
at a part of the ſurface of the earth, which moves with greater velo-
city, than the ſurface of the part of the earth, they come from. So
on the contrary the S.W. winds are warm, as they conſiſt of regions
of air brought from the ſouth, and gain an apparent weſterly direc-
tion, becauſe they arrive at a part of the earth's ſurface, which moves
ſlower than the ſurface nearer the equator, whence they came, and
of which they had previouſly acquired the velocity.
As the common heat of the earth in this climate is 48 degrees,
thoſe tender trees, which will bear bending down, are eaſily ſecured
from the froſt by ſpreading them upon the ground, and covering
them with ſtraw or fern. This particularly ſuits fig-trees, as they
are very flexible, and as they are furniſhed with an acrid juice, which
defends them from inſects; but I have nevertheleſs found them in
this ſituation much eaten by mice.
It has been believed by many, that froſt meliorates the ground;
but it is now well known, that ice contains no nitrous particles, as
was formerly ſuppoſed ; and that though froſt by enlarging the bulk
;
of ſome moiſt foils may leave them more porous for a time after the
thaw ; yet as the water exhales, the ſoil becomes as hard as before,
being preſſed together by the incumbent atmoſphere. And from an
obſervation of Mr. Kirwan's, mentioned in Section XV. 4. 1. it ap-
pears,
a

SECT. XIII. 2. 2.
307
ELECTRICITY.
pears, that moiſt clay becomes denſer or more folid by being frozen ;
and if this ſhould not occur, yet it would quickly become as folid as
before by the ſelf-attraction of its particles, called ſetting by the pot-
ters; as well as by the preſſure of the atmoſphere; as its water ex-
hales, and leaves vacuities between its particles. Add to this, that on
the coaſts of Africa, where froſt is unknown, the fertility of the ſoil
is much ſuperior to our own.
In reſpect to the commonly ſuppoſed falubrity of froſty feaſons to
mankind, and to other animals, the bills of mortality are an evidence
in the negative in reſpect to mankind, as in long froſts many weakly
and old people periſh from debility, occaſioned by the diminiſhed heat
not being ſufficient to excite into action their veſſels previouſly too
inirritable; and many birds, and other wild animals, and tender vege-
tables, periſh benumbed by the degree and continuance of the cold.
It ſhould however be obſerved, as froſty air is alway dry, except
when frozen miſts diſſolve, as they adhere to the warmer ſkins of ani-
mals, that it does not generally affect us with fo great a ſenſation of
cold, as when air near the freezing point is loaded with moiſture; as
the moiſture of ſuch air is perpetually evaporating from our ſkins,
and produces on them a degree of cold greater than the ſimple con-
tact of dry air produces, when it is but a little beneath the freezing
point. Hence froſty air is more agreeable to thoſe young or ſtrong
people, who can keep themſelves warm by exerciſe ; that is, who can
generate heat by increaſed ſecretions. But ſevere and continued
froſts deſtroy the old and infirm, who cannot uſe much exertion ;
and the children of the poor, who want both food, fire, and cloth-
ing, in this harſh climate.
It may nevertheleſs be true, that fnows of long duration in our win-
ters may be leſs injurious to vegetation than great rains and ſhorter
froſts. 1. Becauſe great rains carry down many thouſand pounds
worth of the beſt manure into the ſea; whereas ſnow diffolves gra-
dually, the upper ſurface, as it thaws, ſliding over the under part,
Rr 2
which
a

308
SECT. XIII. 2: 2.
LIGHT, HEAT,
a
which remains frozen, and thence carries away leſs from the land
into the rivers; whence a ſnow flood may be diſtinguiſhed from a
rain flood by the tranſparency of the water.
Secondly. Snow protects vegetables from the ſeverity of the froſt;
fince it is generally in a ſtate of thaw, where it is in contact with the
earth ; as the earth's heat is 48 degrees, and that of thawing ſnow is
32°. The plants between them are generally kept in a degree of
heat about 40, by which many of them are preſerved. On this ac-
count ſome plants from Siberia were ſaid to periſh by the froſts at
Upſal; becauſe the ſnows did not commence at the ſame time as irr
the colder climate, from which they were brought.
Thus the liehen rangiferinus, coral-moſs, vegetates beneath the
fnow in Siberia, where the degree of heat is always about 40; that is
in the middle between the freezing point and the common heat of
the earth. And as this vegetable is for many months of the winter
the ſole food of the rein-deer, who digs furrows in the ſnow to find
it; and as the milk and fleſh of this animal is almoſt the only ſuf-
tenance, which can be procured by the natives during the long winters
of thoſe higher latitudes, this moſs may be ſaid to ſupport ſome mil-
lions of mankind.
Snow protects vegetables, that are covered by it, from cold, both
becauſe it is a bad conductor of heat itſelf, and contains much air in
its pores. When living animals are buried in ſnow, as ſheep, or
hares, the water, which their warmth produces, becomes abſorbed
into the ſurrounding ſnow by capillary attraction, and the creatures
are not moiſtened by its dropping on them; but the cavity enlarges,
as the ſnow diffolves, affording them both a dry and a warm habita-
tion. If this was generally known, many cold and weary travellers
in ſnowy nights might be ſaved by covering themſelves with ſnow
inſtead of endeavouring to proceed,
It ſhould be added that Hafſenfratz has endeavoured to fhew by
ingenious chemical experiments, that rain water and ſnow contain
4
both

Sect. XIII. 2. 3. ELECTRICITY.
309
a
both of them a redundancy of oxygen compared with river water,
which they may have acquired in their deſcent through the atmo-
ſphere; and that as oxygen is ſhewn by the experiments of Ingen-
houz and Senebier to promote the growth of ſeeds and of plants, he
concludes, that rain water and ſnow promote vegetation in a much
greater degree than river water or ice, which ſeems to accord with
the popular obſervations on this ſubject.
3. Mr. John Hunter by applying thermometers to the internal parts
of vegetables newly opened diſcovered, that they poffeffed in froſty
feaſons a degree of heat above that of the atmoſphere, though lefs
than that of cold blooded animals. Whence another deleterious effect
of cold on vegetable bodies muſt be by deſtroying their irritability,
and by that means ſtopping the abſorption and circulation of their
juices ; in the ſame manner as is ſeen in the pale benumbed fingers of
;
fome people, when expoſed to the cold; and which is the immediate
cauſe of death in thoſe, who periſh in the fnow in winter, which
occurs long before their fluids are frozen.
The neceſſity of a certain degree of heat to produce or to preferve
the activity of the abſorbent vefſels of vegetables is well evinced by
the experiments of Hales and Duhamel on the riſing ſap of vines in
the vernal months. On a froſty day, when the ſun ſhone on one
of thoſe wounded trees, the ſap flowed on the ſouth ſide of the tree,
but not on the north ſide. Phyſique des arbres, Vol. II. p. 258. M.
Duhamel further obſerves, that the maples in Canada, where the froſt
is long and ſevere, begin to bleed, when wounded with the firſt
thaw, and ſtop again, when it freezes; and that this in froſty days
occurs only on the ſouth ſide of the tree.
This acquaints us, that one of the principal properties of heat in
reſpect to organic bodies, whether of vegetables or animals, con-
fifts in its acting as a ſtimulus; and that in a greater quantity than
that, which the organized being has been accuſtomed to, it acts as
an exceſs of ſtimulus; and thus increaſes the activity of the ſyſtem
in

310
LIGHT, HEAT, SECT. XIII.
3. I.
in reſpect to the abſorption of its food, circulation of its juices, and
quantity of its fecretions, and conſequently to its more rapid growth;
but all increaſe of ſtimulus becomes injurious by its exceſs, and is cer-
tainly followed by debility; as is ſeen in thoſe of our own ſpecies,
who are habitually kept in too warm rooms, or are accuſtomed to
drink intoxicating liquors.
Hence a wife gardener muſt regard the acquired habits of tender
vegetables; the inhabitants of his green houſe, and thoſe plants,
which have been expoſed to a greater heat for any length of time,
ſhould be gradually cooled, and watered with ſubtepid water; ſince
expoſing them to the cold of this climate is otherwiſe liable to de-
ſtroy their irritability and occaſion their death.
4. The great cold produced by evaporation is now well under-
ſtood. In all chemical proceſſes, where aerial or Auid bodies become
conſolidated, a part of the heat, which was before latent, becomes
preſſed out from the uniting particles; as in the inſtant that water
freezes, or that water unites with quick lime. On the reverſe, when
ſolid bodies become fluid, or fluid ones become aerial, heat is abſorbed
by the ſolution ; whence it may be ſaid in popular language, that all
chemical combinations produce heat, and all chemical ſolutions pro-
duce cold. This ſhould teach the careful gardener not to water ten-
der vegetables in the heat of the ſunſhine, or in a warm dry wind;
left the hafty evaporation ſhould produce ſo much cold as to deſtroy
them; and that more certainly from their having been previouſly
too much ſtimulated by heat, and in conſequence their power of life,
or irritability, having been already diminiſhed; as further ſpoken of
in Sect. XIV. 2. 2.
III. 1. The mechanical theory of electricity invented by Dr.
Franklin is believed by ſome philoſophers not ſo well to explain the
various phenomena of electricity, as may be accompliſhed by an hy-
potheſis of the exiſtence of two electric fluids diffuſed together, and
ſtrongly attracting each other, one of them to be called vitreous, and
8
the

Sect, XIII. 3. T.
311
ELECTRICITY.
the other refinous, electricity. The latter opinion I am inclined to
eſpouſe, but ſhall not here enter into a detail of the theory; but ſhall
only obſerve, that the experiments on vegetation have been principally
made with the accumulation of the vitreous electricity only, and the
conſequent excluſion of the reſinous; that is, with what is commonly
termed poſitive electricity, and not with what is termed negative
electricity. It is therefore to be wiſhed, that ſome future experiments
may be made with the reſinous or negative electricity in preference
to the vitreous or poſitive electricity, or with both of them alter-
ternately or comparatively.
The influence of poſitive or vitreous electricity in forwarding the
germination of plants and their growth ſeems to be pretty well eſta-
bliſhed; though Mr. Ingenhouz did not fucceed in his experiments,
and thence doubts the ſucceſs of thoſe of others; and though M.
Rouland, from his new experiments believes, that neither poſitive
nor negative electricity increaſes vegetation ; both which philoſophers
had previouſly been ſupporters of the contrary doctrine; for many
other naturaliſts have ſince repeated their experiments relative to this
object, and their new reſults have confirmed their former ones. Mr.
D’Ormey and the two Roziers have found the fame ſucceſs in nu-
merous experiments, which they have made in the two laſt years ;
and Mr. Carmoy has ſhewn in a convincing manner, that electricity
accelerates germination.
Mr. D’Ormey not only found various ſeeds to vegetate ſooner, and
to grow taller, which were put upon his inſulated table, and ſuppli-
ed with electricity ; but alſo that filk-worms began to ſpin much
ſooner, which were kept electrified, than thoſe of the ſame hatch,
which were kept in the ſame place and manner, except that they
were not electrified. Theſe experiments of Mr. D’Ormoy are de-
tailed at length in the Journal de Phyſique of Rozier, Tom. XXXV.
p. 270.
Mr. Bartholon, who had before written a tract on this ſubject, and
propoſed
3
a

312
SECT. XIII. 3. 2.
Sect
LIGHT, HEAT,
propoſed ingenious methods for applying electricity to agriculture
and gardening, has alſo repeated a numerous ſet of experiments; and
ſhews, that natural electricity as well as the artificial increaſes the
growth of plants, and the germination of ſeeds; and oppoſes Mr.
Ingenhouz by very numerous and concluſive facts. Ib. Tom. XXXV.
P. 401.
My friend Mr. D. Billborrow in June 1797 ſowed muſtard-feed in
four garden pots at Mr. Hartop's at Dalby Hall in Leiceſterſhire.
He ſubjected one of theſe to poſitive or vitreous electricity, and ano-
ther to negative or reſinous electricity, and obſerved that the ſeeds in
the pot ſubjected to the negative or reſinous electricity germinated a
day before the pot ſubjected to poſitive or vitreous electricity, and
both of them much before the two pots, which were not electriſed,
but otherwiſe expoſed to the ſame circumſtances.
Nor do the injuries occaſionally received from lightning in its paf-
ſage through trees or corn fields from or to the earth or clouds, which
are mentioned in Sect. XIV. 2. 3. in the leaſt invalidate this opinion
of its general utility as well as that of the fluid element of heat; for
the exceſs of the moſt falutary ſtimuli become deleterious both to ve-
getable and animal bodies.
2. Since by the late diſcoveries in chemiſtry there is reaſon to be-
lieve, that water is decompoſed in the veſſels of vegetables; and that
the hydrogene, or inflammable air, of which it in part conſiſts, con-
tributes to the nouriſhment of the plant, and to the production of
its oils, reſins, gums, ſugar, &c. And laſtly, as electricity has by
late experiments been found to decompoſe water into the two airs,
termed oxygen and hydrogen, there is a powerful analogy to induce
us to believe, that it accelerates or contributes to the growth of vege-
tation; and like heat may poſſibly enter into combination with many
bodies, or form the baſis of ſome yet unanalyſed acid.
3. The ſolution of water in air or in calorique ſeems to acquire
electric matter at the ſame time, as appears from an experiment of
Mr.

SECT. XIII. 3. 4.
ELECTRICITY.
313
a
Mr. Bennet. He put ſome live coals into an inſulated funnel of me-
tal, and throwing on them a little water, obſerved that the afcending
ſteam was electriſed plus; and the water, which deſcended through
the funnel, was electriſed minus. Hence it appears, that though
clouds by their change of form may ſometimes become electriſed
minus, yet they have in general an accumulation of poſitive elec-
tricity. This accumulation of electric matter alſo evidently contri-
butes to ſupport the atmoſpheric vapour, when it is condenſed into
the form of clouds; becauſe it is ſeen to deſcend rapidly, after the
flaſhes of lightning have diminiſhed its quantity.
According to the theory of Mr. Lavoiſier concerning the compo-
ſition and decompoſition of water, there would ſeem another ſource
of thunder-ſhowers; and that is, that the two gaffes termed oxygen
gas, or vital air, and hydrogen gas, or inflammable air, may exiſt
in the ſummer atmoſphere in a ſtate of mixture, but not of combi-
nation ; and that the electric ſpark, or flaſh of lightning, may com-
bine them, and produce water inſtantaneouſly.
4. A profitable application of electricity by the gardener or agri-
cultor to promote the growth of plants is not yet diſcovered ; it is
nevertheleſs probable, that in dry ſeaſons the erection of numerous
metallic points on the ſurface of the ground, but a few feet high,
might in the night time contribute to precipitate the dew by facili-
tating the paſſage of electricity from the air into the earth ; and that
an erection of ſuch points higher in the air by means of wires wrap-
ped round tall rods, like angle rods, or elevated on buildings, might
frequently precipitate ſhowers from the higher parts of the atmo-
ſphere.
And laſtly, that ſuch points erected in gardens might promote a
quicker vegetation of the plants in their vicinity by ſupplying them
more abundantly with the electric ether; if the events of the ex-
periments of the philoſophers above mentioned are to be depended
upon, which may at leaſt be worth a further trial.
S s
5. For

>
SECT. XIII. 3. 5.
&
LIGHT, HEAT, &c.
314
5. For the purpoſe of keeping a few flower-pots perpetually ſub-
ject to more abundant electricity, Mr. Bennet of Wirkſworth in Der-
byſhire affixed a ſmall apparatus to the pendulum of a clock, as de-
ſcribed below with a plate; but has not yet ſufficiently attended to
it to determine its effect on vegetation.
a
SECT.

PLATE VIII.

PLATE VIII.
Shews the ſtructure of Mr. Bennet's electric Doubler, applied to the pendulum of a clock
for the purpoſe of ſubjecting a flower pot to perpetual poſitive or negative electricity.
A the braſs plate, which is always inſulated by its glafs pedeſtal, on which the elec-
tricity is accumulated. B the braſs plate, which becomes electrified by the influence of the
moving plate C, which is alſo inſulated. D the pendulum wire. C is inſulated by
the glaſs-tube E E. The wire F F is alſo inſulated by the ſame glaſs, being faſtened to
the middle of it by a brafs ſocket at G. HHHHH are wires to connect the plates with
each other, or with the earth. Il a ſtring to be carried from the plate A over inſulated
hooks to any part of a room, or to an inſulated flower-pot.
Now if A be poſitive, and C moves, till it be parallel to it, and the wires at the bot-
tom touch each other, then C becomes negative, and moving till it be parallel to B, and
its wire touched by the uppermoſt H, then B becomes poſitive; and when C returns to
A, the electricity of A and B becomes united by means of the inſulated wire F F touch-
ing HH. The longer end of F is bent ſo as not to touch the wire of B, till the end is
brought to it. Thus the poſitive electricity of A is increaſed.
The wires are curled into ſeveral rings to make them more elaſtic, as otherwiſe they
would ſoon be puſhed out of their places, and the proper contacts not occur.
The plates
A and B
mау. be fixed on heavy pedeſtals, that they may be moved upon a fhelf to a pro-
per diſtance from the plate, which hangs by the pendulum wire. The heavier the pen-
dulum and the larger the plates, the more electricity may be accumulated. With my
ſmall apparatus fixed to a Dutch wooden clock ſparks are ſometimes produced between
the plates, and ſometimes the clock has been ſtopped by their attraction to each other.
Perhaps the plates ſhould not be circular, but ſomething like a lady's fan, when expande
ed, the bottom being a part of the curve deſcribed by the moving pendulum, with the
fides directed towards the point on which it moves.
This drawing and deſcription of his Pendulum Doubler was ſent me by Mr. Bennet of
Wirkſworth, and is referred to at the end of Sect. XIII. of this work. If another in-
fulated flower-pot was connected with the plate B inſtead of the wire at the uppermoſt
H, perhaps it might be kept in a ſtate of minus, or negative electricity, at the ſame time
that the other flower-pot was kept in a ſtate of plus or poſitive electricity.

Plate VIII.
Sect. VII.
D
H
E
F
H.
H
I
I
H
"!
London, Published Jan 18, by Johnson, Paul Churck Yard.


Secr. XIV.C DISEASES OF PLANTS.
315
S ECT.
XIV.
DISEASES OF PLANTS.
1. Diſeaſes from internal cauſes. 1. Difeafed irritability. Irritability derived from
oxygen. Exhauſted by too great ſtimulus. Shade apricot flowers from the ſun.
Much water after a hot day injurious. Irritability accumulated by leſs ſtimulus.
Experiment on euphorbia. Habits of plants brought from the ſouth. Taken to
America. In the bleeding ſeaſon. Vines in bot-boufes. Habits of plants. Irri-
tability greater after being expoſed to much cold, leſs after much heat. Greateſt in
the morning. Hybernating animals. Variation of heat contributes to health.
2. Eryſiphe mildew. A feſile fungus. Give light and ventilation. Drain the land.
Sow early. Rubigo, ruft. Probably another fungus. Uredo frumenti. Blight.
4 Clavus, ergot. On rye, which it renders unwholeſome. Afcribed to infeets by
Duhamel. 5. Uſtilago, ſmut.
5. Uſtilago, ſmut. Aſcribed to infečts by Linneus. Is probably owing
to want of impregnation. How prevented. 6. Gangrena, canker. AffeEts apple-
trees from old grafts. From wounds. Bind living bark on the wound. Or paint
the alburnum. 7. Suffuſo mellita, honey-dew. If occaſioned by the aphis? Suc-
ceeded by a black powder. 8. Exſudatio miliaris, miliary ſweat. On vines in hot-
houſes from too great heat in confined air. 9. Fluxus umbilicalis, fap-flow. From
wounds in Spring, and after midſummer. Bind on ſponge. Strangulate with wire.
10. Secretio gummoſa, gum fecretion. Bind on lead. Sponge, Indian rubber.
Apply ſolution of green vitriol. Bind on a new bark. II. Diſeaſes from exter-
nal elements. 1. Draught and moiſture. 2. Heat and cold. Shelter early bloſ-
foms from the ſunſhine. 3. Lightning. Injures trees and wheat fields. By de-
ſtroying their irritability, like the ſtimulus of ſome poiſons. By burſting their veſels.
How to prevent. 4. Light. Etiolation of ſea-cale. 5. Of acid clay. Of ſterile
Sand. 6. Noxious exhalations, from lead-works, and lime-kilns. 7. Poiſons of
arſenic, muriatic acid. 8. Condiments. Alcohol. Opium. Sea-falt. Its uſe
and effect on vegetables. Uſe in the worm of ſheep. 9. External injuries. Wound
grape-
SS 2

3:6
SECT. XIV. 1. I.
DISEASES
grape-ſtalks. Caprification. Pluck pears to ripen them. III. Diſeaſes from
inſects. 1. From their nefts and young. On roſes, on quince-bloſſoms, on aco-
nite. 2. Aphis on peach trees. Slugs prefer withered leaves. Cows eat withered
thiſtles. The poiſon of yew leaves. Hiſtory of the aphis. Means of deſtroying
them. Apbidivorous larva and fly. 3. Caterpillars on apple-trees and gooſe-berries.
Burn the leaves. Put a fringe round gooſeberry-trees. Deſtroy white butterflies.
Cabbage caterpillars deſtroyed by ichneumon fly. 4. Inſects in hot-houſes. Smoke
of ſulphur injurious to trees. 5. Beetles beneath the ſoil. Snails. Slugs. Roll
turnips before ſun-riſe. Slugs prevented by lime or ſalt. Caught by a board. Fly
on turnips. Roll them. Steep turnip feeds in liquid manure as in China. 6. Beetles.
Fern-chaffer. Deſtroys crops of wheat. Sow wheat ſhallow. Roll it, or ſtrew
ſalt in fine powder. Thrips phyſaphus on wheat. Corn butterfly. May-chaffers
on hedges. Locuft. Encourage hedge-birds, larks, rooks, hedge-bogs. Some
caterpillars wholeſome to eat, others poiſonous. All very hardy and difficult to de-
Stroy. IV. Deſtruction by vermin. 1. Mice. Tufſocks of wheat from their
granaries. Encourage the breed of owls. 2. Water-rats like beavers, how driven
from a fiſh-pond. They eat vegetables. Are attraeted by ſcents. How to poiſon
them. How to entrap them. 3. Moles never drink. Sometimes ſwim. Work
before ſun-riſe. How to deſtroy them by traps.
The diſeaſes of vegetables may be divided into thoſe, which ap-
pear to originate from internal cauſes, thoſe from the external ele-
ments, and thoſe from the nidifications or depredations of inſects;
to which may be added the depredations of other animals. We ſhall
begin with difeaſed irritability.
DISEASES FROM INTERNAL CAUSES.
I. 1. It has already been ſhewn, that the buds of vegetables are
individual beings, and conſtitute an inferior order of animals; and
that they poffefs irritability, and fenfibility, and voluntarity, and have
aſſociations of motion ; as explained in Zoonomia, Vol. I. Sect. XIII.
But as the three latter kinds of excitability are poſſeſſed in a fo much
leſs

Sect. XIV. 1. I.
317
OF PLANTS.
leſs degree by vegetable buds, than by more perfect animals, we ſhall
only conſider the diſeaſes of their irritability,
M. Girtannir endeavoured to ſhew, that animal irritability originates
from the oxygen, which conſtitutes ſomewhat leſs than a third of
the atmoſphere, which they breathe. And M.Van Ular has applied
the ſame idea to vegetable life; and has endeavoured to ſhew, that
their irritability alſo originates from the oxygen, which they acquire
either by the reſpiration of their leaves, or by the abſorption of their
roots. And indeed, as reſpiration is every minute neceſſary to animal
life, there is reafon to believe, that ſomething immediately neceſſary
to the exiſtence of life is acquired by the lungs of animals from the
atmoſphere rather than from the food, which they digeſt; and that
this, which is believed to be the oxygen only, is mixed with the
blood, and ſeparated again from it by the brain, and ſpinal marrow,
after having undergone ſome change in the circulation or ſecretion of
it.
In the ſame manner it is not improbable, but that the fpirit of ve-
getation may have a ſimilar origin, probably from the uncombined
oxygen of the air, reſpired by the upper ſurfaces of their leaves; and
not from that, which is abforbed by their roots in a more combined
ftate; and that this oxygen is again ſeparated from their juices by
the ſenſorium, or brain, of each individual bud, after having under-
gone ſome change in the circulation or ſecretion of it. See Sect. IV.
a
1.2.
The circumſtances attending vegetable irritability are ſimilar to
thoſe belonging to the irritability of animals upon a leſs extenſive
fcale, as detailed in Zoonomia, Vol. I. Sect. XII.
When vegetable fibres have been long ſtimulated more than na-
tural or uſual by increaſe of heat, the ſpirit of vegetation becomes ex-
haufted ; and in conſequence a ſlighter degree of cold will deſtroy
them; becaufe their fibres after having been long excited by a greater
ſtimulus will ceaſe to act on the application of one, which is much
lefs ;
4

318
Sect. XIV. I. I.
DISEASES
leſs; whence after hot days tender plants are more liable to be de-
ſtroyed by the coldneſs of the night. Whence in more northern cli-
mates the gardeners fhade their tender vegetables, as the flowers of
apricots, in the ſpring-froſts from the meridian ſun, as well as from
the coldneſs of the night; which is generally the greateſt about an
hour before ſunriſe.
In the hot days of June 1798 I twice obſerved ſeveral rows of gar-
den beans become quite ſickly, and many of them to die, from being
flooded for an hour or two with water from a canal in the neigh-
bourhood; which I aſcribed more to the ſudden application of too
great cold, after being much enfeebled, or rendered inirritable, by the
exceſſive heat of the ſeaſon, than to the too copious ſupply of water to
the dry ground; to which ſhould be added, that ſome plants are more
liable to be thus injured than others; as the ſtrawberries, young cab-
bage plants, and onions, which were in the ſame ſituation, received
benefit and not deterioration by being thus occaſionally watered in
that dry ſeaſon.
On the contrary, when plants have been long expoſed to a leſs
ſtimulus of heat than natural or uſual, the ſpirit of vegetation be-
comes accumulated; and if they are too ſuddenly ſubjected to much
greater heat, their too great increaſe of action induces inflammation,
and conſequent mortification, and death; as occurs to thoſe people,
who have had too much warmth applied to their frozen limbs. Ex-
periments of this kind were inſtituted by Van Ular; he increaſed the
irritability of euphorbia peplus and eſula by ſecluding light and heat
from them; and, when he expoſed them to a meridian ſun, they be-
came gangrenous, and died in a ſhort time.
This greater or leſs irritability of plants is to be aſcribed to their
previous habits in reſpect to the ſtimulus of greater or leſs heat. Thus
the times of the appearance of vegetables in the ſpring ſeem occaſion-
ally to be influenced by their previouſly acquired habits, as well as by
their preſent ſenſibility to heat. For the roots of potatoes, onions,
a
will

SECT. XIV. 1.1.
319
OF PLANTS.
a
will germinate with much lefs heat in the ſpring than in the au-
tumn; as is eaſily obſervable, where theſe roots are ſtored for uſe;
and hence malt is beſt made in the ſpring, as the barley will then ger-
minate with a leſs degree of heat.
The grains and roots brought from more ſouthern latitudes ger-
minate here ſooner than thoſe, which are brought from more nor-
thern ones, owing to their acquired habits. Fordyce on Agriculture.
It was obſerved by one of the ſcholars of Linneus, that the apple
trees ſent from hence to New England bloſſomed for a few years too
early for that climate, and bore no fruit; but afterwards learnt to ac-
commodate themſelves to their new ſituation. (Kalm's Travels.)
Vines in grape houſes, which have been expoſed to the winter's
cold, will become forwarder and more vigorous than thoſe, which
have been kept during the winter in the houſe. (Kennedy on Gar-
dening.) This accounts for the very rapid vegetation in the northern
latitudes after the ſolution of the ſnows.
The increaſe of the irritability of plants in reſpect to heat, after
having been previouſly expoſed to cold, is farther illuſtrated by an ex-
periment of Dr. Walker's. He cut apertures into a birch-tree at dif-
ferent heights; and on the 26th of March fome of theſe apertures
bled, or oozed with the fap-juice, when the thermometer was at
39; which ſame apertures did not bleed on the 13th of March, when
the thermometer was at 44. The reaſon of this I apprehend was, be-
cauſe on the night of the 25th of March the thermometer was as low
as 34 ; whereas on the night of the 12th of March it was at 41;
though the ingenious author aſcribes it to another cauſe. Tranſact. of
the Royal Society of Edinburgh, V. I. p. 19.
There is an obſervation in Mr. Tull's work, which he ingeniouſly
afcribes to the acquired habits of plants. “ By the extremely hard
winter of the year 1708 or 1709, ſome lucern in Languedoc was
killed, along with all the olive trees and walnut trees by the ſeverity
of the ſeaſon ; though I could not hear that one walnut tree was
3
killed
a

320
DISEASES Secr. XIV. 1. 2.
2
killed in England. Perhaps thoſe in France having been accuſtomed
to much hotter ſummers were unable to endure the rigour of the
fame winter, that did not deſtroy the ſame plants in England."
Horſe-hoeing Huſbandry, Ch. XIII. p. 201.
By adapted experiments Medicus is ſaid to have found, that the
irritability of plants is greater in the morning, leſs in the middle of
the day, and much leſs in the evening. And Von Uſar found, that
their irritability in reſpect to their contractions was increaſed in cool
and rainy weather. Obferv. on Plants by Schmeiſſer. Edinb. So the
parts of animals become more ſenſible to heat after having been pre-
viouſly expoſed to cold; as our hands glow on coming into the
houſe after having for a while been immerſed in ſnow; and many
inſects, and other animals, which hide themſelves in the earth, and
ſleep during the winter, were obſerved by M. Spallanzani to diſappear
at a ſeaſon, when the heat of the atmoſphere was much higher
than in the ſpring, when they again made their appearance.
Hence it follows, that plants, which are kept in a warm room
during winter, ſhould occaſionally be expoſed to cooler air to increaſe
their irritability; as otherwiſe their growth in the ſpring is obſerved
to be very tardy. Mankind for the ſame reaſon requires the perpe-
tual variations of the heat of the atmoſphere to preſerve or reſtore the
irritability, and conſequent activity, of the ſyſtem. Whence the
health and energy of men are greater, and their lives longer, in this
variable iſland, than in the tropical continents, which poſſeſs greater
warmth, and leſs variation of weather.
2. Linneus in the Philoſophia Botanica has given names to but
four internal diſeaſes, euriſiphe, mildew ; rubigo, ruft ; clavus, ergot,
or ſpur; and uſtilago, ſmut; to which may be added many others as
deſcribed below.
Eryſiphe, a white mucor, or mould, or mildew, with feffile
tawny heads, with which the leaves are ſprinkled; this is frequent
in humulus, hop; lamium, dead nettle; gallopſis, arch-angel ; li-
thoſpermum,

Sect. XIV.1.3.
OF PLANTS.
321
thoſpermum, ſtone-ſeed; and acer, maple. This mucor is a plant
of the fungus kind, which will grow without light, or change of
air, like other funguſes; and with its roots penetrates the veſſels of
the vegetables to which it adheres. But theſe veſſels are probably
previouſly injured by internal diſeaſe. The methods of preventing or
deſtroying it muſt conſiſt in thinning the plant, or removing thoſe
in its vicinity, ſo as to admit more light, and greater ventilation,
which may at the ſame time eradicate the mildew, and reſtore the
internal vigour of the plant.
As the greater dampneſs of fome land ſupplies one permanent
cauſe of mildew, as well as its being too much overſhadowed by
thick foliage, the methods of prevention muſt confiſt in properly
draining the land, and uſing drier kinds of manure, as coal-aſhes and
bone-aſhes, as well as by thinning the crops. And laſtly, it is re-
commended to fow early in the ſeaſon for the purpoſe of procuring
forward crops ; as this diſeaſe is ſaid more to injure late crops owing
to the greater dampneſs of the ground in autumn.
3. Rubigo, ruft, a ferruginous powder ſprinkled under the leaves,
frequent in alchemilla, lady's mantle, rubus ſaxatilis, effula degener;
and particularly in ſenecio or jacobæa; and eſpecially in a burnt woody
foil.
This is probably another fungus ſimilar to the former, or to ſome
kinds of lichen, which grows beneath the leaves of vegetables pre-
viouſly diſeaſed, and may probably be prevented or deſtroyed by ex-
poſing the plant to more light, and greater ventilation, as in the mucor
above mentioned.
An account is given by Mr. Lambert in the Tranſactions of the
Linnean Society, Vol. IV. of a diſeaſe which may probably be ſome-
what fimilar to the rubigo, which he calls uredo frumenti, or blight
of wheat, and deſcribes it to be a fungus, which covers the ſtems of
wheat in wet ſeaſons, when it is nearly ripe, ſo as to give the field
an appearance of being covered with foot. The ſtem of the wheat is
Tt
ſaid
a
a

32:2
SECT. XIV. 1.4.
DISEASES
ſaid to appear to be ſplit, and the growth of the plant to be much
injured. He deſcribes the fungus to be linear-oblong, tawny-black.
4. Clavus, ergot, or fpur, occurs when ſeeds grow out into large
horns, black without, as in fecale, rye, and in carex. This diſeaſe
frequently affects the rye in France, and ſometimes in England, in
moiſt ſeaſons, and is called ergot, ſpur, or horn-ſeed; the grain be-
comes conſiderably elongated, and is either ſtraight or crooked, con-
taining black meal along with the white; and is ſaid to appear to be
pierced by inſects, which are ſuppoſed to caufe the diſeaſe.
Mr. Duhamel aſcribes it to this cauſe, and compares it to galls on
oak-leaves; but this has not yet been eſtabliſhed by ſufficient obſer-
vations. By the uſe of this bad grain amongſt the poor,
diſeaſes have
been produced, attended with great debility, and mortification of the
extremities, both in France and England. Diet. Raiſon. Art. Siegle.
Philof. Tranſact. Vol. LV. 106.
5. Uſtilago, ſmut, when the fruit inſtead of ſeed produces a black
meal, as in wheat, barley, oats, ſcorzonera, tragopogon. Much is
ſaid on this diſeaſe in the Dict. Raiſon of Bomare. Art. Bled, who
recommends ſteeping the grain, before it is ſown, in brine; which is
generally directed to have fo much ſalt added to the water, as may
increaſe its ſpecific gravity, till an egg will ſwim in it; or ſecondly,
to ſteep the feed-wheat in lime water; or thirdly, which he thinks
moſt efficacious, in an alkaline ley made by adding pot-aſh to lime-
water.
manney"
a
In the ſyſtema naturæ of Linneus under the article Vermes, Zoo-
phyta, Chaos uſtilago, there is a quotation from Munchhauſen, that
the uſtilago is a black powder, which is found in the deſtroyed grains
of barley, wheat, and other graſſes; and in the florets of tragopogon
fcorzonera. And that this powder being macerated in warm water
for ſome days paffes into oblong animalcules, hyaline in reſpect to
colour, and playing about like fith, as may be ſeen by a microſcope ;
and

Sect. XIV. 1. 5.
323
OF PLANTS.
and are again mentioned in Linneus's diſſertation on the inviſible
world.
There is an ingenious paper in the publications of the Bath Society,
in which the author obſerves, that the ſmut in wheat only happens,
when wet weather occurs at the time of the flowering of the wheat ;
which may burſt the anthers, and waſh away the farina. He thinks
that ſteeping the wheat in brine or lime water is an ancient error, and
can be of no uſe but to ſeparate light wheat from that which is good.
For he found ſmutty ears and good ones growing from the ſame
root; and thence it could not depend on any contagious material, or
inſects eggs, adhering to the ſeed; and in ſome even the fame ear
contained both ſound and ſmutty corns. And laſtly, that ſome of the
corns had one end ſmutty, and the other ſound; and he concludes,
that it muſt be owing to the want of impregnation from the defect of
the farina fecundans; and that the putrefaction ſucceeded the death
of the grain.
From the obſervations of Spallanzani on leguminous plants the
probability of this opinion is much confirmed. He found that the
feed was produced by the female organ of the plant, long before it
was impregnated; which could not happen, till the flower was open,
and the anther-duſt ripe. Whence it is eaſy to conceive, that for
want of impregnation, or the vivifying principle, the wheat-corn
muſt putrefy like the addle eggs of poultry, which are unimpregnat-
ed, and thence die, and in conſequence putrefy.
If this diſeaſe of ſmut ſhould become a ſerious evil, it might poſ-
fibly be prevented by fowing the grain in diſtant rows; and after
ſome days fowing other rows between them of the ſame, or of ano-
ther kind of wheat; by which means, if wet weather ſhould deſtroy
the anthers of one ſet of rows, the alternate ones might ſupply fa-
rina to their ſtigmas, if the weather became favourable. See Sect.
XVI. 8. 2.
Wheat diſcoloured by ſmut may be waſhed, and readily dried on
a
Tt 2
a malt

324
SECT. XIV. 1.6.
DISEASES
a malt kiln, and may be thus eaſily made marketable and equally
good; for the living grain will not abſorb much water in a ſhort
time; or it may be mixed with clean fand, and after being well agi-
tated the fand may be ſeparated by a riddle; and if neceſſary the
ſame fand may be waſhed and dried for repeated uſe.
6. Beſides the four internal diſeaſes above ſpoken of, as mentioned
by Linneus; and the uredo of Mr. Lambert, there are probably many
others, which have not yet been ſufficiently attended to, as the canz-
ker, gangrena; the honey-ſweat, exſudatio mellita ; the miliary
ſweat, exſudatio miliaris; the ſap-flow, fluxus umbilicalis; and the
gum ſecretion, ſecretio gummoſa.
The canker, which may be termed gangrena vegetabilis, is a pha-
gedenic ulcer of the bark ; which is very deſtructive to apple-trees,
and pear-trees, as it ſpreads round the trunk or branches, and de-
ſtroys them.
Mr. Knight has obſerved this diſeaſe to be moſt frequent and fatal
to thoſe trees, the fruit of which has been long in faſhion; as they
have been perpetually propagated for a century or two by ingrafting;
which he believes to be a continuation of the old tree, though nou-
riſhed by a new ſtock; and that the canker is thus a diſeaſe of old
age, like the mortification of the limbs of elderly people, and ariſes
from the irritability of a part of the ſyſtem.
But it ſeems more probably to be an hereditary diſeaſe, as the buds
of trees being a lateral progeny, and more exactly reſembling their
parents, muſt be more liable to the diſeaſes gradually acquired or in-
creaſed by the influence of ſoil or climate ; and have not the proba-
bility of improvement, which attends the progeny of ſexual genera-
tion.
It is nevertheleſs frequently produced on trees by external violence,
as by a ſtroke with a ſpade by a careleſs labourer, who is digging near
them; but this probably may more eaſily affect the old grafts above
mentioned. When a deſtruction of the bark is thus produced by ex-
ternal
a

SECT. XIV. 1.7
325
OF PLANTS.
a
ternal violence, it may poſſibly be cured by the application of a piece
of living bark from a leſs. valuable tree, bound on as mentioned in
the next article, and in Sect. XVII. 3. 10.
The edges of theſe gangrenous ulcers of the bark ſhould be nicely
pared with a knife, ſo as to admit the air, and to prevent the de-
predations of inſects and the lodgment of moiſture, which might
promote the putrefaction of the ſtagnant juices, and ſpread the gan-
grene; this ſhould be ſo managed as only to cut away the dead lips
of the wound, but not ſo as in the leaſt to injure the living bark.
Some thick white paint may then be ſmeared on the naked albur-
num or ſap-wood on a dry day, which may prevent inſects from ine
ſerting their eggs into it, and produce maggots, which erode and
deſtroy the wood; and may alſo prevent the dews and rains from
rotting it. The paint ſhould nevertheleſs be ſo ſpread, as not to
touch the edges of the wound; as it might injure their growth by its
poiſonous quality; a quarter of an ounce of ſublimate of mercury,
hydrargyrus muriatus, rubbed with about a pound of white lead
paint, might render it-more noxious to inſects. See Sect. XVII. 3.
9. and 10.
7. The honey-dew, which may be called ſuffufio mellita, conſiſts
of a ſaccharine juice, which I have ſuppoſed to be exſuded from the
tree by the retrograde motions of the cutaneous lymphatic veſſels,
connected either with the common ſap-veſſels deſcribed in Sect. II.
or with the umbilical veſſels deſcribed in Sect. III. 2. 8. inſtead of its
being carried forwards to increaſe the growth of the preſent leaf-
buds, or to lay up nutriment for the buds, which are in their em-
bryon ſtate ; and may thus be compared to the diaboetes mellitus, or
to the ſweating ſickneſs of the laſt century.
The ſaccharine and nutritious quality of the honey-dew, ſimilar
to that of the ſap-juice, which riſes in the vernal months from the
birch and maple, is evident from its taſte; and from the number of
bees and ants, which are ſaid to feed on it, when it appears on ſome
trees ;
a

326
SECT. XIV. 1.7.
DISEASES
trees; and which ſhews, that its exſudation muſt be conſiderably
injurious to the tree, as before mentioned in Sect. VI. 6.
3.
In a paper written by the Abbé Borſſier de Sauvages, he deſcribes
two kinds of honey-dew; one of which he concludes to be an exſu-
dation from the tree, and the other he afferts to be the excrement of
one kind of aphis, which the animal projects to the diſtance of ſome
inches from its body on the leaves and ground beneath it; and which
he believes the animal acquires by piercing the ſap-veſſels of the
leaf. This paper is detailed in Wildman's work on Bees, p. 46.
The circumſtances are diſtinctly deſcribed, and by ſo great a philoſo-
pher as Sauvages of Montpellier, that it is difficult to doubt the au-
thenticity of the fact. But that a material ſo nutritive ſhould be pro-
duced as the excrement of an infect is ſo totally contrary to the
ſtrongeſt analogy, that it may nevertheleſs be ſuſpected to be a mor-
bid exſudation from the tree; though theſe inſects might occafion-
ally prey upon it, and void it almoſt unchanged at thoſe ſeaſons, be-
cauſe the inſects continued ſome months after the honey-dew ceaſed,
and before it commenced, as mentioned below; and the upper ſur-
faces of the leaves became covered with a black powder, which had
before been covered with the honey-dew. And laſtly, becauſe on
other trees, as on the peach and nectarine, at other ſeaſons of the
year, no honey-dew is perceived, though the aphis much abounds to
the great injury of the trees.
Early this morning, June 18, 1798, I obſerved a remarkable ho-
ney-dew on an extenſive row of nut-trees, corylus avellana, which
grow by the ſide of a pond of water; the ſun ſhone bright, and the
upper ſurface of every leaf, which was illumined by the ſun, was
covered with a viſcid juice, which taſted as ſweet as diluted honey.
From many of theſe leaves large drops hung from the point, and dur-
ing that day and the following one much of this honey dropped down
ſo as to moiſten the gravel walk beneath the branches of every tree,
and ſeemed more fuid as the ſunſhine became warmer; and the
leaves,
a

SECT. XIV. 1.7.
327
OF PLANTS.
leaves, which were concealed from the ſun, appeared to have leſs of
the honey-dew, and ſome of them none of it.
How long this honey-dew had continued before I obſerved it, I
cannot tell, but probably many days, as the weather was then, and
had been uncommonly dry and warm, and ſhining; and after two or
three days, when the weather changed, the morbid exſudation, if
ſuch it was, or the excrementitious depoſition of this viſcid honey,
became checked and gradually diſappeared.
Beneath every leaf of this extenſive hedge of filberts I diſcerned
fifty or a hundred aphiſes of all ſizes, and many of them had wings;
but I could not perceive, that any of them had been on the upper
ſurfaces of the leaves, where the honey only exiſted; nor were any
bees, or butterflies, or ants, about theſe leaves; on which they muſt
have adhered, if they had ſettled ; which poſſibly they were aware
of, as a hive of bees was at no great diſtance.
M. Duhamel obſerved a ſimilar ſweet juice drop in ſuch quantity
from willows by the ſide of a river in very hot and dry weather, that
children were buſy in catching or gathering it, and that it taſted like
manna, but was more agreeable. He alſo mentions its dropping from
nut-trees. Phyſique des arbres, Vol. I. p. 150. M. Reneaume, in
the Memoires of the Academ, des Sciences, obſerved a ſimilar exſu-
dation from the maple, and fycamore; and adds, 1. That it was
unctuous and ſweet. 2. That it was in the greateſt quantity on the
leaves expoſed to the fun, which appeared wet on their upper ſur-
faces; and that it was not ſeen before fun-riſe. 3. That bees col-
lected it as anxiouſly as common honey. 4. And that ſome leaves-
died, whoſe diſcharge was very great. 5. That it exiſted in a very
dry and hot ſeaſon. But neither of theſe philoſophers ſpeak of its
being attended by the aphis.
The aphis this year was uncommonly numerous, the leaves of the
peach and nectarine trees were half of them deſtroyed by this pernio
cious inſect, and became bliſtered and curled I ſuppoſe by their pune-
6
tures,
a

328
DISEASES
SECT. XIV. 1.7.
a
tures; which were made fome weeks earlier in the year, and by an
aphis without wings, and differing ſomewhat in their ſhape, but
without any appearance of honey-dew on thoſe trees. But I could
not diſcover any punctures or other diſeaſe of the leaves of theſe nut-
trees, and therefore doubt whether theſe inſects, though ſo numer-
ous on the under ſurface of every leaf, could be the cauſe of the mor-
bid exſudation, if ſuch it was, on their upper ſurfaces; and the more
as I could not diſtinguiſh, that they preyed upon the honey thus
produced ; and I afterwards obſerved that they continued in immenſe
numbers under every leaf, when the weather became cooler, and
moiſtes, and the honey-dew ceaſed to be viſible. But after a few
weeks I obſerved the upper ſurface of every leaf became covered with
a black powder like foot; whether this was a new material, or re-
mained after the exhalation of the honey-dew, I did not determine by
experiment. But if both the honey-dew and this ſubſequent black
powder on the upper ſurfaces of the leaves, were the excrement of
the aphis on the under ſurfaces of the leaves over the former, or ow-
ing to an exſudation from the tree, muſt be determined by further
obſervations.
But as a ſecond period of fap-flow is believed to exiſt about mid-
fummer, or a depoſition of vegetable nutriment for the new buds, as
deſcribed in Sect. III. 2. 8. there is reaſon to ſuſpect, that the ho-
ney-dew is owing to the inverted action of the external lymphatics
occaſioned by the debility induced by the continued heat, and per-
haps to the moiſture of ſituation. Whence the nutritive fluid is
thrown upon the external habit inſtead of being applied to nouriſh
the new buds, or to be laid up as a reſervoir for their uſe. And that
if it be voided by the aphis, it is owing to their puncturing the fap-
veſſels with the fine proboſcis, which they poſſeſs, at this ſeaſon only,
or in a diſtempered ſtate of the tree, and drinking more of it than
they are able to digeſt. For a further hiſtory of this inſect fee No.
3. 2. of this Section.
8. Exſudatio
a

Sect, XIV. 1. 8. OF PLANTS.
329
3.12.
8. Exſudatio miliaris, miliary ſweat, appears to be produced by
too great and continued heat, as it exiſts on vines in hot-houſes,
which are kept too warm, or too cloſe in reſpect to their ventila-
tion.
This fecretion has not the ſweet taſte like that of the honey-dew,
but conſiſts of mucilage ; which, as the watery part evaporates by
heat, remains on the plant in very ſmall round hard globules, like
millet feeds, whence their name. I once witneſſed a very ſimilar ap-
pearance of minute hard round globules on the ſkin in a miliary fe-
ver, which eaſily were rubbed off with the finger; and were proba-
bly occaſioned, as in this vegetable diſeaſe, by too great heat, and the
excluſion of air, as deſcribed in Zoonomia, Vol. II. Claſs 2. 1.
In the evaporation of perſpirable matter, which in its diſeaſed ſtate
may be more mucilaginous than natural, in confined bed-rooms or
hot-houſes, I ſuppoſe, the aqueous part only is exhaled, and the mu-
cilaginous part remains in the form of a globule ; in the ſame man-
ner as ſtalactites are formed on the roofs of caverns from a ſolution of
calcareous earth in water, ſimply by the evaporation of the water.
9. Fluxus umbilicalis, fap-flow, this occurs, when the alburnum
or fap-wood of trees is wounded in the vernal months, as in birch
and maple, deſcribed in Sect. III. 2. 2. and conſiſts of a faccharine
and mucilaginous fluid ſimilar to the honey-dew, or ſuffufio mel-
lita ; and is often very troubleſome, when vines in hot-houſes are
pruned too late in the ſeaſon, as the whole branch is liable to bleed
to death, owing thus to the loſs of the fap-juice, which ought to be
employed in nouriſhing the young buds, and expanding their leaves.
When ſome perennial plants have riſen but a certain height from
the ground, if their ſtems are much wounded, or cut off, the roots
are liable to bleed to death from this diſcharge of the umbilical fluid,
or ſap-juice, which ought to have nouriſhed and expanded the new
buds and foliage ; as may be ſeen in cutting down the heracleum
fpondylium, cow parfnep, in April ; and on this account it has been
recommended
a
a
U u

330
Secr.XIV.1.13.
DISEASES
a
recommended to mow down thiſtles, and other weeds, which are
troubleſome from their numerous increaſe, early in the ſpring; as
many of them will then die, and the reſt be much weakened by the
fap-flow, which attends their wounds at that ſeaſon.
In reſpect to trees another period of ſap-flow is ſaid to exiſt, when
the new buds are forming after Midſummer, as ſpoken of in Sect. III.
2.8. Whence wounds at this ſeaſon alſo muſt be injurious; where
this loſs of fap-juice occurs in hot-houſes various applications have
been recommended by gardeners. I ſuſpect that a bit of ſponge bound
upon the end of the cut branch, or on the wound, by means of ſome
elaſtic bandage, muft be the moft certain application ; or a wire
twiſted round the end of the branch cut off, ſo tightly as to ftrangu-
late the whole circulation of juices, and conſequently deſtroy the
part above the ligature.
10. Secretio gummofa, gum fecretion, a morbid production of
gum, which differs from the ſap-juice above deſcribed, as it contains
no ſaccharine quality, though like the former it exſudes from the
wounded alburnum of deciduous trees; whether the wound be ori-
ginally cauſed by internal diſeaſe, or by external violence, as men-
tioned in the gangrene of the bark above deſcribed.
Where this happens to cherry-trees, prunus ceraſus, a gum ex-
fudes like gum arabic; which in dry weather hardens, as it adheres,
and thus prevents the further diſcharge of this nutritive material;
otherwiſe the tree weeps away its life, periſhing from deficient nou-
riſhment. In fimilar manner a. reſin is emitted from the injuries or
wounds of pine-trees, and ſome other evergreens, with great injury
to the growth, or the deſtruction of the tree.
This exſudation of the gum or reſin of trees, as it happens chiefly
in fummer, is probably a part of nutritious fluid deſigned for the new
buds, which in moſt deciduous trees are formed about this time, and
fhould be prevented from continuing to flow by binding on the party.
previouſly made ſmooth by a knife, a metallic plate, as of the lead
in

Secr. XIV. 2.1.
331
OF PLANTS.
in which tea is wrapped, ſo as to prevent rain or dew drops from dif-
folving the indurated gum. A bit of ſponge, or of ſoft leather, or
of Indian rubber, caoutchouc, might be bound on under the lead,
till the wound is healed. Might not a ſtrong ſolution of green vitriol
in water, or ſome ink, if applied to the extremities of theſe bleeding
veſſels, ſtimulate them into contraction, and prevent the further ef-
fuſion of gum?
Another method might be worth trial, which is mentioned in
Sect. XVII. 3. 10. A piece of bark from a ſimilar tree of inferior
value might be cut out, ſo as nicely to fit the wounded part, after its
edges were nicely ſmoothed, and might be tied on by a proper ban-
dage, as the liſting cut from the edges of cloth, or flannel, ſo that
its elaſticity might ſecure a perpetual preſſure without injury.
11. DISEASES FROM EXTERNAL ELEMENTS.
3
1. In climates liable to inceſſant rains or perpetual drought for a
length of time many diſeaſes of vegetables muſt originate from the
exceſs of moiſture, or to the want of it ; which are not very frequent
in this country. In moiſt ſeaſons the leaf-buds of plants, as of grafs
and corn, as well as of trees and perennial vegetables, grow too lux-
uriantly; and the flowers and conſequent fruits or ſeeds are later,
and contain more aqueous, and leſs mucilaginous and ſaccharine
matter.
On the contrary, in dry ſeaſons the leaf-buds are leſs vigorous, and
therefore in leſs quantity, as the crops of hay, and the quantity of
ſtraw; but the fruits and feeds ripen earlier, and are of more grate-
ful flavour, and more nutritious.
2. The effect of heat on vegetation is ſpoken of in Sect. XIII.
The exceſs.of that element is ſeldom much injurious to the
vegetation of this country, unleſs it may contribute to increaſe the
dryneſs of the ſoil, when there is a ſcarcity of moiſture. But the de-
U 1 2
feet
2. 2.

332
SECT. XIV. 2. 3.
DISEASES
fect of the element of heat, or in common language exceſs of cold,
is frequently deſtructive to the early ſhoots of the afh, fraxinus, and
to the early bloffoms of many fruit-trees, as apples, pears, apricots;
as theſe are either more ſucculent, or have lefs irritability, or more
ſenſibility; on both which accounts they are more liable to be diſ-
eaſed by cold.
The blights occafioned by froſt generally happen in the ſpring,
when cold nights ſucceed to warm ſunny days, as the living power
of the plant has then been previouſly exhauſted by the ſtimulus of
heat, and is therefore leſs capable of being excited into the actions,
which are neceſſary to vegetable life, by the greatly diminiſhed fti-
mulus of a freezing atmoſphere.
In ſome norihern climates, where the long ſunny days ſucceed the
diffolving of the ſnows, as in Denmark and in Ruſſia, the gardeners
are ſaid to ſhelter their wall-trees from the meridian fun in the ver-
nal months; which preſerves them from the cold of the ſucceeding
night; and by preventing them from flowering too early avoids the
danger of the vernal froſts.
The deſtruction of the more ſucculent parts of vegetables, as their
early ſhoots, and that eſpecially when expoſed to froſty nights, was
ſpoken of in Sect. XIII. 2. 2. and can only be counteracted by co-
vering them from the deſcending dews or rime by the coping-ſtones
of a wall, or matts of ſtraw.
3.
The blaſts occafioned by lightning are more frequent, I be-
lieve, than is uſually ſuppoſed; as I am informed by thoſe, who
purchaſe extenſive woods, that very many trees on being ſawed
through are found cracked, and much injured by lightning. I had
laſt year a ſtandard apple-tree, and a tall apricot-tree, in full leaf
blaſted at the ſame time by lightning, as was believed. They both
loſt all their leaves; the apple-tree nevertheleſs put out a new fo-
liage, and recovered, and bore fruit this year ; but the apricot, which
was nailed to a high wall, never ſhewed any returning life.
Mr.
a

SECT. XIV. 2.3. OF PLANTS.
333
Mr. Tull aſcribes one injury to the health of wheat plants, and fre-
quently their death, to lightning; the effects whereof, he ſays,
may be obſerved by the blackiſh parts or patches viſible in a field of
wheat, eſpecially in thoſe years which have more thunder-ſtorms
than uſual, and adds that againſt this there is no remedy.
The erection of frequent metallic points could alone ſecure a garden
or field from this misfortune; which probably occurs more frequently
on damp ſituations, than on dry ones ; as mentioned in the account
of Fairy Rings in Botanic Garden, Vol. I. note XIII.
The manner in which lightning deſtroys the life of vegetables
may be fimilar to that, in which it deſtroys animal life; which is I
ſuppoſe by its great ſtimulus exhauſting the ſenſorial power in the
violent action it occaſions, and thus producing total inirritability to the
common ſtimuli, which ought to excite the vital actions of the fyf-
tem ; fimilar to which, though with leſs expedition, ſeems to be the
effect of ſome poiſons on the animal ſyſtem, as the diſtilled water of
lauro-ceraſus, a ſolution of arſenic, the contagious matter of fevers,
and even a common emetic; all which by their ſtrong ſtimulus ſeem
almoſt inſtantaneouſly to render the ſtomach, and other parts of the
ſyſtem, nearly or entirely inirritable, or diſobedient to their natural
ſtimuli.
It
may alſo affect vegetables in another way ſimilar to that, which
probably alſo happens, when their young ſucculent ſhoots are frozen;
that is, by burſting their veſſels, as it paſſes through them, by its
expanſive power; as happens to the large branches of ſome trees,
and to ſtone-buildings, and other bad conductors of electricity, when
they are ſtruck with lightning.
The expanſive power of electricity is not only ſhewn by trees and
towers being rent by lightning, but by the found, which ſucceeds the
paſſage of it through air; ſince a vacuum, or nearly a vacuum, in re-
fpect to air muſt previouſly be made by the preſence of the electric
Auid ; and the ſides of this vacuum ruſhing together, when the
ſtream

334
DISEASES Sect. XIV. 2. 4.
ítream has paſſed, occaſions the conſequent vibrations of the air, which
conſtitute found, whether in the audible ſpark of electricity, or the
tremendous craſh of thunder. See Sect. XIII. 3.
4. The element of light, as well as that of heat, is neceſſary to ve-
getation. In this climate they both ſeem in general to be injurious
only by their defect, and ſeldom by their exceſs. But as light acts as
a ſtimulus on the more irritative or ſenſitive parts of plants, which
appears by the expanſion of many flowers, and of ſome leaves, when
the ſun ſhines on them; and by the nutation of the whole flower, as
of the ſun-flower, helianthus; and by the bending of the ſummits of
all plants confined in houſes towards the light; there may be diſeaſes
owing to the exceſs of this ſtimulus, which have not been attended
to; to prevent which the flowers of tragapogon falſafi, and of other
plants, cloſe about noon. Other unobſerved diſeaſes may be owing
to a defect of the ſtimulus of light; as a mimoſa, ſenſitive plant,
which I had confined in a dark room, did not open its foliage, though
late in the day, till many minutes after it was expoſed to the light.
The exceſs of light has not been obſerved to be attended by vege-
table diſeaſes in theſe more northern latitudes; but the diſeaſe pro-
duced by the deficiency of it, which is termed etiolation, or blanching,
has been ſucceſsfully uſed to render ſome vegetable leaves and ſtalks
eſculent by depriving them of much of their acrimony, and of their
coheſion, as well as of their colour; as is ſeen in the blanching of
celery, apium; endive, cichorium; cinara, cardoon; ſea-cale,
crambe.
The following method of the growth and etiolation of fea-cale is
tranſcribed from the letter of a friend ; to which ſhould be added,
that the young heads of this vegetable without blanching are equal
or ſuperior to moſt kinds of brocoli, braſſica. “ Sea-cale feed ſhould
be ſowed the latter end of March or beginning of April in drills,
and then earthed up. In autumn it ſhould be tranſplanted into high
beds, one row of roots in a bed, about a foot afunder, and in the
a
winter

SECT. XIV. 2. 5.
335
OF PLANTS.
winter it ſhould be covered up. It muſt be kept dry, that is, the
beds made in the drieſt ground; it is not fit to be eaten till the third
year after it is ſowed. The year before it is eaten it muſt be co-
vered
up in the beginning of winter, firſt with ſtable dung, which
may be kept from preſling on it by a few ſticks placed like a cone
over each root ; then with long litter two or three feet high; the
higher the better, becauſe the more it is forced, the earlier it is fit to
be gathered, and the whiter it will be. It is to be gathered about
the beginning of January, and ſo on till May, one bed being kept
under another. It Tould be boiled and ſent up on toaſt like aſpara-
gus, and is an excellent vegetable, and at an early ſeaſon."
5. The earth, on which vegetables inſert their roots, ſometimes
preſents noxious materials to their abſorbent ſyſtem, as the acidity of
ſome clays; into which when the roots of ſome fruit trees penetrate,
they are ſaid to loſe their health, as mentioned in Sect. II. 9. by
the death or decay or their root-fibres.
Pure filiceous fands alſo prevent vegetation from their containing
no carbonaceous matter, and by their ſo readily permitting the dews
and rains to exhale from them, eſpecially in hotter climates, where
they conſtitute a moving ſurface unfriendly to all organized life.
6. There are alſo noxious exhalations diffuſed in the atmoſphere in
the neighbourhood of ſome manufactories; which are ſaid to injure
the growth or deſtroy the life of vegetables ;, as the ſmoke from the
furnaces, in which lead is ſmelted from the ore, from potteries, and
from lime-kilns; to which may be added the marine ſalt, or marine
acid, which abounds in the too great vicinity of the ſea.
To theſe belong the experiments of Dr. Peſchier of Geneva,,
who immerſed ſeveral plants in vapours of nitrous acid, of volatile
alkali, and of ether, to the great injury or death of the plants. Jour-
nal de Phyſique par Delametherie, T.ii. p. 3450
7. Unwholeſome or poiſonous materials may be applied to vegeta-
bles ſo as to diſeaſe or deſtroy them; as their abſorbent ſyſtems like
thoſe
а.

336
Sect. XIV. 2.8.
DISEASES
thoſe of animals are liable to imbibe many noxious materials, as men-
tioned in Sect. II. 8. A flight ſolution of arſenic, ſprinkled on a
peach-tree in the ſpring, deſtroyed the branches which received it.
A ſolution of liver of ſulphur was equally fatal to the branches of a
nectarine-tree, and alſo oil of turpentine.
Mr. Von Ullar affirms, that watering plants with a due quantity
of oxygenated muriatic acid will increaſe their irritability; and if
carried beyond a certain degree will injure or deſtroy the vegetable
by giving it too much oxygen ; which is known in due quantity
to be a ſalutary material, and the moſt neceſſary of all others to ve-
getable as well as to animal life.
8. There are materials called condiments, which are believed to
poſſeſs ſtimulus without nutriment in reſpect to animal bodies, as
ſpice, ſalt, bitters, as the hop, and probably opium and vinous ſpirit.
Theſe when taken into the ſtomach increaſe its activity, and render
the animal for a time fat, and even ſtrong; but as all increaſe of
ſtimulus, beyond what is natural, is followed by debility; after a time
the animal becomes weak, and emaciated; and enervated in mind as
well as body; as is uniformly ſeen in thoſe who are addicted to the
uſe of much beer and wine, or of opium ; and in a leſs degree where
fpice, or ſalt, or bitters, are taken in too large quantity.
What then ſhall we ſay to the uſe of common falt in agriculture ?
as it is a ſtimulus, which poſſeſſes no nouriſhment, but may incite
the vegetable abſorbent veſſels into greater action; it may in a cer-
tain quantity increaſe their growth by their taking up more nutri-
ment in a given time, and performing their circulations and ſecre-
tions with greater energy. In a greater quantity its ſtimulus may be
ſo great as to act as an immediate poiſon on vegetables, and deſtroy
the motions of the veſſels by exhauſting their irritability.
After a time I ſuſpect vegetables will always be liable to diſeaſe
from this ſtimulating innutritive material ; and that though it may
increaſe the early growth of the plant, it will injure its flowering or
feed-
a

Sect. XIV. 2. 8. OF PLANTS.
337
а
ſeed-bearing; and that hence, if it be uſed at all, it ſhould be a little
before the time, that the plant would acquire that part of its growth,
which is wanted. Thus if the herb or young ſtem only be wanted,
as in fpinage, mercury, aſparagus, apply falt early; if the flower be
wanted, as in brocoli and artichoke, or in tulip or hyacinth, moiſten
them with a ſlight ſolution of falt, when the flower-bud is formed.
When the fruit or ſeed is wanted, as in melons or cucumbers, or
peas and beans, apply the ſolution of ſalt ſtill later, and at all times
with rather a parfimonious hand. See Sect. X. 7. 4.
Similar to this, where animals diſeaſed with ſuperabundancy of fat
are required, it is cuſtomary, I am told, to feed poultry for the Lon-
don markets by mixing gin and even opium with their food, and to
keep them in the dark; but they muſt be killed as ſoon as their cor-
ulency is formed, or they ſoon become weak, and emaciated like
human drunkards. And in ſome countries, as in Languedoc in
France, the livers of geeſe and ducks are required to be enlarged and
difeaſed; as they are reckoned a dainty by modern epicures, as well
as by the ancient ones, who ſpeak of the tumidum jecur anſeris; and
for this purpoſe the animals are kept in the dark, and crammed with
more than their natural quantity of nutriment; but are ſaid to be-
come lean, and to die, if not killed as ſoon as this diſeaſe is
pro-
duced.
It is nevertheleſs to be obſerved, that fea-falt as well as other ſtic
mulating condiments may be advantageouſly uſed as medicines,
though injurious as common food. Thus it is aſſerted by Baron
Schulz in the communications to the board of Agriculture, Vol. I.
Part III. and IV. p. 318, that it deſtroys the faſciola hepatica, or
fewk-worm in ſheep. Some have recommended one ounce of ſalt to
be given every day diffolved in water, but it is probable, it might be
uſed with greater advantage, if hay was moiſtened with the ſolution,
which would thus at the ſame time ſupply them with better nouriſh-
ment
Xx

338
Sect. XIV. 2. 8.
DISEASES
a
a
ment than generally falls to the lot of theſe diſeaſed ſheep, on ſuppo-
ſition that they would eat it.
The rot of ſheep, I ſuſpect, ariſes from the inactivity of the abſor-
bent vefſels of the liver of that animal; whence the bile is too dilute,
eſpecially in moiſt ſeaſons; whence the flewk-worm, as I have ſeen
in the ſhambles, inhabits the common bile-duct, and at length erodes
the liver, cauſing ulcers; which from the ſympathy of the lungs with
the liver occaſions a cough, and a hectic fever from the abſorption
of the matter. Hence the ſalt by its additional ſtimulus may render
the bile leſs dilute by promoting a greater abſorption of its aqueous
parts, as well as a greater ſecretion of it; which however I ſuſpect
would be much more efficacious, if about ſixty grains of iron-filings
made into a ball with flour was given every morning for a week along
with the falt, as further explained in Zoonomia, Part III. Art. 4. 2.
6. 4.
Since writing the above account of common falt as a condiment,
and the probable conſequences attending the uſe of it, I have met
with ſome experiments publiſhed by Lord Kaimes in his Gentleman
Farmer, which ſeem much to confirm the preceding account. He
watered fome Jeruſalem artichokes, helianthus tuberoſus, which
were planted in ſeparate pots, with a ſolution of fixed vegetable al-
kali, others with volatile alkali, others with weak lime water, others
with ſtrong lime water, others with putrid urine, and laſtly others
with water impregnated with putrid animal and vegetable ſubſtances,
I ſuppoſe as they exiſt in a duoghill. All theſe faline ſolutions at firſt
encouraged the growth of the reſpective plants, ſo as much to fur-
paſs thoſe in the pot, which was moiſtened only with common wa-
ter, as a ſtandard to compare the others to; but by additional quanti-
ties of the ſolutions, they all, except the laft, gradually loſt their
vigour, and periſhed in the end, as I ſuppoſe, by the exceſs of fti-
mulus,
There

Sect. XIV. 2. 9.
OF PLANTS.
339
a
There is alſo an experiment in the works of Mr. Anderſon, which
ſeems to ſhew, that common falt poſſeſſes no nutritive quality adapt-
ed to vegetable growth; and that in ſome foils, or to ſome vegeta-
bles, it would ſeem not even to act as a ſtimulus or condiment. He
marked out a circle of fix feet diameter in the middle of a graſs field,
which he diſtinguiſhed by driving a ſtake in the centre; on this circle
he ſtrewed common ſalt, ſo as to lie nearly an inch thick on the
ground. The graſs ſprung up in this circle in the ſame manner as
in the other parts of the ground, and the place could only be diſtin-
guiſhed by the ſtake, though it was left there for ſome years. Encycl.
Britan. Art. Agriculture. See Sect. X. 7. 5. of this work. This ex-
periment is worthy to be repeated, left there might have been fome
miftake attending it; as ſo many authors have given experiments
with contrary reſults; and as ſome other neutral ſalts were ſhewa
to promote vegetation in the experiments of Dr. Home.
9. Some diſeaſes from external violence have been already men-
tioned in this Section, in which the injury is a remote rather than a
a
proximate cauſe of the diſeaſe, as in the canker ſometimes, and the
ſap-flow, and gum-ſecretion. But ſome other diſeaſes from external
violence have been purpoſely produced, as well as that of etiolation,
and turned to advantage ; as the bunches of grapes, which have ac-
quired their full ſize, are ſaid to ripen ſooner, if the ſtalk of the
bunch be cut half through. Tournefort ſays, that the figs in Pro-
vence and about Paris ripen ſooner, if the buds be wounded with a
ſtraw dipped in olive-oil. And laſtly, the figs in the iſland of Malta
are made to ripen ſooner by caprification; as ſpoken of in Botanic
Garden, Vol. II. note on Caprificus. And it may daily be remarked,
that thoſe apples and plums ripen ſooner, which have been wound-
ed by infects; and that pears will ripen conſiderably ſooner, if they
be immaturely plucked from the tree, which muſt be eſteemed in-
jurious to the life of the pear; and as the converſion of auſtere acid
juices of fruit into ſugar in the proceſs of ripening may be in part che-
X x 2
mical,

340
Sect. XIV. 3.1.
DISEASES
mical, it may proceed more haſtily, when the life of the fruit is im-
paired or deſtroyed; as ſeems to occur in the drying of germinated
barley, and in baking pears, as well as in bruiſing apples for the
pur-
poſe of making cyder ; which laſt effect might probably be much
improved by the addition of warmth.
III.
DISEASES OCCASIONED BY INSECTS.
1. Among the diſeaſes of plants Linneus adds in his Philoſophia
Botanica the neſts of thoſe inſects, which depoſit their eggs in plants;
whence a variety of excreſcences. Theſe are, 1. The galls of oak,
of ground-ivy, ciſtus, trembling poplar, willow, and hawk-weed.
2. Bedequar of roſes, or briar-balls. 3. Follicles of piſtachia, and
black poplar. 4. Contortions of ceraſtium, chick-weed, veronica,
ſpeedwell, and lotus. 5. Scales of firs, willows, and roſes.
He then adds, that the duplicature and prolification of flowers is
often occafioned by inſects, as common chamomile, matricaria, is
thus made proliferus; and that carduus caule criſpo bears larger flo-
rets, with the piſtils growing into leaves, by the wounds of inſects.
It muſt be obſerved, that theſe excreſcences on the leaves of ſome
plants, or mutation of their manner of growth, are not always the
conſequence of a fimple wound or puncture of the inſects, but of the
depoſition of their eggs, or young offspring; which afterwards con-
tinue to ſtimulate the growing plant into unnatural motions, and
conſequently into unnatural growth ; like the inflammation and con-
ſequent new granulations of fleſh in the wounds of animal bodies ;
which, if the fkin is prevented from ſpreading over them, will riſe
into large ſubſtances of fungous fleſh; or beneath the ſkin, where it
is looſe, as in wens.
Many flowers are deſtroyed or rendered unprolific by the depre-
dation of inſects, as roſe-buds by the cynips; and I remember ob-
ſerving one dry ſummer, that every bloſſom of a large quince tree
was

SECT. XIV. 3. 2.
341
OF PLANTS.
was pierced by a fly, and rendered unprolific before the bloſſoms had
opened. I have alſo ſeen the hood of the aconite, ſo replete with an
acrid juice, pierced by infects to plunder it of its honey.
2. The curling of the leaves of nectarine, and peach, and cherry-
trees, with the cells or bladders on their ſurfaces, are formed in con-
ſequence of the wounds inflicted by the aphis; in the ſame manner
as the galls and bedeguars on the oak and ſweet-briar by other inſects,
but without their nidification or the depoſition of their eggs; though
from the ſudden and general appearance of theſe injuries they have
been aſcribed to blights from inclement weather.
Some obſervers have believed nevertheleſs, that theſe affected leaves
were previouſly out of health; which occaſioned them to ſupply a
proper ſituation for thoſe infects, which moleft them; as I have fre-
quently obſerved, that ſnails or flugs eat thoſe leaves, which have
been plucked from cucumber plants, and are beginning to wither; in
preference to thoſe, which are growing in perfect health..
Mr. Lawrence relates, that in June the leaves of ſome of his wall!
pear-trees were much injured by a hail-ſtorm, which leaves were af-
terwards blighted, and become full of tumours from inſects; and the
pears, which were then as large as walnuts, all periſhed. On this
Mr. Bradley remarks, that inſects generally lay their eggs on the dead
or putrefying parts both of vegetable and animal bodies; and adds a
conjecture, that the parent inſects may circulate in the juices of the
plant, which however is not probable, as though microſcopic animals
have been diſcovered in the ſtagnating juices of animal bodies, as in
the puſtules of the itch, and in the fæces in the dyſentery, and even in
the ſemen, which may have ſtagnated in the veſiculæ feminales; yet:
no ſuch animalculæ have, I believe, ever been detected in recent blood,
or any recent ſecretions from it.
A predilection for ſome withered leaves appears alſo in larger ani-.
mals as well as in infects; cows will eat young thiſtles, a few hours-
after they are cut down, as their prickles become flaccid; and horſes
refuſe

342
Sect. XIV. 3. 2.
DISEASES
;
refuſe the young ſhoots of yew-trees, as they grow; but will eat
them when they are cut off, and begin to wither; and on that ac-
count loſe a part of their acrimony; though there is ſtill often ſuf-
ficient poiſon within them to deſtroy the animal. And it is even
probable, that when the leaves of yew are withered to a greater de-
gree, their poiſonous acrimony becomes ſo far deſtroyed, that they
ceaſe to be deleterious to horſes; ſo that in Heffe in Germany it is
cuſtomary in the winter to crop the young ſhoots of yew-trees, and
mixing them with other provender to give them as common food to
horſes. See Anderſon on Agriculture, Vol. III. p. 590.
On this account if wall-trees are frequently watered by an engine,
ſo as to moiſten their leaves or branches as well as the ground at their
roots on the dry days in ſpring, by which they will be kept in vi-
gorous growth, I was told, that they would totally or nearly eſcape
the depredations of inſects; but I found by an experiment well con-
ducted on three trees, that this management had no effect; and I alſo
obſerved in the ſpring and ſummer of this year, 1798, which ſeems
to have much favoured the production of the aphis, that they at-
tacked the moſt healthy leaves of peach and nectarine trees, as well
as the others; and that plums, cherries, black currants, and many
other trees ſuffered by their depredations, though previouſly in perfect
vigour. And laſtly, that on repeatedly having waſhed off many thou-
ſands of aphiſes from peach and nectarine leaves by a ſtrong ſtream
from a forcible water-engine, that they evidently crawled again up
the ſtems of the trees, or on the wall to which they were nailed, as
in another day the lowermoſt branches were thus more infeſted with
them than the upper ones.
The hiſtory of the aphis, puceron, or vine-fretter, is ſo curious,
the deſtruction it commits on the foliage of the peach and nectarine
is in dry ſummers ſo irreſiſtible, and its exiſtence on other trees ſo
extenſive, that it demands our particular attention. See No. 1. 7. of
this Section. From the obſervations of Swammerden, Bonnet, Dr.
Richardſon,
a

Sect. XIV. 3. 2.
OF PLANTS.
343
182.
Richardſon, and of other philoſophers, this extraordinary inſect riſes
in the ſpring from eggs, which are ſaid to be attached by the parent
aphis to the twigs of trees in the autumn, and are believed to produce
not a larva or caterpillar, but a progeny finilar to the parent; every
one of which produces in about ten days not an egg, but another liv-
ing progeny to the ninth generation, without being connected amato-
rially with each other. The ninth generation produces males and fe-
males, ſome of both kinds with wings, and others without them ;
and this tenth generation from thoſe, which were hatched from eggs,
become amatorially connected, and produce eggs; which are laid on
the new twigs of various trees for the next year's progeny to be
hatched by the vernal ſun. Philoſ. Tranſact. Vol. LXI.
P.
In this uncommon circumſtance the eggs of the aphis reſemble the
ſeeds of plants; which firſt produce ſome ſucceſſive generations of
leaf-buds, which are a viviparous progeny, before they again pro-
duce ſeeds, which are their oviparous progeny, as mentioned in Sect.
IX. of this work. Nor is this to be aſcribed to what has been
termed equivocal generation, or to an impregnation of nine fetuſes
encloſed within each other, as ſome have ſuppoſed. But this central
production of the viviparous progeny of the aphis ſeems to reſemble
the lateral production of a viviparous progeny from the polypus,
which in time detach themſelves from their parents; like the buds
of the polygonum viviparum, or the bulbs of the magical onion, al-
lium magicum ; which are produced from the flower-cup inſtead of
feeds, and in time detach themſelves, and fall on the ground. So
that theſe aphiſes are not, I ſuppoſe, to be eſteemed fecundated fe-
males, but proliferous males, as explained in Zoonomia, Vol. I.
Sect. 39. on generation.
This double mode of reproduction, fo exactly refembling the buds
and feeds of trees, accounts for the wonderful increaſe of this inſect;
which according to Dr. Richardſon conſiſts of ten generations, and
of fifty at an average in each generation ; ſo that the ſum of fifty
multiplied
3.1.

DISEASES
Sect. XIV.3. 2.
344
multiplied by fifty, and that product again multiplied by fifty nine
times, would give the product of one egg only in countleſs millions ;
to which muſt be added the innumerable eggs laid by the tenth
ge-
neration for the renovation of their progeny in the enſuing ſpring,
Thei pun&tures of the leaves of peach and nectarine trees in the
vernal months, and of cherry, plum, and currant trees in the ſum-
mer, produce a ſwelling and elevation of the cuticle of the leaf on its
upper ſide, and a conſequent curling of it with its upper ſurface out-
wards, which terminates in a deſtruction of it to the great injury of
the tree, and frequently to the death of it ; while the leaves of the
nut-trees, mentioned above, in No. 1.7. of this Section, appeared to
be but little injured by them, though fifty or a hundred of theſe in-
ſects were ſeen under every leaf about Midſummer, both before and
after their affuſion with the honey-dew.
From Dr. Richardſon's account the aphiſes on the roſe-tree ap-
peared in February, when the weather happened to be warm, from
ſmall black oval eggs; which were depoſited on the laſt year's ſhoots
in autumn; and that, when the weather became colder, great num-
bers of them periſhed, by which circumſtance the roſe-trees are in
fome years almoſt freed from them.
They came to their full growth before April, and after having
twice caſt off their exuviæ, every one of them produced about fifty
young ones; all of which came into the world backwards, and ad-
hered ſometime to the vent of the parent by their mouths or fore-
part ; as ſhewn in a magnified ſtate at fig. 2. plate IX; and were at
length ſet down on ſome tender ſhoots of the plant, and came to ma-
turity in about ten days, caſting off their coats two, three, or four
times.
The ninth generation in October conſiſted of males as well as fe-
males, which were ſeen to cohabit; and the eggs produced by their
intercourſe, he afferts, were depoſited generally near the new buds,
or on other parts of the twigs of the trees, which they poffeffed.
8
There

Sect. XIV. 3. 2.
345
OF PLANTS.
;
Theſe were at firſt green, but in a few days became brown, and by
degrees quite black. They were of regular oval figures about one
tenth of an inch in length, and about half as broad, and adhered
firmly by means of ſomething glutinous, and refifted the ſeverity of
the winter.
Other inſects, which are produced from eggs, and become winged
butterflies or moths, live for ſome time in the intermediate ſtate of
caterpillars or larvæ. During this ſtate of their exiſtence they feed on
the leaves, on which they are hatched; or on fruits or kernels; but
after they have acquired wings and organs of reproduction, ſome of
them take no food, as the filkworm; and others live only upon ho-
ney, as bees, and moths, and butterflies. Now the aphis, I ſuppoſe,
has no intermediate ſtate between the egg and the fly, and there-
fore makes no holes in the leaves by eating them ; or if any of them
previouſly exiſt in a caterpillar, or larva ſtate, it can be only thoſe
which are produced from eggs in the early ſpring, which is worthy
of future attention.
Whence I ſuppoſe, that this fly lives not by conſuming the fo-
liage of the plants, which it inhabits; but by piercing the pulmo-
nary veſſels in their natural ſtate, or the lymphatic veſſels of the leaf
in their retrograde ſtate, by a fine tube or proboſcis, which it poſſeſſes,
and which it may be ſeen by a common lens perpetually to employ,
as ſhewn under its chin in the magnified inſect at figure firſt of plate
IX. For the fap-juice or vegetable chyle is brought from the radi-
cles of each leaf-bud, and propelled up the long caudex to the pulmo-
nary artery of the leaf, where it becomes oxygenated, and converted
into vegetable blood. And may thus be extracted by the tubes of
theſe infects before its fanguification.
Perhaps thoſe aphiſes, which were from eggs, might eat ſome part
of the peach leaves during their larva ſtate, if ſuch exiſts, and occa-
fion them to curl up. While thoſe, which were a viviparous progeny,
might only pierce the ſap-veſſels, or blood veſſels, and thus not ap-
parently
Y y

346
DISEASES
SECT. XIV. 3. 2.
parently injure the leaves; as on the nut-trees, where perhaps they
were not hatched from eggs, but might have come thither in their
winged ſtate, and have then produced their innumerable viviparous
offspring; as on the nut-trees above mentioned I could not diſcern
the eggs, from which they were hatched, and a few larger aphiſes.
with wings appeared early in the ſeaſon amongſt the ſmaller ones
without wings.
We may finally conjecture on this intereſting ſubject, firſt, that the
aphiſes produced from eggs early in the ſpring may have a larva or
caterpillar ſtate, and that during that ſtate they may feed on the
young leaves of peaches, nectarines, plums, and cherries, and thus
occaſion them to curl and die. 2. That thoſe, which are not from
eggs, have no larva ſtate, and only puncture the larger chyle veſſels
of the young twigs, or the pulmonary arteries of the leaves, which
receive the vegetable ſap-juice from the roots, and thus that they
fuck it up, and live on it, before it is converted into blood, as moths,
butterflies, and bees, live on honey in their winged ſtate, though on
other parts of vegetables, as on their leaves, or anther-duft, in their
larva ſtate ; and that theſe punctures are attended with no viſible in-
jury to the leaf. 3. That for a week or two about Midſummer, when
the umbilical veſſels of the new buds convey the fap-juice to them,
or to the reſervoirs of nutriment preparing for them, that the aphiſes
by piercing theſe veſſels, or the pulmonary arteries of the leaves, ac-
quire ſo large a quantity of this faccharine material, that it paíſes
through them almoſt unchanged, falling on the leaves and ground
beneath them, and produces what is called the honey-dew; but that
this happens only for a ſhort ſeaſon, as a week or two about Mid-
ſummer, during the production of the new buds. And laſtly, that
the black powdery material on the upper ſurface of the leaves of the
put-trees and plum-trees, and of the ſhrubs which grow beneath
them, is an excrement from the aphiſes, which hang on the under
furfaces of the leaves above them, like the black bitter powder in the
nut-

SECT. XIV. 3. 2.
OF PLANTS,
347
nut-ſhell; which is the excrement of the curculio, which has eaten
the ſweet kernel.
Secondly, having laſt year written the above, I have had ano-
ther opportunity of attending to the aphis during the ſummer of
1799, and ſhall add the further remarks, which I have been able to
make on this moſt curious and important animal, which may
in
pro-
ceſs of time deſtroy the vegetable world.
As the month of June was again in this fummer very dry, though
not very warm, the aphis was propagated in immenſe numbers on a
great variety of trees, ſhrubs, and herbaceous plants. The row of
nut-trees mentioned in No. 1. 7. of this Section was infeſted with a
greater number of them this year than in the preceding one; yet
during the ſeaſon about Midſummer there was ſo little honey-dew
this year, that it might have eſcaped obſervation, if it had not been
particularly attended to; yet what did appear was only on the upper
ſurfaces of thoſe leaves, which had other leaves impending over them
crowded with aphiſes ; whence I had no doubt, but that it was voided
by the millions of aphiſes, which adhered on the under ſurfaces of
thoſe ſuperior leaves with their backs downwards.
On examining them with a ſtrong magnifier I could frequently
perceive them inſert their proboſcis or trunk into the vefſels of the
inferior ſurface of the leaf; and particularly obſerved, that when
they were not moving from place to place, that they generally ſtood
with their heads towards the foot-ſtalk of the leaf of nut-trees, or to-
wards the baſe of the twigs of plum-trees, which circumſtance I
of my
friends.
Both before and after the exiſtence of the honey-dew a black ma-
terial, which was ſometimes moiſt and ſometimes dry, appeared on
the upper ſurfaces of thoſe leaves only, which had other leaves crowd-
ed with aphifes over them, and even on the upper ſurface of the
nit
leaves of fome herbaceous plants, which grew under theſe nut-trees,
and
Thewed to many
Yyz

348
Sect. XIV. 3. 2.)
DISEASES
a
and alſo on others, which grew under plum-trees, which were
much infeſted with an aphis of a greener colour.
To prove beyond poſſibility of error that this black matter was de-
jected on the leaves below by the aphiſes, which were walking with
their heads downwards on thoſe above, I ſewed flightly with a needle
and thread under ſeveral leaves a piece of writing paper about the fize
of the leaf; and obſerved on the next day that many black marks
were diſtinguiſhable on the paper.
On plum-trees and on many herbaceous plants innumerable aphiſes
were ſeen on the upper tender part of the upright ſhoots, adhering
with their heads downwards; and on the hanging ſhoots with their
heads upwards; and inſerting their proboſcis into the veſſels, I fup-
poſe, which contained the aſcending ſap-juice. But on the nut-trees
the moſt tender or uppermoſt parts of the young ſhoots were covered
with very numerous briſtles, which appeared to be an armour pur-
poſely produced to defend them from theſe deſtructive inſects, and
hence they were principally found on the under ſurfaces of the
leaves.
As the chyle of animals is mixed with the venous blood, and is im-
mediately projected by the force of the heart into the pulmonary ar-
tery, at the extremities of which it is principally converted into blood
by its expoſure to the air ; fo in the vegetable fyftem the fap-juice
muſt be mixed with the returning venous blood, and carried forwards
to the extremities of the pulmonary artery of the leaf, before it is
converted into vegetable blood. Theſe pulmonary arteries paſs along
the under ſurfaces of leaves, as the upper ſurfaces of them are cover-
ed by the fine terminations of them on an air-membrane for the pur-
poſe of reſpiration; hence on theſe under ſurfaces of leaves the aphiſes
adhere, and pierce the branches of the pulmonary arteries with their
proboſcis ſtanding with their heads towards the ſtalk of the leaf, that
they may thus meet the ſtreams of chyle or fap-juice yet unchanged
ވާ
into

Sect. XIV. 3. 2.
349
OF PLANTS.
a
into blood; which accounts both for their exiſting in all kinds of
weather on the inferior ſide of the leaves, and for their ſtanding with
their heads towards the foot-ſtalks of them. Thus on an upright
twig of a plum-tree I this day obſerved a number of aphiſes adhere
with their heads downwards with their proboſciſes inſerted into the
tender ſtem, and ſo near to each other, that the tail part of the lower
ones extended one third of their length over the head part of thoſe
above them, and gave ſomewhat the appearance of fcales; while on
the hanging twigs they adhered with their heads upwards, ſtill intent
to meet the ſtreams of fap-juice in the aſcending chyle veſſels, or in
the pulmonary arteries.
Dr. Bradley and others obſerve, that about Midſummer there ap-
pears to be a pauſe in vegetation, and that at this time the new buds
are generated; and Duhamel and others found, that the bark of fe-
veral trees became at this time as eaſily to be ſeparated from the al-
burnum as in the ſpring; as is related in Sect. III. 2. 8. of this work.
At this time therefore there exiſts a new flow of fap-juice to ſupply
preſent nutriment, or to furniſh a reſervoir of future nutriment to
the newly generated or expected embryon, either before or after its
vivification, or its impregnation, if ſuch a proceſs may be ſuppoſed to
occur in the production of buds.
At this time then, when there exiſts a ſummer-flow of ſap-juice,
this pernicious inſect in uncounted millions pierces the ſap-veffels
round the new ſhoots, or the pulmonary arteries beneath the leaves ;
and thus drinks the vegetable chyle, or fap-juice, with ſuch avidity,
as to part with much of it again almoſt unchanged. This I now
believe with Sauvage to be the origin of one kind of honey-dew cer-
tainly; and if another kind of honey-dew exiſts, as he mentions,
where there are no aphiſes, I ſuſpect, as obſerved in No. 1.7 of this
- Section, that it muſt ariſe from the inverted action of the lymphatic
veſſels of the leaf, at the time of the increaſed quantity of fap-juice
about
3
a

350
DISEASES
Sect. XIV. 3. 2.
about Midſummer; but have not had an opportunity to aſcertain
theſe facts.
Thirdly. There appears to be a power impreſſed on organized bo-
dies by the great author of all things, by which they not only in-
creaſe in ſize and ſtrength from their embryon ſtate to their matu-
rity, and occaſionally cure their accidental diſeaſes, and repair their
accidental injuries, but alſo a power of producing armour to prevent
thoſe more violent injuries, which would otherwiſe deſtroy them.
Of this laſt kind are the poiſonous juices of ſome plants, as of atropa
belladonna, deadly nightſhade, hyoſcyamus, hen-bane, cynogloſſuin,
hounds-tongue. Other plants are armed with thorns and prickles
to prevent the depredation of animals, as ilex, holly, cratægus, haw-
thorn, ribes groſſularia, gooſeberry; the leaves of which would be
perpetually devoured but for this kind of protection. Other plants
fecrete a viſcid juice to agglutinate the inſects, which crawl up to-
wards their fructification, as filene, catchfly, droſera, fun-dew ; and
others by the contraction of their leaves or petals arreſt or deſtroy the
infeets, which attack them, as diongea muſcipula, and apocynum an-
droſemifolium.
But how can vegetables protect the whole inferior ſurfaces of their
leaves, and of their young rifing ſtems from the innumerable pro-
geny of the deſtructive aphis, which penetrates their chyle veſſels and
their arteries; and which from their immenſe numbers may in pro-
ceſs of time deſtroy the vegetable world. Many vegetables have not
yet acquired any means of defence, and have therefore the firſt growth
of their foliage much injured, or totally deſtroyed by this deſtructive
infect, as the nectarine, and peach, and plum, and cherry-trees, in
many parts of this country, as is every year ſeen and lamented.
Some vegetables have nevertheleſs already acquired an armour,
which leſſens, though it does not totally prevent, the injuries of this
animal. This is moſt conſpicuous on the ſtems and floral-leaves of
moſs-

Sect. XIV. 3. 2. OF PLANTS.
351
mofs-roſes, and on the young ſhoots and leaf-ſtalks of nut-trees.
Both theſe are covered with thickſet briſtles, which terminate in glo-
bular heads, and not only prevent the aphis from ſurrounding them
in ſuch great numbers, and from piercing their veſſels ſo eaſily, but
alſo ſecrete from the gland, with which I ſuſpect them to be termi-
nated, a juice; which is inconvenient, or deleterious to the inſect,
which touches it.
Hence moſs-roſes appear to be leſs injured by the aphis, than other
roſes, which have leſs of this armour; and while on plum-trees,
and on many herbaceous plants, they hang round the upright young
fhoots with their heads downwards, and inſert their trunks, ſo as
totally to conceal the riſing ſhoct; yet on nut-trees, though they are
feen in millions beneath the leaves on the unarmed parts, they never
appear round the young ſhoots, nor on the large trunks of the vef-
fels beneath the leaves, all which have acquired a panoply of briſtles
with glandular heads to them, like thofe round the moſs-roſe, but
without the branching ſtructure of the latter. While thoſe plants,
which are not infeſted with the legions of this ſelf-productive animal,
have probably acquired ſome material mixed with their fap-juice, or
blood, which is poiſonous to them; as thoſe plants, which poſſeſs a
milky or a yellow blood, as the fpurges euphorbia, or the celandines
chelidonium, or the fig-tree, ficus.
Nor is this more aſtoniſhing, than that the holly-trees ſhould an-
nually ſupply prickles only to their lower leaves, about fix or eight
feet from the ground, as high as the animals can reach them, which
would prey upon them; but refuſe the expence of puiting forth
prickles in their higher branches, which are ſaved by their ſituation,
as I have repeatedly obſerved on the numerous holly-trees, which
are the ornament of Needwood foreſt.
From hence I ſuſpect, that another reaſon, why the leaves of nut-
trees and of roſe-trees are not curled up or bliſtered like thoſe of
nectarines, peaches, plums, and cherries, is becauſe their foot-ſtalks,
and
а
I

352
DISEASES
.
Sect. XIV. 3. 22.
and the larger branches of the pulmonary arteries, are defended by
theſe briſtles, which are perhaps only beginning to appear on the
leaf-ſtalks of the plum, but which may increaſe in the progreſſion
of time; as all the works of nature may be approaching to greater
perfection, as mentioned more at large in No. 2. of the laſt Section
of this work.
Fourthly. The means of deſtroying an inſect ſo extenſively inju-
rious not only to gardens and hot-houſes, but to half the vegetable
world, would be indeed a valuable diſcovery. If the eggs exiſt on
the young buds, as Dr. Richardſon affirms, ſome application to theſe,
before they are hatched, which might diffolve their ſhells, as by very
dilute marine acid injected on them; or by ſome adheſive material,
which might in viſcate them as ſoon as they are hatched, whether
they appear firſt in their larva ſtate, like minute caterpillars, or in the
form of the parent aphis, as foap-ſuds injected on the twigs before the
leaves begin to unfold; or perhaps by rubbing them with oil or glue
by means of a ſponge, or a painter's bruſh ; but experiments alone
can determine the effect of theſe applications, both on the inſect and
on the tree.
Lime water alone will not readily deſtroy the aphis, as I obſerved
by immerſing leaves with aphiſes on them; which crept up
the
leaves, and thus eſcaped. But if pot-aſh, or fixed alkali, be mixed
with lime, the ſolution becomes ſo cauſtic as to deſtroy many inſects
without injuring the foliage of trees, or the ſtems of wheat, if we
may credit M. Socoloff, who in the tranſactions of an Academy at
Peterſbnrgh, Vol.V. aſſerts, that he added three parts of quick-lime
newly made to two parts of a ſaturated ſolution of fixed alkali in wa-
ter; which poured on the ground deſtroyed the earth-worms, and
ſprinkled on the leaves of trees deſtroyed the caterpillars, but did not
injure, or much injure the foliage of trees, or the leaves of wheat
plants.
Tar water has lately been ſaid to deſtroy flugs, white ſnails with-
a
out

Sect. XIV. 3. 2.
OF PLANTS.
353
ter, 93
out ſhells, and might be worthy a trial by injecting it on trees at
firſt with caution, left it ſhould injure them; as it is probably the
vegetable acid chiefly, with a ſmall portion of eſſential oil, which is
diſſolved, or mixed with the water, by agitation. See No. 3. 5. of this
Section.
Previous to the pullulation of the buds, it is alſo believed to be of
great ſervice to water wall-trees with lime-water, or with ſoap-ſuds,
or perhaps with the addition of ſome pot-aſh to either of them to
make a more cauſtic ley, ſuch as is recommended for ſteeping ſeed-
wheat ; but this with caution, as I have known a ſolution of hepar
ſulphuris kill the branches of a tree, which were moiſtened with it,
as well as the inſects, which were upon it. Nor am I certain that
this will anſwer the purpoſe from the obſervations I have heard from
thoſe, who have tried it.
The eſſential oils are all deleterious to certain inſects, and hence
their uſe in the vegetable economy, being produced in flowers or
leaves to protect them from the depredations of their voracious ene-
mies. One of the eſſential oils, that of turpentine, is recommended
by M. de Thoffe for the purpoſe of deſtroying inſects, which infect
both vegetables and animals. Having obſerved that the trees were
attacked by multitudes of ſmall in ſeets of different colours (pucins
ou pucerons), which injured their young branches, he deſtroyed them
all entirely in the following manner. He put into a bowl a few handfuls
of earth, on which he poured a ſmall quantity of oil of turpentine; he
then beat the whole together with a ſpatula, pouring on it water, till
it became of the conſiſtence of ſoup; with this mixture he moiſtened
the ends of the branches, and both the inſects and their eggs were
deſtroyed, and other inſects kept aloof by the ſcent of the turpentine.
He adds, that he deſtroyed the fleas of his puppies by once bathing
them in warm water impregnated with oil of turpentine. Mem.
d'Agriculture, An. 1787, Printemp. p. 109.
I ſprinkled ſome oil of turpentine by means of a bruſh on ſome
branches
a
Zz

354
DISEASES
Sect. XIV. 3.2.
a
a
branches of a nectarine-tree, which was covered with the aphis ; but
it killed both the infect and the branches. A ſolution of arſenic much
diluted did the ſame. Might not the ſcent of turpentine, or of tar,
ſmeared on a fruit-wall deter the flies from approaching the trees to
depoſit their eggs? or might not arſenic mixed with honey be
ſmeared on the wall, to which the trees are nailed, be likely to at-
tract the aphis as well as other kinds of flying inſects. But none of
theſe fhould be ſmeared on the branches, leſt it injure or deſtroy the
tree. Perhaps if a few twigs ſmeared with turpentine, mixed with a
little oil of turpentine to make it more fluid, and to increaſe its odour,
were fixed in quince-trees, or in apple-trees, the flowers of which
are liable to be deſtroyed by the eggs depoſited in them by a ſmall
fly; they might be deterred from approaching the tree, as the great
uſe of eſſential oils, which cauſe the fragrance of flowers, ſeems to
be to deter inſects from infeſting their leaves, or preying upon their
honey.
It is probable, that if infuſions were made in hot water, or perhaps
for a longer time in cold water, of thoſe leaves which no inſects de-
vour; as of the walnut, juglans; lauro-ceraſus, laurel; foxglove,
digitalis; hen-bane, hyoſcyamus; hounds-tongue, cynogloſſum ;
rag-wort, ſenecio jacobæa; or of tobacco, nicotiana; and many
others; and were ſprinkled on the curled leaves of wall-trees, or on
the buds before they open, by a pump, or by a bruſh, or ſponge;
they might deſtroy the inſects without injuring the trees, which
might be determined by a few experiments.
The duſt of tobacco is frequently ſpread on affected leaves, but not
I believe with very encouraging ſucceſs, owing perhaps to the powder
not being very fine, or not foon enough applied. Some kinds of lime
ſtrewed on in powder might probably be too cauſtic, and deſtroy the
leaf along with the inſects; which alſo might be ſubjected to experi-
ment. The powder of ſulphur, or of tobacco, or of any of the poi-
ſonous leaves above mentioned, might be injected upon affected trees
by

Sect. XIV. 3.2.
OF PLANTS.
355
by a powder-puff, ſuch as hair-dreffers uſe, or the ſmoke of tobacco,
or of any other of the poiſonous leaves above inentioned, might be
forcibly blown on them by an adapted pair of bellows, as the ſmoke
of many of them may poſſeſs as poiſonous a quality as that of to-
bacco; and even the ſteam of a decoction of others, as of lauro-cera-
ſus, and walnut; the poiſon of the former of which is known to riſe
in diſtillation, might probably be uſed with effect ; but this muſt de-
pend on the greater or leſs fixity of their eſſential oils. The ſmoke
or fteam might be applied to wall-trees by previouſly fufpending over
them a large ſheet of matting, or of linen, or of paper, or an old
carpet ; but may however be uſed with greater advantage in hot-
houſes, than in the open air.
Since the above was written I directed in the early ſpring of this
year one nectarine-tree to be moiſtened with tar-water, and parts of
the wall to be ſmeared with tar; another to be moiſtened with lime
and pot-aſh diſſolved in water; a third with ſoap-ſuds and lime added
to them; and many both nectarine and peach-trees with ſoap-ſuds
alone. This was done by means of a bruſh before any flowers ap-
peared, and was repeated thrice on different days; but to my great
diſappointment, when the leaves appeared, they became affected with
the aphis as on former years. I alſo afterwards dipped many nut-
leaves crowded with the aphis in ſtrong infuſion of tobacco, for a few
minutes, as the leaves hung on the trees without, as I believed, de-
ſtroying the inſects; though ſome of them appeared for a time to be
rendered torpid.
Nevertheleſs on covering a low nut-tree with ſome ſheets of brown
paper ſewed together, and throwing the ſmoke of tobacco under it
from a proper pair of bellows, great numbers of aphiſes were killed,
many of which dropped from the upper leaves on thoſe below them,
and many adhered motionleſs to the under ſurfaces of the leaves. The
fine powder of tobacco called Scotch ſnuff ſprinkled on the apliſes
by turning up fome of the leaves quickly deſtroyed them.
Z z 2
As
a
a

356
.
DISEASES
.
Secr. XIV. 3.2As walnut-leaves may be had in great quantity in the autumn, and
the whole plant of ſenecio jacobæa, rag-wort, at any time, both which
are probably deleterious to inſects, as they ſeem never to be injured
by them, theſe might be procured at ſmall expence, and might pro-
bably, when dried and burnt, produce a ſmoke equally deſtructive
to them.
be
Fifthly. The moſt ingenious manner of deſtroying the aphis would
be effected by the propagation of its greateſt enemy, the larva of the
aphidivorous fly; of which I have given a print, and which is ſaid by
Reaumeur, Tom. III. Mem. 9. to depoſit its eggs, where the aphis
abounds; and that, as ſoon as the larvæ are produced, they devour
hundreds around them with the neceſſity of no other movements but
by turning to the right or left, arreſting the aphis and ſucking its juices.
If theſe eggs could be collected and carefully preſerved dnring the
winter, and properly diſpoſed on nectarine and peach-trees in the early
ſpring, or protected from injury in hot-houſes; it is probable, that
this plague of the aphis might be counteracted by the natural means
of devouring one inſect by another; as the ſerpent of Moſes devour-
ed thoſe of the magicians.
Mr. Horrocks of Derby ſhewed me this larva of the aphidivorous
fly, which I ſaw devour two or three aphiſes, and Mr. Swanwick of
this town at my requeſt made an accurate drawing both of the larva
and fly, which he kindly favoured me with, accompanied with the
following note.
“ On Auguſt the 4th Mr. Horrocks obligingly ſent me an aphidi-
vorous larva in a box on a leaf of a plum-tree, on which were a
number of aphiſes; and I had almoſt immediately the pleaſure of ſee-
ing it eat one.
" The method of taking his prey is thus: he is like the floth in
his diſpoſition, for he does not ramble about, while he has food around
him. He only lifts up his head, and ſtrikes it down again, extending
it in various directions, as if he was blind, and repeating the above ac-
8
tion.

Sect. XIV. 3.2. OF PLANTS.
357
tion. If by ſo doing he happens to feel an aphis, he immediately ſeizes
it by the back, lifts it up and poiſes it in the air, as if to prevent it
from liberating itſelf by its ſtruggles againſt the ſurface of the leaf, or
that it may fall more eaſily into the cavity of his mouth. In this po-
ſition he holds it, while he pierces it, and fucks the juice out of the
body; which having done, he drops the ſkin, licks his lips round
with his little black tongue, contracts his head, and drops it down;
thus reſting in perfect repoſe for ſome time, after which he repeats the
ſame actions. But if he is in the midſt of plenty, he ſeldom gives
himſelf this trouble, but waits till an aphis touches him, when he
immediately turns his head round, and with fatal certainty ſeizes him,
poizing him as before.
'For the purpoſe of ſeeing what fly was produced from this cater-
pillar, I procured him food for about ten days. During this time he
eat a great number of aphiſes, and grew to about an inch in length;
when he left off eating, contracted himſelf to about half his former
length, fixed himſelf to the box by a little gluten, which he diſcharg-
ed from his mouth, and without caſting a ſkin changed to a chry-
ſalis.
- In this ſtate he lay about ten or eleven days, at the end of which
time he burſt his cell, and came out a beautiful fly, of which the
figure is a good repreſentation."
No. 1. The caterpillar with an aphis in his mouth.
No. 2. The chryſalis open at one end.
No. 3. The fly.
Another enemy to the aphis is ſaid to be a beautiful ſmall ſpotted
beetle, called a lady-bird by the people. Several of theſe were ſeen
on the nut-leaves, and are believed firſt to appear there in their larva
ſtate, and to feed on the aphis; they then change to a chryſalis, and
laftly to a ſmall wing-fheathed beetle ; and finally, 1 fuppofe, they
1
bore holes into the earth, as would appear from their pofleffing
fheaths to their wings, and that they there depoſit their eggs to be
hatched,

358
DISEASES
SECT. XIV. 3.3.
hatched, and to climb the trees infeſted with the aphis in the enſuing
ſpring
Thus from the exertions of a few aphidivorous larve or caterpil-
lars, from the poiſonous juices of ſome plants, and from the briftly
armour on the young twigs and leaves of others, the vegetable world
is ſo far protected from the deſtruction, with which it has been, and
is threatened, by the fine proboſcis of this multitudinous inſect, which
in its manner of attack reſembles that of the large bat of Aſia, veſ-
pertilio-vampyris; which is aſſerted by Linneus to drink the blood
by night of ſervants, who fleep in the open air, Syft. Natur. p. 46;
and is ſaid by others to be ſo ſkilful an operator as not to wake the
patient by the puncture, which it inflicts, as it agreeably fans them
with its wings.
3. Many of the orchards of apple-trees in this country are liable to
loſe all their leaves by the depredations of caterpillars ; the ſame oc-
curs to gooſeberry-trees in ſome gardens, and to cabbages in the latter
part of the ſummer.
A few years ago I obſerved, that the bloſſoms of the quince-tree,
before they were quite expended, were perforated by a fly; as the
wound could be eaſily diſcerned like that on young nuts, when
wounded by the curculio; and all the bloſſoms of a large tree were
thus deſtroyed by a ſmall caterpillar. And in this late ſummer of
1799 the apple-bloſſoms in this country are much injured by a cater-
pillar, which eats the feed in the pericarp of each bloſſom either be-
fore or at the time of its impregnation, the petals of the flower clof-
ing again over it and dying.
The leaves of many trees are renewed after having been totally de-
ſtroyed in the early part of the ſeaſon ; as thoſe of the apple-tree above
mentioned, which had loſt its leaves entirely by lightning; as the
mulberry-trees in Italy, which are thus robbed of their firſt leaves to
feed filk-worms, as the tea-tree in China, which is thus robbed for a
faſhionalle potation. And laſtly, as the euonymus, or ſpindle-tree,
which

Sect. XIV. 3. 3.
359
OF PLANTS.
which in this country has its firſt crop of leaves almoſt perpetually
deſtroyed by caterpillars. But though the leaves are reſtored after the
depredation of this inſect, yet there follows an irremediable injury to
the fruit. See Sect. IX. 2. 6..
As the eggs of butterflies are in the autumn wiſely depoſited in
ſituations, where the young can find proper food, when they are
hatched by the warmth of the ſpring; thoſe on apple-trees, and
on gooſeberry-trees, are frequently depoſited on the leaves, as
well as on other parts of the tree; and as theſe leaves fall on the
ground, the eggs are thus covered and protected from the froſts, and
the young caterpillars are believed to climb the trees in ſearch of their
food. If this be true, it would be an advantageous practice to rake
together the leaves in orchards, and to burn them ; which ſome have
done from an idea, that the ſmoke. thus produced was noxious to
the eggs-of inſects depoſited on the branches.
Some gardeners for this purpoſe rear their gooſeberry trees on one
ſtem only; and believe, that by tying a fringe round this ſtem the
inſects, which are hatched in the ſoil, if ſuch there be, can not climb
up the tree thus ſurrounded with a fringe; and as thoſe caterpillars,
which are already on the tree, let themſelves down by a thread, when
the tree is ſhaken, from the fear of being hurt by the vibrating twigs ;
if this thread be then broken, by moving a ſtick round under the tree,
theſe inſects cannot reaſcend. A paper recently tarred on the outſide
might be wrapped round the ſtem of the tree inſtead of the fringe -
with perhaps more certain ſucceſs; but the tar ſhould not be ſmeared
on the bark of the tree, leſt it ſhould injure or deſtroy it.
It may be obſerved in the choice of apple-trees, that thoſe kinds, ,
which flower early, are leſs liable to the depredation of inſects; and
thoſe, which flower late, are leſs liable to the injuries of froſt. In ap-
ple-trees perhaps the former is in ſome ſituation the greater evil, but
in pears I ſhould ſuſpect the latter, the bloſſoms of which are ſo of
ten totally deſtroyed by one night's froſt.
The

360
Sect. XIV. 3. 4.
DISEASES
The white butterflies, which depoſit their eggs on cabbage plants,
are ſeen flying about awkwardly in ſummer, and ſhould be caught,
and deſtroyed by the gardener. Or they perhaps might be invited
and poiſoned by a mixture of honey, and water, and arſenic; as a
wealthy man in Italy was ſaid to have poiſoned his neighbour's bees.
See Sect. VI. 6. 3. Theſe cabbage-caterpillars would increaſe in de-
ſtructive numbers, but are half of them annually deſtroyed by a ſmall
ichneumon fly; which depoſits its own eggs in their backs, which
are there hatched by the warmth of the animal, and live on the filk
there ſecreted for its future neſt; and eroding their way out ſpin
ſmall cacoons of their own; ten or twelve of which hang on each
caterpillar; which thus periſhes inſtead of changing into a butterfly.
This I ſaw happen to a great many of them, which were put into a
box on bran with a few cabbage leaves, and covered with gauze, a
few days before they were ready to change into chryſolifts. This
ichneuman fly ſhould therefore be encouraged, if his winter habita-
tion could be diſcovered.
4. The variety of inſects, which infeſt hot-houſes, as the acarus,
thrips, aphis, and cocci, and the means commonly uſed to deſtroy
them by the ſmoke of tobacco, or by the powder of ſulphur and to-
bacco, or by ſolutions of lime and ſulphur, are deſcribed in Speechly's
books on the Vine and Pine; but require ſome caution in their ap-
plication. A friend of mine, by ſubjecting a wall-tree to the ſmoke
of fulphur by hanging a matt before it during the fumigation, killed
both the inſects and the tree.
5. Other kinds of inſects are produced beneath the ſoil, or occa-
ſionally retire into terreſtrial habitations. Of theſe are the various
families of ſnails, with and without ſhells, and other inſects with
ſheaths over their wings, with which they are furniſhed to prevent
any injury from the friction of the ſides of the holes they make or
defcend into.
It has been lately ſuppoſed, that the great deſtruction of the crops
of
a

Sect. XIV. 3. 5.
361
OF PLANTS.
a
of turnips, which occaſionally occurs, is owing to the depredation of
a white flug, or ſnail, which comes out of the ſoil before ſun-riſe in
dewy mornings; and that by rolling the young turnips with a heavy
roller before ſun-riſe for a few mornings, theſe pernicious inſects may
be deſtroyed, and add manure to the riſing plants they have injured.
The white flugs in gardens are very deſtructive to many flower-
ſtems, as they riſe out of the ground, as to dictamnus fraxinella,
apocynum androſemifolium, to phaſeolus, kidney-bean, to cinara,
artichoke, and many other plants. I well remember in one ſeaſon
favourable to their production in a garden by the ſide of the Derwent
obſerving, that many artichoke ſtems above a foot high were eaten
by them near the moiſt earth till they fell down, like trees felled by
the ax. It has lately been aſſerted, that watering the ground with
tar-water will deſtroy them; which may be made by adding a few
pounds of tar to a hogſhead of water, and well ſtirring it, without
perceptible injury to the tar. A circle of lime round the flower-
ſtems, or of falt, or even of bran in dry weather, are means of pre-
venting the approach of flugs; and ſome gardeners lay a board lightly
on the ground between the alleys, under which the ſlugs hide them-
ſelves when the ſun riſes, and are hence eaſily caught and deſtroyed.
The leaves of the young turnip are alſo believed to be deſtroyed by
a fly; which, if it be of the ſcarabæus, or beetle kind, which ariſes
out of the earth, may likewiſe be deſtroyed by rolling. The Chi-
neſe are ſaid by fir G. Staunton to ſteep all their feeds in liquid ma-
nure until they ſwell, and their germination begins to appear; which
they believe not only haftens the growth of the plants, but alſo de-
fends them againſt inſects beneath the ſoil; and that to this ſir George
obſerves it may be owing, that the Chineſe turnips eſcape the fly ſo
injurious to them in this country. Embaſſy to China, Svo edit.
Vol. III. p. 310. An obſervation of Mr. Guillet in the Bath Agri-
culture, Vol. II. Art. 44, ſeems to confirm this idea. He afferts, that
when turnip ſeed is ſown during rain, or has rain immediately after-
wards,
9
3 4

362
Sect. XIV. 3.6.
DISEASES
a
wards, that the firſt leaves are fo vigorous that the fly never attacks
them; or that the rain itſelf is ſo inconvenient to the fly, as to pre-
vent its appearance. It is alſo aſſerted by Mr. Exeter in the Tran-
ſactions of the London Society for Arts, Vol. XVI. p. 191, that the
ſowing turnips in drills deeper than by broad caft, accelerates the
growth of the plant by giving it more moiſture; whence it ſooner
puts forth its rough leaves, and eſcapes the depredations of the fly.
He ſpeaks highly of the uſe of the drill, adviſes the rows to be one
foot diſtant, uſes three quarters of a pound of ſeed to an acre, and
fows them from one inch and a half to two inches deep.
6. The great numbers and varieties of animated beings, which
live under the ſoil, and ſleep in winter, deſcending beneath the reach
of froſt, is truly aſtoniſhing. I once obſerved ſuch immenſe num-
bers of ſmall wing-ſheathed inſects, which I believed to be the ſca-
rabæus ſolſtitialis, or fern-chaffer, as they were not one fixth part of
the ſize of a May-chaffer, ſcarabæus melolontha, though much of the
ſame form and colour; which arofe out of the ground near the cold
bath at Lichfield, that I gueſſed, that one or two emerged from every
fquare inch of many acres of land.
The grubs or maggots, from which theſe wing-ſheathed flies aroſe,
I ſuſpect in ſome ſeaſons and ſituations favourable to their production
to be very deſtructive to the wheat in ſpring, or the early part of
ſummer, devouring the ſtem near the furface of the ground at the
joint, which is ſweet, till it falls down or withers, by which many
crops were nearly deſtroyed this year, 1797, and that, I was inform-
ed, on ſome lands, which had been previouſly well limed.
Mr. Tull in his huſbandry, ſpeaking of wheat, adviſes not to low
it deeper than an inch, ſince the thread or caudex, which connects
the lower or ſeminal root with the upper or coronal root, he believes
to be then not ſo readily found by worms in the winter, as one three
inches long might be, both on account of the greater length of the
9
latter,

Sect. XIV. 3. 6.
OF PLANTS.
363
latter, and becauſe inſects do not riſe ſo near the ſurface in the win-
ter months.
Where this peſtilential grub occurs, perhaps rolling the land early
in the mornings in the ſpring might cruſh them. And when the fly
is ſeen to come out in ſuch abundance in the ſummer evenings on
graſs land or fallows, it is probable, that rolling the ground in the
evening might prevent the return into the earth both of theſe and of
the May-chaffers to depoſit their eggs, and thus prevent their future
progeny; or during their grub ſtate, when they exiſt at the roots of
wheat above or juft beneath the ſurface of the ſoil, perhaps flaked
lime might be ſprinkled over the crop in powder, or ſea-falt in pow-
der, which might be waſhed down the ſtems of the corn in a wet
day, and deſtroy the infect without injuring the vegetable ; or laſtly,
by tar-water; all which might be firſt tried on a ſmall part of a field;
for as lime is not all of equal purity, it is not all of the ſame ſtrength
or cauſticity.
Another inſect is ſaid to injure wheat when in flower, and is ſup-
poſed to be the thrips phyſapus of Linneus, as mentioned in the
tranſactions of the Linnean Society, Vol. III. But as it only attacks
the late flowering ſtems, it may poſſibly be prevented by fowing the
wheat early, if it ſhould ever become a ſerious evil.
Some time ago an inſect called a corn-butterfly committed great
ravages in France while in its vermicular ſtate, ſo as to ruin two hun-
dred pariſhes. A cure for it was at length diſcovered, which con-
ſiſted in drying the wheat in an oven before fowing it, and thus ex-
poſing it to ſuch a degree of heat as would deſtroy the eggs of the
inſect without injuring the ſeed; or perhaps which hatched them
without ſufficient moiſture to ſoften the grain for their ſupport. See
Encycl. Britan. Agricult.
Between Cheſterfield and Plaiſly in Derbyſhire I well remember
above forty years ago to have ſeen for two or three miles together
every leaf of the hedges devoured by the May-chaffers, ſcarabæus
3 A 2
melolontha,
a

364
Sect. XIV. 3. 6.
DISEASES
melolontha, which hung on each other, where the foliage was de-
ſtroyed, like bees in a fwarm. And to have found in the ſame year,
as it lay dead in a field pear Cheſterfield, a true locuft, like a very
large graſs-hopper with very long and broad wings; which I pre-
ſerved in ſpirits, and was informed, that many of them were found
in other parts of England about the ſame time.
All theſe noxious animals might be deſtroyed or diminiſhed by
encouraging the breed of ſmall hedge-birds, and perhaps of larks, and
of rooks, by not taking their nefts. I have obſerved, that houſe ſpar-
rows deſtroy the May-chaffer, eating out the central part of it, and
am told that turkeys and rooks do the ſame; which I thence con-
clude might be as grateful food, if properly cooked, as the locuſts or
termites of the eaſt. And probably the large grub, or larva of it,
which the rooks pick up in following the plow, is as delicious as the
grub called groogroo, and a large caterpillar, which feeds on the palm;
,
both of which are roaſted and eaten in the Weſt Indies. The various
ſpecies of linnets carry ſmall caterpillars to their gaping young; and
hedgehogs are ſaid to devour ſnails, and on that account to be profit-
ably kept in gardens.
When a ſevere froſt occurs, before the ground is covered with
ſnow, thoſe inſects, which do not penetrate deeply into the earth dur-
ing their hybernation, as the ſhell-leſs ſnails or flugs, are liable to
be deſtroyed, and probably many of the larvæ of the fern-chaffer and
May.chaffer, as is ſeen by their diminiſhed numbers in the enſuing
ſeaſon.
In China the aurelia of the filk-worm, after the filk is wound off,
and the white earth-grub, and the larva of the ſphinx moth, furniſh
articles at the table, and are ſaid to be delicious. Embaſſy to China.
Nevertheleſs all the caterpillar tribes may not be equally innocuous;
as in this climate the hairy caterpillars, if laid between the fingers,
where the ſkin is tender, I have obferved to produce an itching, and
leave ſome of their pointed briſtles in the ſkin. And M. Vaillant,
in

Sect. XIV. 3. 7
OF PLANTS.
365
in his travels in Africa from the Cape, aſſerts, that both a black and a
white hairy caterpillar becomes ſo poiſonous, when it feeds on a large
euphorbia, that the natives put them in bags, bruiſe them, and after
a few days poiſon their arrows with them. But that they are leſs
poiſonous if they feed on leſs acrid vegetables.
There muſt be great difficulty in deſtroying the larvæ, or grubs,
or caterpillars, of many infects, which are injurious to the fruits and
kernels, as well as to the foliage of plants, by any chemical mix-
tures; as in this ſtate, I ſuppoſe, ſome of them are uncommonly
hardy or tenacious of life. Mr. Gouch affirms, that he kept the cur-
culio nucum, or worm found in nuts, in brandy for ſeventeen hours,
which recovered ; and I remember putting a worm, which came
from a perſon, who called it an aſcaris, though it was above an inch
long, and nearly as thick as a thin crow-quill, into a ſaturated folu-
tion of ſugar of lead in water; which lived many hours without
apparent injury. See Nicholſon's Journal, No. 21, for November
1798.
7.
. A
great
number of bees, as well as of moths, and butterflies,
muſt be very injurious to flowers, and conſequently to the produc-
tion of fruits, as all of them plunder the nectaries of their honey,
and thence deprive the anthers and ſtigmas of their adapted nouriſh-
ment, as mentioned in Sect. VI. 6. 3. This would be more deſtruc-
tive to the feminal products of plants, but that many of them poſſeſs
means of defending their reſervoirs of honey, and yet of expofing it
to the influence of the air, ſome of them by long winding canals, as
in the bottom of the tubes of the honey-ſuckles, trefoils, and lark-
ſpurs, lonicera, trifolium, delphinium; others by covering it with a
hood, as in monkſhood, aconitum ; others by a gluten, as in catchfly,
filene, and in fun-dew, drofera; others by contracting ſome part of
their leaves or flowers, and deſtroying the hoſtile infect, as in dionda
muſcipula, and in apocynum androſemifolium ; and finally, many
other flowers have probably acquired the habit of fecreting more ho-
ney

366
Secr. XIV. 3. 7.
DISEASES
ney than is neceſſary for their own conſumption, as cacalia fuaveolens,
alpine colts-foot, and polygonum fagopyrum, buck-wheat. From
all theſe contrivances the flowers of plants probably receive leſs in-
jury from the depredations of bees, moths, and butterflies, in this
country, and from the humming bird in tropical climates, than they
otherwiſe would be ſubject to.
But beſides the loſs of much of their honey an abundance of bees
muſt likewiſe injure the ſeminal products of vegetables by plunder-
ing the ſtamina of flowers of their anther-duft for bee-bread, as Mr.
Hunter believes; and alſo of the wax, which covers the anthers for
their defence againſt rain. Nevertheleſs, as mankind convert to their
own purpoſes the honey thus collected by bees, and the wax, with
which they fabricate their combs; and as the ſeeds of plants and their
fruits are nevertheleſs in fufficient abundance ; the depredations of
bees are not counteracted like thoſe of other inſects, but on the con-
trary encouraged.
The following obſervations, which I made this ſummer, may be of
ſervice to thoſe who keep bees, and which I ſhall therefore here relate.
The bees of one ſociety frequently attack thoſe of another ſociety,
plunder them of their honey, and deſtroy moſt of them, perhaps all
of them, in battle; in this reſpect reſembling the ſocieties of man-
kind! This war for plunder occurs more frequently than is com-
monly ſuſpected. Laſt year I had one hive of bees totally deſtroyed,
and the year before another, which I did not take means to prevent,
though I ſaw the conteſt, and the number deſtroyed in the latter;
but not early enough in the commencement of hoſtilities.
Laſt week, June 16, I happened to ſee a great number of bees on
the wing near the mouth of my only hive, and ſuppoſed that they
were about to ſwarm. In an hour or two, on again attending to
them I diſtinctly ſaw it was a violent battle; and at night obſerved
about a hundred dead bees on the ground, and on the bench before
the hive. I then directed a board about an inch thick to be laid on
the

SECT XIV. 4. 1.
OF PLANTS.
367
a
the bee-bench, and ſet the hive on this board with its mouth ex-
a@ly on the edge of this board, the mouth of the hive was alſo con-
tracted to about an inch in length, and a ſemicircular hollow was
made in the board immediately under the mouth of the hive. By
this means the aſſailing bees were obliged to alight on the bee-bench,
and then to climb perpendicularly up the edge of the board, on which
the hive was now placed ; and thus appeared to act with great diſ-
advantage; and a much leſs number of bees appeared to be flain in
this day's battle; whence it would be advantageous always to place
;
bee-hives in this manner.
Nevertheleſs, as the war did not ceaſe, I directed early on the next
morning to remove the bee-hive to a diſtant part of the garden, and
to a more eaſterly aſpect, and found to my great ſatisfaction, that the
hoſts of the enemy did not follow ; and that in a few hours the un-
aſſailed bees reſumed their work, as appeared by their going into the
hive with loaded thighs; and though a few of them were ſeen on
the following two nights reſting on their old habitation, theſe were
carried early on the enſuing morning in their torpid ſtate to their
new ſituation, and the war ended without exterinination of either fo-
ciety.
a
IV.
DESTRUCTION BY VERMIN.
1. The deſtruction of grain, after it is ſown, by the field-mice,
which mine their way very quickly under newly ploughed lands near
the ſurface, is ſaid-by Mr. Wagſtaff, in the papers of the Bath So-
ciety, Vol. VI. to be effected in ſome ſeaſons to a very great extent.
He adds, that the tuſſocks of wheat, ſeen to ariſe in many fields, are
owing to the granaries of theſe diminutive animals; which he has
often found to contain nearly a hatful of corn, which grows into a
tuft, if the owner becomes accidentally deſtroyed.
Mr.Wagſtaff alſo aſſerts, that they feed much on the young plants,
as

368
SECT. XIV.4.2,
DISEASES
;
as they ariſe from the ſeed, and multiply at that time very faſt. He
detects their habitations by ſmall mounds of earth being thrown up
on or near the apertures of their dwellings, or of the paſſages, which
lead to their neſts or granaries; and by following the courſe of theſe
paſſages he found and deſtroyed the parents and the progeny.
Mr. Wagſtaff recommends the taking up and dividing the tuffocks
of wheat, thus ſown in the autumn by the field-mice, and tranſ-
planting them in the ſpring; and alſo to thin other parts of a young
crop, as they appear too thickly fown, which he eſteems an advanta-
geous practice.
Acorns when ſown, and garden beans, and peas, are liable to be
dug up or devoured by theſe voracious little animals, which may be
deſtroyed by traps baited with cheeſe; or beſt of all by the encou-
ragement of the breed of owls, ſo active in the purſuit of nocturnal
vermin, and thence ſo uſeful to the gardener and farmer, who ſtill
permit their ſervants and children to deſtroy both their eggs and cal-
low young
a
2. This country was infeſted with two kinds of rats, the houſe-rat
and the water-rat; but it is believed, that within the laſt half cen-
tury the water-rat has deſtroyed the houſe-rat. The water rats pof-
ſeſs ſome kinds of ingenuity ſimilar to the beaver in the conſtruction
of their houſes near the brinks of rivers and pools; which have two
apertures, one above ground amongſt the graſs, and the other beneath
the ſurface of the water; and unleſs they can hide their upper open-
ing amid weeds or graſs, they forſake the ſituation. Thus if a rim,
three or four feet in breadth, round a fiſh-pond be kept ſo low as to
riſe only two, or three, or four inches above the level of the water;
and if this be kept clean from high graſs, or weeds, the rats will de-
ſert the pond.
I have ſeen a young water-rat devour a large leaf of water-plantain,
aliſma plantago, and therefore ſuppoſe that they occaſionally prey on
the foliage, as well as on the feeds and fruits of vegetables, and on
young animals, as ducklings and rabbits. As theſe animals, like the
dog,

Secr. XIV. 4. 2.
OF PLANTS.
369
a
dog, are of a laſcivious nature, and as ſome materials have a ſtrong
ſcent, reſembling perhaps that of their venereal orgaſm, they are
liable to be attracted by ſuch ſmells, as dogs are, on the ſame account,
I ſuppoſe, inclined to roll themſelves on putrid carrion; and male
cats to eat marum, valerian, and cat-mint. On this account it is
uſual for rat-catchers to avail themſelves of this propenſity, and to
mix effential oil of rhodium, or mulk, with the poiſonous powders
of ſtrychnos nux vomica, or of delphinium ſtaviſagria, or perhaps
of arſenic.
The great injury to vegetation effected by theſe rats conſiſts in
their making innumerable burrows beneath the ſoil, and feeding on
the roots of a great variety of vegetables. Some new planted apple-
trees I remember to have ſeen taken out of the ground with nearly
the whole of their ſmaller roots eaten, and the larger ones peeled by
theſe reptiles. They will alſo deſtroy young ducks, young rabbits,
and young chickens; and devour with great avidity every kind of
food, with which poultry and ſwine are uſually fed; and are bence
in many ways injurious in ſituations near water.
The ſubſequent receipts for poiſoning this miſchievous vermin are
printed in the papers of the Bath Agricultural Society, and ſaid to
have been attended with great ſucceſs. Firſt, to a quart of oatmeal
add fix drops of oil of rhodium, one grain of muſk, and two or three
of the nuts of nux vomica finely powdered ; make it into pellets, and
put them into the rat-holes. This was at firſt greedily eaten, and did
great execution, but the wiſe animals after a time ceaſed to eat it.
The ſecond conſiſted of three parts of oatmeal, and one of ſtaviſa-
gria, ſtave’s-acre, mixed well into a paſte with honey. Pieces of this
paſte were laid in their holes, and again did great execution. A third
method of deſtroying them there recommended is by laying a large
box down on its front ſide with the lid ſupported open by a ſtring
over a pully; and by trailing toaſted cheeſe, and a red herring, from
their holes to this box; and placing oatmeal and other food in this
box,
3 B

DISEASES
SECT. XIV. 4. 3.
a
370
box, which they are for a few nights permitted to eat unmoleſted;
and finally to watch them by moonlight, the infide of the box being
painted white; and, when many of them are ſeen, to let down the
hd; by which contrivance fixty of them were taken at once.
3. Moles, as well as rats, have occaſionally increaſed ſo greatly in
numbers as to much injure the agricultor ; they perforate the earth
near its furface, and are ſaid never to drink, but to feed on the
roots of vegetable, as well as on fubterraneous inſects; and though
they are believed never to drink, yet they have been ſeen occaſionally
to ſwim over lakes of water to the iſlands which they ſurround, of
which an ocular proof is related in the tranſactions of the Linnean
Society, Vol. III. 1797. Some have recommended to inject the
ſmoke of burning ſulphur, or of tobacco, into their ſubterraneous
manſions; but as the earth frequently falls in behind them, as they
paſs, or is accumulated behind them by their hindermoſt feet, as they
perforate the ſoil with their foremoſt feet or hands, this method of
attack can ſeldom fucceed, unleſs the neſt of the animal be near the
fumigated aperture. Others have adviſed to pour water into their
holes, which is equally inefficacious in general, though it may have
effect in particular ſituations. Some alſo have baited traps with
worms, and others have adviſed to put poiſon into their holes; but
they are not to be attracted together like rats from their not appear-
ing above ground.
The following method was related to me by Francis Paget of El-
fton near Newark, a very popular and ſucceſsful mole-catcher, whom
I once attended in his occupation to witneſs his operations. The
moles have cities under ground, which conſiſt of houſes, or neſts,
where they breed and nurſe their young; communicating with theſe
are wider and more frequented ſtreets, made by the perpetual jour-
neys of the male and female parents; as well as many other leſs fre-
quented allies or bye roads, with many diverging branches, which
they daily extend to collect food for themſelves or their progeny.
This

Secr. XIV. 4. 3
OF PLANTS.
371
This animal is more active in the vernal months, during the time
of the courtſhip of the males; and many more burrows are at this
time made in the earth for their meeting with each other. And
though theſe animals are commonly eſteemed to be blind, yet they
appear to have ſome perception of light even in their ſubterraneous
habitations; becauſe they begin their work as ſoon as it is light, and
conſequently before the warmth of the ſun can be ſuppoſed to affect
them. Hence his method of deſtroying them conſiſted firſt in at-
tending their ſituation early before fun-riſe; and at that time he fre-
quently could ſee the earth move over them, or the graſs upon it ;
and by a ſmall light ſpade he frequently cut off their retreat, by
ſtriking it into the ground behind them, and then dug them up.
He added, that by laying the ear on a newly raiſed mole-hill, the
found of the ſcratching mole might ſometimes be heard at a diſ-
tance, and direct where to find it; as the folid earth conveys ſmall
vibrations better, or to a greater diſtance, than the light air. And
that a terrier dog, after having been accuſtomed to the buſineſs, was
frequently of ſervice in detecting by his noſe the place of the mole
beneath the ſoil, and by endeavouring to ſcratch the earth over it.
The mole he ſaid generally ſuckles four or five, and ſometimes fix,
young ones; which are placed conſiderably deeper in the ground
than their common runs; and as theſe neſts are funk much deeper
into the ground than their ſtreets or bye-roads, and the mole-hills
conſequently farger, the earth on the ſummit of thoſe mole-hills is
generally of a different colour, and is raiſed higher than that of the
other ones.
Theſe neſts are to be dug up, having firſt intercepted
the canal between them and the mole-hills in their vicinity, to cut
off the retreat of the inhabitants.
The next important circumſtance is to diſcover, which are the fre-
quented ſtreets, and which the bye-roads, for the purpoſe of ſetting
ſubterraneous traps. This is effected by making'a mark on every new
Inole-hill by a light preſſure of your foot; and on the next morning
а
3 B 2
by

372
Secr. XIV. 4. 3
DISEASES, &c.
by obſerving whether a mole has again paſſed that way, and obliterat-
ed the foot mark, and this is to be done two or three fucceffive
mornings. Theſe foot-marks ſhould not be deeply impreſſed, leſt
it ſhould alarm the animal on his return, and he ſhould form a new
branch of road, rather than open the obſtructed one.
The traps are then to be ſet in the frequented ſtreets, ſo as nicely
to fit the divided canal. They conſiſt of a hollow femicylinder of
wood with grooved rings at each end of it, in which are placed two
nooſes of horſehair, one at each end, faſtened looſely by a peg in the
center, and ſtretched above ground by a bent ſtick. When the mole
has paſſed half way through one of the noofes, and removes the cen-
tral peg in his progreffion, the bent ftick riſes by its elaſticity, and
ftrangulates the animal. He added, that where the ſoil was too
moiſt or tenacious, that the moles in paſſing the old runs ſometimes
puſhed a little of it before them, and thus looſened the central peg
before they were in the nooſe ; in which caſe he fixed the peg a little
faſter in the trap.
By theſe means Francis Paget cleared many of the neighbouring
pariſhes of this kind of vermin in a few days, or a week or two,
and laid them under an annual tax for the defence of their territories
from theſe invaders. And added, that ſome other mole-catchers had
carried moles into thoſe farms, whoſe occupiers refuſed to pay them
an annual ftipend, a practice which he ſcorned to uſe. I have de-
tailed this method to prevent this impoſition, and to enable every
farmer to be his own mole-catcher, or to teach the art to his fer-
vants.
PHYTOLOGIA,

PLATE IX.

PLATE IX.
Exhibits the aphis, puceron, or vine-fretter, and the infects which deſtroy it.
Fig. 1. repreſents the aphis of the roſe-tree without wings very much magnified, copied
from M. Bonnet, with its antennæ before, and its two horns behind, which are not half
the length of the antennæ, are immoveable, and ſaid by Bonnet to be hollow canals from
which the ſweet juice called honey-dew is evacuated'; laſtly, with the trunk under its
head in the poſition in which it penetrates the leaves. In ſome the horns behind are want-
ing, and little knobs ſupply their place, which Reaumur thinks ſupply the ſame ſweet
juice. That ſome poffefling wings, and others not, does not diſtinguiſh the ſexes is agreed
by all obſervers.
Fig. 2. repreſents a magnified aphis of a pear-tree; from which a young one is ſuf-
pended for ſome time after it is otherwiſe born.
Fig. 3. repreſents the aphidivorous larva, with an aphis in its mouth, and the chryſalis of
the ſame infect, before it is transformed into the fly at fig. 4. All theſe were drawn from
nature, and exactly reſemble fimilar repreſentations in the work of Bonnet.
Fig. 5. repreſents an inſect from Bonnet, which he terms an aphis lion, as it fo edily
devours the aphiſes. This infect is transformed into the fly at fig. 6.
Fig. 7. repreſents a ſpotted hemiſpheric ſcarabeus, called by ſome a lady-bird, into
which the inſect at fig. 8. is transformed, which is alſo ſaid to be a great aphis-eater..
Oeuvres de C. Bonnet, T., 1.

Fig. 1.
1.
2
3
3 ))
4
5
6
7
8


PHYTOLOGIA
PART THE THIRD.
AGRICULTURE AND HORTICULTURE,
SECT. XV.
THE PRODUCTION OF FRUITS.
trees.
Buds immediately from feeds never produce ſeeds. Neither in annuals nor trees. As
in wheat, tulip, apple-tree. Buds from the broad caudex of a tulip, and the long
caudex of trees, are of different maturity. Leaf-buds changed into flower-buds at
Midſummer, or flower-buds into leaf-buds by art. I. To produce fruit-bearing
1. Seedling-trees. Their puberty. Ingraft walnut and mulberry trees.
-
If unpruned young trees or eſpalliers bear fruit ſooner than other
ſtandards ? Buds
on bended branches earlier and larger. An opple four on one ſide. How to pro-
duce fine ſeedling-trees or flowers. Leaves of ſeedling-trees. 2. Root-fuckers
from apples, vines, briers, figs, are like ingrofted ſcions. 3. Scions from branches
planted in the earth. A quick-bedge thus raiſed. Chineſe method. Vines how
raiſed by Mr. Michel. 4. An ingrafted ſcion ſometimes affeets the ſtock. Acquires
vigour from a vigorous ſtock. On trees of the ſame genus. On trees of different
genus. Subjeet to hereditary diſeaſes, not to old age, like the parent tree. Sum-
mits die firft. Talicotius's ingrafted noſes. Sour apple on one ſide. Apply rind
to rind in grafting. Flower-bud not proper for inoculation, Sweeter apples have
whiter blojams. Colour of black cherry and purple grape knewn by their red leaves
in autunn. Lines from Virgil's Georgics. II. To increaſe the number of fruit-
buds. Leaf-buds are furniſhed with new caudexes down the trunk. Flower
buds not fo. Retard the production of new caudexes. Viviparous and oviparous
progeny. Production of new caudexes, or bark filaments, are compound in in-
grafted trees, and ſuddenly generated.. 1. Bend down the viviparous branches,
and

374
Secr. XV.
PRODUCTION
and they become oviparous, and receive more nutriment. Apple-trees, trained in
horizontal circles. Nektarines and peaches trained on the ground. 2. Twiſt a
wire or tie a cord round viviparous branches. Apple-trees become dwarfs by fre-
quent ingrafting on them. 3 Wound or break a viviparous branch, or cut off a
cylinder of the bark. The veſſels of the alburnum ſometimes act as capillary tubes.
Decorticated oaks. Tepped birch and maple. Decorticate alternate branches about
Midſummer. Decorticated roots produce root-ſcions. Grafted roots. Layers.
Take bark off and replace it. Cut three or four circular inciſions, or a ſpiral line.
-
To make dwarfs. 4. Tranſplant a tree, or cut the roots, or confine them. Pluck
up and tranſplant beans, brocoli, ſtrawberries. Alſo crowd the roots of ſtrawberries.
Put a brick' fioor under fruit-trees. Confine lily of valley in pots. Orchis. Cu-
cumbers and melons. 5. Cut away central viviparous branches. Why Spurs are
oviparous. Why terminal buds are viviparous. Effect of it. Management of
melons. Management of vines. Pinch of viviparous ſecondary buds, and they
become oviparous next year at the ſame eye. A longer beat to ripen the wood ex-
plained. If this could be praťtiſed on other fruit-trees. 6. Lines from Botanic
Garden. III. To perfect and enlarge the fruit.
1. Shorten the oviparous
branches. Cut
Cut away root-fuckers. 2. Pinch of uſeleſs viviparous buds. Pick
out ſecondary buds. And of melons. 3. Thin wall-fruits, and grapes. Mucor
grows without light. 4. Tie waxed thread round twigs of fig-trees and pear-trees
when in flower, to prevent new leaf-buds. 5. Give additional moiſture, manure,
and warmth. Moiſture enlarges fruit by relaxing their cuticle, and preventing ab-
forption from them. Of ſuckling gooſeberries. Watering rice when in flower. Ma-
nure adds nutriment. Much warmth with much moiſture both enlarges fruit and
adds to its flavour. Hot-houſes heated by ſteam. Pines cultivated in water.
6. Protect flowers and fruits from froſt. A low ſituation is not proper for a
.
garden. Walls covered with projecting coping ſtones are uſeful in ſpring, not in
ſummer. Moveable coping fbeds. Fire-flues in garden-walls. A ſecret in the
management of them. Shade flowers from the ſun. 7. Fruits ripen ſooner if
wounded, or gathered before they are ripe, or baked in the hot-houſe, or in an oven.
IV. 1. To preſerve fruit. Keep it from heat ord cold, and from moiſture. How
heat and cold deſtroy the life of fruit. Congelation separates ſalts, vinous fpirit,
and vinegar, from water. Condenſes clay. Repels mucilage. Thaw frozen
fruit ſlowly. Preſerve fruits in ice-houſes, or by ſteam. 2. Gather fruit during
I
its

Secr.XV. 1.1.
375
OF FRUIT S.
its acid ſtate. Evaporate part of its water. Keep it cool. 3. Impregnate fruit
with ſugar. Brandy poiſons mucor or mould. 4. Fruits preſerved in brine, in
vinegar, in ſpirit of wine, ratifie. V. Verſes on pruning trees and melons.
a
a
The obje&ts of the culture of the farm or garden may be divided
into the production of fruits, feeds, roots, barks, woods, leaves, and
flowers.
We have repeatedly endeavoured to ſhew, that the buds immedi-
ately ariſing from ſeeds are not themſelves capable of producing
ſeeds neither in herbaceous nor in arboreſcent vegetables; but that
the firſt bud from every ſeed is ſucceeded by a ſecond bud more per-
fect than itſelf; and that by a third, fourth, or many more; each
generation being more perfect than the preceding one, till they ac-
quire a puberty, if it may be ſo called, or a power of producing ſexual
organs, and a conſequent feminal progeny.
In thoſe plants, which are called annuals, becauſe their feeds are:
ſown, and produce other ſeeds, in the ſame year, and then periſh,
fome ſucceſſive buds grow on each other, before a flower can be pro-
duced; as is ſeen in the ſtems of wheat, and fowthiſtle, triticum,
fouchus; which conſiſt of joints, which appear to be ſucceſſive buds.
growing on each other.
From the tulip feed a ſingle bud ariſes the firſt year with a circu-
lar Alat caudex exiſting beneath it, on which one principal new bulb
is formed annually more perfect than its parent, as is ſeen by the
larger leaf; and alſo ſome leſs bulbs are produced around the more
perfect one in the boſom of each rudiment of a leaf, which compoſes
or encloſes the principal bulb, as deſcribed in Sect. VII. 1. 3. and
Sec. IX. 3. 1. and 3.6. Theſe leſs perfect bulbs round the principal
one, after the principal one has acquired its puberty, or power of
producing ſexual organs, are of greater or leſs degree of maturity,
as appears by their fize; and thence I ſuppoſe muſt require more or
fewer years, before they flower.
Similar
a

376
Secr.XV. 1. I,
PRODUCTION
a
Similar to this circumſtance of the tulip-root, the buds of trees,
which firſt-ariſe from the feed, produce annually other buds more
perfect than themſelves, till they acquire the power of feminal.ge-
neration ; and afterwards not only a flower-bud is formed, which is
in fome trees the central bud on the extremity of the twig, as in
pear-trees, and on the ſpurs of apple-trees; but alſo many leaf-buds
of greater or leſs maturity are formed around the principal, or flower-
bud; which require more or fewer years, before they obtain the ma-
turity neceffary to produce a flower.
It was ſhewn in Sect. VII. 1.7. that every part of the long cau-
dex, extending from a bud on the ſummit of a tree to the root, can
produce a bud, like every part of the broad caudex of a tulip-root ;
but thoſe produced in the boſom of the leaf I believe generally to be
the moſt mature; and thoſe which ariſe from a lower part of the
caudex to be leſs mature, and will in confequence require more ſuc-
ceſſive buds to proceed-from them, before they cant form a flower.
Thus when the whole branches of a fruit-tree are lopped from the
trunk, the new buds are produced from the lower parts of the cau-
dexes of the branch-buds, which have been lopped off, and are there-
fore an immature progeny, and require ſome years before they can
flower.
It hence appears, that a number of buds or bulbs in all vegetables
muſt ſucceed each other from the ſeed, before a flower and conſe-
quent fruit can be generated ; but that theſe ſucceſſive generations
are more numerous or fewer in ſome plants than in others; that they
in ſome plants may only ſucceed each other annually ; in others per-
haps many of them in the ſame ſummer, as in the herbaceous plants,
as wheat ; and in thoſe trees, whoſe annual joints have their pith
-divided from each other, as in vines. And laſtly, that the number
of theſe fucceſſive generations, or the times of their production, whe-
ther only annually, or many of them in one ſummer, may be dimi-
niſhed

Sect. XV. 1.1.
377
OF FRUIT S.
nithed or accelerated by art; and that in attending to all theſe cir-
cumſtances conſiſts the ſucceſsful management of fruit-trees.
The new buds on deciduous trees in this climate are produced
about Midſummer, as obſerved in Sect. IX. 2. 9; and it is believed
by the Linnean ſchool, that many of them at this time may be ſo
affected by art, as to become either leaf-buds or flower-buds. At
this ſeaſon therefore the production of buds on wall-trees, or eſpa-
liers, or on ſtandards, ſhould employ the attention of the horticultor ;
as thoſe ſeedling-trees produce leaf-buds only, which are too young
to produce flower-buds; and as the particular ſhoots or buds of other
trees are not ſo mature as to produce flower-buds; and laſtly, as ſome
trees flouriſh too vigorouſly, as it is termed, to produce flower-buds.
The things to be attended to are the age of the tree, from which
the graft was taken, which now forms a branch ; the maturity of
the particular buds, which you wiſh to encourage; and the vigour of
the whole tree, or its tendency to produce leaf-buds in preference to
flower-buds.
>
I.
TO PRODUCE FRUIT-BEARING TREES.
1. There are four methods of procuring fruit-trees for the pur-
poſes of horticulture, by ſeeds, by root-fuckers, by planted fcions, or
by ingrafted ſcions.
1. Of Seedling Trees.
It was obſerved above in Section IX. 3. I. and 3. 6. that in tulips
and hyacinths, and even in potatoes and onions, the bulbs ſucceed
each other for two or three years or longer, before they produce
flowers; and that the ſame happens to the buds of ſeedling-trees,
which are many years a ſucceſſion of leaf-buds only, before the pro-
pagation of a ſingle flower-bud; for the power, which produces the
lateral
з С

378
PRODUCTION
SECT. XV. 1. 1.
lateral germination of buds, ſeems to require a leſs mature organiza-
tion than that, which is employed in the ſexual generation of ſeeds;
whence a kind of puberty of the plant ſeems to be acquired for the
production of the ſeminal or amatorial progeny, analogous to the
transformation of caterpillars into butterflies; which appears to be
effected ſolely for the purpoſe of propagation.
M. Speechly, in his treatiſe on the Culture of the Vine, p. 49,
ſeems to ſay, that feedling vines muſt be three or four years old, be-
fore they produce fruit; whereas a planted ſcion, or an ingrafted
one, from an aged tree, will produce fruit the firſt or ſecond year;
and according to the obſervations of Mr. Knight, ſeedling apple-trees
will not bear fruit till they are twelve or fourteen years old ; and other
fruit-trees in fimilar manner require ſome years after their birth from
the feed, before they arrive at ſufficient maturity to bear flowers. See
Sect. VII. 1. 3. Hence he adviſes the horticultor to procure ſcions for
grafting from ſuch trees as already bear fruit ; but pays no regard to
the ſtock, into which they are to be inſerted; and adds, that he be-
lieves, if ſcions from 'a bearing walnut or mulberry tree were in-
grafted on a ſeedling one, that it would produce fruit in two or three
years; which otherwiſe would not occur in leſs than twenty. Trea-
tiſe on Apple and Pear. Longman, London. And hence we ſee the
advantage of ingrafting on ſeedling orange or lemon-trees in our
green-houſes the ſcions taken from thoſe, which bear fruit; as other-
wiſe they would continue ſo many years before the buds would ac-
quire ſufficient maturity to generate flowers.
Some have believed that young trees will bear fruit ſooner, if they
are not pruned, but permitted to grow quite wild in large buſhes.
It is poſſible, that this may occur either from the unſkilful horti-
cultor pruning off all the terminal twigs, whoſe buds were forwarder
in reſpect to age, than the lateral ones much beneath them. Or
becauſe the great number of new leaf-buds, proceeding from an ex-
uberant branching head, may ſo crowd the bark of the trunk with
their

Sect, XV. 1.1. OF FRUIT S.
379
their caudexes, that ſome of them may ſooner find a difficulty in
forming their embryon caudexes, and may in conſequence become
flower-buds. But I much doubt, that this can frequently occur from
either cauſe, as I think, I have ſeen eſpaliers bear ſome years ſooner
than ſtandards, which were ingrafted at the ſame time, and from the
fame trees. And I have been informed of other ſeedling apple-trees,
which have born fruit in not much more than half the time above
mentioned by Mr. Knight.
It is much to be wiſhed, that proper experiments were made on
feedling trees by planting them as eſpaliers, or againſt walls, and
bending down their branches below the horizon, fince the diffi-
culty of their generating leaf-buds might be thus increaſed; as they
could not ſo eally form their embryon caudexes on the compreſſed
bark of the bended branch ; and the fap-juice for the nouriſhment of
fruit-buds would be thus rather increaſed than diminiſhed, accord-
ing to an experiment of Dr. Walker, who found the buds at the
extremities of bended branches to ſwell ſooner in the ſeaſon, and to
become larger, than thoſe of an equal height on the more upright
branches. Edinburgh Tranſactions, Vol. I.
Mr. Bradley has mentioned an apple, which was ſweet and boiled
ſoft on one ſide, and four and boiled hard on the other; and aſcribed
it probably to the real cauſe with much ingenuity in the year 1721,
long before the publication of the ſyſtem of Linneus. He aſcribes
it to the male farina of ſome neighbouring harſh apple-tree affecting
at the time of the impregnation the ftigma of the flower of a ſweet
one; and thus a production of different ſeeds might be generated
in the ſame pericarp, and a conſequent different kind of nutriment
prepared for each ; and thus the different parts of the apple become
four or ſweet, which is analogous to a bitch producing different kinds
of puppies at the ſame birth, reſembling the different dogs with which
ſhe had cohabited. The ſame circumſtance is ſaid to have occurred
in oranges and in grapes of different kinds.
3 C 2
a
a
Ву

380
SECT. XV. 1.1.
PRODUCTION
are
By this method of applying the farina of one good variety of fruit,
as of apple or pear, to the ſtigma of another good variety, it is very
probable, that ſome very excellent new. varieties of fruit might be pro-
duced from the feeds, which might ſupply for a century the orchards
of the curious, inſtead of our golden pippins, and nonpareils; which
re ſaid to be fuperannuated, and ſo liable to canker as not to be
worth cultivation. It is probable alſo, that new varieties of tulips
and hyacinths, and of melons and cucumbers, as well as of all other
vegetables, might be thus produced.
The following obſervations are from Mr. Knight's treatiſe on
Apple and Pear, p. 47. “Every ſeed, though taken from the ſame
apple, furniſhes a new and diſtinct variety; and ſome of theſe will
grow with more luxuriance than others; and the fruits produced by
the different plants will poffefs different degrees of merit ; but an
eſtimate may be made of their good and bad qualities at the con-
cluſion of the firſt ſummer by the reſemblance the leaves bear to the
highly cultivated, or to the wild kinds; as has been remarked by
the writers on this ſubject of the laſt century. The plants, whoſe
buds in the annual wood are full and prominent, are uſually more
productive than thoſe whoſe buds are ſmall and ſhrunk into the bark ;
but their future produce will depend much on the power the blof-
ſoms poffefs of bearing cold; and this power varies in the different
varieties, and can only be known from experience. Thoſe, which
produce their leaves and bloſſoms rather early in the ſpring, are ge-
nerally to be preferred; for though they are more expoſed to injury
from fröfl, they leſs frequently ſuffer from the attacks of inſects, the
more common cauſe of failure.
“ The leaves of young feedling plants annually change, become
more thick and fleſhy, and affumé more the character of the culti-
vated kinds. Theſe external changes indicate ſome internal ones
in the conſtitution of the plant, which may poſſibly be ſimilar in
their nature to thoſe, which take place in animals tetween their in-
fancy

Sect. XV. 1. 2.
381
OF FRUIT S.
fancy and the time, when they become capable of propagating their
fpecies.
2. Of Root-ſcions.
a
Root-fuckers from bearing bur-apples, or from bearing codlings,
are believed to become fruitful as ſoon as grafts from thoſe trees;
becauſe they are a viviparous offspring, as well as the ſcions or twigs
from the branches; and are therefore not fimilar to the oviparous
progeny, or the young trees produced from ſeeds. This muſt ne-
vertheleſs in great meaſure depend upon the age of the ſucker; as
thoſe root-buds, which riſe into ſuckers, are not formed or generated
in the boſom of a leaf, but from a part of one of the long caudexes
of a branch-bud ; and will therefore, I ſuppoſe, require a ſucceſſion
of buds for fome years, before they will acquire ſufficient maturity to
produce a flower; as the central buds from the boſom of a leaf I
ſuppoſe to be much forwarder than the lateral buds from the ſame
caudex; as is ſeen in the central or flower-bulb of a tulip, and its im-
mature lateral bulbs from the fame caudex.
Root-fuckers from thoſe trees, which have been ingrafted on the
roots of other trees, as the robinia on the acacia, may ariſe above
the grafted part, which is beneath the ſoil; but thoſe root-fuckers,
which ariſe from trees, which were grafted above ground, are ſimilar
to the ſtock, not to the fruit-bearing head; which might have been
a wild pear or wild apple; and will in that caſe produce crab-pears,
or crab-apples, with thorny ſtems.
When a branch of a vine, or briar, or of many other trees, is bent
down, and a part of it inſerted into the ground with its fummit in
the air, it will emit roots at the joints, and become a new tree. So
the rough knobs on the bark of a bur-apple-tree, I am informed, will
ſhoot out roots, if ſurrounded with moiſt earth'; and the branch may
be then cut off, and ſucceſsfully planted. And from almoſt every
joint of a fig-tree roots will protrude, if ſurrounded even with a
woollen
a

382
Sect. XV. 1.3.
PRODUCTION
woollen ſhred, which happens to be frequently moiſtened by the dews
or rain ; and the branch may be fucceſsfully bent down and planted
in a garden-pot. All theſe, like ſuckers from the roots of ſeedling-
trees, or like grafted fcions, will become fertile, as ſoon as the tree,
from which they are the offspring; whether it be a ſeedling-tree or
not.
This circumſtance does not occur exactly ſimilar in the inſertion
of buds from one tree into the bark of another; as thoſe buds, which
do not ariſe from the boſom of a leaf, but from lower parts of the
caudexes of a branch-bud, as from the bark of a branch, whoſe fum-
mit has been cut off, are leſs mature, I believe, than the ſummit-buds,
or thoſe which ariſe from the boſom of a leaf; and will therefore re-
quire ſome years before they can produce flowers; as is ſeen in thoſe
apple or pear trees, whoſe ſummits have been entirely lopped off.
This is a new obſervation, I believe, and worth the attention of thoſe,
who inoculate the buds of one fruit-tree into another.
Root-fuckers may probably be liable to degenerate in reſpect to
their vigorous growth by hereditary diſeaſes, owing to the too great
age of the original plant of that variety, like the ingrafted fcions from
the branches. Whence it may be neceſſary to procure root-fuckers of
raſpberry-plants, and of gooſeberries, and even of artichokes, and
ſtrawberries, from ſuch as have been raiſed from ſeed not too long
ago, when any of theſe begin to degenerate.
3. Of Planted Scions.
The fcions taken from the branches of many trees, if planted in
the earth, will emit roots, and flouriſh in the ſame manner, as when
they are grafted on other trees. This fucceeds with great certainty,
if an inverted glaſs be put over them for a few days to prevent their
perſpiring more at firſt, than their abſorbent vefíels can ſupply. See
Sect. I. 1. I have been informed, that a quickſet, or hawthorn
9
hedge,
a

Secr. XV.1.3.
383
OF FRUIT S.
а
a
hedge, cratægus, was thus planted and became a good fence con-
fiderably ſooner than from ſowing the ſeed.
The Chineſe are ſaid by fir G. Staunton to be unacquainted with
the art of ingrafting, and to produce dwarf fruit-trees, which are
brought to table loaded with fruit at their feſtivals, by ſurrounding a
branch of a bearing fruit-tree at its bifurcation with a bag of earth,
which is kept moiſt for ſome months; till the branch puts out roots,
probably from the lips of a wound in the bark, and is at length ſepa-
rated, and tranſplanted into a pot. Embaſſy to China, Vol. II. p. 54,
8vo. edition, and it is then rendered a dwarf by repeatedly cutting
out the central buds, as in the management of melons, as mentioned
in No. 2. 5. and 3. 2. of this Section.
Vines poffefs fo vigorous a power of vegetation, that the preſent
moſt approved method of propagating them in grape-houſes conſiſts
in planting their ſcions. The late Rev. John Michel of Thornhill,
in Yorkſhire, the philoſopher, who diſcovered to the world the art of
making artificial magnets, which had been concealed by Mr. Knight;
whoſe friendthip I long poflefled, and whoſe loſs I have long lament-
ed; amuſed himſelf and family at vacant hours in his hot-houſe.
The obſervations of a man of ſuch accurate and univerſal knowledge
are always worth recording; and though his ideas on this ſubject
have already appeared in Mr. Speechly's Culture of the Vine, I ſhall
here tranſcribe a part of one of his letters to me dated in May 1785.
“ The way in which we raiſe our vines we account our own; for
I don't know, that it was practiſed by any body before we ſet the ex-
ample. It is now pretty generally adopted however by the gar-
deners and nurſerymen in this part of the world. Inſtead of leaving
three or four eyes on the cuttings, as uſed formerly to be done,
which made them awkward ſtraggling things, we never plant more
than a ſingle eye to each, cutting them with as long a part below.
the eye as they can admit, without encroaching too much upon the
next eye below; that is to ſay, we leave perhaps about half an inch,
or

384
PRODUCTION
Sect. XV. 1.3.
a
a
or a little more, as it may happen, above it. Theſe cuttings we
plant by half a dozen or a dozen together, at the diſtance of three,
four, or five inches, in the bark-bed, where it is pretty warm, but not
ſo hot as to endanger the burning of the roots, when they ſhall come
out; and where it is alſo pretty moiſt, or elſe we water them. We
plant them floping ſo as to make an angle of about thirty degrees
perhaps, a little more or leſs, with the horizon, the eye being higheſt;
but taking care that it alſo ſhall be covered about an inch with the
baik, which is a very neceffary precaution ; for though it ought juſt
to ſmell the freſh air, it muſt be kept moiſt, to prevent the bud and
ſhoot, when it comes, from drying; otherwiſe it will very fre-
quently die away preſently after it has ſhot a little, or at beſt it will
grow unkindly, not having yet made roots ſufficient to ſupply it with
the fap necefiary for its ſupport; which will not be the caſe, if the
bud is ſufficiently covered at firſt, and till it has acquired more roots.
We generally plant our vines in this way, about the beginning or
middle of January ; and if the bark is pretty warm, and as moiſt as
it ſhould be, the cuttings will begin to puſh both at top and bottom
in about a fortnight or three weeks at the moſt. When the vines
have ſhot a little, perhaps three or four inches, but before the roots
are got too long, in which caſe it would be impoſſible to avoid break-
ing them by removing, on account of their extreme tenderneſs and
brittleneſs) we diſplace a good deal of the bark very near them, till
we can throw them down all together, which ſhakes the bark very
gently from their roots; ſo that one may diſengage them ſufficiently
eaſy, and without much hurting them. We then plant three or
four of the moſt promiſing and thriving ones out of the whole num:
ber fingly in ſmall pots in earth, which has previouſly ſtood in the
hot-houſe a day or two to get warm, letting the roots drop down on
a little earth at the bottom, at firſt, as they conveniently can, and
then covering them with more earth carefully, till the pot is pro-
perly filled, and the item about three or four inches long, as I ſaid
before,
a

SECT. XV. 1.4. OF FRUIT S.
385
more room.
before, ſtanding in the middle; and then plentifully watering the
earth to ſettle it to the roots. We now plunge them again in the
bark, where in five or fix weeks, more or leſs, they will have filled
their pots pretty well with roots; when they will begin to fhew by
their little progreſs, and the ſmallneſs of the ſhoots, that they want
We then take them carefully out of theſe ſmall pots,
diſturbing the ball of earth as little as poſſible, and put it all together
into larger pots, putting a little freſh earth at bottom and round
about, and watering well as before; and we then again plunge them
into the bark.
By about the latter end of May, or beginning of June, the beſt
of them will be four or five, or perhaps fix feet high, and ought now
to be removed, diſturbing the roots as little as poffible, into the na-
tural ground, where they are to remain. If this is done carefully,
and the earth well watered about them to ſettle it to their roots, they
will frequently begin growing again almoſt immediately, but at leaſt
in three or four days; and will then often ſhoot in the hot-houſe two
inches in a day, and by the end of the year will have ſhot from
eighteen or nineteen, to three, four, or five and twenty feet. Though
we approve of this as rather the beſt, yet if theſe cuttings are planted
in the ſame way either fingly in ſmall pots, or two or three together
in each, with earth, inſtead of planting them in the bark, deſtroying,
all but the beſt one, when they have ſhot a little, and plunging them
either in the bark, or in default of a bark-bed, in a common hot-bed,
they will do equally, or nearly equally well; only taking care, that
the hot-bed is not too hot, ſo as to injure the roots, of which there
is fometimes danger.”
a
4. Of Ingrafted Scions.
The art of ingrafting trees is of great antiquity, and is attended
with numerous well known advantages, but is not yet arrived to its
utmoſt
3 D

386
SECT. XV. 1.4
PRODUCTION
utmoſt perfection ; for it is not yet certainly known, whether the in-
grafted ſcion gives or takes any property to or from the tree, which
receives it, except that it acquires nouriſhment from it.
There is one inſtance recorded by Bradley, where the ſcion of a
variegated jaffamine gave variegation to the leaves beneath it of the
unvariegated jaffamine, on which it was ingrafted, though the graft
itſelf periſhed. See Sect.V.1. This ſeems to fhew, that a commu-
nication of juices exiſts between the graft and the ſtock; and that
thus ſome change in the colour of the leaves of the ſtock might be
occaſioned by the inoſculation of the veſſels of the new bud with
thoſe of other buds in its vicinity. Thus if a ſcion of a purple grape
was ingrafted on a white one, the leaves of the latter might proba-
bly become ſomewhat red in the autumn, like thoſe of the purple-
vine; but there are no inſtances recorded, where this communication
of juices from the graft to the ſtock, or from the ſtock to the graft,
has varied the flavour or the form of the flowers, or fruit of either
of them.
For though the fame vegetable blood paffes along both the upper
and lower part of the caudex of the new ſcion, which extends from
its ſummit on the branch to its baſe in the earth; yet the molecules
ſecreted from this blood are felected or formed by the different glands
of the part of the caudex, which was brought with the ingrafted
ſcion, and of the part of it which remained on the ſtock, in the ſame
manner as different kinds of ſecretions are produced from the ſame
blood in animal bodies.
Some have nevertheleſs believed, that fcions, ingrafted on more
vigorous trees of the fame genus, have acquired greater vigour in the
growth both of their leaf-buds and fruit-buds. Mr. Speechly afferts,
that he has improved many kinds of vines by ingrafting thoſe, which
bear ſmall grapes, and which have generally weak wood, on ſtronger
ones, which he has often experienced ; and recommends the Syrian
vine to graft upon, and prefers thoſe, which were raiſed from ſeed
8
for

Secr. XV. 1. 4.
OF FRUIT S.
387
for this purpoſe; and the contrary ſeems to appear, where more vi-
gorous ſcions have been ingrafted on lefs vigorous ſtocks; as apple-
fcions on crab-ſtocks; where in a few years the part above the graft-
ed joint becomes much larger in diameter than that below it.
Grafted fcions ſucceed well in general on trees of the ſame genus,
as in the common ingraftment of fruit-trees; ſo the laurel, prunus
lauro-ceraſus, will grow on the common cherry, prunus ceraſus, and
produce a tall evergreen tree. But there are ſaid to be inſtances alſo
of ſucceſs in the ingraftment of trees not only of different genera,
but even of different orders, and claſſes; as I have been informed, that
apple-fcions, pyrus malus, have grown, when ingrafted on hazels,
corylus. And one of the fathers of the Carthuſian order is ſaid to
have ſucceeded in grafting a vine, vitis, on a fig-tree, ficus; and a
jaſſamine on an orange. Travels in France and Italy, by E.Wright.
It is hence probable, that many new diſcoveries might be made by
more frequent experiments on this ſubject.
It nevertheleſs appears, that in grafted trees, though the ſtock an-
nually becomes covered with a new bark, as well as the graft, yet it
does not change its nature; ſince any new buds, which come out
from the ſtock afterwards, are ſimilar to the ſtock, not to the graft ;
and in many trees the graft grows ſo much faſter as to become nearly
of double the diameter of the ſtock, as is frequently ſeen in old
cherry-trees, and is ſpoken of in Sect. VII. 1. 7.
Thus the buds of fruit-trees, like the bulbs of tulips, when raiſed
from ſeed, annually improve in their colour, length, thickneſs, and
eften in the ſhape of their leaves, for a certain number of years; and
then acquire a male, or a female, organ of reproduction, as in the
claſſes of monæcia, and diæcia; or both, as in hermaphrodite flowers.
After this period the central buds and bulbs annually produced are in
every reſpect ſimilar to their parents, as mentioned in Sect. VII. 1. 3.
except in the nearer progreſs to old age of the tree, or of the bulb-pro-
geny; and the conſequent tendency to hereditary diſeaſes. But the
3 D 2
lateral

388
SECT. XV. 1.4.
PRODUCTION
lateral buds from the lower parts of the caudex of the central ones,
which are not generated in the bofoms of leaves, are of a more im-
mature kind, and in that reſpect do not reſemble the central bud, or
bulb; but require ſome years before they flower.
Mr. Knight has obſerved, that the grafts from thoſe fruit-trees,
which have been in public eſtimation for a century or two, are now
ſo liable to canker, that they bear very little fruit, and are not worth
cultivation; which he aſcribes to the age of the tree; as a graft he
ſays is fimply an elongation of the parent tree. And as it demands
ſome years to acquire the puberty neceſſary for ſexual generation, ſo
it may become weak and inirritable by age, and periſh about the ſame
time with the original tree; which is ſomewhat countenanced by
another remark of Mr. Knight, that the ſummits, or long extremi-
ties of old trees, frequently die many years before ſome ſmaller
branches from the trunk, which continue to flouriſh, as is frequently
ſeen in old oaks as well as in fruit-trees; and which he might ſup-
poſe to be occafioned by the greater age of the terminal buds than
of the lateral ones, as well as from the greater length of their ab-
ſorbent veſſels, and the conſequent greater reſiſtance to the aſcent of
the fap-juice, which may alſo be ſooner impeded, or totally ſtopped
by the inirritability of old age.
Nevertheleſs as the buds of trees are ſucceſſive progenies, and can-
not therefore be liable to old age, as they die annually; the degeneracy
of the buds of very old trees, or of thoſe which have long ſucceeded
each other by their lateral, and not by ſexual generation, muſt ariſe
from their being liable to hereditary diſeaſes only, and not to heredi-
tary improvements, as obſerved above in Sect. XIV. 1.6.
That the degeneracy of ſome plants is owing to hereditary dif-
eaſes, and not to old age, appears from their continuing for long
uncounted periods of time after the production of theſe diſeaſes, as
berberries without ſeeds, and vines without ſeeds, and ſtrawberries
without fruit, though probably with feeds, as the barren hautbois
ſtrawberries,

SECT. XV. 1. 4. OF FRUITS.
389
ſtrawberries, which bear no fruit, ſo called, have perfect ſtamina and
piſtilla, as I this day obſerved with a good lens; to which may be
added thoſe female figs which have no aperture to admit impregna-
tion, and the monſtrous double flowers, which have loſt the power
of ſeminal propagation, and ſome mule-plants, which never poffeff-
ed it.
We have nothing in the animal ſyſtem, except in the polypus, and
a few obſcure inſects, fimilar to lateral generation ; and cannot there-
fore decidedly argue on this ſubject. Nor have we any thing ſimilar
to ingraftment in animals, except that of inflamed parts growing to-
gether, the tranſplantation of teeth, and contruction of artificial
notes from the ſkin of the patient's arm, ſeriouſly delivered by Tali-
cotius, with many engraved plates in a work on that ſubject. But
this ingraftment of noſes was unfortunately burleſqued by the author
of Hudibras ; and perhaps this ingenious idea of Mr. Knight, that the
ingrafted ſcion becomes dileaſed by age, and periſhes about the ſame
time with the parent tree, may be liable to a fimilar ridicule by ſome
future writer on gardening.
So learned Talicotius from
The brawny part of Porter's bum
Cu ſupplemental noſes, which
Would laſt as long as parent breech;
But when the date of Knock was out,
Off drop'd the ſympathetic fnout.
CANTO I. 1. 281.
а
There is an apple ſaid to exiſt at New York in America, which
is aſſerted to be four on one ſide of it, and ſweet on the other fide;
and to have been produced by flitting a fcion of a ſour apple, and ano-
ther ſimilar one of a ſweet apple, taking care to cut the buds of each
ſcion with a very ſharp knife exactly in half, and by applying them
and binding them nicely together, and then ingrafting this double
9
ſcion

390
PRODUCTION
SECT. XV. 1.4.
a
fcion on a tree. I mention this, as it is related by Mr.Jay in the
a .
communications to the Board of Agriculture, Vol. I. part 3 and 4,
,
p. 362; and is referred to in the Memoirs of the American Aca-
demy, Vol. 1. p. 386. But there muſt undoubtedly have been ſome
miſtake in reſpect to the production of ſuch an apple by any method
of grafting, and which is ſo well explained as above by Mr. Bradley.
It only remains here to add in reſpect to grafting, that it is neceſ-
ſary to apply the bark, which contains or conſiſts of the caudex of
the young ſcion, exactly to the bark of the branch, into which it
is inſerted, or applied; and then all ſpecies of ingrafting fucceeds,
whether it is performed on a branch or on a root; and whether by
exciſion, or inoculation, or inarching. But I ſuſpect, that where a
ſingle bud is inoculated, it has often failed from the unſkilful operator
having ſelected a flower-bud inſtead of a leaf-bud; which probably
unites its caudex to thoſe of the ſtock with leſs vigour, and certainly
dies after it has ripened its ſeed; or by his imprudently holding the
bud in his mouth, as he aſcends the ladder, or while he makes the
incifion, and thus deſtroying it by heat, as I once obſerved. A leaf-
bud may in general be diſtinguiſhed from a flower-bud by its being
ſharper pointed and leſs ſpherical.
Where the ſummits of very young ſcions of only a few weeks
old are to be uſed to ingraft with and upon, it may be neceſſary alſo
to apply the pith exactly to the pith; as this ſummit bud is yet a
primary being, and not like a lateral one, whoſe whole caudex exiſts
in the bark, which adheres to it, when it is taken off for inocula-
tion.
The choice of buds for the purpoſe of inoculation is probably of
more conſequence than has hitherto been imagined. As we have
endeavoured to ſhew, that buds from parts of the bark diſtant from
the central bud, and which are not generated in the boſom of a leaf,
are in different ſtates of maturity; they muſt require more years be-
fore they can produce a ſexual progeny of flowers, and a conſequent
feminal
a
a

Secr.XV. 1.5.
391
OF FRUITS.
feminal offspring, with the refervoir of nutriment, or fruit, which
attends it. A ſubject which is new, and merits to be further inquired
into.
It is curious to obſerve, that when harſher fruits become ſweeter,
that the bloſſom becomes whiter, as is univerſally ſeen in thoſe of our
native crabs, and of our cultivated apples; and that the buds become
larger, and the green leaves alſo become of larger area, and of paler
complexion.
Thus Mr. Knight obſerves, “ that the width and thickneſs of the
leaves generally indicate the ſize of the future apple; and the colour
of the black cherry and purple grape may be known by their autum-
nal tints; and that even in plants, which have ſprung from feed in
the preceding ſpring; as the tinging matter in the leaves of theſe
plants is probably of the ſame kind as that, to which the fruits will
in future owe their colour.” The leaves of the purple grape become
quite red in autumn, as well as thoſe of the geranium robertianum,
and many other kinds of foliage, which I ſuppoſe may be owing to
their abundancy of acid, which uniting with the blue part of what
conſtitutes along with the yellow part the green colour of vege
table leaves, converts it to red; as it changes the colour of blue
flowers into red ones.
5. A tranſlation of the beautiful lines in Virgil's Georgics on ine
grafting may amuſe the reader.
а
Where cruder juices ſwell the leafy vein,
Stint the young germ, the tender bloſſom ſtain;
On each lop'd ſhoot a foſter ſcion bind,
Pith preſs’d to pith, and rind applied to rind.
So ſhall the trunk with loftier creſt aſcend,
And wide in air robuſter arms extend,
Nurſe the new buds, admire the leaves unknown,
And bluſhing bend with fruitage not its own,
II. TO

392
Secr. XV. 2. 1:
PRODUCTION
II.
TO INCREASE THE NUMBER OF FRUIT-BUDS.
m
a
The terms ſtrength and weakneſs, in their uſual acceptation, when
applied to the vegetation of trees, are metaphorical expreſſions, or
denote the effect or conſequence, rather than the cauſe, of their
bearing leaf-buds or flower-buds, as ſpoken of in Sea IX. 2.7. For
the production of leaf-buds, or flower-buds, though it may be ſaid to
accompany the greater or leſs vigour of a tree, depends on the "fa-
cility or difficulty, with which the long caudexes of the new buds,
which conſtitute the filaments of the bark, can be generated.
Thus the new vegetable production formed in the axilla of a leaf
about Midſummer, which is called a leaf-bud, conſiſts of many em-
bryon buds, perhaps twenty or thirty, which are to form the next
year's Thoot ; and each of theſe muſt be furniſhed at the ſame time
with a long caudex in miniature, extending from the leaf or ſummit
to its radicle or baſe; which conſiſts of umbilical veſſels for its verval
nutriment, and of a continuation of other abſorbent veſſels, and of
arteries and veins, as deſcribed in Sect. VII. 1.7. which paſſes along
the branches and trunk from the apex or leaf of the bud in the air
to its baſe or radicle in the ground; and which thus forms the new
bark, and contributes to thicken and ſtrengthen the trunk and branches
of the tree; becauſe each new leaf-bud with its ſummit, caudex, and
radicle, continues afterwards to adhere to the parent tree.
But the production in the axilla of a leaf, which is called a flower-
bud, or fruit-bud, confifts only of an individual vegetable with the
rudiments of a number of flowers, with one caudex for its growth
and nutriment; for as the ſeed falls from the tree, when ripe, no
new apparatus of caudexes in miniature for each individual feed, as
for each individual embryon-bud, is required to paſs down the trunk
into the ground to form a new bark, and thus to thicken and
to ſtrengthen the trunk and branches.
Add
a

SECT. XV. 2. I.
393
OF FRUIT S.
3
Add to this, that not only the ſeeds require no new caudexes to
país down the trunk, but that probably the ſtamina and coral of each
flower ſtrike their roots only into the blood-veſſels, which commu-
nicate with the bractes, like moſſes or funguſes, which grow on trees,
or like cuſcuta, dodder, viſcum, mifletoe, and tillandla, and epiden-
drum; and therefore require no caudexes and radicles to paſs down
into the ground.
Whence it appears, that by rendering it more difficult for new
buds to acquire new caudexes along the branches or trunk from the
ſummit into the ground, the tree will be neceſſitated to produce
flower-buds in preference to leaf-buds; a theory, which was firſt de-
livered in the Botanic Garden, Vol. I. canto 4. l. 470, note, and ex-
plains the whole art of the management of fruit-trees.
Vegetables therefore in reſpect to their mode of propagation are ei-
ther viviparous or oviparous. The live progeny of vegetables con-
ſiſts of the buds, which riſe on their branches in the boſom of each
leaf, or on its long caudex extending down the bark of trees ; or
which ariſe on the bulbs, knobs, wires, or ſcions, from the broad cau-
dex on the roots of herbaceous plants. The egg-progeny
of
vege-
tables conſiſts in their feeds, with the previous apparatus of the
flower, and concomitant nutriment in the fruit and cotyledons. And
as plants, or parts of plants, are ſaid to be in greater vigour, when
the viviparous progeny is prevalent; as the caudexes of this adherent
offspring form a new bark, and thence thicken and ſtrengthen the
trunk and branches; and to be in leſs vigour when the oviparous
progeny is prevalent; as the ſeeds fall from the tree, and confe-
quently require no caudexes to form a new bark, and thence to
thicken and ſtrengthen the tree. We ſhall generally uſe the word
viviparous inſtead of vigorous, when applied to vegetables, which ge-
nerate leaf-buds principally; and oviparous inſtead of weak, when
applied to vegetables, which generate flower-buds principally; for the
words
3 E

394
PRODUCTION
Secr.XV. 2.1.
words vigorous or weak may properly expreſs the greater or leſs
health of vegetables in both theſe ſituations.
The reader will pleaſe to obſerve, that in the Botanic Garden we
have called the bark of trees an intertexture of the roots of each in-
dividual bud; but that this is not accurate language, as the filaments,
which conſtitute the bark, are each of them the caudex of a bud, or
central part of it; which has a leaf at its upper extremity, and a ra-
dicle at its lower one. And that each new caudex, or bark filament,
is generated along the whole trunk of the tree by the caudex or bark
filament beneath it; as appears in thoſe fruit-trees where one, or two,
or three ſcions have been ingrafted on each other, as mentioned in
Sect. VII. 1.7. for in theſe compound trees, when a bud ariſes from
any part of the trunk, it is ſeen to reſemble that part of the ſtock,
and not to reſemble the new grafted fcion above it. We finally fupa
poſe, that this whole long caudex of a new bud is generally generat-
ed all at the ſame time by the ſympathetic action of the parts of
the parent caudex along with the bud in the bofom of the leaf of
that parent caudex ; and that it is not gradually produced, as we firft
ſuppoſed, by the elongation of the roots of each budlet in the boſom
of the leaves.
The following methods will contribute to prevent the young buds
from ſo readily acquiring new caudexes on the trunk of the tree; and
will therefore retard the generation of leaf-buds, and conſequently
aſſiſt the generation of fruit-buds; and ſhould be executed about
Midſummer, or ſoon after, as at that time the new buds are formed.
1. The firſt method confifts in bending the viviparous branches to the
horizon, which converts them into oviparous ones, for by the curvature
of ſuch branches the bark will be compreſſed on the under fide, and
extended on the upper ſide of the curve, and its vefſels on both ſides
will be contracted in their diameters, and thus the difficulty of pro-
ducing new caudexes for the generation of embryon leaf-buds will
6
be

Sect. XV. 2. I.
395
OF FRUIT S.
be increaſed, in whatever ſtate of miniature they may be conceived
to exiſt.
a
a
A curious fact ſeems to be eſtabliſhed by the experiments of Dr.
Walker in the firſt volume of the Edinburgh Tranſactions, which
ſhews, that the bending of a branch even below its inſertion into the
trunk does not impede the aſcent or derivation of the vernal fap-juice
into it; but on the contrary, that it rather appears to aſſiſt it, reſem-
bling in ſome meaſure a capillary ſyphon, as mentioned in Sect. III.
2. 4. which may be owing to the vernal fap-juice aſcending princi-
pally, or entirely, in the fap-wood, as appears by the new leaves ex-
panding to a certain degree on decorticated oak-trees, as ſhewn in
Sect. IX. 2.8. And as the veſſels of this alburnum are more rigid,
they may be leſs liable to contraction or coarctation by bending down
the branch than the bark-veſſels, as well as from their being placed
within the latter, and therefore leſs liable to compreſſion beneath the
curvature, and to elongation above it.
Whence it appears, that the bending down a branch of a fruit-tree
а
below the horizon does not diminiſh the nutriment of the fruit-buds,
but rather increaſes it; as Dr.Walker obſerved theſe buds to grow
ſooner and larger at the extremities of the bended branches than on
other parts of equal height.
It was aſſerted by Mr. Lawrence, that the more the branches of
any tree are carried horizontally, the more apt that tree is to bear
fruit; and that the more upright or perpendicular the branches are
led, the more diſpoſed is that tree to increaſe in wood; which he
aſcribes to the bending down of the branches impeding the circula-
tion of the ſap. Art of Gardening. Mr. Hitt in his Treatiſe on Fruit
Trees, affirms, that if a vigorous branch of a wall-tree be bent down
to the horizon or beneath it, it loſes its vigour, and becomes a
bearing branch; and therefore recommends his method of nailing the
branches of wall-trees, and of tying thoſe of eſpaliers, in an hori-
zontal direction or ftill lower; as in this conſtrained ſituation there
a
muſt
3 E 2

396
SECT. XV. 2.2
PRODUCTION
a
muſt occur greater difficulty, I ſuppoſe, in the production of the new
caudexes, neceſſary for the embryon progeny of buds, upwards or ho-
rizontally along the bended branch contrary to their natural habits,
as well as from the compreſſion of the bark beneath the curvature
of the branch, and its extenſion above it; whence more flower-ſhoots
are produced, which do not require new caudexes to paſs along the
bended branch ; but which permit their progeny, the feeds, to fall
upon the earth, and penetrate it with their new roots.
In Lord Stafford's gardens at Trentham I remember to have ſeen
many years ago ſome ſtandard dwarf apple-trees with all their
branches bent down, and fixed on a flight frame-work about a foot
from the ground'; which ſeemed to be uncommonly prolific, as a
circle of white and purple flowers twenty feet in diameter on branches
radiated from a center, appeared to a diſtant eye like a lunar halo, or
a carpet of rich embroidery. doloroso bus
The greater production of fruit-buds on branches bended to the
horizon muſt contribute, I ſhould ſuppoſe, to the prolific effect of
training nectarine and peach-trees on tiles laid on the ground, or on
the gentle declivity of a bank of earth facing the ſouth, which has
lately been recommended by ſome one, whoſe name I do not recol-
lect, who gained a patent for his diſcovery. And it is indeed proba-
ble, that both theſe modes of training fruit-trees, one of which may
be called an horizontal wall-tree, and the other an horizontal eſpa-
lier, would repay the labour of the horticultor ; as they would be ex-
poſed to a more vertical fun in ſummer, which might more cer-
tainly ripen their fruit; and would be kept ſomewhat backwarder in
the early fpring, by the greater obliquity of the ſun-beams, and might
be therefore leſs liable to injury from the vernal froſt; and when in
bloſſom might eaſily be covered in the night, when neceſſary, by
mats thrown over them ſupported by ſtakes with horizontal poles
on them.
2. Secondly. The twiſting a wire, or tying a waxed ftring, round
the

Secr. XV. 2.3. OF FRUITS.
397
the viviparous branches of a tree, induces them to become oviparous, as
obſerved by Mr. Whitmill, who bound not only the viviparous ſhoots
of various wall-trees with ſtrong wire, but alſo fome of their large
roots, and thus increaſed the product of his fruit. Bradley on Gar-
dening, Vol. II. p. 155. And M. Buffon produced the ſame effect: by
a tight cord round the branches, which previouſly produced leaf-
buds inſtead of flower-buds. Act. Paris. ann. 1738.
M. Buffon concludes from the above experiments, that an ingraft-
ed branch bears fruit more copiouſly, and more certainly, from its
veffels being compreſſed by the callus around the ingrafted junction;
which may have this effect, and at the ſame time contribute by pre-
venting the luxuriant growth of its leaf ſhoots to render the tree of
more dwarfiſh ſtature. I am informed that many dwarf apple-trees,
which are now planted in garden pots both in France and England,
bear much fruit, and are elegantly placed in the centre of a deſert at
luxurious tables ; and that the principal art of producing them con-
fifts in ingrafting them three or four times, ſcion on ſcion ; ſo that
the ſtem is compreſſed by the callus of three or four ingraftments bes
fore the branches are permitted to divaricate ; and the trees are thus
rendered beautiful dwarfs.
The effect of thus compreſſing the bark by a wire, or a cord, or by
the callus round the junctures of the ingrafted ſcions, is undoubtedly
accompliſhed by the increaſed difficulty oppoſed to the production of
the caudexes for each new embryon leaf-bud, as above explained, and
the conſequent generation of flower-buds inſtead of them.
3. Thirdly. The wounding, or breaking a viviparous branch, or cut-
ting away a ring of the bark, as of pear-trees, or a ſemi-cylinder of the
bark of other fruit-trees, induces them to become oviparous.
Where young trees diſcover too great vigour, Mr. Lawrence ad--
viſes to cut the moſt vigorous ſhoots two parts in three through, leav-
ing a large notch, that the wound may not heal too ſoon ; which he
adds will both render them fruitful, make them more readily cone
form
a

398
PRODUCTION
Secr. XV. 2.3.
a
form to the wall or eſpalier, and preſerve ſuch as are dwarfs from
too much aſpiring in very ſtrong branches, eſpecially of pears; he re-
commends two or more ſuch inciſions to be made in the ſame
branch.
Another method he propoſes is to break the too vigorous branches
half through with the hand, which he has practiſed with ſucceſs in
apricots and peaches, when the branches were formed directly for-
ward from the wall, and theſe branches have continued ſeveral
years
to bear fruit, though foine have occaſionally died by effufing gum;
and though theſe inciſions and breaking the branches may be per-
formed at any time of the year, he prefers the ſpring on account of
the wet or froſt of winter. Art of Gardening.
A complete cylinder of the bark about an inch in height was cut
off from the branch of a pear-tree againſt a wall in Mr. Howard's
garden at Lichfield about five years ago ; the circumciſed part is now
not above half the diameter of the branch above and below it, yet this
branch has been full of fruit every year ſince, when the other branches
of the tree bore only ſparingly. I lately obſerved, that the leaves of
this wounded branch were ſmaller and paler, and the fruit leſs in ſize,
and ripened ſooner than on the other parts of the tree; and another
branch has the bark taken off not quite all round with much the ſame
effect.
The theory of this curious vegetable fact receives great light from
the foregoing account of the individuality of buds. A flower-bud dies
when it has perfected its feed, like an annual plant, and hence re-
quires no place on the bark for new caudexes to paſs downwards ;
but on the contrary leaf-buds, as they advance into ſhoots, form new
buds in the axilla of every leaf; which new buds require new cau-
dexes to paſs down the bark, and thus thicken as well as elongate
the branch. Now if a cylinder of the bark be deſtroyed, many of
theſe new caudexes cannot be produced; and thence more of the buds
will be converted into flower-buds.
In

SECT. XV. 2.3.
399
OF FRUITS.
In this curious circumſtance the caudexes of the buds of the tree
above the decorticated part ſeem to have emitted ſhort radicles into
the alburnum ; the veſſels of which muſt thus have acted as capillary
tubes between the upper and lower caudexes of thoſe buds; as capil-
lary tubes will raiſe water by the attraction of their internal ſurfaces
nearly to their ſummits, when they are not too high in proportion to
their diameter ; but water will in no cafe flow over their fummits,
but will always ſtand with a concave ſurface below the uppermoſt
rim of the tube, in which ſituation it may readily be abſorbed by ve-
getable radicles; and may be ſupplied from beneath by the fap-juice
raiſed by the vegetable action of the abſorbent veſſels of the caudexes,
whoſe radicles terminate in the earth.
It is cuſtomary to debark oak trees in the ſpring, which are intend-
ed to be felled in the enſuing autumn; becauſe the bark comes off
eaſier at this ſeaſon; and the ſap-wood, or alburnum, is believed to
become harder, and more durable, if the tree remains till the end of
fummer. The trees thus ſtripped of their bark put forth ſhoots as
uſual with acorns on the ſixth, ſeventh, and eighth joints, like vines;
but in the branches I examined the joints of the debarked trees were
much ſhorter than thoſe of other oak-trees, the acorns were more
numerous, and no new buds were produced above the joints which
bore acorns. From hence it appears, that the branches of decorticated
oak-trees produce fewer leaf-buds, and more flower-buds. And ſe-
condly, that the new buds of debarked oak trees continue to obtain
moiſture from the alburnum after the ſeaſon of the aſcent of the ſap
in other vegetables ceaſes; which in this unnatural ſtate of the de-
barked tree may act as capillary tubes, like the alburnum of the ſmall
debarked cylinder of a pear-tree above mentioned ; or as the veſſels
of the alburnum may not yet have loſt their vegetable life, they may
continue to abſorb fap-juice or water from their radicles, and carry
it to the buds at the ſummits by their ſpiral contractions as in the
bleeding ſeaſon.
It

400
PRODUCTION Secr. XV. 2. 3.
It is probable, that if oaks were debarked in the ſummer, that much
fewer leaf-buds would appear amidſt the flower-buds; becauſe many
of the latter muſt be advanced too far, when the trees are debarked
in the ſpring, to be converted into flower-buds by preventing the
production of their caudexes, or by impeding the aſcent of the nu-
tritive ſap-juice ; which in theſe trees is lodged principally I ſuppoſe
in the alburnum, as ſpoken of in Sect. IX. 2. 8. On the ſame ac-
count, when much fap-juice is taken in the vernal months from the
birch or maple for the purpoſes of making wine in this country, or
ſugar in America, I am informed, that no great difference occurs in
the reſpective numbers of flower-buds or leaf-buds, which then
ſucceed; but that the general luxuriance of the tree is diminiſhed ;
which evinces, that for the deſign of generating more flower-buds
and fewer leaf-buds by partial decortication, it ſhould be performed
about Midſummer.
The cylindrical or ſemicylindrical decortication of a large root of a
tree, as well as of a branch, is ſaid to anſwer the purpoſe of increaſ-
ing the production of fruit-buds by leſſening the number of leaf-
buds; but may be ſubject to two inconveniences; firſt, that the
wounded root being near the ſurface of the ground may be liable to
rot like the bottoms of hedge-ſtakes ; or like timber, which is kept
in moiſt cellars; or the poſts of wooden bridges, which are alter-
nately expoſed to water and to air. A ſecond inconvenience may oc-
cur from terreſtrial inſects having acceſs to the alburnum of the root,
which is often full of ſweet fap-juice to invite them, and is other-
wiſe generally defended by an acrid rind.
The parts of a tree immediately below a decorticated or a ſtrangu-
lated branch or rdot will generally become viviparous, and will
thence be ſaid to be increaſed in vigour; that is, it will produce
new leaf-buds, and thoſe of a luxuriant appearance; becauſe the in-
jury of the bark of the branch or root will prevent the parts above
from receiving ſo much of the nutritive ſap-juice, as in their ſound
ftate;
a
a

Secr.XV. 2. 3.
401
OF FRUIT S.
a
ſtate; and conſequently the parts beneath will poſſeſs more of it ;
and alſo becauſe theſe new buds are generated from a lower part of
the caudex, and will thence be a few years before they will acquire
that maturity, or puberty, which is neceffary for the generation of
flower-buds, or the production of a ſexual or ſeminal progeny;
whence by ſtrangulating or decorticating the alternate branches of a
pear-tree they will bear for fix or eight years; and the other alternate
ones will become in the ſame time ſtrong and vigorous, ready to un-
dergo a ſimilar operation, when the former ceaſe to be of further uſe;
but the fruit will become ſmaller in ſize, though in greater number,
and ripen earlier in the ſeaſon.
In the ſame manner new root-ſcions are ſaid to be produced by
ſtrangulating a branch of a root near the ſurface with a tight ſtring,
or by ſitting a root near the trunk, Evelyn's Sylva; as in theſe caſes
the aſcent of the fap-juice is impeded, and the part below becomes
viviparous, or produces new leaf-buds for the reaſons mentioned in
the laſt paragraph ; as is frequently ſeen where the end of a branch
is lopped, or beneath the ſcar of the junction of an ingrafted fcion.
On the ſame account it is not uncommon to ingraft with ſucceſs on
roots taken out of the ground, and afterwards replanted; as the ro-
binia on the root of acacia, and any other apples on the roots of the
ſuckers of bur-apple, or codling, mentioned in Sect. IX. 3.5.
For the ſame reaſon the roots of ſome plants, which are otherwiſe
bot eaſily propagated, will ſhoot up buds ; if a part of them next the
ſtem of the plant be half cut through, or raiſed out of the ground,
and expoſed to the air ; as in pyramidal campanula, and geranium lo-
batum. And for the ſame reaſon the lateral branches of numerous
ſhrubs, as well as of herbaceous plants, will put forth roots, when
they are bent down into the ground, if they are previouſly wounded
to prevent the free ſupply of the vegetable nutriment in its uſual
courſe, as in laying carnations, dianthus.
A method of converting the viviparous branches of pear and apple
trees
a
3 F

402
Sect. XV. 2. 3.
PRODUCTION
a
trees into oviparous branches is deſcribed by Mr. Fitzgerald in the
Philofph. Tranſact. Vol. LII. and ſeems to be fuperior to the exſec-
tion of a cylinder of the bark above mentioned ; as the alburnum is
not left naked after the operation. In the month of Auguſt he made
a circular inciſion round the principal branches of ſeveral pear-trees,
apple-trees, plum-trees, and cherry-trees, near the ſtems of each,
quite through the bark. About three or four inches higher he then
made another inciſion round the bark, and then a perpendicular one,
joining theſe two circular ones, and ſeparated the cylinder of bark
nicely from the wood, covering it, and the bare part of the wood,
from the air for about a quarter of an hour, when the wound began
to bleed. He then replaced the bark with great exactneſs, and bound
it round rather tightly with baſs, ſo as to cover the wound entirely,
and half an inch above and below the circumciſions.
In about a month the bark began to ſwell above and below the
bandages, he then unbound them, and found the parts quite healed.
He rebound them ſlightly with baſs, and let them remain ſo till the
beginning of the next ſummer, when he again took off the bandages,
and found them all healthy; and every one of them bore plentifully
that feaſon, though it was in general reckoned a ſcarce fruit year.
He treated two young pear-trees in this manner, which never had
yet had any bloom; on one of them he operated on the main arms,
and on ſeveral of the leſs branches from thoſe main arms; and on
only one of the main arms of the other. The firſt, he fays, bore a
ſurprizing quantity of fruit in the next ſummer; and the circumciſed
arm of the other bore a moderate quantity; though no other part of
the tree had any appearance of bloom.
Mr. Fitzgerald afterwards took a cylinder of the bark from the
branches of two young apple trees about the ſame fize, as exactly as
he could by meaſure; and changing them, bound them each on the
other tree. The bark of one had a leaf-bud and two apples growing
on it; the barks of both of them healed perfectly, the leaf-bud put
forth
a
a

Secr. XV. 2.4.
403
OF FRUIT S.
forth leaves, and the apples remained on and ripened ; and both the
branches bore ſo plentifully, that one broke with its load, and it
was neceſſary to prop the other.
The theory of the ſucceſs of theſe curious experiments confirms
that delivered above concerning the ſcars made by the junction of
ingrafted fcions with the ſtocks; and it is probable, that three or
four circular inciſions through the bark on viviparous pear or apple
trees, or a ſpiral inciſion, as deſcribed in Sect. IX. 2. 8. might anſwer
the purpoſe without detracting and replacing the bark; as ſcars or
callous circles would be thus produced, which might render it more
difficult for the new caudexes of the embryon leaf-buds to be gene-
rated, or their parts united, and conſequently increaſe the number of
flower-buds.
Mr. Fitzgerald further obſerves, that he changed cylinders of the
bark with equal ſucceſs of nectarine and peach trees; and that the
branches thus operated upon were retarded in their general growth;
which coincides with the idea of repeatedly grafting one ſcion above
another on the apple-trees deſigned for dwarfs to be ſet in garden
pots, as deſcribed in No. 2. 2. of this Section.
4. The tranſplanting a viviparous fruit-tree, or deſtroying ſome of its
roots before Midſummer, or the confining its roots in a garden pot, or
on a floor of bricks beneath the ſoil, will induce it to become oviparous.
Mr. Knight, in his treatiſe on the Culture of the Apple and Pear,
p. 83, has the following paſſage. 6. In the garden culture of the
apple, where the trees are retained as dwarfs or eſpaliers, the more
vigorouſly growing kinds are often rendered unproductive by the ex-
ceffive, though neceſſary, uſe of the pruning knife. I have always
ſucceeded in making trees of this kind fruitful by digging them up,
and replacing them with ſome freſh mould in the ſame fituation.
The too great luxuriance of growth is checked, and a diſpoſition to
bear is in confequence brought on.” The ſame obſervation was made
by Mr. Lawrence, who took up trees which were too vigorous ;
a
that
3 F2

404
Secr. XV. 2.4.
PRODUCTION
that is, which produced viviparous buds inſtead of oviparous ones,
and replanted them to render them fruitful. Art of Gardening. Lond.
1723
.
In tranſplanting trees for any purpoſe it may be obſerved, that
they ſhould not be replanted deep in the ſoil, ſince the moſt nutri-
tive or falubrious parts of the earth are thoſe within the reach of the
ſun's warmth, of the deſcending moiſture, and of the oxygen of the
atmoſphere. And as the root-fibres of trees, like thoſe of ſeeds, al-
ways grow towards the moiſteſt part of the ſoil, as the young ſhoots
and leaves grow towards the pureſt air and brighteſt light; it fol-
lows, that the root-fibres ſeldom riſe higher in the ground than they
were originally ſet, and ſeldom elongate themſelves even perfectly
horizontally; ſo that when a fruit-tree is planted too deep in the
earth, it ſeldom grows with healthy vigour, either in reſpect to its
leaf-buds or its flower-buds.
flower-buds.
This curious effect cannot be produced by generally debilitating
the tree from its want of due nouriſhment; becauſe it is faid to fuc-
ceed beſt in very good foil, or by the addition of new garden mould,
as before directed ; but by rendering more difficult the production
of radicles from the caudexes of the embryon leaf-buds; which de-
ſcend to the fineſt ramifications of the old roots, and elongate them-
ſelves beyond the extremities of their ultimate fibrils; a great num-
ber of which roots being torn off by tranſplantation, or compreſſed
in a garden pot, the production or progreſs of many of the new radi-
cles muſt be impeded or prevented; and the numerous caudexes of
new leaf-buds be in conſequence formed with greater difficulty,
whence an increaſed tendency to generate flower-buds.
For the ſame reaſon if beans, vicia faba, which are but a few
inches high, be tranſplanted; they do not become ſo tall, but they
flower and ripen their feeds ſooner; becauſe they can not ſo eaſily
generate new leaf-buds. The ſame occurs in frequently tranſplant-
ing brocoli, braſſica; the plant does not grow ſo tall, but has earlier
flowers,

Secr.XV. 2. 4.
405
OF FRUITS.
а
flowers, and in greater number ; and it is hence better to pluck them
up, than to dig them up, for the purpoſe of replanting them; as by
that means more of the root-fibres are torn off, and the plants be-
come almoſt totally oviparous.
It is well known, that the veffels of animal bodies are leſs liable to
bleed, when they are torn aſunder, than when they are cut with a
ſharp inſtrument; as their diameters are contracted, or their internal
furfaces brought into contact with each other, in the act of extend-
ing them, till they break. Thus if the navel-ftrings of new born ani-
mals are cut inſtead of torn, they are liable to bleed to death; and
there is a remarkable caſe of a miller's ſervant, who had his arm and
fhoulder bone, or ſcapula, torn off in a windmill without much loſs
of blood. This is mentioned to ſhew, that it may alſo be better to tear
up roots, which are tranſplanted for this purpoſe, than to dig them
up; as they may thence effuſe leſs vegetable blood, and in conſe-
quence be leſs weakened by the operation.
In tranſplanting ſtrawberries many of the roots being torn off, fewer
leaf-buds, and conſequent wires, are produced from the difficulty,
which their embryon caudexes find in producing new radicles over
the old ones to ſupply nutriment to the wires, till they bend down
and protrude roots into the ground at their other extremities, whence
a greater number of flower-buds are generated ; on this account the
roots of ſtrawberries ſhould generally be tranſplanted, or new ones
from the wires ſhould be cultivated, every third or fourth year, to pre-
vent the too luxuriant growth of their wires ;, or a ſimilar difficulty
of producing wires or leaf-buds may be effected by crowding the
roots of ſtrawberries together, as ſome gardeners recommend; but
I ſuppoſe by theſe means the fruit may become ſmaller from ſcarcity
of nutriment, though more numerous.
A floor of bricks, or of ſtone, extended about two feet deep be-
neath the roots of wall trees, has been practiſed in ſome gardens from
an idea, that the roots ſhot themſelves too deep into fome unwhole-
fome

406
Sect. XV.2.5.
PRODUCTION
ſome ſtratum of earth; and it has been obſerved, that the trees be-
came better fruit-bearers. In ſome ſituations it is poſſible, this might
be the cauſe of the new prolific property of the trees; but I ſuſpect
it has occurred generally from the difficulty oppoſed to the number
and elongation of the root-fibres, and conſequently to the generation
of the new caudexes of the embryon leaf-buds; whence a greater
production of flower-buds enſued.
In fimilar manner it is aſſerted by one of the Linnean ſchool in the
Amoenitates Academicæ, that ſome bulbous rooted plants, which
ſeldom produce feeds in Sweden, will produce prolific ſeeds, if their
roots be confined in a garden pot, till they crowd each other; as
thoſe of the lily of the valley, convallaria. And that the orchis will
bear prolific ſeeds, if the new root early in the ſeaſon be ſevered from
the old one, which has put up the flower-ſtem. This muſt occur
in the former caſe from the difficulty, which the plants find to ge-
nerate new offsets at their roots, which are their viviparous progeny;
and in the latter caſe from the new offset being deſtroyed ; whence
in both fituations more nutriment is expended on the flower.
On the ſame account it is probable, that confining the roots of cu-
cumbers and melons in ſmall garden pots would ſtop the too lux-
uriant growth of their leaf-buds, and render them ſooner oviparous,
if care was taken to ſupply them with water more frequently, and
with ſufficient nutriment by mixing with the water ſome of the car-
bonic black fluid, which has drained from a manure heap.
5. If the central viviparous branches of a plant be cut away or hort-
ened, the lateral ones will ſooner or more completely become oviparous.
1. There are many very ſmall buds on the lower parts of large
branches, which do not ſeem to grow to maturity, and in confequence
produce neither new leaf-buds nor new flower-buds. There are other
lateral ſhoots on many trees, which only puſh out a few inches, and
are called ſpurs, and which bear fruit the ſucceeding ſummer at their
extremities. In many other plants the lateral branches are oviparous,
6
except

Secr.XV. 2. 5.
OF FRUITS.
407
except at the extremity, which is terminated with a viviparous bud;
while the central branches continue long to generate only a vivipar-
ous progeny, as in vines and melons.
The firſt of theſe, or the unprolific exiſtence of the buds at the
Dottom of large branches, may be owing in part to their feebler ef-
forts of pullulation from the want of fufficient ſunſhine and venti-
lation ; and alſo in part, like the ſpurs, and other lateral branches, to
the difficulty they encounter in producing the embryon caudexes of
new leaf-buds along the trunk ; which is already occupied by thoſe
of the more vigorous vegetation of the central branches, which poſ-
feſs a greater ſhare of ſunſhine and ventilation.
But the principal cauſe, which renders the fpurs and lateral branches
oviparous, reſults from the reſiſtance the embryon caudexes of leaf-
buds experience by the curvature of the lateral branch, where it joins
the trunk, and the conſequent coarctation of its veſſels, added to the
difficulty every lateral bud has to encounter from its own curvature
at its exit from the parent twig; on which laſt account the central
bud at the extremity of an oviparous branch is generally viviparous,
becauſe it has not any curvature at its exit. All this correſponds with
the fact above deſcribed, that when the viviparous arms of wall-trees
are bent down to the horizon, they become oviparous. See No. 2. 1.
of this Section.
2. What then happens in all theſe fituations when the central parts
are cut away or ſhortened? Firſt the dwarf buds at the bottom of
theſe large viviparous branches, which are in part cut away, will find
more room to puſh down the embryon caudexes of new leaf-buds;
and will produce a viviparous progeny; and thoſe at the bottom of
oviparous branches, which are ſhortened by cutting off their vivipar-
ous extremities, will alſo now pullulate, and produce flower-buds for
the ſucceeding year, owing to the derivation of fome of that nouriſh-
ment to them, which would otherwiſe have been expended on the
fummit-bud. Secondly, the ſpurs will generate an oviparous pro-
geny,

408
PRODUCTION Sect. XV. 2. 5.
geny, but will acquire more nutriment, becauſe all the veſſels of
plants inofculate, as mentioned in Sect. IX. 2. 10. and will thence
produce larger fruit, and more certainly ripen it. Thirdly, the other
lateral branches will receive more nouriſhment, and become more
vertical, and will thence find leſs oppoſition to the production of the
caudexes, both of their flower-buds and leaf-buds; either of which
may become ſtronger or more numerous according to the greater or
leſs inclination of the branches to the horizon; and both of them
may be more vigorous properly ſpeaking; that is, they may become
larger leaf-buds, or larger flower-buds, than others of the ſame tree.
3. Thus in the management of MELONS, which would grow into
branches much too extenſive for the artificial glaſs-frames of our
climate, and would not have time to ripen their later fruit in our ſhort
fummers; it is neceſſary firſt to check the vigour, properly ſo ſpeak-
ing, of the whole plant. This is done by waſhing the feed from the
ripe fruit, which ſhould naturally contribute to nouriſh it; and by
keeping the ſeed four or five years, that the mucilaginous nutriment
depoſited in the cotyledons may alſo be in ſome degree impaired ; it
is alſo probable, that confining the roots of melons and cucumbers
in garden-pots, if they were well ſupplied with nutriment, warmth,
and water, might be advantageous for this purpoſe.ws
Secondly, as ſoon as the leaf appears an inch in diameter, experienc-
ed gardeners pick out the central bud, which cauſes an oviparous,
though a more vigorous, lateral ſhoot ; which therefore ſooner bears
fruit, and that of a larger kind; as it acquires more nouriſhment
from the deſtruction of the central one.
And as theſe lateral branches are liable to produce other viviparous
ſhoots at their extremities, after they have generated lateral flower-
buds, it again becomes neceſſary to pinch off the viviparous extre-
mities of them, not only to accommodate them to the ſize of the
glaſs-frame, but alſo to ſupply them with more nutriment, which
would otherwiſe have been expended on the viviparous ſummit.
The

SECT. XV.2.5.
409
OF FRUIT S.
The central bud, or ſummit, of the lateral branches, is generally
viviparous, as well as of the central branches ; becauſe the embryon
caudexes of its new offspring are oppoſed in the production along the
bark by only one curvature at the infertion of the branch into the
trunk; whereas the lateral buds of the lateral branches have the
pro-
greſs of the embryon caudexes of their new buds oppoſed by two cur-
vatures, one of the bud to the branch, and another from the branch
to the trunk.
There is another reaſon, why the lateral buds of many plants pro-
duce flowers ſooner than the ſummit; which is, that the lateral buds
of thoſe plants, where the pith of the upright central ſhoot is not
divided, are propagated from the central ſhoot, and are therefore one
generation older ; and have thus acquired the maturity neceſſary for
amatorial reproduction. In other plants, where the pith of the ſtem
is divided at every joint, the ſummit bud has been preceded by more
generations, and is therefore more mature for the purpoſe of produc-
ing flowers, than the lateral ones, as in a ſtem of wheat ; and pro-
bably in the artichoke, and on the ſpurs of ſome fruit trees, as of
pears.
4. It was obſerved in Sect. IX. 3. 1. that in the ſtems of wheat
three or four joints are formed above each other previous to that,
which bears the ear; and that in many other annual or biennial
plants two or three viviparous lateral ſhoots occur, as in artichoke,
cinara ; and falſafi, tragopogon, before the central one flowers. The
fame happens to the vine-ſhoots; two or three joints with a leaf and
a viviparous bud at each are always firſt produced ; and as each of
theſe have a diviſion of the pith between every joint, as remarked in
Sect. I. 8. I ſuppoſe, that theſe joints are ſeparate plants growing on
each other like the joints of the ſtem of wheat; and that hence in
vine-ſhoots three or four ſucceſſive generations of leaf-ſhoots muſt
exiſt, before the new ſhoot can attain fufficient maturity to form a
flower; as the amatorial generation of ſeeds was ſhewn to require
higher
and com
a
a
3 G

410
Sect. XV. 2.5
PRODUCTION
higher animation, if it may be ſo called, than the lateral generation
of leaf-buds. The ſame mode of growth occurs in the young ſhoots
of oaks, and which is thus curiouſly accounted for.
The lateral branches of many mature trees, though they bear
flower-buds on their fides, are generally terminated with a leaf-bud,
as above explained; but it happens in ſome of them, and particularly
to vines, that after two or three flower-buds are produced on a lateral
branch, that it ſhall proceed to grow in length, and to produce leaf-
buds at every joint above the flower-buds, as well as at the ſummit;
which may be thus perhaps fatisfactorily explained. After the third,
and fourth, and fifth joints of a new lateral ſhoot have generated
flowers, which require few or no more caudexes; room enough is left
on the bark of the ſhoot for thoſe above them to acquire the numer-
ous new miniature caudexes of embryon leaf-buds, and where the new
caudexes of embryon buds can eaſily be produced along the bark, and
fufficient nutriment is ſupplied ; all vegetables are more liable to pro-
pagate themſelves by buds than by ſeeds.
Hence in the management of VINES, as well as of MELONS, it is
uſeful at two or three joints above the laſt bunch of fruit to pinch
off the viviparous end of the new branch, not ſo much to accommo-
date the length of it to the houſe, as to ſupply the growing fruit with
more nouriſhment from the inofculations of the veſſels of the cau-
dexes of theſe viviparous buds, which are now cut off, with thoſe of
the oviparous ones, which remain.
A curious vegetable fact, which appears in the culture of vines in
hot-houſes here preſents itſelf to our notice. When a vigorous ſhoot
advances without producing fruit-buds at the third or fourth joint, it
is frequently permitted to grow in length to above twenty feet; but
at every joint the new or ſecondary bud is pinched off, either foon
after its appearance, or after it has ſhot out one or two joints. By
this management of permitting the central ſummit of the ſhoot to
grow till Auguſt or September, the eyes, whoſe buds have been
9
pinched

SECT. XV. 2.5.
411
OF FRUIT S.
pinched off, do not put out a freſh during that ſummer ; but new
buds are formed at each eye, which germinate the next ſummer, and
almoſt all of them produce fruit.
If however ſome of the ſhoots in the bofom of theſe leaves are
pinched off too ſoon after their appearance, they are occaſionally lia-
ble to generate new leaf-buds, which ſhoot out afreſh from the ſame
eye; and it is ſaid, that theſe eyes, which have thus produced two
leaf-buds in ſucceſſion in one ſummer, will not generally produce
buds of any kind in the ſucceeding ſummer; for as ſeveral of theſe
joints in vigorous vines bear two or three buds from the ſame eye at
the ſame time, ſo others bear them in ſucceſſion.
The theory of theſe important facts may not be eaſy to inveli-
gate; it is commonly ſuppoſed, that pinching off the lateral ſhoots
at every bud of a new vine-branch ſtrengthens the next year's expect-
ed bud, by not expending ſo much nutritive juice; and that giving
the vines a fortnight's artificial heat, after the ſummer heat lefſens,
ripens the wood for the production of the next year's fruit ; but theſe
are words, I imagine, without accurate ideas. I ſuppoſe, when each
lateral ſhoot of this year's branch of a vine is pinched off, that its
caudexes, which had already formed a part of the bark, coaleſce; and
may thus render it more difficult for the caudexes of the ſucceeding
embryon bud in the fame eye, which is to be expanded next ſpring,
to be produced along the bark, by having previouſly occupied the
ſituation which thoſe new caudexes would require; and that thus the
ſecondary buds of theſe eyes become flower-buds, which might
otherwiſe have been leaf-buds.
The continued heat a week or two above the uſual time of ſum-
mer, which is ſaid to ripen the wood, may contribute to dry and
harden it, as well as to forward the growth of the buds; and thus
both to render the protruſion of embryon roots more difficult, and
conſequently to produce flower-buds, and thoſe of a larger kind.
Whether a ſimilar method to this practiſed on vines could be ap-
3 G 2
plied
a
a

412
SECT. XV. 2. 5.
PRODUCTION
a
а
plied with advantage in the management of other fruit-trees is a cir-
cumſtance of great importance, and can only be determined by ex-
periment. But as the firſt foliage of euonymus is generally deſtroyed
by inſects in this country, and yet a ſecond growth of foliage is pro-
duced ; and as I witneſſed laſt year, that the whole firſt leaves of an
apple-tree were deſtroyed, as was believed, by lightning, and which
yet put forth an entire new ſet of leaves in a few weeks ; is there not
reaſon to conclude, that if the leaf-buds were picked out early in the
ſeaſon from a ſtrong ſhoot of peach or apricot, either new leaf-buds
might be produced in that ſummer, or flower-buds in the ſucceed-
ing one, as happens to the vine-ſhoots above deſcribed ; and that our
wall-trees might be thus rendered more certainly prolific. And laſtly,
might not the clipping out with fine fciffars the extremities of young
vine-ſhoots, which would otherwiſe be barren ones, convert fome of
their tendrils into bunches by thus ſupplying them with additional
nutrinient, by preventing its expenditure in the elongation of the
viviparous branch? This experiment might be the more readily
tried, as ſome aſſert, that the barren buds may be diſtinguiſhed from
the prolific ones by their form before they expanda
6. Arts of producing flower-buds.
The following quotation, partly from the Botanic Garden, Vol. I.
Canto 4. 1. 465, may amuſe the reader, and conclude the ſecond part
of this Section.
If prouder branches with exuberance rude
Point their green germs, their barren ſhoots protrude ;
Lop with ſharp ſteel the central growth, or bind
A wiry ringlet round the ſwelling rind;
Biſect with chiſel ſharp the root below,
Or bend to earth the inhoſpitable bough.
So, while oppoſed, no embryon leaf-bud ſhoots
Down the reluctant bark its fibre-roots;
8
New

Sect. XV. 3.1.
413
OF FRUIT S.
New germs ſhall ſwell with amatorial power,
And ſexual beauties deck the glowing flower ;
While the clos'd petals from nocturnal cold
With filken veil the virgin ſtigma fold,
Shake into viewleſs air the morning dews,
And wave in light their irideſcent hues;
With graceful bend the anther by her ſide
Shall watch the bluſhes of his waking bride,
Give to her hand the honey'd cup, or ſip
Celeſtial nectar from her ſweeter lip,
Hang in wild raptures o'er the yielding fair,
Love out his hour, and leave his life in air.
III. TO PERFECT AND ENLARGE THE FRUIT.
It is believed by ſome of the Linnean ſchool, that flower-buds or
leaf-buds may be converted into each other in the early ſtate of their
exiſtence, as mentioned in Sect. IX. 2. 8. It is indeed probable, that
either a flower-bud or leaf-bud may be generated inſtead of each
other reciprocally, before either of them exiſts; but after either of
them has obtained a certain degree of maturity, ſo as to be diſtin-
guiſhed by its form being more pointed or more ſpherical ; I ſuſpect
no addition or detraction of nutriment, or of the facility of the pro-
duction of its embryon caudexes down the bark and radicles beneath
can change its deſtination.
1. Shorten the oviparous branches, when the leaves fall off, by prune
ing their viviparous ſummits, and cut away the root-fuckers. The
fummits of the lateral branches, as well as the erect ones, are fur-
niſhed generally with viviparous buds ; which in many wall-trees
ſhould be cut off, after the leaves fall in autumn; that more nutri-
ment may be derived to the fruit-buds, which may occaſionally be-
come ſomewhat enlarged during the milder days of winter; as they
are now certainly too far advanced to be changed into leaf-buds; and
if
.

414
Secr.XV. 3. 2.
PRODUCTION
if this pruning be deferred till late in the winter months, the flower-
ubds will not be quite ſo forward, as if it be performed earlier. For
the ſame reaſon the root-fuckers alſo ſhould be cut away in the au-
tumn, that all the nutriment, which they would otherwiſe expend,
may be derived to the flower-buds, and induce them early to ea-
large themſelves.
2. Pinch or rub off all uſeleſs viviparous buds in the Spring or ſum-
mer, as they occur. In thoſe trees where the fruit-buds ariſe on the
new leaf-ſhoots along with the leaf-buds, and cannot therefore be
ſooner diſtinguiſhed or approached, as in figs and vines, the ſum-
mit leaf-buds ſhould be pinched off two joints above the fruit-buds,
as ſoon as they appear, that more nutriment may be conveyed to the
fruit-buds. See No. 3. 4. of this Section.
And in the hardier wall-trees the new leaf-buds, which appear
during the ſpring and ſummer months in wrong places, where they
cannot be trained properly againſt the wall, or where they are too
numerous, ſhould be rubbed or pinched off, as they occur; whence
more nouriſhment will be derived to the ripening fruit, and to thoſe
new leaf-buds which are to remain to produce future flower-buds.
And if the new buds, which are ſeen in their young ſtate in the
axilla of the leaves of the new ſhoots, were picked out by the point of
a knife, or pinched off, where they grow long enough for that pur-
poſe, as the ſecondary ſhoots of vines in grape houſes are pinched; it
might probably induce thoſe eyes to produce flowers in the ſucceed-
ing year, as ſpoken of in No. 2. 5. of this Section, as well as con-
tribute to enlarge the preſent fruit by the expenditure of leſs nutri-
ment on the leaf-buds, an idea well deſerving the teſt of experi-
ment.
In the ſame manner in the cultivation of melons and cucumbers af-
ter the central bud is pinched off, as mentioned above, No. 2. 5. the
viviparous extremities of the lateral branches ſhould be alſo deſtroy-
ed, as foon as a fufficient number of female flowers are impregnated;
that

SECT. XV. 3. 3.
415
OF FRUIT S.
that a greater ſhare of nutriment may be derived to them, inſtead of
crowding the frame with new branches, whoſe fruit-buds would be
too late to ripen in our ſhort fummers.
3. Thin all thoſe fruits, which are too numerous; pluck off apricots,
peaches, gooſeberries; and cut out many grapes from each bunch with
Jeiſſars. By the inofculation of the veſſels of vegetables mentioned in
Sect. I. 3, when any parts of a tree are deſtroyed, thoſe in their vi-
cinity become more vigorous. On this account when part of the
fruit is taken away as early as may be, the remaining part acquires
more nutriment. Add to this, that, where fruit is crowded, ſome of
it becomes precluded from the ſun and air, and in conſequence does
not perfectly ripen, and is liable to become mouldy; for mucor is a
vegetable production, which like other fungi does not require either
much light or air, as appears from the growth of ſome funguſſes in
dark cellars, and of common muſhrooms beneath beds of ſtraw, as
mentioned in Sect. XIII. 1. 4.
4. Prevent the produ&tion of new leaf-buds.
In ſome pear trees the whole of the bloſſoms become ſterile, and
fall off without any apparent injury from cold, and this for many
fucceffive years. The ſame occurs ſometimes to cheſnut trees, æf-
culus pavia, after the flower the fructification entirely falls off ; fome
of theſe might be male flowers, as Miller obſerves, but the whole
could not be ſuch. The ſame happens very frequently to the fig-
trees of this climate, ſometimes the whole crop falls off, when they
are about the ſize of filberts; that is, while they are ſtill in flower,
which though concealed within the fig, muſt precede the ſwelling
of the ſeeds, whether theſe be impregnated or not.
A correſpondent fact occurred to me a few years ago. I had fix
young trees of the Iſchia fig with fruit on them in pots in a ſtove.
On removing them into larger boxes the figs fell off, which I aſcrib-
ed to the increaſed vigour of the plants; as they protruded very vigor-
ous ſhoots occaſioned by the accumulation of new ſoil round their
roots.

416
SECT. XV. 3. 4.
PRODUCTION
roots. Perhaps theſe plants might rather be ſaid to have been in
flower than in fruit, and perhaps theſe flowers were all male ones
only, or accompanied only with imperfect female ones?
Whence I conclude, that about the ſeaſon when the corals of theſe
flowers with their ſtamens and ſtigmas die, the trees generate and
nouriſh too many new leaf-buds, owing to the facility with which
they can produce the new caudexes of theſe young buds down the
bark; and that by the whole of the vegetable fap-juice being derived
to the new buds for their preſent growth, or to form reſervoirs for
their future growth, the pericarp and feeds, whether impregnated
or not, are deprived of their due nutriment and fall off. See Sect.
XVI. 1.4.
Hence I propoſe to tie waxed thread or fine wire round the twigs
of pear-trees, which have uſually miſcarried, as ſoon as they are in
flower, ſo as to compreſs, but not ſo as to ftrangulate them; or to
wound the bark by a circular or ſemicircular inciſion, which might
counteract their facility of procreating new leaf-buds; which I ſur-
pect would be more effectual in preventing the flowers from falling
off, than pinching off the new leaf-buds, as they appear; which is
recommended by Dr. Bradley in the management of fig-trees, and is
done to vines in hot-houſes ; but which I found to be ineffectual on
many fig-branches both in the natural ground and in pots, and aſcrib-
ed its failure to the continuance of the efforts of the fig-tree to pro-
duce new leaf-buds; whereas in vines, I ſuppoſe, the grapes would
ripen, whether the new leaf-buds remain or are deſtroyed. See
No.
3.2
2. of this Section.
Pontedera obſerved, that in the iſlands of the Archipelago fome fig-
trees bear in the ſpring many male flowers, and few female ones,
the former of which fall off; and that they bear a ſecond crop chiefly
of female flowers in the autumn, which ripen in the enſuing ſpring.
Anthologia. Can this occur in the fig-trees of this country?
Other figs are ſaid not to ripen but to fall off before their maturity,
unleſs
-

Secr. XV. 3.5.
OF FRUITS.
417
unleſs they be wounded by infects in their caprification, or punctur-
ed by a ſtraw. A further inveſtigation of this ſubject is much wanted
to propagate figs with ſucceſs in this climate. See Botanic Garden,
Vol. II. note on caprificus. See alſo Milne's Botan. Diction. Article
caprification.
5. Give additional moiſture, manure, and warmth, during the early
part of the growth of fruit. By additional moiſture the fruit becomes
larger ; in hot-houſes this may be effected two ways, one by water-
ing the earth on which the vegetables grow, and another by produc-
ing ſteam by watering the warm Alues or floors; which will after-
wards in the colder hours be again condenſed, and ſettle in the form
of dew on the fruit and leaves.
By ſupplying vegetables as well as animals with an abundancy of
fluid, they are liable to increaſe in bulk, both becauſe the external
cuticle, which confines the growth of both of them, becomes relax-
ed, as is ſeen in the hands of thoſe women, who have many hours
been employed in waſhing; and alſo becauſe the cutaneous abſorbent
veſſels will thus imbibe more fluid from the external ſurface; and the
cellular abſorbents will therefore imbibe leſs from the internal cells,
and conſequently more mucus or fat will remain in them.
Thus in Lancaſhire, where premiums are given for large gooſe-
berries, I am told, that ſome of thoſe, who are ſolicitous for the prizes,
not only thin the fruit of a gooſeberry-tree, ſo as to leave but two or
three gooſeberries on a branch, but then by ſupporting a tea-ſaucer
under each of theſe gooſeberries, bathe it for ſome weeks in ſo much
water as to cover about a fourth part of it, which they call ſuckling
the gooſeberry.
In ſome parts of the Carnatic, where rice is cultivated, they are
ſaid not to derive the water on it, till it is in flower; becauſe that
would induce the ſtem to ſhoot too luxuriantly, like our wheat-crops
in wet-ſeaſons; but, as ſoon as it is in flower, they find it expedient
to flood it with water for the purpoſe of filling and enlarging the
3 H
ears,

418
Secr.XV. 3.5
PRODUCTION
ears, (Communications to Board of Agriculture, Vol. I. p. 355,)
which it may effect both by relaxing the cuticle of the grain, and
preventing the too great internal abſorption of the mucus or ſtarch
depoſited in the cells of it; and laſtly by ſupplying it with more nu-
triment.
There are two circumſtances to be attended to in giving water to
plants; which are, not to water them during the hot part of the day
in ſummer, nor in the evenings of ſpring, when a froſt may be ex-
pected ; in both theſe circumſtances we may be faid to copy nature,
as rain is generally preceded by a cloudy ſky, and is never accom-
panied by froſt; though that ſometimes follows it, and is then very
injurious to vegetation.
When plants have been long ſtimulated by a hot ſunſhine into
violent action, if this ſtimulus of heat be too greatly and too ſud-
denly diminiſhed by the affuſion of cold water, or by its ſudden eva-
poration, their veſſels ceaſe to act, and death enſues; exactly as has
too frequently happened to thoſe, who have bathed in a cold ſpring of
water after having been heated by violent and continued exerciſe on
a hot day. When ſevere froſt follows the watering of plants, they
are rendered torpid, and die by the too great and ſudden diminution
of the ſtimulus of heat ; which is equally neceffary to the activity of
vegetable as to animal fibres; and in ſome inſtances the circulation
of their fluids may be ſtopped by the congelation of them; and in
others their veffels may be burſt by the expanſion attending the con-
verſion of water into ice; or laſtly, by the feparation of their different
fluids by congelation. See See. XV. 4. I.
When an addition of manure can be procured, as where the black
carbonic juice from a dunghill mixed with water, or ſoap-ſuds,
which have been uſed in waſhing, can be employed inſtead of water
alone; it muſt undoubtedly add to the nutriment, and conſequently
enlarge
a

SECT. XV. 3. 5.
419
OF FRUIT S.
enlarge the ſize of the fruit by that means alſo, as well as by the ad-
ditional water.
Where too much moiſture is given without at the ſame time an
addition of warmth, ſome inconveniences are liable to occur, as a
lefs aromatic and faccharine flavour of the fruit. When therefore
fruits become nearly ripe, leſs water ſhould be given them, unleſs it
is convenient at the ſame time to increaſe the heat, in which they are
immerſed, as may be done in ſome hot-houſes; and then the flavour
of the fruit may be heightened, as well as its ſize increaſed, as ſhewn
by Mr. Baſtard in the Philoſophical Tranfact, who planted pine-apple
plants in vefſels of water, and placed theſe vefſels near the top of the
hot-houſe, or on the fire-flues, for the purpoſe of fupplying them
with a greater heat; and produced by theſe means both larger, as he
aſſerts, and better flavoured pine apples.
On this important ſubject I ſhall tranſcribe his words, and ſhall
only add, that ſteam from boiling water is now ſucceſsfully uſed in
ſome hot-houſes for the growth both of vines and of pines, but muſt
require ſome attention in the application of it; as it is occaſionally
conveyed through ſmall apertures, which perforate a brick arch,
which is conſtructed ſomewhat like the floor of a malt-kiln, where
the water boils beneath the beds of bark or of ſoil; and is occaſionally
admitted into the room above, and thus ſupplies moiſture and heat
both to the ground and to the air of the hot-houſe.
My hot-houſe is covered with the beſt crown glaſs, which I ap-
prehend gives more heat than the common ſort of green glaſs gene-
rally uſed for hot houſes. In the front part of the houſe, and
indeed any where in the loweſt parts of it, the pine-apple plants will
not thrive well in water. The way in which I treat them is as fol-
lows. I place a ſhelf near the higheſt part of the back wall, ſo that
the pine-plants may ſtand without abſolutely touching the glaſs, but
as near it as can be. On this ſhelf I place pans full of water, about
feven or eight inches deep ; and in theſe pans I put the pine-apple
plants,
3 H 2

420
.
PRODUCTION
SECT.XV. 3.5
plants, growing in the ſame pots of earth, as they are generally
planted in to be plunged into the bark-bed in the common way; that
is, I put the pot of earth with the pine-plant in it in the pan full of
water; and as the water decreaſes, I conſtantly fill up the pan. I
place either plants in fruit, or young plants as ſoon as they are well
rooted, in theſe pans of water, and find they thrive equally well;
the fruit reared this way is always much larger, as well as better fla-
voured, than when ripened in the bark-bed. I have more than once
put only the plants themſelves without any earth, I mean after they
had roots, into theſe pans of water, with only water ſufficient to keep
the roots always covered, and found them flouriſh beyond expecta-
tion. A neighbour of mine has placed a leaden ciſtern upon the top
of the back flue, (in which, as it is in contact with the flue, the wa-
ter is always warm, when there is fire in the houſe,) and finds his
fruit excellent and large. 11
66 The
way
I account for this fuccefs is, that the warm air al-
ways aſcending to the part, where this ſhelf is placed, as being the
higheſt part of the houſe, keeps it much hotter than in any other
part. The temperature at that place is, I believe, ſeldom leſs than
what is indicated by the 73d degree of Fahrenheit's thermometer ;
and when the ſun ſhines, it is often at above 100°; the water the
plants grow in ſeems to enable them to bear the greateſt heat, if ſuf-
ficient air be allowed; and I often ſee the roots of the plants growing
out of the holes in the bottom of the pot of earth, and ſhooting vi-
gorouſly in the water.
“ It is not foreign to this purpoſe to mention, that, as a perſon was
moving a large pine-plant from the hot-bed in my houſe laſt ſum-
mer, which plant was juſt fhewing fruit, by ſome accident he broke
off the plant juſt above the earth in which it grew, and there was no
root whatever left to it; by way of experiment I took the plant, and
fixed it upright in a pan of water (without any earth whatever) on
the

Sect. XV. 3.6. OF FRUIT S.
421
e
the ſhelf; it there foon threw out roots, and bore a pine-apple that
weighed upwards of two pounds.” Philof. Tranſact. Vol. LXVII.
6. Proteet the early flowers and the late fruits from froſt. The vernal
frofts are very pernicious to the early bloſſoms of apples and pears, and
of all the tender wall-trees; various contrivances have been uſed to
ſhelter them, as mats ſuſpended before wall-trees; which in Den-
mark are ſaid to be uſed to ſhelter them from the mid-day fun, as
well as from the night-froſts; both to prevent them from flowering
too early, and being thence expoſed to ſeverer froſts; and becauſe ve-
getables ſuffer more from great cold, as well as animals, after having
been expoſed to great heat, as explained in Sect. XIV. 2: 2:
Thoſe parts of vegetables, which are moſt ſucculent, ſuffer moſt
from froſt, as the young tops of tender trees, as of the aſh, fraxinus,
and weeping willow, falix babylonica ; and alſo all other vegetables
after having been expoſed to much moiſture, as to rain or dews;
which probably may occur in part from the greater ſenſibility of
the tender juicy ſummits of the preſent year's growth, and partly
from the expanſion of their frozen juices, which may burſt the con-
taining veſſels.
An important queſtion here occurs, is a low ſituation to be choſen
for a garden? The greater warmth of low ſituations, and their be.
ing generally better ſheltered from the cold north-eaſt winds, and the
boiſterous ſouth-weſt winds, are agreeable circumſtances; as the N.E.
winds in this climate are the freezing winds; and S.W. winds being
more violent, are liable much to injure ſtandard fruit-trees in ſummer
by daſhing their branches againſt each other, and thence bruiſing, or
beating off the fruit ; but in low ſituations the fogs in vernal evenings,
by moiſtening the young ſhoots of trees, and their early flowers,
render them much more liable to the injuries of the froſty nights,
which ſucceed them, which they eſcape in higher ſituations. Theſe
fogs, which are ſeen by the ſides of rivers, and on damp plains or val-
leys after ſun-ſet, are converted into rime during the night. And as

422
Sect. XV. 3.6.
PRODUCTION
at the time of theſe fogs there is generally no wind, the dew falls per-
pendicularly, and the rime is formed moſt frequently on the upper
ſurface of objects, which may then therefore be more readily ſhelter-
ed from it than at other times, when the freezing fog is blown for-
wards by the wind, and the rime is formed on one ſide of the branches
of trees.
In ſome circumſtances the rime is believed to defend the vegetables
on which it is formed, by the heat it gives out at the inſtant of its
freezing, and by covering them from the cold like ſnow
upon
the
ground; and thence the black froſts, which are not attended with
rime, are ſaid to be more prejudicial. But where dew or miſt de-
ſcends on vegetable leaves before the act of freezing commences, and
is in part abſorbed by them; they become more ſucculent, and hence
are deſtroyed by their fluids being converted into ice, and burſting the
vefſels already diſtended with more water, than they would otherwiſe
poſſeſs. See Sect. XIII. 2. 2.
Mr. Bradley gives a deciſive fact in regard to this ſubject. A friend
of his had two gardens, one not many feet below the other, but ſo
different, that the low garden often appeared flooded with the even-
ing miſts, when none appeared in the upper one; and in a letter to
Mr. Bradley he complains that his lower garden is much injured by
the vernal froſt, and not his upper one.
A ſimilar fact is mentioned
by Mr. Lawrence, who obſerves, that he has often ſeen the leaves
and tender ſhoots of tall afh-trees in blaſting miſts to be frozen, and
as it were finged, in all the lower parts and middle of the tree;
while the upper part, which was above the miſt, has been uninjured.
Art of Gardening. In confirmation of this idea I well remember
many years ago to have travelled fixty miles, partly in the valley of
the Trent, and partly over adjacent hills, on the ſixth of May; and
to have obſerved that the new ſhoots of all the aſh-trees in the val-
lies had their young extremities entirely turned black by the froſt of
the preceding night; but that on the hills they had eſcaped, which
I at

Secr.XV. 3.6. OF FRUIT S.
423
I at firſt aſcribed to the trees being leſs forward on the hills, but be-
lieve it was more probably owing to the greater ſucculence of thoſe
in the valleys, and to their having been previouſly expoſed to the
moiſture of the evening mift.
The precipitation or adheſion of moiſture to vegetables, when miſty
air is blown againſt them, is well deſcribed by Mr.White in his hif-
tory of Shelborne; who obſerved on a foggy day with ſome wind,
that ſo much moiſture was depoſited on a tree, that it ran down uponi
the ground, and filled the ruts of a lane beneath it, which was dry
elſewhere. On the ſame account in the early ſpring the graſs is ſeen
to become green ſooner under the ſpreading branches of trees than in
their vicinity. See Botanic Garden, Vol. I. note 26.
It is hence evident, that very low and damp ſituations are not to be
preferred for gardens and orchards in this climate ; and that it is in
all gardens an object worthy attention to protect in the early ſpring
the bloſſoms and the young ſhoots from being moiſtened by the de-
ſcending night dews; for this purpoſe ſome have put coping ſtones
at the top of the fruit-walls, ſo as to project fix or eight inches over
the trees. By the ſhelter of theſe coping ſtones the deſcending
dews, which would moiſten the young leaves and flowers, are pre-
vented from falling on them, and in conſequence no rime is ſeen in
the morning on theſe trees. I had once an opportunity of obſerving
ſome trees beneath a projecting coping to be much ſafer in reſpect
both to their fruit and foliage, than thoſe in their vicinity, and in
the ſame aſpect, where there were no coping ſtones over them.
But I am informed, that after the vernal froſts have ceaſed, this
kind of ſhelter is certainly injurious to the growth and perfection
of the fruit; which may ariſe from the ſame cauſe, namely, the
want of the ſummer night-dews to moiſten the fruit, and alſo the
perpendicular fun-beams to ripen it. On theſe accounts I have pro-
poſed to make temporary ſheds of boards to project eight inches from
the walls, to be held on by iron hooks, which might eaſily be re-
anoved,
7

424
SECT. XV. 3.6.
PRODUCTION
moved, as ſoon as the vernal froſts ſhould ceaſe; and in one experi-
ment on a ſingle apricot tree it appeared to ſucceed well.
From fome experiments in a late volume in the Philoſophical
Tranſactions, it appears, that very much more rain was caught in
glaſſes placed on the ground near a high church, than was caught in
fimilar glaſſes on the roof of it ; which evinces, that a much greater
quantity of moiſture exiſts in the lower parts of the atmoſphere, and
is precipitated from it, than from the higher parts; whence to pro-
tect the bloſſoms more effectually from the deſcending dews coping
boards might be placed at every two feet or leſs above each other,
with their front edges pointing upwards to the meridian fun in
March, and ledges nailed on the back edges to convey the rain or
dews towards the central part of the tree, where by another croſs
ledge at the end of each board it might be carried from the wall.
A ſimilar inconvenience from autumnal froſts affects ſome of the
late fruits, as figs and grapes, which might alſo receive advantage
from replacing the coping boards in the autumn.
Another method of effectually guarding againſt the vernal froſts,
and alſo the autumnal ones, is by building the garden-walls with fire-
flues in them, which is now frequently practiſed. There is one ſecret
neceſſary to be known, and well attended to, in the management of
fire-flues; and that is in the firſt place to plant trees, which will open
their flowers about the ſame time, againſt the ſame flue, and then
diligently to obſerve not to put fire into this flue, till the trees, it is de-
ſigned to affift, are in flower; ſince if the fire be applied ſooner, the
flowers are forwarded, and in conſequence expoſed to more danger
from the ſeverer froſts. One friend of mine, who diligently attends
to this circumſtance, aſſures me, that he never fails of producing a
plentiful crop of excellent fruit.
And it is poſſible that one uſe of covering apricot trees, before they
flower, from the mid-day fun, which is ſaid to be practiſed in Den-
mark, may be to protract their time of flowering, and thus expoſe
them

SECT. XV. 3.7.
425
.
OF FRUITS.
a
them to leſs danger from froſt, as well as to prevent their irritability
from being exhauſted by the heat, and thus cauſing the night air to
be more injurious to them.
7. Fruits may be fooner ripened by wounding them, or by gathering
them. The wounds inflicted by inſects on many fruits promotes their
more ſpeedy ripening, as well as thoſe inflicted by caprification, men-
tioned in Sect. XIV. 3. 3. and in No. 3. 4. of this Section. It is ſaid
that cutting the ſtalk of a bunch of grapes half through, which has
acquired its due fize, will expedite the ripening of it; becauſe it will
then be ſupplied with a leſs quantity of new juices, and the change
of its acerb juices into faccharine ones, which is partly a chemical,
and partly a vegetable proceſs, proceeds more rapidly. See Sect. X.
8. 1. . On the ſame account the pears on a branch, which has had a
circle of its bark cut away, will ripen its fruit ſooner; and thoſe an-
nual plants, which are ſupplied with leſs water than uſual, both
flower ſooner, and ripen their feed ſooner.
To which may be added, that gathering pears from the tree before
they are ripe, and laying them on heaps covered with blankets, is
known conſiderably to forward their ripening, by ſomething like a
chemical fermentation added to the living action of the fruit, which
advances the faccharine proceſs with greater rapidity. -
I have ſeen apricots at table, which I was informed were plucked
from the tree, and kept ſome days in a hot-houſe, and thus became
deliciouſly ripe; in the ſame manner as harſh pears ripen almoſt into
a ſyrup during twelve or twenty hours baking in a flow oven; which
occaſioned the jeſt of a French traveller, who on being aſked on his
return, what good fruit they had in England, anſwered, that the only
ripe fruit he happened to taſte was the baked pear.
a
IV. THE ARTS OF PRESERVING FRUIT, as they depend on the
prevention of the chemical proceſſes, which produce their diſſolution,
ought to be here mentioned. 99
31
1. As

426
Sect. XV. 40-10
PRODUCTION
a
1. As life whether animal or vegetable prevents putrefaction, and
as many fruits exiſt long, after they are gathered from the tree, before
they become ripe and die ſpontaneouſly, and in conſequence putrefy,
as crabs, floes, medlars, and auſtere pears. The art of preſerving
,
theſe conſiſts in ſtoring them, where the heat is neither much above
or below 48 degrees, which is the temperature of the interior parts of
the earth; that is, in a dry cellar, or beneath the ſoil, or well covered
with ſtraw or mats in a dry chamber. As greater heat might make
them ripen ſooner than they are wanted, by the increaſed activity of
their vegetable life ; and froſt by deſtroying that life would ſubject
them to putrefy, when they become thawed; as perpetually happens.
to apples and potatoes, which are not well defended from froſt. And
laſtly, the moiſture would injure them many ways; firſt by its con-
tributing to deſtroy their vegetable life ; fecondly in promoting the
chemical proceſs of putrefaction; and thirdly by its encouraging the
growth of mucor, or mould, which will grow in moiſt ſituations
without much light or air.
Too great warmth deſtroys both animal and vegetable life by ſti-
mulating their veffels into too great activity for a time, whence a
ſubſequent torpor from the too great previous expenditure of the live
ing power, which terminates in death. After the death of the organi-
zation a boiling heat coagulates the mucilaginous fluids, and if con-
tinued would I believe prevent the chemical fermentation of them;
and that thus both vegetable and animal ſubſtances might be preſerv-
ed. The experiment is difficult to try, and could not therefore be of
much practical utility if it ſhould fucceed.
Great cold on the contrary deſtroys both animals and vegetables by
the torpor occafioned by the defect of ſtimulus, and a conſequent
temporary death. Afterwards if a great degree of cold be continued,
in ſome caſes the expanſion of their freezing juices may burſt the ve-
getable veffels, and thus render the life of them irrecoverable. But
there is another curious thing happens to many aqueous ſolutions, or
diffuſions,
I

Secr. XV. 4. I.
423
OF FRUITS.
milk, may
diffuſions, which is, that at the time of congelation the diffolved or
diffuſed particles are puſhed from the ice, either to the centre, if the
cold be applied equally on all fides, or into various cells, as mentioned
in Sect. XIII. 2. 2.
This excluſion of falt is ſeen in freezing any ſaline ſolution in wa-
ter; as common falt or blue vitriol expoſed to ſevere froſt in a two-
ounce phial are driven to the center of it. Wine, vinegar, and even
be thus deprived of much of their water. Very moiſt.clay,
when expoſed to froſty air, ſhrinks and becomes much more ſolid ac-
cording to the affertion of Mr. Kirwan. Mineralog. Vol. I.
p. 9,
the
freezing water covering its ſurface with ice, and driving the mole-
cules of clay nearer the centre. And laſtly, the mucilage produced
by boiling wheat flour in water, like book-binders paſte, if not too
thick, loſes its coheſion by being frozen, the water driving, as it
freezes, the ſtarch from its cryſtallization s and from this circum-
ſtance probably is occafioned the change of flavour of apples, potatoes,
and other vegetables, on being thawed after they have been frozen.
It is nevertheleſs affirmed, I think, by Monf. Reaumeur, that if
frozen apples be dipped in cold water repeatedly, and the ice thus
formed on their ſurface be wiped off, or if they be left in a large pail
full of very cold water, ſo that they may not thaw too haſtily, they
will not loſe their flavour. If this be true, and the apples will keep
found ſome time afterwards, it would ſeem that the vegetable life
was not deſtroyed; but that, like ſleeping inſects, they were reani-
mated by the warmth; otherwiſe, if the flavour be not deſtroyed,
and they could be immediately eaten or uſed in cookery, it is ſtill a
valuable diſcovery if true, and might lead us to preſerve variety of
fruits in ice-houſes, as ſtrawberries, currants, grapes, and pines, to
the great advantage of ſociety. See Sect. XVII. 2.4.
As the proceſs of fermentation will not commence or continue, I
believe, in the heat of boiling water, or 212; and as this degree of
heat can be eaſily preſerved by ſteam, or by the vicinity of veſſels
3 1 2
containing

428
Sect. XV. 4. 2.
PRODUCTION
a
containing boiling water; it is probable, that fruits for the uſe of
cookery might be thus preſerved throughout the year, as the pulp
of boiled apples, gooſeberries, &c. put into bottles, and placed fo as
to be expoſed to the waſted ſteam of ſteam-engines, or immerſed in
the hot water, which flows from the condenfing of it ; or near the
boilers fixed behind ſome kitchen fires; as I ſuſpect, that if fuch a de-
gree of heat could be applied once a day, it would counteract the ten-
dency to fermentation de la dobu 10
.
2. Another method of preſerving ſome fruits is by gathering them
during their acid ſtate, before that acid juice is converted into fugar,
as lemons, oranges, gooſeberries, pears, and ſome apples; and if a
part of the water be evaporated by a boiling heat ſo as to leave
the acidity more concentrated, it is leſs liable to ferment, and in
conſequence will be longer preſerved. For this purpoſe the fruit
ſhould be kept in a cellar, and corked in bottles, ſo as to be preclud-
ed from the changes of air, and variations of heat; gooſeberries, and
rhubarb-ſtalks, are thus ſucceſsfully preſerved for winter ufe; and if
a tea ſpoonful of brandy be put into each quart bottle, it will
prevent
the growth of mucor or mould upon them.
lat
3. As ſugar will not paſs into fermentation unleſs diluted with
much water, and leſs fo in low degrees of heat, many fruits may be
thus preſerved by impregnating them with ſugar, and the better if
they are kept in a dry cellar. Dr. Hales found that by inverting
the end of a branch of a tree into a bottle of brandy for a few hours,
that the whole branch died; hence it is uſual and ufeful to cover pre-
ſerved fruits with a paper moiſtened with vinous fpirit, which pre-
vents the growth of mucor or mould upon their ſurfaces, which is a
vegetable thus eafily killed by the intoxicating ſtimulus nett
If ſweet fruits be dried by heat, not only the fuperfluous water
becomes exhaled, but the faccharine proceſs is alſo promoted, and
much of the mucilaginous or acid particles are converted into ſugar,
as in baking pears, or in drying figs, dates, raiſins, apricots ; fo that
by
a
а.

SECT. XV. 4.4.
429
OF FRUIT S.
by gradually drying them many fruits may be well preſerved, and re-
quire afterwards ſimply to be kept dry.
4. Some fruits, as the olive, are preſerved in their unripe ſtate in
ſalt and water; the unripe pods of kidney-beans, and the hats of
muſhrooms, may be thus alſo kept for months in weak brine in a
cool cellar encloſed in bottles without much change. But the oily
kernels of nuts are well preſerved in cellars beneath the ſoil to pre-
clude the variations of heat, and covered in jars to prevent their eva-
poration. Other fruits are converted into pickles and preſerved in
vinegar, but loſe their flavour; and others by being immerſed in
vinous fpirit are preſerved, as cherries, and thus tranſmuted from
food to poiſon. And when the kernels of apricots, cherries, or bitter
almonds, are preſerved in brandy, which is called ratafia, we poffefs a
mixture of two of the moſt poifonous productions of the vegetable
kingdom ; except perhaps the leaves of lauro-ceraſus diſtilled in al-
cohol, which was fold as ratafia in Dublin, and produced many
ſudden deaths in the gin-ſhops.
v. The following lines are inſerted to amuſe the reader, and to
imprint ſome of the foregoing doctrine on his memory.
ART OF PRUNING WALL-TREES.
Behead new-grafted trees in ſpring,
Ere the firſt cuckoo tries to fing:
But leave four ſwelling buds to grow
With wide-diverging arms below;
Or fix one central trunk erect,
And on each ſide its boughs deflect.
In ſummer hours from fertile ſtems
Rub off the ſupernumerous gems;
But where unfruitful branches riſe.
In proud luxuriance to the ſkies,
Exſeet

430
Secr.XV. 5.
PRODUCTION
Exſect the exuberant growths, or bind
A wiry ringlet round the rind;
Or ſeize with ſhreds the leafy birth,
And bend it parallel to earth.
When from their winter-lodge eſcape
The ſwelling fig, or cluſtering grape;
Pinch off the ſummit-ſhoots, that riſe,
Two joints above the fertile eyes ;
But when with branches wide and tall
The vine ſhall crowd your trellis'd wall;
Or when from ſtrong external roots
Each rafter owns three vigorous ſhoots ;
Watch, and as grows the aſcending wood,
Lop at two joints each lateral bud.
So ſhall each eye a cluſter bear
To charm the next ſucceeding year ;
And, as the ſpiral tendrils cling,
Deck with feſtoons the brow of ſpring.
But when the wintry cold prevails,
Attend with chiſel, knife, and nails;
Of pears, plums, cherries, apples, figs,
Stretch at full length the tender twigs;
Vine, nectarine, apricot, and peach,
Cut off one third or half of each;
And, as each widening branch extends,
Leave a full ſpan between the ends.
Where crowded growths leſs ſpace allow,
Cloſe lop them from the parent bough;
But when they riſe too weak or few,
Prune out old wood, and train in new.
So, as each tree your wall receives,
Fair fruits ſhall bluſh amid the leaves.
a
ART

SECT.XV. 5.
431
OF FRUIT S.
ART OF PRUNING MELONS AND CUCUMBERSOM
When melon, cucumber, and gourd,
Their two firſt rougher leaves afford,
Ere yet theſe ſecond leaves advance
Wide as your nail their green expanſe;
Arm'd with fine knife, or fciffars good,
Biſect or clip the central bud;
Whence many a lateral branch inſtead
Shall riſe like hydra's fabled head.
When the fair belles in gaudy rows
Salute their vegetable beaux ;
And, as they loſe their virgin bloom,
Shew, ere it ſwells, the pregnant womb;-
Lop, as each crowded branch extends,
The barren flowers, and leafy ends.
So with ſharp ftings the bee-ſwarm drives
Their uſeleſs drones from autumn hives.
But if in frames your flowers confin'd.
Feel not one breezy breath of wind,
Seek the tall males, and bend in air
Their diſtant lovers to the fair;
Or pluck with fingers nice, and ſhed
The genial pollen o'er their bed.
So ſhall each happier plant unfold
Prolific germs, and fruits of gold.
SECT.
:

PRODUCTION
Secr. XVI.
SEC T. XVI.
THE PRODUCTION OF SEEDS.
1. To produce ſeeds early. 1. Sow before winter, or in warm ſituations. 2. Tranſ-
plant the roots. 3. Cut off fuperfluous shoots. 4. Give leſs water. II. To pro-
duce ſeeds in great quantity. 1. Sow early, or when the feed ripens. 2. Tranſ-
plant the roots deeper, or earth them up. Horſe-hoe and hand-boe. Improved
drill huſbandry. Dibbling. Corn lands laid level. Egyptian wheat with branch-
ing ears.
3. Deſtroy the central ſhoot. Eat down wheat and roll it. This is
Sometimes injurious. 4. Pinch of uſeleſs ſummits of beans. Eat down too vigour-
ous wheat. 5. Roll it to leſſen the ſtraw. 6. Give leſs water. III. To ripen
ſeeds. 1. Warmth and dryneſs. 2. Froſty nights. 3. Lime forwards the ripen-
ing of ſeeds. 4. Cut off bulbs and root-fuckers of orchis. Helianthus tuberoſus.
Rheum palmatum. IV. To generate beſt kinds of ſeeds. Chooſe early plants
inſulated from others. Impregnate the ſigmas of ſome with the anther-duſt of
others. Whence peas may be produced of different colours. V. To collect good
feeds. Change of ſeeds is uſeleſs, unleſs for better kinds. Chooſe the earlieſt feeds.
Pick out the largeſt potatoes for planting, and the beſt radiſhes for ſeed, and the
earlieſt ears of wheat. VI. To determine the goodneſs of ſeeds. Weigh a
meaſure of them. Caſt them into falt water. Beans more economical than oats
as provender. Seeds continue to improve during the water-months. VII. To
preſerve feeds.
1. Collect before they feed naturally. Dry them before they are
ſtacked. Gluten of wbeat deſtroyed by fermentation. Make the corn--ſtack higheſt
in the middle. The great durability of ſeeds. Keep them dry. Not in contaat
with walls. Convenient oat-boxes for ſtables. Wheat dried on a malt-kiln to pre-
2. Ventilation prevents mould. 3. Seclude them from heat, beneath the
soil. In ice-houſes. 4. Magazines of grain ſuffered to vegetate at top. Covetous
farmers. 5. New and old ſeeds. 6. Preſerve feeds in fugar, or in charcoal, for
Long voyages. And fleſh-meat in treacle. VIII. To ſow ſeeds advantageouſly.
ſerve it.
Native

SECT. XVI. I. 1.
433
OF SEEDS.
Native feeds, foreign ones. Sow ſoon after the ground is turned over, and early
in the ſpring, in the autumn. 2. Economy of fowing three kinds of graſs-Seeds, and
two kinds of wheat. Kinds of ſoil. 3. Mix fand or ſoil with ſome ſeeds. Soak
them in water, ſalt and waterslime. Steep barley in dunghill water. Wood-aſhes.
Sow wet as well as dry. 4. Bury the fruit with the ſeed. 5. Wah the ſeeds of
too luxuriant plants. Sow them early. IX. Queſtion concerning general en-
cloſure. Cain and Abel.
MANY of the circumſtances above related concerning the produc-
tion and enlargement of fruit are applicable to the production of
the ſeeds, which are included in them; but thoſe ſeeds, which con-
tribute moſt to the nouriſhment of mankind, many of which are the
progeny of annual or biennial plants, require other modes of culti-
vation.
As an introduction to this ſection it may be obſerved, how much
more ingenuity was required in the diſcovery of nouriſhing mankind
by the ſmall feeds of the graſſes, which have probably been ſince
much enlarged by perpetual cultivation, than by the large roots of
potatoes. The Ifis or Ofiris of Egypt ſeems to have invented the
proceſs of cultivating wheat, as well as flax, on the banks of the
Nile; and afterwards Ceres and Triptolemus to have taught the
former of theſe important diſcoveries all over the known world.
While in later ages the Incas or Motezumas of Peru and Mexico ſeem
to have deſtroyed the cannibals, or men-eaters, of that continent,
and to have diſcovered and taught their people to ſupport themſelves
by the cultivation of potatoes,
I. 1. To produce ſeeds early in the ſeaſon.
Thoſe plants, which are required to yield a forward crop, as the peas
and beans of our gardens, and thoſe which our cold and ſhort fummers
will not otherwiſe perfe&tly ripen, as wheat, ſhould be fowed before
the commencement of winter, either in natural ground, as in the
cultivation
3 K

434
SECT. XVI. 1. 2.
PRODUCTION
a
cultivation of wheat, or in ſituations ſheltered from the north-eaſt,
as in the garden cultivation of peas and beans; or they may be fowed
very thick in hot-houfes, or under hot-bed frames, or under warm
walls, and be tranſplanted, when they are one or two inches high,
into the natural ground at due diſtances, when the weather is milder,
and the plants are become hardier or leſs liable to be deſtroyed from
their having longer acquired the habits of life.
When young plants of any kind are tranſplanted, the ground ſhould
be recently dug, as their expeditious growth depends ſo much on the
atmoſpheric air being buried in the pores or interſtices of the earth
by the production of carbonic and nitrous acids, and ammonia, and
heat.
The fame advantage occurs by foaking feeds in water, or in the
drainage from manure heaps, till they are ready to ſprout, and then
fowing them in a foil lately turned over ; as their roots will then im-
mediately put out by the newly generated heat, and newly produced
carbonic acid in its fluid not its gaffeous ſtate.
2. The tranſplanting of young roots, if they be ſet no deeper than
before, does not, I fuppofe, multiply the number of ſtems, as occurs
when wheat is tranſplanted fo deep as to cover the ſecond joint; but
by tearing off ſeveral ſmall extremities of the roots, the new produc-
tion of many viviparous buds is prevented, and that of oviparous buds
increaſed in conſequence, for reaſons mentioned in No. 2. 4. of the
preceding Section.
When the roots of wheat are tranſplanted and divided, not only a
great increaſe of the crop is produced, but I believe the feed is like-
wiſe ripened earlier, as is aſſerted by Mr. Bogle. Bath Society, Vol. III.
P. 494. And it is well known to gardeners, that tranſplanting garden-
beans forwards them in reſpect to time, but ſhortens the height of
the ftem. Hence tranſplanted vegetables grow leſs in height, as
tranſplanted beans, and leſs branchy, as tranſplanted melons, but
produce and ripen their feeds earlier ; which is a great advantage in
the
O
T

Secr.XVI. 1.4.
OF SEEDS.
435
a
the ſhort fummers of this climate; and if the roots can be divided,
as in wheat, or new ſcions can be produced by their being tranſplant-
ed deeper, as alſo occurs in wheat, the quantity of the ſeed
may
alco
be wonderfully increaſed by tranſplanting. See Sect. XII. 6.
3. Another mode of forwarding the production of ſeeds, and of
fooner ripening them, conſiſts in pruning off the viviparous tops or
lateral ſhoots, which will bear no ſeeds at all, or only fmall or im-
perfect ones, in our northern fummers. For this purpoſe the cutting
away the tops of beans and of peas, and the lateral branches of arti-
chokes, after the fruit-buds are formed, both forwards and enlarges
the flowers and feeds, which remain, as more nouriſhment is derived
to them.
4. As a ſuperfluous ſupply of water is more friendly to the produc-
tion of leaf-buds than to the generation of flower-buds, to derive leſs
water than uſual to the roots, forwards the production of ſeeds, a fact
well known in the gardens of warmer climates, which are perpetually
watered from reſervoirs or wheel-engines. But when the blofſoms
appear, an addition of water muſt forward their growth by ſupplying
nouriſhment, which ſhould again be leffened when the fruit has ac-
quired its full fize, both to expedite its ripening, and to increaſe its
flavour; as the faccharine matter and effential oil will be leſs diluted
with water.
In the dry ſummer of 1799 I had the opportunity of flooding fome
rows of beans in my garden, which by being done too frequently, or
too copiouſly, occafioned them to grow to a much greater height
than uſual, and in conſequence to bring to perfection few ſeeds, and
ſome of them none. As I ſuppoſe the new ſhoots of fig-trees in the
beginning of ſummer occaſions the firſt production of young figs to
fall off from the want of that nouriſhment, which is now expended
in the growth of new leaf-buds. See Seet. XV. 3. 4. Whence the
facility of producing leaf-buds ſeems evidently to prevent the genera-
tion
3 K2

436
SECT. XVI. 2. I.
PRODUCTION
tion of flower-buds, and the uſe of cutting off the ſummits of tall
beans is thus explained, as directed above.
II. 1. To produce ſeeds in great quantity from annual or biennial
plants they ſhould be brought forward in reſpect to the ſeaſon in our
northern ſummers; that a greater quantity of viviparous buds may
arrive early at their maturity for the purpoſe of generating oviparous
buds ſoon enough in the ſummer to ripen their ſeeds; on this ac-
count thoſe ſhould be ſown in the autumn which will bear the fe-
verity of the winter.
Nevertheleſs the ſeeds of thoſe plants, which are natives of this cli-
mate, ſhould probably be fowed at the time they become perfectly
ripe, as occurs to them in their natural ſtate; that is, either when
the feed is ſhed upon the ground by the parent plant, or when the
fruit or huſk, which encloſes it, becomes naturally ripe after it has
fallen on the ground. Thus I have ſeen crabs covered with leaves in
hedge-bottoms, which have not decayed till the early ſpring. Many
pears do not become ripe in our ſtore-rooms till March or April ; and
ivy berries and holly berries hang on their reſpective trees till the
vernal months, and are not till that time eaten by the thruſhes,
Hence it is probable, that the ſeeds in theſe durable fruits or berries
continue to ripen, or to become more mature, and prepared for their
future growth during the winter months.
2. It was ſhewn in Sect. IX. 3. 7. that when wheat was tranſ-
planted ſo deep as to immerſe the firſt joint above the root into the
ſoil, many new ſtems would ſhoot up and ſtrike their roots into the
earth; and that thus four or fix new plants, or more, would be ge-
nerated by the caudex of the leaf-bud, which conſtitutes that joint.
This mode of tranſplantation therefore will much increaſe the quan,
tity of the crop of ſeed, if it can be done foon enough for theſe ad-
ditional ſtems to ripen their corn, before the ſummer ends.
There is another mode of increaſing this product of additional
ftems

Sect. XVI. 2.2.
437
OF SEEDS.
а
ſtems without tranſplantation, which conſiſts in fowing the wheat in
rows by what is called a drill-plough according to Mr. Tull's method;
and when the firſt ſtems riſe a few inches high, a horſe-hoe, made
like a very ſmall plough, is to be brought ſo near each row, as to
turn up fome earth againſt the ſtems, ſo as to cover the firſt joint
above the root with foil; whence new ftems will be generated, and
ſhoot up round the old one; and thus increaſe the crop in the ſame
manner as by deep tranſplantation.
The theory of Mr.Tull's drill huſbandry is explained in Sect. IX.
3. 7. and in XII. 5. which is of late years ſuppoſed to have been im-
proved by introducing the hand-hoe in place of the horſe-hoe, and
thus giving an opportunity of ſowing the rows or drills nearer toge-
ther, as will be ſeen by the following method, now introduced into
almoſt general uſe in Norfolk by Mr. Coke; though Mr. Tull him-
ſelf much prefers the horſe-hoe as turning over the earth much
deeper than the hand-hoe, and thus rendering that part of it more
expoſed to the air, which was before more deeply ſecluded from it;
and alſo rendering it more pervious to vegetable roots; to which may
be added, that both kinds of hoeing render the ſurface more perme-
able to the rains and dews, and prevent the cracks in dry weather,
which are very injurious to the roots of plants; both which advan-
tages depend on the poroſity of the ſoil, which muſt extend deeper
by the uſe of the horſe-hoe than the hand-hoe.
Mr.Tull makes other ingenious remarks on the uſe of horſe-hoe-
ing. In the beginning of winter, when the wheat has obtained one
blade like graſs, or two or three leaves, the horſe-hoe is brought
near the rows and deep, and the earth turned from them ſo as to
form a ridge between them. By this ridge in level grounds he thinks
the rows are ſhaded from the cold winds in ſome ſituations, and that
the roots of the wheat are kept drier, and thence leſs injured by froſts.
In the ſpring this ridge in the intervals between the rows is divided
by the horſe-hoe, and turned back againſt the rows of corn after iti
has

438
PRODUCTION . Sect. XVI. 2. 2.
a
1
.
has been fertilized by the air and rains, and dews of winter. See
Tull's Huſbandry, Ch. IX. and Sect. XII. 5. of this work.
Mr.Coke of Holkham in Norfolk aſſured me, that in thirteen years
experience on a farm of 3000 acres he had found the drill huſbandry
in that country greatly ſuperior to fowing feeds of all ſorts by the
hand in what is termed the broad-caſt method, but differs in the
number and arrangement of his rows from the method of Mr. Tull in
the following circumſtances.
Mr. Tull drilled two rows of feed a few inches from each other,
and then left a ſpace of two or three feet, and then drilled two more
rows near each other, for the purpoſe of paſſing a hoe between each
double row drawn by a horſe, which was therefore termed a horſe-
hoe; but Mr. Coke drills all his rows of wheat and of peas nine inches
from each other, and thoſe of barley fix inches and three quarters
from each other; this is performed by a drill plough made by the
Rev. Mr. Cook, which drills fix rows at a time, and thus ſows an
acre of land in an hour, and is drawn by a ſingle horſe; and the
quantity of feed confumed is about fix or ſeven pecks to an acre,
which is about half what is uſed in the fowing by the hand in the
broad-caſt method.
Early in March Mr. Coke uſes the hand-hoe, which for hoeing
the rows of wheat and of peas is about fix inches wide, and for hoe-
ing thoſe of barley about four inches wide. By this hoe the ſurface
is not only turned over, and the weeds between the rows rooted up,
but it is alſo accumulated about the roots of the growing corn, and
covers and conſequently deſtroys the low growth of poppies amongſt
them; which are a very frequent weed in that part of the country.
A ſecond hoeing is performed about the middle of May, and the ſoil
is again not only cleared from weeds but accumulated againſt the
riſing corn, each of which hoeings coſt about twenty-pence an acre.
Nevertheleſs I am informed, that fome attentive agricultors uſe the
horſe-hoe belonging to Mr. Cook's drill-machine, though the rows
4
of

Sect. XVI. 2. 2.
439
OF SEEDS.
of corn are but nine inches from each other; and affert, that this
occaſional trampling of the horſe on the young plants is of no very
ill conſequence, a circumſtance well worth obſerving, as it removes
the principal diſadvantage of the horſe-hoe, which conſiſts in the too
great diſtance of the alternate rows of the corn-plants.
By the earth being thus accumulated againſt the roots of the corn
it is ſaid to tiller or tellure much; that is, to throw out four or fix
ſtems, or more, around the original ſtem, and thus to increaſe the
number of ears like tranſplanting the roots, inſomuch that Mr.Coke
obtains by this method between four and five quarters of wheat on
every acre, which in the broad-caſt method of fowing did not yield
more than three quarters on an acre, beſide ſaving a ſtrike and half of
the feed corn, unneceſſarily conſumed in the broad-caft method of
ſowing. To this ſhould be added another advantage, that as the
land is thus kept clear from weeds, and has it's ſurface twice turned
over, and thus expoſed to the air, it is found to fave one ploughing
for the purpoſe of a fucceeding crop of turnips.
It is probable, that one hand-hoeing in the beginning of winter, ſo
managed as to turn the ſoil from the roots of the corn, and to leave it
rather elevated between the rows, as Mr. Tull recommends to be
performed by his horſe-hoe, might give a fimilar advantage to this
mode of cultivation; and alſo if another hand-hoeing was applied, as
foon as the wheat is out of bloſſom, to ſupply more nouriſhment to the
young feed might increaſe its plumpneſs and weight, as mentioned in
No. 2. 3. of this Section.
The lands thus managed by Mr. Coke are laid level, and not in
ridges and furrows, and can thus be ploughed croſswife ; and the
crop is equally good throughout the whole; whereas in the furrows
of ſome lands it is leſs forward or leſs prolific than on the ridges ;
whence much light corn is mixed with the good, which is obliged to
be ſeparated from that, which is marketable, and uſed for hogs or
poultry, Add to this, that in this mode of huſbandry the ſtraw is be-
lieved
a

440
Sect. XVI. 2.2.
PRODUCTION
و
lieved to be larger and in greater quantity as well as the grain, and
the land to be leſs impoveriſhed, as no weeds are ſuffered to grow on
it, and as its ſurface is fo frequently turned over, and expoſed to the
air.
In China the corn lands are laid on a level, not in ridges and fur-
rows; which is ſuppoſed to be the moſt advantageous plan in almoſt
every ſituation, which is proper for the cultivation of corn, as by being
thus rendered capable of being divided by croſs-ploughing, almoſt any
kind of ſoil may be rendered more proper for the uſe of the drill huſ-
bandry, by which it is ſeen in the above account of the Norfolk ma-
nagement, that twelve ſtrikes more of wheat are raiſed on an acre,
and one ſtrike and a half ſaved in the conſumption of feed-wheat,
which at ſix ſhillings a ſtrike ariſes to a conſiderable fum on a large
farm.
Nevertheleſs there ſeem to be many advantages attending the
forming the ſurface of land into ridges and furrows; in wet lands
with a ſubſtratum of clay the furrows are convenient channels to
carry off the water, where there is a ſufficient declivity, as treated of
by Mr. Tull in his Horſe-hoeing Huſbandry, Ch. XVI. Add to this,
that in ſome ſituations a deeper ſtratum of the ſoil, where it is valu-
able, may be occaſionally turned up, and expoſed to the air, and to
the roots of vegetables, by gradually changing the locality of the
ridges; and laſtly, in every ſituation a greater ſurface both of the
foil, and of the ſummits of the ſtems, or ears, are expoſed to the
influence of the air by means of ridges and furrows; for as the plants
of wheat are but three or four feet high, the ſurface of a crop of
wheat is increaſed as well as the ſurface of the ground it grows upon,
and not as the baſe on which the declivities or hills reſt, as ſome
have erroneouſly ſuppoſed. See Seet. X. 3.8.
There is another method of ſowing wheat in rows uſed in ſome
counties, which is termed dibbling in the language of agricultors,
and conſiſts in making perpendicular holes one inch and half or two
inches

Secr.XVI. 2. 2.
441
OF SEEDS.
inches deep, as is commonly done in planting potato-roots; theſe
holes are made by a man, who has a proper ſtaff ſhod with iron in
each hand, and as he walks backwards is able by looking at the
part of the row already made to keep nearly in a ſtraight line, and to
make two holes at once at about nine inches diſtant from each other
every way. Two or more children attend the man, and drop two,
or three, or four feeds into each perpendicular hole, which are af-
terwards covered by drawing over them what is called a buſh-har-
а
row.
This method by ſowing the wheat in rows adapts it for the uſe of
the hand-hoe, as by fowing it by a drill machine, but muſt be attend-
ed with greater expence, and I ſuſpect with leſs accuracy of the dif-
tribution of the ſeed, owing to the hurry or fatigue of the children
employed; and I alſo ſuſpect that ſowing in drills is preferable, be-
cauſe a greater quantity of earth is turned over, and much air in con-
ſequence included in its interſtices; whereas in making perpendicular
holes the ſides of the holes are compreſſed, and rendered more ſolid;
whence potato-roots alſo might probably be more advantageouſly
planted by making drills inſtead of perpendicular holes.
A correſpondent of the board of agriculture aſſerts, that on looking
over a field of potatoes near Leiceſter, which had all been planted at
the ſame time, and on land equally manured, he obſerved a great
difference of the growth of one part of the field, which on inquiry
he found to have been owing to the roots having been planted in
drills, where the plants were ſo much ſtronger; and by a ſetting
ſtick in holes, where they were ſo muchleſs vigorous; Engliſh En-
clyclopedia, Art. Huſbandry, p. 483: which difference of growth I
ſuppoſe to have been owing to the circumſtances above mentioned.
A few ears of wheat were lately given me, which were branched,
having four or five leſs ears growing out of each ſide of the principal
ear; it was procured at Liverpool, and was called Egyptian wheat,
or Smyrna wheat. It is deſcribed in the Supplem. Plantarum of the
younger
3L

442
Secr. XVI. 2. 3.
PRODUCTION
a
;
younger Linneus, as well as in the ſpecies Plantarum of the elder;
and is ſaid to be a native of Egypt, and to be cultivated at Naples; it
is called " triticum compoſitum, or wheat with a compound ear,
crowded with leſs ears, awned; and is ſaid to be related to triticum
æſtivum, ſummer wheat; but the ſpike is four times larger, a hand
in length, compoſed of leſs ſpikes, two faced, alternate, approximat-
ed, from nine to twelve, the lower ones being ſhorter, and the top
one folitary." Suppl. Plant. p. 115
The plant, which was given me, had five tall and thick ſtems from
one root, but ſeemed to have been plucked up before it was quite
ripe, whence I cannot judge of the ſize of the grain, but ſhould
imagine, that it is a ſpecies well worthy of attention. The few ears,
which I poſſeſſed, were fown in the ſpring of this year, 1799, not
having obtained them foon enough to fow in the autumn. When
they were an inch or two high, they were tranſplanted into a moiſtiſh
part of my garden ; and though the year has been uncommonly cold
and wet, and a great part of the autumn-fown wheat of this country
is blown down upon the ground, and is not yet ripe, yet almoſt
every root of the Egyptian wheat has from ten to twelve ſtems, and
ſtands upright on ſtrong ſtraw about three and a half, or four feet
high. The beſt ſtems have one principal ear about five inches long,
with five or fix ſhorter ones branching out on each ſide of it. They
begin to appear brown, and I hope will ripen. I have fince found that
this ſpecies of wheat is mentioned in Tull's Huſbandry under the
name of Smyrna wheat. He adds that it is highly productive, but
on that account requires a good foil.
3. Another method of promoting the growth of lateral ſtems con-
fiſts in deſtroying the central ſhoot ; when this is done, other new
ſtems ariſe from the joint immediately above the root, which in
wheat is in contact with the earth. On this account, when wheat
plants are ſufficiently forward in reſpect to the ſeaſon, it is thought
to be advantageous to eat the firſt ſtem down by ſheep to increaſe the
quantity
a

Secr.XVI. 2. 3.
443
OF SEEDS.
quantity of the ſubſequent crop. See Sect. IX. 3. 7. It ſhould be
nevertheleſs obſerved here, that the trampling of the ſheep on lands,
which are not too adheſive, will preſs down the firſt or ſecond joint
into the earth, and thus aſſiſt the production of many ſide ſhoots.
But in very adheſive foils this trampling of the ſtems into the ground
may be injurious. See a paper in Bath Agriculture, Vol. I. Art. XV.
In foils which are not too adheſive, when the crop appears thin, it is
probable, that a roller drawn over it by preſſing the firſt or ſecond
joint into the foil, might promote the production of fide ſhoots, or
make them tiller, or tellure, in the language of agricultors. And
when graſs or clover ſeeds are deſigned to be ſown on the wheat-
land, it might firſt be harrowed, and then either rolled or trampled
by the ſheep, which eat it; either or both of which might preſs
down the root-ſtems of the corn, and cover the newly fown clover-
feeds with foil.
This mode of eating down forward wheat with ſheep is analogous
to cutting off the central buds of melons and cucumbers to make
them produce earlier fruit, and in this climate perhaps in greater
quantity; as thoſe produced after the great extent and elongation
of the central branches would be too late to ripen in this climate:
and by their exuberant generation of a viviparous progeny would re-
tard the fucceffion of lateral ſhoots, and a conſequent quicker pro-
duction of flowers.
Nevertheleſs where the crop is not too luxuriant or too forward,
the eating down the firſt ſtem by ſheep may be an injurious practice;
as Mr.Tull thinks, that by thus deſtroying the firſt ſtem, the ears of
the later ones have not time to ripen, and thence become light in re-
ſpect to the ſize or plumpneſs of the grain ; and that theſe ſecondary
ſtems become weak, and are liable to fall down, both which he ſays
commonly occur where the crops are eaten by ſheep.
Mr.Tull, whoſe work is throughout a great effort of human genius,
adds a very wiſe axiom, “ that it is moſt advantageous to haſten,
3 L 2
what
a

444
PRODUCTION Secr.XVI. 2. 4.
what we can, the time of bloſſoming; and to protract the time of
ripening." Horſe-hoeing Huſbandry, Ch. XI. p. 147 ; for it is the
farinaceous reſervoir of nutriment laid up in the cotyledon of the new
feed for the future growth of the corculum or new embryon, for
which we cultivate the plant; and this reſervoir is formed between
the bloſſoming and ripening of the grain, either before or after the
impregnation of the pericarp, or feed-veſſels, and thus renders the
grain plump and heavy. Mr. Tull in another part of his work re-
commends an additional horſe-hoeing immediately after the bloſſom
is over, to ſupply more nutriment to the ripening grain. Ch. IX.
p. 120. Mr. Tull eſteems the eating down of wheat by ſheep to be
generally a very injurious practice in this climate, by rendering the
ears light and the ſtraw weak; by retarding the time of bloſſoming,
as well as the growth of the ſtems.
4. In the moiſt ſprings of this climate many annual or biennial
plants are liable to ſhoot out too many or too ſtrong viviparous
branches, which can not generate flower-buds foon enough to ripen
their feeds in our cold and ſhort ſummers. This always happens to
cucumbers and melons, which were brought from warmer countries,
and to the peas and beans of our gardens, and ſometimes to corn-
plants, which are liable in wet ſeaſons to produce too ſtrong ſtems
and foliage, which have not time to generate the flower-bud at their
ſummit foon enough to perfect and to ripen the feed. Melons and
cucumbers have been mentioned in Sect. XV.2. 5. and in reſpect to
garden beans their viviparous tops ſhould be pinched off, which if not
too old may be eaten as an agreeable vegetable, when well boiled;
and thus more nutriment is derived to the oviparous buds beneath,
which renders them larger, and perhaps more numerous.
vent field peas from running into ſtraw in moiſt foils leſs manure
ſhould be uſed; and field beans may have their tops cut off by a
ſcythe fixed into a ſtraight ſhaft.
Annual cotton plants are much cultivated in ſome colder parts of
the
To pre-

SECT. XVI. 2. 5 OF SEEDS.
445
the Chineſe empire, and the cultivators lop off the tops to increaſe the
number of pods, and to haften their production ; and in the Weſt
Indies the flowers of the roſe tree are believed to be accelerated and
increaſed by topping the branches. Embaſſy to China by fir G. Staun-
ton, Vol. III. p. 202. Svo. edit.
When the ſtems and foliage of wheat are thus too vigorous, it
may be advantageous to eat it down by ſheep as above mentioned ;
which may not only deſtroy the too vigorous viviparous central ſtems,
but alſo produce a greater number of lateral ones; which may ſooner
terminate in oviparous ones, ſo as to produce more grain with leſs
ſtraw.
5. It is alſo probable, that rolling them as mentioned above, if it
be done in a morning before the dew is off, might ſo far bruiſe the
ftems and roots, as to ſtop their too great propenſity to nouriſh the
viviparous buds, and in conſequence to favour the growth of the ovi-
parous buds on their ſunimits; which might forward the harveſt ſea-
fon, as well as increaſe the product of grain in proportion to the quan-
tity of ſtraw. From rolling wheat in ſpring on fields where the fur-
face remains uneven or cloddy, another advantage may be derived,
by breaking the clods or eminences, and thus earthing up many
the ſtems above the ſecond joint, and thus inducing a new ſet of root-
fcions to put forth, or tiller. See Sect. XII. 3.
6. The garden plants, which are too vigorous, in ſituations where
there is a command of water, as in the gardens of warm climates,
ſhould have lefs water derived to them, till the bloſſoms appear; be-
cauſe a greater quantity of moiſture facilitates the production of vivi-
parous buds ſo much as to retard that of oviparous, ones, and thus
diminiſhes the quantity as well as retards the ripening of the crop.
But in theſe ſituations, as ſoon as the bloſſoms appear, a greater ſup-
ply of water ſhould be allowed, which will contribute to nouriſh and
enlarge them, as mentioned above; as is practiſed in ſome countries
of the eaſt, where they do not flood their rice-grounds, till they are in
flower.
of
a

446
SECT. XVI. 3. 1.
PRODUCTION
flower. See Sect. XV. 3. 4. But leſs water is again required, when
the feed has arrived at its full ſize, as before ſpoken of.
III. 1. To forward the ripening of ſeeds. A due degree of warmth
and of dryneſs ſeems to include the circumſtances principally requir-
ed. The warmth not only accelerates the various ſecretions of vege-
tables by increaſing their irritability and conſequent activity, but, af-
ter the mucilaginous, ſtarchy, ſaccharine, and oily matters are ſecret-
ed into proper reſervoirs, may contribute perhaps chemically to their
change into each other, or to their greater perfection. And the
dryneſs of the air, whether hot or cold, is neceffary to give perfect
ripeneſs to ſeeds; as otherwiſe the due exhalation of the aqueous parts
of the ſecreted fluids, which form the nutritive parts of ſeeds, does
not properly proceed ; and the ſeed gathered in this condition is liable
to mildew in the barn or granary, or to become thrivelled and
wrinkled, as it dries.
2. It is believed in Scotland, that even the froſty nights of au-
tumn contribute to ripen the late crops in that inclement climate,
which ſome have aſcribed to the moonlight, but, which I have in-
deed ſuſpected, that the froſt may in ſome meaſure effect by convert-
ing the mucilage of the grain ſooner into ſtarch. This I was induc-
ed to imagine by having obſerved that bookbinder's paſte, made by
boiling wheat-flour in water, loſt its adheſion after having been
frozen ; and alſo from a culinary obſervation, that when ice or ſnow
is mingled with flour inſtead of water in making pancakes, that it
much improves them; the truth of which I have heard boldly aſ-
ſerted, but never witneſſed the experiment. See Sect. VI. 3. 3.
There is nevertheleſs an experiment related by Dr. Roebuck in
the Edinburgh Tranſactions, Vol. I. which ſeems to thew, that the
grains of oats continue to fill and to become heavier even during
the autumnal froſts; which may probably occur during the ſunſhine
of the middle part of the day, as occurs in the vernal froſts of this
part of the country. In 1780 near Borrowſtoneſs the oats were green
a
even

Secr.XVI. 3. 3.
447
OF SEEDS.
even in October, when the ice was three fourths of an inch thick,
He ſelected ſeveral ſtalks of oats of nearly equal fulneſs, cut half of
them, and marked the remainder, which continued fourteen days
longer in the field; after being dry, the grains of each parcel were
weighed; and eleven of thoſe grains, which had remained in the
field, weighed thirty of thoſe which had been cut a fortnight ſooner.
This important experiment ſhould teach our farmers not to cut
their
peas
and beans too early in inclement autumns; which are ſo
frequently ſeen to become ſhrunk and thrivelled in the barn or gra-
nary, and inclined to rot from deficient ripeneſs, and conſequent
ſoftneſs or moiſture; and thus contain much leſs flour in proportion
to the huſk or bran.
3. The wheat produced after land has been much limed, is believ-
ed to be thinner ſkinned, and to yield more good meal, than other
wheat, and to make better bread. See Sect. X. 6.7. On this ac-
count I ſuppoſe one uſe of lime is to forward the ripening of feeds by
converting their mucilage ſooner into ſtarch or oil; as according to
the experiments of M. Parmentier the goodneſs of bread depends
much on the quantity of ſtarch contained in it; who found, that
if the ſtarch taken from eight pounds of raw potatoes, by grating
them into cold water, was mixed with eight pounds of boiled pota-
toes, as good bread might be produced as from wheat flour, See
Sect. VI. 3.
4. The ſeeds of ſome plants, which alſo propagate themſelves by
bulbs at their roots, will not ripen in this climate naturally, as the
orchis; but are faid to ripen, if the new bulb be cut off early in the
ſeaſon; or if the propagation by their roots be retarded or prevented
by confining them in garden-pots, as the lily of the valley; and it is
probable, that the ſeeds of potatoes might be rendered more perfectly
ripe, and in conſequence better for the cultivation of new varieties;
if the young roots were taken away early in the ſeaſon from that,
which is to bear feed; or if they were confined in garden pots.
If
7

448
4.1.
PRODUCTION Secr. XVI.
If the orchis could by theſe means be cultivated from feed on
moiſt meadows or moraffes, it might become a profitable article of
huſbandry; as when it is fcalded in boiling water, and the peel rub-
bed off, it is ſold by the name of falep, and might become a nutri-
tive article of diet, like fago and vermicelli, if it could be propagated
at leſs expence.
It is alſo probable, that Jeruſalem, or ground artichokes, helian-
thus tuberoſus, might be induced to ripen its ſeeds in this country,
if the new roots from a few of the forwardeſt plants were taken
away early in the ſeaſon, or if they were confined in garden pots.
And if this plant could be propagated by ſeed, it might make an uſe-
ful product in agriculture, as horſes are very fond of the leaves, and
ſwine of the roots; both of which are produced in great quantity;
and as the latter contain much ſugar, they muſt be very nutritive;
and in reſpect to their culinary uſe are remarkably grateful to moiſt
palates, as well as nutritive, when cut into ſlices, and baked in beef
or mutton pies; but are ſaid to be flatulent in the bowels of thoſe
whoſe digeſtion is not very powerful; a property which might be
worthy attention, where the propenſity to fermentation is required,
as in making bread with potatoes, or in the diſtillery.
It is alſo probable, that if the large new root-fuckers of other pe-
rennial plants, which do not bear bulbous or tuberous roots, and
which are late in ripening their ſeeds, or do not ripen them perfectly
in this climate, were cut or torn off early in the ſeaſon, as of the
rheum palmatum, palmated rhubarb, or rheum hybridum, mule
rhubarb; or if their roots were confined in garden-pots, that they
might be more liable completely to ripen their reſpective ſeeds. See
Sect. XV. 2. 4.
IV.1. To
o generate the beſt kinds of ſeeds the moſt healthy plants
muſt be choſen, and thoſe which are moſt early in reſpect to the ſea-
ſon; theſe ſhould be ſo inſulated, as to have no weak plants of the
ſame ſpecies, or even genus, in their vicinity, left the fecundating
4
duft

Secr. XVI. 4. 1.
449
OF SEEDS.
a
duſt of weaker plants ſhould be blown by the winds upon the ftig-
mata of the ſtronger, and thus produce a leſs vigorous progeny.
Where new varieties are required, the male duſt of one good va-
riety, as of the nonpareil apple, ſhould be ſhed upon the ſtigmas of
another good variety, as of the golden-pippin; and it is probable
fome new excellent variety might be thus generated.
Mr. Knight has given a curious experiment of his impregnating
the ſtigmas of the pea-bloſſoms of one variety with the farina of ano-
ther. He ſays, Treatiſe of Apple and Pear, p. 42, " Bloſſoms of a
ſmall white garden-pea, in which the males had previouſly been
deſtroyed, were impregnated with the farina of a large clay-coloured
kind with purple bloſſoms. The produce of the feeds thus obtain-
ed were of a dark grey colour, but theſe having no fixed habits, were
foon changed by cultivation into a numerous variety of very large and
extremely luxuriant white ones; which were not only much larger
and more productive than the original white ones, but the number
of feeds in each pod was increaſed from ſeven or eight to eight or
nine, and not unfrequently to ten. The newly made grey kinds I
found were eaſily made white again by impregnating their bloſſoms
with the farina of another white kind. In this experiment the feeds,
which grew towards the point of the pod, and were by poſition firſt
expoſed to the action of the male, would ſometimes produce feeds
like it in colour, whilſt thoſe at the other end would follow the fe-
male.
• In other inſtances the whole produce of the pod would take
the colour of one or other of the parents; and I had once an inſtance
in which two peas at one end of a pod produced white ſeeds like the
male, two at the other end grey onės like the female, and the central
feeds took the intermediate ſhade, a clay colour. Something very
ſimilar appears to take place in animals, which produce many young
ones at a birth, when the male and female are of oppoſite colours.
From ſome very imperfect experiments I have made, I am led to ſuf-
peat
3 M

450
SECT.XVI. 5.1.
PRODUCTION
V
pect that conſiderable advantages would be found to ariſe from the
uſe of new or regenerated varieties of wheat, and theſe are eaſily ob-
tained, as this plant readily ſports in varieties, whenever different
kinds are ſown together.” See Sect. VII. 2. 6. of this work.
2. The white and blue peas ſown in fields as well as in gardens
ſometimes poſſeſs the property of becoming ſoft by boiling, at other
times not. This circumſtance is ſaid to depend on the nature of the
ſoil, but has not yet been ſufficiently inveſtigated; perhaps the
greater or leſs maturity of the peas at the time of reaping them may
have more or leſs contributed to fill their fibrous cells or diviſions with
mucilage or ſtarch. The greater or leſs mealineſs produced by boil-
ing potatoes ſeems to be an analogous circumſtance, and is thought
by fome to ariſe from the nature of the ſoil rather than from the fpe--
cies or variety of the planted root.
The mealineſs of ſome boiled potatoes, and the ſoftneſs of ſome
boiled peas, may occaſionally be affected by the acidity of the ſpring
water, in which they are boiled; but is generally I ſuppoſe ow-
ing to the mucilage of fome of them being more or leſs coagulable
by heat, than that of others. Something ſimilar to which obtains in
animal mucus, as the cryſtalline humour of the eyes of fiſh become
hard and opake by boiling; while the ſkins of animals, and the ten-
dons of their feet, become a ſoft mucus or jelly by boiling; and ſome
of the liquids, which are found in the cells or cavities of the body in
dropfies, are obſerved to coagulate by heat, and others to become
more fluid. The cauſes of this difference merits further inquiry.
V.1. To collect good feeds, according to the obſervations of Mr.Cooper
of Philadelphia, conſiſts not in procuring new ſeeds from diſtant
places, as is generally ſuppoſed, but in ſelecting the beſt feeds and
roots of his own; which though he has continually fown or planted,
them in the fame foil, every article of his produce is greatly ſuperior
to thoſe of any other perſon, who ſupplies the market, and they ſeem
ſtill in a ſtate of improvement. He believed that, no kind of inceſt
would
a

SECT. XVI. 5. I.
451
OF SEEDS.
would degenerate the breeds of vegetables, and therefore adopted the
plan of Mr. Bakewell in England in reſpect to quadrupeds, who con-
tinued to improve his flocks and herds by the marriages of thoſe, in
which the properties he wiſhed to produce were moſt conſpicuous
without regard to confanguinity or inceſt.
Mr. Cooper was led to his preſent practice, which he began more
than forty years ago, by obſerving that vegetables of all kinds were
very ſubject to change with reſpect to their time of coming to matu-
rity, and other properties, but that the beſt ſeeds never failed to pro-
duce the beſt plants. Among a great number of experiments he par-
ticularly mentions the following.
“ About the year 1746 his father procured feeds of the long wa-
tery ſquaſh, and though they have been uſed on the farm ever ſince
that time without any change, they are at this time better than they
were at the firſt.
“ His early peas were procured from London in the year 1756, and
though they have been planted on the ſame place every ſeaſon, they
have been ſo far from degenerating, that they are preferable to what
they were then. The ſeeds of his aſparagus he had from New York
in 1752, and though they have been planted in the ſame manner,
the plants are greatly improved.
“ It is more particularly complained of, that potatoes degenerate,
when they are planted from the ſame roots in the ſame place. At
this Mr. Cooper ſays, he does not wonder, when it is cuſtomary with
farmers to ſell or conſume the beſt, and to plant from the refuſe;
whereas having obſerved that ſome of his plants produced potatoes,
that were larger, better ſhaped, and in greater abundance than others,
he took his roots from them only, and the next ſeaſon he found, that
the produce was of a quality ſuperior to any, that he had ever had be-
fore. This practice he ſtill continues, and finds that he is abundantly
rewarded for his trouble.
6 Mr. Cooper is alſo careful to fow the plants, from which he raiſes
his
3 M 2

452
Sect. XVI. 5.2.
PRODUCTION
his feed, at a conſiderable diſtance from any others. Thus, when
his radiſhes are fit for uſe, he takes ten or twelve, that he moſt ap-
proves, and plants them at leaſt one hundred yards from others, that
bloilom at the ſame time. In the ſame manner he treats all his other
plants, varying the circumſtances according to their nature.
“ About the year 1772 a friend of his fent him a few grains of a
ſmall kind of Indian corn, not larger than gooſe ſhot, which produc-
ed from eight to ten ears on a ſtalk. They were alſo ſmall, and
he found, that few of them ripened before the froſt. Some of the
largeſt and earlieſt he ſaved, and planted them between rows of a
larger and earlier kind, and the produce was much improved. He
then planted from thoſe that had produced the greateſt number of
the largeſt ears, and that were the firſt ripe, and the next ſeaſon the
produce with reſpect to quality and quantity was preferable to any,
that he had ever planted before.
1.6 The common method of ſaving ſeed-corn by taking the ears
from the heap is attended, he ſays, with two diſadvantages; one is
the taking the largeſt ears, of which in general only one grows on a
ſtalk, which leffens the produce; and the other is taking ears that
ripen at different times.
Many years ago Mr. Cooper renewed all the feed of his winter
grain from a ſingle plant, which he had obſerved to be more produc-
tive, and of a better quality than the reſt; which he is ſatisfied has
been of great uſe. And he is of opinion, that all kinds of garden
vegetables may be improved by the methods deſcribed above, par-
ticular care being taken that different kinds of the ſame vegetables do
not bloom at the ſame time near together ; ſince by this means they
injure one another." Communications to the Board of Agriculture,
Vol. I. part 3. Letter from Dr. Prieſtley.
2. As the varieties of plants are believed to be produced by different
foils and climates, which varieties will afterwards continue through
many generations, even when the plants are removed to other ſoils
and

Sect.XVI. 6. 1.
453
OF SEEDS.
a
a
and climates, it muſt be advantageous for the agricultor to inſpect
other crops as well as his own; and thus wherever he can find a
ſuperior vegetation to collect feeds from it; which is more certain to
improve his crops than an indiſcriminate change of feed.
But where ſeed-corn is purchaſed without a previous obſervation
of its ſuperior excellence, perhaps it would be more advantageous to
take that from better kinds of ſoil, and from ſomewhat better cli-
mates ; as the good habits acquired by ſuch feeds may be continued
long after their removal to inferior ſituations. And on the contrary,
care ſhould be taken not to collect a change of ſeeds from worfe cli-
mates or inferior foils, unleſs the agricultor is previouſly certain that
they are of a ſuperior kind.
VI. 1. To determine the goodneſs of ſeeds, the weighing a given mea-
fure of them may generally be eſteemed a criterion; as it is known,
that when ſeeds are put into cold water, thoſe which are leſs perfect
are liable to ſwim, and the ſound ones to fink; thus the imperfect
ſeeds of rye-graſs and of clover may be detected by throwing a ſpoon-
ful of them into water; but the feeds of rye-graſs are ſaid to be fre-
quently adulterated by a mixture of the ſeeds of twitch or dog's graſs,
which can only be difcovered by an experienced eye. This even is
faid to be a teſt of the goodnefs of malt; as thoſe grains, which are
not perfectly germinated, will ſwim with one end upwards, I ſuppoſe
the root end; and thoſe which are perfectly germinated ſwim on their
fide, whilſt the found ungerminated barley finks in water.
It is therefore a proper criterion of good feed-wheat to caſt it into
ſalt and water, juſt fo faline as to float an egg; as the more falt is
diffolved in the water, the heavier it becomes; and hence none but
quite ſound grains of wheat will fiok in this brine; and that which
ſwims is properly rejected. This rejection of the light grains by
ſteeping wheat in brine is probably of greater conſequence to the en-
ſuing crop, than the adheſion of any ſalt to the grain, which has
7
been
9

434
SECT. XVI. 6. 2.
PRODUCTION
a
a
peas
a
been believed to deſtroy the eggs of inſects ſuppoſed to adhere to it,
or to fertilize the foil.
2. The weight of a given meaſure of corn will alſo with confider-
able certainty diſcover the quantity of huſk or bran contained in it,
compared to the quantity of flour ; as that grain, which is cut too
early, or which is otherwiſe not quite ripe, as happens in wet-ſea-
fons, ſhrinks in the barn or granary, and becomes wrinkled, and has
thus a greater proportion of ſkin or bran, than that which has been
more perfectly ripened, and will hence weigh lighter in proportion.
A teſt of this kind may enable us to determine whether peas and
beans, or oats, are preferable in reſpect to economy as provender for
horſes. A ſtrike or buſhel of oats weighs perhaps forty pounds, and
a ſtrike or buſhel of peas and beans perhaps fixty pounds; and as
the ſkin of peas and beans is much leſs in quantity than that of oats,
I ſuppoſe there may be at leaſt fifteen pounds of flour more in a ſtrike
of and beans than in a ſtrike of oats. There is alſo reaſon to be-
lieve, that the flour of beans is more nutritive than that of oats, as
appears in the fattening of hogs; whence according to the reſpec-
tive prices of theſe two articles I ſuſpect, that peas and beans gene-
rally ſupply a cheaper provender for horſes than oats, as well as for
other domeſtic animals.
But as the flour of peas and beans is more oily, I believe, than that
of oats, it may in general be fomewhat more difficult of digeſtion ;
hence when a horſe has taken a ſtomach full of peas and beans alone,
he may be leſs active for an hour or two, as his ſtrength will be more
employed in the digeſtion of them, than when he has taken a ſtomach
full of oats. According to the experiment of a German phyſician,
who gave to two dogs, which had been kept a day faſting, a large
quantity of fleſh food ; and then taking one of them into the fields
hunted him with great activity for three or four hours, and left the
other by the fire. An emetic was then given to each of them, and
a
3
the

Seet. XVI. 6. z.
4:55
OF SEEDS.
the food of the ſleeping dog was found perfectly digeſted, whilſt that
of the hunted one had undergone but little alteration.
Hence it may be found adviſable to mix bran of wheat with the
peas and beans, a food of leſs nutriment, but of eaſier digeſtion; or
to let the horſes eat. before or after them the coarſe tuffocks of four
graſs, which remain in moiſt paſtures in the winter; or laſtly, to
mix finely cut ſtraw with them.
3. Another way of diftinguiſhing light corn from heavy is by win-
nowing; as the ſurface of the light grains being greater in proportion
to their ſolid contents, they will be carried further by the current of
air, which is produced by the van; though the heavy grains would
roll further on the floor after rolling down a grate to ſeparate the
duft; becauſe their vis inertiæ would carry them further, after they
are put in motion ; and their ſurfaces would be reſiſted by the air no
more than thoſe of the lighter grains.
4. Finally, there is reaſon to believe that a progreſſive improve-
ment of many. ſeeds exiſts during the warmer days of winter in our
granaries, which probably conſiſts in the proceſs of the converſion of
mucilage into ſtarch ; in the ſame manner as the harſh juices of crab-
apples, and of auſtere pears, are continually changing into ſugar dur-
ing the winter ; both which proceſſes are probably in part chemical,
like the flow but perpetual change of ſugar into vinous fpirit, when
the juices of ſweeter apples and pears, or grapes, are put into bottles,
in the manufacture of cyder, perry, and wine..
This improvement of wheat, and of barley, and of oats, is well-
known to the baker, the maltſter, and the horſe-dealer; as better
bread is made from old wheat, and barley is converted into better
malt in the vernal months; and horſes are believed to thrive better,
and to poffefs more vigour, when they are fed with old than with
new oats.
VII. 1. The preſervation of ſeeds next demands our attention.-
Thoſe ſeeds which are liable to lie upon the ground, as peas and
corn,

456
SECT. XVI. 7.1.
PRODUCTION
a
a
corn, when thrown down by ſtormy or wet ſeaſons, ſhould be ga-
thered rather earlier ; left they ſhould begin to germinate, as they lie
upon the ground, and would hence become a kind of malt after dry-
ing. Other feeds ſhould be gathered, before they would ſpontane-
oufly fall from their pericarps, to prevent the loſs which muſt other-
wiſe enſue in the reaping, or mowing, and carrying them to the
barn, which often amounts to as much as is neceſſary to fow the
land, which produced it, as well as to ſupply the depredations of
birds, inſects, and vermin.
Monf. B. G, Sage accuſes the farmers of ſome parts of France of
collecting their wheat with many green weeds immediately after
reaping it, and preſſing it cloſe together in their barns; by which
the ſtack undergoes a fermentation with great heat like ſome hay-
ſtacks; and that the corn is by this fermentation killed, and will not
grow when ſown like hay-ſeeds from a fermented hay-ſtack, men-
tioned in Sect. X. 11.7; and alſo that the gluten, or vegeto-animal
matter of the corn, is deſtroyed; and it on that account makes leſs agree-
able and leſs wholeſome bread; and laſtly, that the ſtraw is much in-
jured by becoming mouldy. Journal de Phyſique, Sep. 1794.
Monf. B. G. Sage adds, that the following proceſs will diſcover,
whether wheat has been thus injured, which may be intereſting both
to the baker, and wheat-buyer, who wants it for ſeed-wheat. Make
a paſte with flour and water, then waſh it with your hands under
water, which muſt be frequently changed, till it no longer becomes
diſcoloured. The ſubſtance remaining in the hands is the gluten;
if the corn be good, this is elaſtic, and will contract when drawn
out; if the corn has begun to heat, it is brittle; if the corn has fer-
mented, none of the gluten will be obtained.
In this country, where corn is ſeldom cut too early, or preſſed to-
gether on the ſtack, the principal circumſtance required is to keep
it dry; as the ſtraw is not liable to ferment like new hay made with
young graſs, which contains ſugar at every joint of the ſtem. To
preſerve
,

Sect. XVI. 7.1. OF SEEDS.
457
a
a
preſerve a ſtack of wheat dry, a good cover of thatch may ſeem ſuf-
ficient; but as this is liable to injury by vermin, it would be an ad-
ditional ſecurity, if at the time of making the ſtack the ſheaves were
laid higheſt in the middle, and lower on every fide, ſo that if any
wet ſhould find its way into the ſtack, it might drain onwards along
the ſtraw of the ſheaves, which would thus act like thatch through
out the whole ſtack.
There are inſtances of great durability of feeds, which have been
preſerved dry, and ſecured from either fo great heat or ſo great cold, as
might deſtroy their life or organiſm. Thus there is an account of the
ſeeds of Indian wheat, which grew well in a hot-houſe after having
been kept thirty-four years, as was accurately aſcertained. Bath So-
ciety, Vol. V. p. 464. And it has been lately aſſerted, that
many
ſeeds of more than a hundred years old, which were found in ſome
old herbarium at Vienna, have been made to germinate by the uſe of
oxygenated muriatic acid and water. Philof. Magaz. But if the or-
ganic life of a ſeed be deſtroyed by froſt, or fire, or mechanic injury,
putrefaction ſucceeds, and decompofition; as when the organic life of
an egg is deſtroyed by violently agitating it, it is known foon to pu-
trefy.
To preſerve feeds in barns or granaries our principal attention
ſhould be firſt to make them dry, and ſecondly to keep them dry;
becauſe no ſeeds can vegetate without moiſture. The art of drying
moſt feeds muſt conſiſt in duly ventilating them, eſpecially on dry
days; which may be done by frequently turning over the heaps of
them; and to preſerve them dry in this climate the door and windows
of granaries ſhould open to the ſouth to receive the warmth of the
fun, with apertures round the building for ſufficient ventilation ;
which muſt be prevented from admitting rain or ſnow by ſheltering
boards on the outſide.
The heaps of corn ſhould be ſurrounded with boards to keep them
from contact with brick or ſtone walls; which, when warm moiſt
ſouth-
3 N

458
PRODUCTION SECT. XVI. 7.2.
fouth-weſt winds ſucceed cold north-eaſt winds, are liable to precipi-
tate the moiſture from the atmoſphere by their coldneſs, and to com-
municate it to all bodies in contact with them. For a ſimilar purpoſe
in ftables ſome have put up a tall wooden trunk from the chamber to
the room below, three or four feet ſquare, and ten or twelve feet high,
with a ſliding valve to draw out the corn below, which is poured in
at the top ; in three or four places a tin or wooden pipe full of holes
is made to paſs horizontally through the box to give air to the corn,
the whole of which, when any of it is drawn out below, is moved
in deſcending; and new ſurfaces of corn are applied to the air-holes
of the horizontal tubes.
The moſt ſecure way of preſerving a great quantity of wheat, ac-
cording to Mr. Tull, is by gently drying it on a hair-cloth in a malt-
kiln, with no other fuel but clean ſtraw, and no greater heat than
that of the ſunſhine. In this ſituation the wheat remained from four
hours to twelve hours, according to the previous dampneſs of it. Mr.
Tull knew a farmer in Oxfordſhire who purchaſed wheat, when it
was cheap, and kept it by thus drying it for many years, and made a
large fortune by ſelling it again in dearer ſeaſons. The life of the
ſeed was not deſtroyed by this proceſs; as he aſſerts, that ſome of it
grew, which had been kept in this manner ſeven years; whereas in
drying potatoes on a malt-kiln ſo great heat was employed as to de-
ſtroy their life, and violent putrefaction enſued, as mentioned in Sect.
a
a
X. 9. 2.
و
2. A due ventilation alſo, where corn is kept in the common
warmth of the atmoſphere in this climate, is neceſſary, except in
ſeaſons of froſt, and alſo the admiſſion of light; as otherwiſe the ve-
getable mucor, called mould, is liable to grow upon the corn, and in-
jure it; as this mucor like ſome other funguſes will grow, where
there is little or no change of air, and without light, as in cellars, if
there be ſufficient moiſture and warmth.
3. Another method of preſerving ſeeds may conſiſt in fecluding
them

SECT. XVI. 7. 4.
459
OF SEEDS.
them from heat, as in granaries beneath the ſoil ; which are ſo deep
or ſo well covered with earth, as not to be affected by the difference
of ſeaſons. Thus there have been inſtances of muſtard-ſeed produc-
ing a crop on digging up earth, which had not been removed for
many
years, and, as was believed, even for ages. And in ice-houſes it is
probable, that not only ſeeds might be long preſerved, but perhaps
fruits alſo; if they were afterwards very gradually thawed by putting
them into cold water, that they might not be deſtroyed by the too
great ſtimulus of ſudden heat, as mentioned in Sect. XV. 4. I.
4. Where it has been neceſſary ſuddenly to collect and to pre-
ſerve great heaps of corn without ſhelter for the proviſion of armies,
ſome have moderately moiſtened the upper ſurface of the heap daily,
which has occafioned the upper grains to grow, and thus to produce
a ſward or turf over thoſe below; which, it is ſaid, has thus pre-
ſerved the lower part of the magazine. But in reſpect to granaries for
the purpoſe of laying up very large quantities of grain to prevent fa-
mines in ſcarce years, I ſuppoſe the ſtacks of covetous farmers, who
keep their corn in cheap years, hoping to ſell it at a better price in
ſcarce ones, is a more certain method, and a cheaper one to the pub-
lic, to keep up a ſufficient ſtock of corn, than by any other experi-
ment that can be deviſed.
5. Gardeners in general prefer new ſeeds to old for their principal
crops, as they are believed to come up ſooner, and with greater cer-
tainty, and to grow more luxuriantly." But peas and beans of a
year old,” Mr. Marſhall obſerves, " are by ſome preferred to new,
as not ſo likely to run to ſtraw. And cucumbers and melons are beſt
to be ſeveral years old, in order to their ſhooting leſs vigorouſly, and
thence becoming more fruitful. But this principle is carried too far
by ſome gardeners, who ſay theſe ſeeds cannot be too old, and will
allow ten years to be within bounds; three for cucumbers, and four
for melons, however is age enough.
56 As to the age of ſeeds, at which they may be fown, it is uncer-
N2
tain,
3
22

460
Secr. XVI. 7. 6.
PRODUCTION
a
tain, and depends much upon how they are kept; thoſe of cucum-
bers and melons are good a long time, becauſe very carefully pre-
ferved.
" Peas and beans will germinate very well at ſeven years of age ;
but the ſeeds of lettuces and kidney-beans, and ſome others, are not
to be depended upon after a year or two; and generally ſpeaking the
ſmaller ſeeds are of the leaſt duration.” Marſhall on Gardening.
6. Where ſeeds of a periſhable nature are to be carried to, or brought
from, diſtant countries, I ſuſpect that covering them in fugar would
be the moſt certain and falutary method of preſerving them; and
even, that fleſh meat cut into thin ſlices, and covered with ſugar, or
ſyrup, or treacle, would be better preſerved than in brine, and afford
a much more falutary nouriſhment to our ſailors.
Since I wrote the above I have ſeen a paper in the Tranſactions of
the Society of Arts, Vol. XVI. from Mr. Sneyde of Belmont in Staf-
fordſhire, who having obſerved ſome feeds, which came accidentally
amongſt raiſins, to grow readily, directed many feeds to be ſent from
the Weſt Indies covered with raiſins, and others in fugar, and others
in the ufual manner of ſending them, and found, that thoſe im-
merſed in ſugar or covered with raiſins both looked well, and grew
readily; whereas many of the others would not vegetate.
Since the powder of freſh burnt charcoal is known ſo powerfully
to abſorb all putrid vapours, it is probable the ſeeds mixed with and
covered with charcoal duft, which has been recently burnt, or not
long expoſed to the air, might be ſucceſsfully employed for the pre-
ſervation of ſeeds either in long voyages, or in domeſtic granaries.
VIII. 1. To ſow ſeeds advantageouſly, it is probable, that thoſe of our
native plants might be ſuffered to drop on the ſurface of the earth in
the autumn, as they fall from their parent plants, covered only by
their deciduous leaves ; in which ſituation their fruit might contri-
bute to nouriſh them, as our crabs and floes; or defend them from
inſects, as the acrid hulk of the walnut; or from birds, as the hard
ſtones

SCET. XVI. 8. 1.
461
OF SEEDS.
a
ſtones or ſhells of nuts and cherries, fince this is the proceſs of
nature.
But when the ſeeds brought originally from other climates are to be
ſown, an attention is required to the circumſtance of ſeaſon and of
foil. Thoſe, which will ripen their feeds in the ſame year, are to be
ſowed in the early ſpring, and covered lightly with earth to preſerve
them from birds and inſects; and ſhould be buried thus beneath the
foil, foon after it has been ploughed or dug, as its interſtices are then
replete with atmoſpheric air ; which may be neceflary to ſtimulate
into elevation the plume of the embryon plant; as the moiſture of
the earth is neceſſary to ſtimulate the root into its elongation down-
wards.
Thoſe feeds nevertheleſs, which will not perfect their vegetation in
the ſame year, muſt be fown in the early autumn; and though all
;
feeds vegetate better, when placed but a little beneath the ſurface of
the ſoil, as one inch, becauſe they have then a better ſupply of at-
moſpheric air, which may be neceſſary for their firſt growth, before
they have acquired leaves above ground; yet as many foreign feeds
may not be ſufficiently hardy to bear our inclement winters, it may
be neceſſary, as ſome believe, to bury them an inch and a half, or
two inches, deep in the ſoil, to prevent the froſts from doing them
injury, as well as to preſerve them from the depredation of birds.
And the drill femination, or fowing all kinds of ſeeds in rows, is the
moſt convenient method for fowing them at a determined depth, and
alſo for the purpoſe of keeping the young plants clear from weeds by
the more eaſy application of the hoe.
To fow many ſeeds earlier than is uſually practiſed is much re-
commended. There is a paper by Lord Orford in Mr. Young's An-
nals of Agriculture, Vol. IX. p. 385, who ſeems to have found con-
fiderable advantage by ſowing barley ſo early as the ſeventh of Fe-
bruary, three and a half buſhels on an acre. But as much moiſture
with or without ſubſequent froſt is more liable to deſtroy the em-
bryon

462
PRODUCTION Sect. XVI. 8. 2.
;
bryon in its very early ſtate in the ſeed, than after it has ſhot out
roots and a ſummit, and thus acquired ſome habits of life; this
early fowing muſt ſometimes be practiſed with caution. Seeds may
nevertheleſs be fown ftill earlier in hot-houſes, or in warm fitua-
tions, as peas, beans, wheat, and may be afterwards tranſplanted in
the vernal months with ſafety and advantage. See Sect. X. 3.
6.
The difficulty of determining the beſt ſeaſon for fowing feeds in the
ſpring, owing to the variation of the weather in the ſame latitude,
as well as in laying down the exact ſeaſons for ſowing in different
latitudes, occaſioned Linneus to conſtruct, what he terms a calendar
of Flora ; which was afterwards adapted to this climate by Stilling-
fleet; which conſiſted in obſerving the firſt appearance of the root-
ſcions, or flowers of the uncultivated native vegetables ; with direc-
tions to ſow the cerealia, or harveſt ſeeds, when ſuch plants or
flowers became viſible. By attention to ſuch obſervations on the un-
cultivated native plants in many climates, it is probable, that ingeni-
ous tables might be produced, which might direct the beſt time of
ſowing the uſeful feeds in all latitudes, and in all ſituations.
Another table of the climates, where plants grow naturally, and of
their native ſituations in reſpect to moiſture or dryneſs, hill or valley,
with the kind of foil where they were originally found, might alſo
contribute to their ſucceſsful cultivation.
2. In the gardens near large towns, where the land is more va-
luable and better manured, gardeners ſometimes low two or three
kinds of ſeeds on the ſame ground for the purpoſe of economy. Thus
Mr. Marſhall obſerves, that " on the ſame ground they low radiſhes,
lettuces, and carrots; the radiſhes are drawn young for the table, the
lettuces to plant out, and a ſufficient crop of carrots is left; for car-
rots, if you wiſh them to be large, ſhould not grow very near to
each other."
In defence of this mode of culture it is ſaid, if one crop fails, the
others may do well, and there is no loſs of ground or time; and if
all

Secr.XVI. 8. 2. OF SEEDS.
463
all ſucceed, they do very well. Radiſhes and ſpinach are commonly
fown together by the common gardeners, and many manoeuvres of
inter-cropping are made by them, as the fowing or planting between
rows of vegetables that are wide aſunder, or preſently to come off,
or in the alleys of things cultivated on beds.
“ Thus if a piece of horſe-radiſh be new planted, it may be top-
cropped with radithes or ſpinach, &c.; or if a piece of potatoes be
planted wide, a bean may be put in between each fet in
every or
every other row; a thin crop of onions upon new aſparagus beds,
is a common practice, drawing them young from about the plants."
Introduc. to Gardening. Rivington.
The farmer likewiſe, in the cultivation of graſſes for feeding ſheep,
finds an advantage in ſowing a mixture of ſeeds on the ſame ground,
as rye-graſs, trefoil, and clover, which are ſaid to ſucceed each other
in reſpect to the production or maturity of their herbage, as in Sect.
XVIII. 1. 1. And for the purpoſe of preventing ſmut it may be uſe-
ful, as I have before obſerved, to ſow in the ſame ground in ſeparate
rows two kinds of wheat, one of a forwarder nature than the other ;
whence if the farina of one kind ſhould be injured by wet weather,
that of the other may impregnate the ears of both. The two kinds
of wheat recommended are bearded wheat and ſmooth-headed wheat,
which are called by farmers cone wheat and Lammas wheat; of both
of which there are many varieties, and it is aſſerted that one third of
cone wheat is frequently lowed with two thirds of Lammas wheat,
and that the crops are much ſuperior to either of them ſeparately.
Hall's Encyclop. Art. Agriculture.
In reſpect to kinds of ſoil thoſe ſhould be choſen, which have
been found by obſervation to ſuit particular ſeeds, both in regard to
their nutritive properties, and the moiſture and warmth of their
ſituations. And for thoſe ſeeds, which produce tuberous roots within
the earth previous to their flowering, as potatoes, parſnips, radiſhes,
a foil of leſs coheſion ſhould be found or prepared.
3. Add

464
PRODUCTION
Secr. XVI. 8.3
3. Add to this, that there are ſome ſeeds, as thoſe of carrots, that
are ſo difficult to be diſſeminated in uniform quantities, that it has
been cuſtomary to mix them previouſly with fand or garden mould,
for the purpoſe of giving them weight, or bulk, or to detach them
from each other. And ſome even ſuffer them to begin to put forth
their roots in ſuch a mixture of moiſt fand or garden mould for the
purpoſe of more regularly diſperſing them.
In dry ſeaſons the ſoaking feeds in water, a day or two before
committing them to the ground, will forward their growth, as well
as by artificially watering the ground before or after fowing them;
and the ſoaking them in a ſolution of ſalt and water may have ano-
ther advantage of giving an opportunity of rejecting the light
feeds, which float, and perhaps of deſtroying ſome inſects which may
adhere to them; the ſprinkling ſome kinds of ſeed with lime may
alſo be of advantage for the purpoſe of deſtroying infects, if ſuch ad-
here to them, and of attracting moiſture from the air, or lower parts
of the earth, or for its other uſeful properties; but where the feed,
ſoil, and ſeaſon, are adapted to each other, none of theſe condiments
are required.
It may nevertheleſs on other accounts be very advantageous to ſteep
many kinds of grain in the black liquor, which oozes from manure
heaps. Mr. Chappel, in the papers of the Bath Society, found
benefit by ſteeping barley in the fluid above mentioned for twenty-
four hours, and ſkimming off the light grains. On taking it out of
the water he mixed wood-aſhes fifted with the grain to make it ſpread
regularly, and obtained a much finer crop, than from the fame corn
ſown without preparation. To this we may add, that to ſteep the
feed in a ſolution of dung in water, as in the draining from a dung-
hill, is believed in China both to forward the growth of the plant,
and to defend it from variety of inſects, according to the information
given to fir G. Staunton.
There is an old proverb, “ ſow dry and ſet wet;" but where the
4
earth

Secr. XVI. 8. 4. OF SEEDS.
465
earth has been lately turned over by the plough or ſpade, there can
be no bad conſequence from ſowing during rain in general; but in
ſome clay grounds much ſoftened by rain, if feed be put into holes,
and a dry ſeaſon ſucceeds, an impenetrable cruſt may fupervene by the
exhalation of the water, and the ſetting, as it is called, of the clay :
but even this could not frequently occur, when ſeeds are fown in the
moiſt weather of the autumnal months; but generally in both caſes
the growth of the ſeed would be forwarded by the moiſture.
4. Where the fruit, which ſurrounds any kind of ſeeds, can be
fowed along with them, it may anſwer fome uſeful purpoſe. Thus
the fruit of crabs, quinces, and ſome hard pears, will lie all the
winter uninjured covered only with their autumnal leaves, and will
contribute much to nouriſh their germinating ſeeds in the ſpring. So
the holly-berry and the ivy-berry remain during the winter months
uninjured by the rains or froſts, and undevoured by birds or inſects,
and contribute to nouriſh their germinating ſeeds, when they fall on
the ground in the ſpring. The acrid huſk of walnuts fowed along
with them preſerves the ſweet kernel from the attack of inſects; the
fame muſt be the uſe of the acrid oil of the caſhew-nut. The haw-
thorn poſſeſſes both a nutritive covering and a hard ſhell for the above
purpoſes; and the ſeeds of roſes are armed with ſtiff pointed briſtles,
as well as furniſhed with a nutritious fruit, ſo long known as an
agreeable conſerve in the ſhops of medicine, conſerva cynoſbati; the
former conſtitutes a defence againſt inſects, and the latter ſupplies a
reſervoir of nutriment for the germinating ſeeds.
5. To this ſhould be added, that in our ſhort and cold ſummers the
viviparous buds of ſome vegetables are too luxuriant, and do not pro-
duce oviparous buds ſoon enough to ripen their ſeeds, as melons and
cucumbers, and many other plants, in thoſe ſeaſons which are moiſter
than common. It is believed, that by waſhing the ſeeds of melons
and cucumbers from the faccharine and mucilaginous matter of their
fruit, and by keeping the feed three or four years before it is uſed,
that
a
30

466
SECT. XVI. 9.2.
PRODUCTION
that the viviparous buds become leſs vigorous, and the oviparous ones
more numerous, and forwarder in their flowering; and for the pro-
duction of earlier as well as of larger crops all ſuch luxuriant vegeta-
bles ſhould be fown early in the vernal ſeaſon, or in the autumnal
months, if they are not too tender to bear the winter froſts.
a
IX. Queſtion concerning general encloſure.
The politicaladvantage or diſadvantage of the general encloſure of a
country belongs to this place, as it more particularly affects the pro-
duction of the cerealia, or corn-agriculture.
There can certainly be no objection to the encloſure of commons,
or at leaſt to the diviſion of them into private property, as they are be-
lieved to produce more than tenfold the quantity of ſuſtenance to
mankind, if they are employed in agriculture, or even in paſturage,
than by nouriſhing a few geeſe, ſheep, or deer, in their uncultivated
ftate covered with fern, heath, or gorſe.
2. The advantage of encloſing paſture-lands, or meadows, can not
be doubted; as the management of fattening cattle, of milch-cows,
ſheep, and horſes, becomes ſo much eaſier; as well as the more con-
venient uſe of the aftermath, when the hay is carried away.
3. The lands alfo appropriated to the production of garden vegeta-
bles and fruit, as well as to the production of other perennial plants,
which are uſed in the arts, as hemp, flax, madder, woad, rhubarb;
and of the efculent roots or herbage raiſed for the conſumption of eat-
tle, as turnips, potatoes, carrots, cabbages, certainly require to be
encloſed.
4. The political queſtion therefore finally concerns only the arable
.lands, and aſks fimply, whether a general encloſure of arable lands be
favourable or unfavourable to the population, and conſequent pro-
ſperity of the country, which muſt depend on the comparative quan-
tity of nutritive proviſion, which is likely to be produced from the
different modes of its cultivation.
6
Now

Secr. XVI. 9.4. OF SEEDS.
467
Now as paſturage requires fewer hands in the management of it,
and leſs art and attention to conduct it, than agriculture ; and as its
products in fleſh, cheeſe, butter, take a higher comparative price at
market, and are articles of greater luxury, than the products of arable
land in corn, we may conclude, that pafturage will prevail in all en-
cloſed provinces over agriculture. And as perhaps tenfold the num-
bers of mankind can be ſupported by the corn produced on an hun-
dred acres of land, than on the animal food which can be raiſed from
it, it follows, that an encloſed province will afford ſuſtenance to a
much ſmaller population; and as the number of inhabitants of a
country depends on the eaſe, with which parents can procure fuſte-
nance for their families, marriages will become fewer, and the people
decreaſe, when an arable country is converted into paſturage.
This laſt circumſtance appears already to operate in theſe realms,
ſince about half a century ago much corn was exported annually, but
for ſeveral years laſt paſt great quantities of it have been annually im-
ported for our own ſuſtenance; and that even though potatoes are
much cultivated, and muſt therefore leſſen the conſumption of grain,
and the ungraceful faſhion of covering the head with wheat-flour is
much diminiſhed. Is this to be ſolely aſcribed to the numerous en-
cloſures of arable lands, or in part to the conſumption of corn in the
diſtilleries?
One very important conſequence of any country producing a
greater quantity of corn, than it conſumes, and of thence exporting it
to foreign nations, even by means of a bounty, conſiſts in its cer-
tainty of preventing famine, the moſt dreadful of human calamities;
as in years of ſcarcity the ſtream of exportation can be ſtopped, and
produce an ample ſupply by its ſtagnation at home.
Hence when a great part of any tract of country becomes employ-
ed in paſturage inſtead of agriculture, the inhabitants will become
conſumers of fleſh inſtead of conſumers of grain, and will conſe-
quently decreaſe in number from the want of ſufficient ſuſtenance.
Beſides
30 2

468
Sect. XVI. 9.4
PRODUCTION
Beſides which the people of agriculture are more active and robuſt
than the people of paſturage, and more ingenious in the invention
and uſe of machines neceſſary for the more artful cultivation of the
foil, as well as more numerous, and will conſequently become ſupe-
rior to them in arms and arts, and may in proceſs of time conquer
them ; which reminds us of the Egyptian Dynaſty of Shepherd-
kings, who were ſubdued by their agricultural rivals; and alſo of
the allegorical hiſtory of Cain flaying Abel, which were probably the
names of two political hieroglyphic figures repreſenting the ages of
paſturage and of agriculture before the invention of letters.
It muſt hence certainly be an object of good policy to encourage
agriculture in preference to paſturage, which in this country might
be effected by preventing the encloſure of arable lands, and alſo of
thoſe parts of commons, which are beſt adapted to the growth of
corn; though the whole might be advantageouſly divided into pri-
vate property. Unleſs ſome other means could be deviſed of pre-
venting a nation from becoming too carnivorous, or of duly promot-
ing the cultivation of grain, the former of which was heretofore pro-
duced by religious faſt-days twice a week, and the latter by bounties
on the exportation of corn. To which might be added a total pro-
hibition of the deſtructive manufactory of grain into ſpirits, or into
ſtrong ale, and thus converting the natural nutriment of mankind
into a chemical poiſon, and thus thinning the ranks of ſociety both
by lefſening their quantity of food, and ſhortening their lives by dif-
eaſe.
In many villages, where much arable lands have been lately en-
cloſed, the numbers of labouring people have quickly been much di-
miniſhed both by the ſcarcity of food, and want of employment.
Worſe fares the land, to haftening ills a prey,
Where wealth accumulates, but men decay ;
Princes or lords may flouriſh, or may fade,
A breath can make them, as a breath has made ;
But
W
a

SECT, XVI.-9.42
469
OF SEEDS.
a
But a bold peafantry, their country's ſword,
When once deſtroy'd, can never be reſtor'd.
GOLDSMITH'S DESERTED VILLAGE
Mankind nevertheleſs ſeems by nature to be deſigned to ſubfiſt on
both vegetable and animal nutriment, which appears from the length
of his inteſtines, which like thoſe of ſwine are much longer than the
inteſtines of carnivorous animals, and much ſhorter than thoſe of the
vegetable eaters; and which alſo appears from the ſtructure of his
teeth, which partakes of the ſtructure of thoſe of the carnivorous and
phytivorous animals; and laſtly, becauſe thoſe people, who live ſolely
on vegetables, as the Gentoo tribes, and thoſe who ſubſiſt ſolely on
animals, as the fiſh-eaters of the northern latitudes, are undoubtedly
a feebler generation than thoſe of this country, who exiſt on a mix-
ture of both. A due proportion therefore of the two kinds of nou-
riſhment, ſuch as perhaps at preſent exiſts, or lately did exiſt, in this
nation, muſt be decidedly the beſt; the preſervation of which, with
the prohibition of ſpirits, or of ſtrong fermented liquors, except oc-
caſionally as medicines, might probably render theſe kingdoms more
populous, robuſt, proſperous, and happy, than any other nation in the
world. But if the luxurious intemperance of conſuming fleſh-meat
principally, and of drinking intoxicating liquors, ſhould increaſe
amongſt us, ſo as to thin the inferior orders of ſociety by ſcarcity of
food, and the higher ones by diſeaſe both of mind and body, it may
hereafter be ſaid of Great Britain, amid her foreign conqueſts, as for-
merly of ancient Rome,
Sævior armis
Luxuria incubuit, victumque ulciſcitur orbem.
SECT.

470
Secr. XVII.
PRODUCTION-OD
SECT. XVII.
PRODUCTION OF ROOTS AND BARKS.
Barks of trees are ſimilar to their roots. All roots now known were originally from
ſeeds. I. 1. Tuberous or bulbous roots of turnip, carrot, parſnip, beet, are re-
ſervoirs of nutriment for the future ſtem. Not ſo in graſſes. Sugar viſible in
beet roots. Small beer from parſnip roots. Alcohol from carrots.
The knobby
root and flower-ſtem are ſucceſve plants. SeleEt forward ſeeds from vigorous
plants, and a ſoil not cobeſive. Radiſhes on bot-beds. 2. Tuberous roots from ſub-
terraneous wires, as potatoes. Pinch of the flowers. Make a cellular foil.
Aerial potatoes. Curled leaf of potatoes. Sow the feed. Plant large roots and
whole ones. Early potatoes. 3. Improve ground artichoke and pignut by feed.
4. Onions, method to improve them. s. Orchis, ripen the feeds of it
. Snow
. 5.
drops. Hyacinths. Crocus. Martagon lily. II. 1. Palmated, or branching
roots, not immediately from
ſeed. Perennial roots, like barks of trees, continue to
increaſe in fize. Should remain four or five years in the ground, not longer, as
rhubarb. 2. Pinch off the flowers, as in rhubarb. 3. Roots of aquatic plants.
Nymphea, butomus, cultivated for nutriment, wine, or vinegar. 4. Art to pre-
ſerve roots. Keep them alive, between 32 and 48 degrees of heat, covered with
pounded charcoal, faw-duft, and thatch, or dry them by ventilation and heat.
5. Of muſhrcoms. Their gills are their lungs. Are animate beings without locomo-
tion. Are of animal origin. Conduet galvaniſm. Muſhroom ſtone, trufless mo-
rels, muſhrooms with acrid juice. Ear-fungus. III. 1. Barks contain ſugar and
mucilage, and other ingredients. They ſhould be taken off before the buds expand.
2. Oaks, why barked in ſpring. 3. Barks of elm and maple might make ſmall
beer. Of holly eſculent. Bird-lime like caoutchouc. 4. Bitter, aromatic. Acrid
barks. 5. Reſtringent and colouring barks for tanning and dying. 6. Fibrous
barks of flax, papyrus, mulberry, and birch. 7. To increaſe the bark pinch off the
flowers.

Sect. XVII.
471
ROOTS AND BARKS.
flowers. 8. Rub off the moſs. Sprinkle with water. 9. Wounds of the bark.
Paint the naked alburnum. 10. Canker. Bind on a new bark. Plant the
branch in a divided garden-pot.
3
of re-
а
As the barks of trees are compoſed of a congeries of the long cau-
dexes of the individual buds, which conſiſt of the abſorbent veſſels,
which imbibe nutriment from the earth, and of the arteries and veins,
which ſupply nutriment to the growing vegetable; of the glands,
which ſecrete from the vegetable blood the various acrid, aftringent,
or narcotic, juices to defend them from the depredation of infects;
and the various mucilaginous, oily, or faccharine, materials for the
nouriſhment of their embryon buds; and laſtly, of the organs
production. There exifts the ſtrongeſt analogy between the barks
of the trunks of trees, and of their roots, in every reſpect; except
that the former poffeffes a cuticle adapted to the contact of the dry
atmoſphere, and the latter a cuticle adapted to the contact of the moiſt
earth, which differ from each other like the external ſkin, and the
mucous membranes of animals. And finally, as theſe long caudexes
of the buds of trees, which form the filainents of the bark, termi-
nate in radicles beneath the ſoil, and in leaves in the air, like the
broad caudexes with the radicles and aſcending ſtems, or foliage, of
herbaceous plants, they exactly reſemble each other:
We ſhall therefore divide roots for the purpoſe of treating of their
production into bulbous or tuberous roots, into palmated or branch-
ing roots, and into barks; obſerving that though roots and buds
might poſſibly have exiſted before feeds, and though a great number
of the roots uſed for nutriment, or for the purpoſes of medicine, or
for the arts of dying and tanning, are immediately produced by buds,
or bulbs; yet are they all, which we now poſſeſs, originally derived,
I ſuppoſe, from feeds; becauſe thoſe varieties, which have been pro-
pagated from buds or bulbs for many centuries, are believed to ace
quire hereditary diſeaſes, and gradually to periſh.
1. Of

472
PRODUCTION OF Sect. XVII. 1.-1.
1. Of tuberous and bulbous roots.
1. Some tuberous roots, as the turnip, braſſica rapa, are immedi-
ately produced from feeds, but differ from the other plants, which
are called annual or biennial, in this circumſtance; that, as they are
generally fowed fo late in the ſeaſon as not to have time to produce
flowers and feeds in the ſame year, they produce a knobby root,
which confifts of a reſervoir of nutritious matter for the future
flower-ſtem, which is to riſe and flouriſh in the ſucceeding ſpring
and ſummer; whereas the common annual graſſes, as oats and bar-
ley, do not previouſly lay up a magazine of nutriment in their roots,
but in their joints, which are ſweet ; and therefore their roots are
not uſed for culinary purpoſes, or for provender.
Other tuberous roots are raiſed in the fame manner rom ſeeds,
but are generally fown alſo fo late in the ſeaſon as not to form their
flower-ſtems in the ſame year ; as the carrot, daucus carota ; the
parſnip, paſtinaca ſativa ; and the beet, beta vulgaris; theſe alſo lay
up a ſtore of mucilaginous and faccharine matter in their roots for the
growth of the future flowers. In the beet-root the cryſtals of ſugar
are ſometimes viſible by a microſcope ; and I was well informed, that
a labourer in Lincolnſhire made ſmall beer from a decoction of parf-
nip roots, which was fpirituous enough, and not of diſagreeable fla-
vour; and Mr. Hornby of York, by boiling carrots, and fermenting
the juice expreſſed from them, produced two hundred gallons of
proof ſpirits from twenty tons of carrots. Edinb. Tranſact. Vol. II.
p. 28. Now as all vinous ſpirit has been ſugar, there is foundation
to hope that a method may be diſcovered of producing and ſeparating
ſugar from theſe plants of our own climate in fufficient quantity for
our demeſtic conſumption, or even for exportation.
Other tuberous roots are propagated from ſeeds in the fame man-
ner ; and though they are fowed early, and produce their flower-ſtem
and feeds in the ſame year, yet they form a knobby root, which con-
9
a
fifts

Secr. XVII. 1.2.
473
ROOTS AND BARKS.
fiſts of a magazine of nutritious matter, previous to the elevation of
the flower-ſtem, as the radiſh, rhaphanus ſativus, and carrot, and
beet, when fown early. I nevertheleſs ſuſpect that theſe, as well as
the preceding, confift in reality of two ſucceſſive plants; that which
forms the knobby root, and that which is formed from it, as ſpoken
of in Sect. IX. 3. 6.
6
For the production of roots of theſe kinds, which are immediately
or ſecondarily propagated from ſeeds, our attention muſt be applied
to collect the forwardeſt ſeeds, and from the beſt plants of the kind;
and to fow them at the proper ſeaſon of the early ſpring, or early au-
tumn; and in a foil which contains ſufficient vegetable nouriſhment,
obſerving, nevertheleſs, that as carrots, parſnips, beets, and radiſhes
conſiſt of knobs formed in the ground, a leſs adheſiye ſoil is to be
ſelected; as one abounding with ſiliceous or' calcareous fand, as well
as with carbonic earth. But as the turnips are formed chiefly above
ground, this attention to the coheſion of the ſoil becomes leſs neceſ-
ſary, ſo that it is ſufficiently penetrable by the fibres of their ra-
dicles.
There is another art of producing larger roots from feed, and at
an earlier ſeaſon, as of radiſhes; which is by fowing them in hot-
beds in the early ſpring, and expoſing the tops to the cold air during
the day, as this prevents the luxuriant growth of the ſummit, and
increaſes that of the root.
2. Other tuberous roots are generally propagated by ſubterraneous
wires, or root-buds, from the tuberous roots of their parents through
a long generation, and not either primarily or ſecondarily from
ſeeds; as the potato, ſolanum tuberofum ; and the ground artichoke,
or tuberous ſun-flower, helianthus tuberoſus; and perhaps the pig-
nut, bunium bulbocaſtanum.
As the tuberous roots of the potato planted in the ſpring not only
produces many other ſimilar tuberous roots, but flowers alſo during
the ſummer ; I was led to ſuſpect, that pinching off the flowers, as
they
з Р

474
Sect. XVII. I. 2.
PRODUCTION OF
they appeared, would contribute to increaſe the number or enlarge
the ſize of the new roots; which experiment has been made on a
ſmall ſcale by one, who believed it to ſucceed in a degree deciſive of
its utility. See Sect. XIX. 3. 1. and Sect. VII. 1. 3, where it is ſaid,
that pinching off the flower-ſtems of bulbous-rooted flowers, when
they firſt appear on young bulbs only a few years from the feed, is
believed to render the flower duplicate,
As the roots of potatoes are formed beneath the earth, the ſoil,
in which they are planted, ſhould be laid hollow and full of cells, or
ſhould poſſeſs leſs coheſion than uſual, to facilitate the protruſion of
their wires, and the enlargement of their roots. This ſhould be done
by burying ſome long litter of ſtraw and ſtable dung under the foil;
for as potatoes are believed to require more carbonaceous earth than
carrots, a mixture of ſand is leſs advantageous to them.
I was this day ſhewn by my friend Major Trowel of Derby a new
variety of the potato in his excellent new-made garden, the ſoil of
which confifts of marl mixed with lime and ſtable-manure. From
one root there appeared to iſſue fix or eight ftems three or four feet
long, at every joint of which were produced new potatoes; at the
lower joints there were three of theſe aerial potatoes, one large one
the ſize of a pullet's egg, and a ſmaller one on each ſide of it. At
the upper joints only one new aerial potato adhered, and theſe be-
came fmaller the further they were removed from the root; and
finally, at the ſummit there had been a flower as there was now a
ſeed-veſſel, called a potato-apple. All theſe new potatoes at the joints
of the ſtems were green, becauſe they had not been etiolated by be-
ing ſecluded from the light, but the terreſtrial roots were white. The
larger new tuberous roots had eyes on them like a common potato,
but the ſmaller ones had begun to ſhoot out a new ſtem or leaves
from their upper part. This variety, which may be termed an aerial
potato, is analogous to the magical onion, and other ſpecies of al-
lium, which bear cloves, or roots on their fummits inſtead of feeds,
W
a
I
and

SECT. XVII. 1. 2.
475
ROOTS AND BARKS.
and like the viviparous polygonum ; but differs in this circumſtance,
that in all thoſe, I believe, the flowers are barren in reſpect to bear-
ing feeds, as thoſe are on the ſummit of the ſpike of polygonum vi-
viparum ; but in the aerial potato there was alſo a feed-bearing
flower at the ſummit of the ſtem, and the new roots only at the la-
teral joints. I ſhould hope this proliferous variety by cultivation may
become permanent, and give riſe to a new ſpecies, which may pro-
duce both aerial potatoes and ſubterraneous ones, a lwofold viviparous
progeny.
The curling of the leaves of potatoes, which is attended with ſo
great a diminution of the quantity and fize of the new roots, is fup-
poſed to be owing to their continued propagation by ſubterraneous
buds or root-wires, inſtead of by ſeed; that hence they acquire he-
reditary diſeaſes, like the canker or gangrene of apple trees, which
have for one or two centuries been propagated by grafting the ſcions,
as mentioned in Sect. IX. 3. 4. and XV. 1. 4. Hence by ſowing the
ſeeds of potatoes, and cultivating the roots thus produced, new va-
rieties may probably be ſoon acquired, exempt from the diſeaſe of the
curled leaf, and which may be as good in other reſpects as thoſe
which have been too long propagated by their roots. Some have
nevertheleſs affirmed, that they have ſeen curled potato-plants in the
ſecond year from the feed ; and others, that they have ſeen numer-
ous infects on theſe curled leaves ; and others, that the potato-root,
the leaves of which are curled, remains hard, and leſs diſſoluble in
the ſoil, which I have myſelf witneſſed. More obſervations are
wanted to elucidate this ſubject.
Another cauſe of the degeneracy of potatoes has ariſen, I believe,
from planting the leaſt inſtead of the largeſt roots, ſee Sect. XVI. 5.
and which conſequently poffefs leſs vigorous vegetation, as buds and
bulbs ſo exactly reſemble the parent plant. Thus the ſmall bulbs,
which ariſe from tulip-roots, will produce a rather larger bulb an-
nually for three or four years, as I am informed; but it is the large
new
3 P2

476
Secr. XVII. 1. 2.
PRODUCTION OF
new central bulb only, which will produce a flower the next ſum-
mer, and another large central bulb like itſelf. See Sect. IX. 3. 1.
Another cauſe of the degeneracy of potatoes may ariſe from dividing
the larger roots into too many ſets, which muſt deprive the embryon
plant of much of its appropriated nutriment; as the umbilical part
of the root is generally thrown aſide by thoſe idly-ingenious diffecters
of it; for though the part, where the umbilical veffels were inſerted,
may not after the mature growth of the bulb appear to poffefs new
veſſels from the embryon plants, ſuch as are ſeen on the lobes of a
growing garden-bean; yet, as it becomes decompoſed, it muſt ſup-
ply mucilaginous or faccharine nutriment to the roots of the new
plants.
As the potatoes raiſed from feeds do not flower on the ſecond or
third year, reſembling in this circumſtance the bulbs of tulips and
hyacinths; theſe new roots, I am told, are ſold as early potatoes, and
that they are forwarder in their growth from their being generally
planted without being divided ; and that they form their new roots
fooner, as they do not flower. To improve the feeds of potatoes ſee
Sect. XVI. 3. 4.
The following method of planting whole potatoes is recommended
in Mr. Adam's Effays on Agriculture, and has a promiſing appear-
ance.
66 The idea," ſays he, " which I mentioned before, reſpecting the
culture of the Scotch and Anjou cabbages, might be ſucceſsfully ap-
plied to that of potatoes. Let us ſuppoſe the ground, in which they
are to be ſet, is properly prepared by plowing: let then the furrows
be drawn in it at four feet diſtance all over the field, and croffed by
other furrows at an equal diſtance. Where theſe interſect each other
lay in ſome dung from a wheelbarrow, extending from the point of
interſection fourteen or fifteen inches each way: let a man follow-
ing ſpread a little of the mould from the furrow over the dung:
let a third hand put one whole found potato at the point of interſec-
4
tion,

Sect. XVII. 1.3.
477
ROOTS AND BARKS.
tion, and one in each furrow, at a foot diſtance from the centre,
which will make five in all: a fourth hand ſhould now follow with
a barrow full of leaves, and lay them over the plants; ſhould then
ſprinkle ſome mould lightly over them, and leave them ſo till the
plants ſhoot.
66 Thus the plants will occupy a ſpace of two feet each way, out
of the four feet between the furrows; and the remaining intervals
between the plants on each ſide will alſo be two feet, which intervals
I would horſe-hoe at the proper periods, firſt one way of the field,
and then acroſs, laying the mould upon the plants at each hoeing,
ſo that the ſpaces which the plants occupied would by theſe means
become little ſquare hills filled with roots; and the intervals be-
tween being thus hoed and croſs hoed, would have the uſual good
effects of pulverizing the foil, deſtroying the weeds, and preparing
the land in the beſt manner poffible for a crop of wheat."
3. The ground artichoke, helianthus tuberoſus, ſeldom ripens its
ſeeds in this country, and might probably be much improved by
uſing methods to ripen the ſeed, which are mentioned in Sect. XVI.
3.4; and by thus producing new varieties ; and the pignut, bunium
bulbocaſtanum, might probably by cultivation from the ſeed ſupply
an agreeable and falutary root to be eaten like cheſnuts either raw or
roaſted.
4. The ſeeds of the common onion, allium cepa, generally pro-
duce no flower-ſtems the firſt year; but each ſeed produces concen
tric leaves, which gradually form a large bulb below them with one
or two, and ſometimes three, leſs internal bulbs, included within
three or four general concentric coats, beſides the three or four coats
appropriated to the individual bulbs, as deſcribed in. Sect. IX. 3. 2.
On the next year fome ſpecies of this genus produce bulbs after their
flowers inſtead of ſeeds, as allium ſativum and magicum ; others pro-
duce not only flowers but alſo bulbs, as allium moly, and ſpheroce-
phalum. If the bulbs of theſe leaſt kinds of allium were planted
with
9

478
Secr. XVII. 1.5.
PRODUCTION OF
a
with deſign to produce other bulbs, and not to produce feeds; it is
probable, that pinching off the flowers might enlarge the new bulbs,
as the pinching off the flowers of potatoes; and that by ſuch means
a larger kind of bulbs of ſome of this genus might be procured.
5. Another bulbous root, which might be well worthy cultivation
in moiſt ground, is the orchis morio ; which is ſold under the name
of falep, after it has been prepared by firſt ſcalding it in hot water to
detract the ſkin, and afterwards by drying it in an oven ; and which
then affords a nouriſhing mucilage, which will long keep uninjured.
And, if it was cheaper, might probably be brought into more exten-
five uſe as a culinary vegetable, as mentioned in Sect. XVI. 3. 4.
The orchis morio produces one large new root annually, and proba-
bly ſome ſmaller offsets, as otherwiſe I do not perceive, how it could
increaſe in our meadows, as it does not ripen its ſeeds in this coun-
try.
If the new root be taken away from the old one early in the year,
it is affirmed, that the feeds will ripen in Sweden ; which are other-
wiſe in that country, as in this, always unprolific; this experiment
might therefore be very advantageous to the cultivator. Another
method of inducing orchis to bear prolific feeds may be by confining
the roots in garden pots, which might be immerſed in a moiſt foil,
and would probably bear ripe ſeeds; as the lily of the valley, con-
vallaria, is ſaid to do by crowding its roots ſo much as to prevent the
production of more of them, Amenet. Academ. Vol.VI.p. 120. A third
method of procuring feed from orchis might be by cultivating a few
of them in a hot-houſe for that purpoſe.
The root of the fnow-drop, galanthus, if dug up in winter, and
prepared in the ſame manner, might poſſibly ſupply a nutritious mu-
cilage ſimilar to that of the orchis; as I once boiled a few of them,
and found on tafting them, that they had no diſagreeable flavour, If
prolific feeds could be procured from this plant, it might be worth
cultivation for the fame purpoſes as the orchis; and the roots of the
hyacinth,
.
a

Sect. XVII. 2. I.
479
ROOTS AND BARKS.
hyacinth, I am informed, are equally infipid, and might be uſed as an
article of food; but the roots of crocus, which I boiled and taſted,
had a diſagreeable flavour, and might probably therefore be infalu-
brious.
Mr. Gmelin in his Hiſtory of Siberia afferts, that the roots of the
lilium martagon are uſed as food in that country; and it is probable,
,
that the root of the arum, though it be acrid in its raw ſtate, might
ſupply palatable and falutary nutriment by cookery; as Mr.White
afferts in his Hiſtory of Selborne, p. 43, that it is ſcratched up and
eaten by thruſhes in ſevere ſnowy ſeaſons, and it is known foon to
loſe its acrimony even by expoſing its dry powder to the air ; we may
add, that the root of the aſphodelus ramofus is uſed to feed ſwine in
France, and that good ſtarch is obtained from the roots of white:
bryony and of alſtromeria lieta.
Other bulbous roots are propagated by floriſts with great attention
for the beauty of their flowers, as tulips, hyacinths, lilies, and many
others. For an account of ſome of theſe ſee Sect. IX. 3. on the
growth of bulbs, and Sect. XIX. 3. 1. on the production of flowers.
11. Palmated or branching roots.
1. The bulbous and tuberous roots already mentioned were either
Such, as were primarily derived from ſeeds, as the turnip, carrot,
parſuip, radiſh, beet, falſafi ; or ſuch as were fecondarily derived
from ſeeds, but immediately from bulbs or knobs fimilar to thema
ſelves, as potatoes, ground artichoke, orchis, pig-nut. But the
branching or palmated roots, which are uſed as food, or in medicine,
or in the arts of dying, are ſeldom produced immediately from ſeeds,
but generally from preceding roots, and are hence the product not
of annual but of perennial plants; as the root of liquorice, gly-
cyrrhiza; of marth mallow, alcea; of rhubarb, rheuin; and of mad.
der, rubia tinctoria,
The roots of theſe perennial plants ſhoot out not only annual!
ſtems

480
Sect. XVII. 2,2.
PRODUCTION OF
ſtems with numerous flower-buds above ground, but alſo other new
buds on their caudex, or upper part of the roots beneath the ſoil ;
all which buds protrude their new caudexes not only over thoſe
ftems, but alſo over the old root-branches; and thus form annually
a new bark over the old root, which remains alive beneath the
ground, though the ſtem periſhes by the winter froſts. This happens
exactly in the ſame manner as the bark of trees, which annually is
produced over the old bark of the root as well as of the trunk; but
in trees the ſtem-bark as well as the root-bark ſurvives the winter,
Hence theſe palmated or branching roots of perennial herbaceous
plants, as of rhubarb, madder, liquorice, continue to increaſe in ſize
by the ſuper-addition of an annual new bark; but in four or five
years the internal part begins to decay, and the roots therefore ſhould
be taken out of the ground for uſe before that time. It is ſaid in the
tranſactions of the Society for Encouragement of Arts, Vol. XVI.
p. 226, that thoſe rhubarb roots, which were not taken up, till they
were ſeven or more years old, were moſt of them good for nothing
from the decay of the internal part of the root. The ſame is ſaid to
happen to ſome bulbous roots, as the hyacinth ; and occurs in all
thoſe roots, which are ſaid to be end-bitten, as a ſpecies of ſcabius
called devil's-bit. See Sect. IX. 3. 5. .
They ſhould then be taken up in the winter months, before the
new buds or flower-ſtems begin to acquire nouriſhment from the
root, by which it would be deprived of a part of the nutritious, co-
louring, or medical matters; which principally reſide in the bark, or
alburnum of it. On this laſt account alſo theſe roots ſhould not be
permitted to continue in the ground a much longer time than that
above mentioned, though the internal or woody part of the root may
not decay; as the woody part is leſs adapted to the purpoſes expect-
ed than the bark and alburnum, which cover or conſtitute the nu-
merous branches of the root.
2. One method to increaſe the ſize of theſe palmated or branch-
ing

Secr. XVII. 2. 2.
481
ROOTS AND BARKS.
ing roots may be by pinching off the flowers, as ſoon as they appear,
when the feeds are not wanted; this I once faw practiſed on the
rheum palmatum with apparent advantage, as well as on potatoes, as
mentioned above; as more nutriment may thus be derived to the
new buds forming on the roots.
The colouring matter fold under the name of annotta, or arnotta,
which is ſaid to be obtained from the fkin of the kernel of the bixa
of South America, or of the enonymus fhrub cultivated in our gar-
dens, is believed to be much adulterated with madder, rubia tinctoria;
the root of which for the purpoſe of colouring cheeſe may be uſed
inſtead of arnotta, and is to my knowledge a perfectly harmleſs root,
though it tinges the bones of young animals red, who eat it mixed
with their food, and may be grown by cheeſe-farmers in their own
gardens, as it is a very hardy perennial plant, and requires no art of
cultivation. It may be uſed either by pounding the freſh root and
boiling it in water, or by drying the root for the purpoſe of preſerv-
ing it, and afterwards bruiſing and boiling it.
For the cultivation of rubia tinctoria fee Miller's Gardener's Dic-
tionary, who deſcribes with ſeveral plates the manner of growing and
of afterwards preparing this root in prodigious quantities in Holland;
and adds, “ that if the cultivation of madder was carried on properly
in England, that it would not only fave to the nation the great an-
nual fum now expended in the purchaſe of it from the Dutch, but
would employ a great number of hands, from the time harveſt is
over, till the ſpring of the year, which is generally a dead time for
labourers; and the pariſhes might thence be much eaſed of the poor's
rates, which is a confideration well worthy public attention."
The external part of the root of rubia tinctoria is coloured red, and
its internal part yellow, which diſtinguiſhes it from moſt other roots,
which are generally etiolated owing to their ſecluſion from the light;
which liberates their ſuperfluous oxygen, which otherwiſe deprives
them of colour as in bleaching, by uniting with their colouring mat-
ter,
3Q

482
Sect, XVII. 2. 3.
PRODUCTION OF
ter, and converting it into a colourleſs acid, except where the colour-
ing matter abounds in too great quantity. This etiolation of moſt
roots is evidently owing to the want of light, becauſe many of them,
as of white potatoes, become green if they grow above ground.
3. The roots of ſome aquatic plants are uſed in medicine both of
the bulbous and palmated kinds, as ſcilla maritima, ſquill or ſea-
onion, and the iris luteus, yellow water flag, and the acorus cala-
mus, aromatic flag. Other aquatic roots are ſaid to have ſupplied
food, as the ancient lotus in Egypt, which has been by ſome writers
ſuppoſed to be the nymphæa nelumbo. Herodotus affirms in his En-
terpe, that the Egyptian lotus grows in the Nile, and reſembles a
lily; and that the natives dry it in the ſun, and take the pulp out of
it, which grows like the head of a poppy, and bake it for bread. The
white-flowered and the yellow-flowered nymphæa of our ponds and
rivers has a palmated root ſometimes three inches in diameter. In
Siberia the roots of the butomus, flowering ruſh, are eaten; both
which well deſerve further attention, as they grow ſpontaneouſly in
our ditches and rivers, which at preſent produce no eſculent vegeta-
bles, and might thence become an article of uſeful cultivation. See
Sect. IX. 2. 5.
Some other aquatic roots, as well as terreſtrial ones, might proba-
bly become eſculent and nutritive by boiling or roaſting them to de-
ſtroy their acrimony. Or it is probable, that a wholeſome ſtarch might
be obtained from them, as from the roots of white bryonia, as is af-
firmed by M. Parmetier, by the ſimple proceſs of grating the root by
a bread-grater of tinned iron into cold water, and depriving it of its
acrid mucilage by frequent cold ablution. And laſtly, that they might
be ſo managed as to undergo fermentation either by previous germi-
nation, or by adding yeſt to the juice expreſſed from them after
boiling, and thus be converted into wine or beer, from which a ſpirit
might be diſtilled, or vinegar produced. See Sect. XI. 2. 5.
4. The art of preſerving roots, when taken out of the ground,
confifts
a

SECT. XVII. 2. 4.
483
ROOTS AND BARKS.
conſiſts either in keeping them alive during the winter without ſuf-
fering them to germinate, as life prevents the fermentation or putre-
faction of their juices; or fecondly, by depriving them of their water.
For the firſt purpoſe the roots, whether bulbous or palmated, ſhould
be kept in a degree of heat above the freezing point of 32 ; fince
freezing them deſtroys their life; whence they not only undergo a
ſudden change in their flavour and nutritive quality, but quickly tend
to putrefaction in conſequence of their loſs of life like the eggs of
animals. Nevertheleſs both vegetable and animal products, as fruits
and fleſh, as well as roots, may probably long exiſt unchanged in a
frozen ſtate in ice-houſes ; and if they are at length gradually thawed
by covering them with melting ice, or immerling them in cold
ſpring water, it is ſaid by Mr. Reaumure, who tried the experiment
on apples, that they do not loſe much of their flavour, if they be af-
terwards foon made uſe of; otherwiſe, I ſuppoſe, as the froſt has de-
prived them of life, they foon begin to undergo chemical changes.
If theſe roots are kept in a degree of heat above 48, which is the
heat of the internal parts of the earth, and conſequently of ſpring
water, they are liable to germinate, as happens to onions and pota-
toes in our ſtore-houſes during the vernal months. And if they be
expoſed to a much greater heat, ſo as to deſtroy the life of the root,
they ſoon run into fermentation or putrefaction, or become covered
with mould ; unleſs the water which they contain be quickly diffi-
pated by evaporation. A friend of mine once fent many ſtrikes of
potatoes to be dried on a malt-kiln, hoping by that means to preſerve
them during the ſummer ; but as the life of theſe roots was deſtroy-
ed by the degree of heat, and only about half of their water evapo-
rated, they foon became ſo putrid after being returned into his ſtore-
room, that the ſtench of them was intolerable, and even the ſwine
refuſed to eat them. Nevertheleſs I believe, if the parts either of ve-
getables or animals could be kept in an heat at or above the boiling
point of 212 in cloſe veſſels, ſo as not to ſuffer their fluid part to eva-
;
porate,
3 Q 2

484
PRODUCTION OF Sect. XVII. 2. 4.
,
porate, that neither fermentation nor putrefactiou would enſue; but
that they might be kept for years unchanged, as in the cold of 32.
.
The degree of heat required for preſerving roots fecure from froſt,
and from the proceſs of germination, which is that between the de-
grees of 32 and 48 of Farenheit's thermometer, may be well manag-
ed by ſtoring them beneath the ſoil in dry ſituations, as in dry cellars,
or in pits dug for that purpoſe, or even in barns; but this requires
more attention than is uſually employed in the common manner of
ſtoring potatoes, which are liable to be injured both by froſt and by
germination. Theſe pits in a dry ſoil ſhould be covered with mate-
rials, which conduct heat ill, and alſo with ſuch as might abſorb any
putrid exhalations, which may occur, and thus check the progreſs of
putrefaction, if it ſhould commence.
Air is a bad conductor of heat, if it be confined over the ſurface of
any body, but not ſo if it be perpetually changed; as it then carries
away heat very rapidly, as any one may experience by being fanned
on a hot day. Hence all ſuch materials as poſſeſs large pores or in-
terſtices full of air, are bad conductors of heat; as blankets, faw-
duft, wood-thavings, or ſtraw ; and will thence preferve the bodies,
they cover, both from external cold and from external heat. But as
charcoal in coarſe powder not only includes much common air in its
pores, but alſo has the property, eſpecially if recently burnt, of ab-
forbing putrid exhalations; and is -alſo itſelf of an unperiſhable na-
ture ; it ſeems peculiarly adapted to the purpoſes above mentioned.
Hence the heaps of potatoes, or carrots, or parſnips, or ground arti-
chokes, or even the roots of turnips or of beets, and the heads of
cabbages, and perhaps pears, and apples, as well as nuts, almonds,
and walnuts, might be well preſerved in pits or cellars, or even in
barns, if they were firſt covered with powdered charcoal an inch
or two in thickneſs, and over that a covering of faw-duft, and
finally over theſe a thick impenetrable thatch of ſtraw ; whence a
fore of provender for the winter months and the ſucceeding ſpring
9
6
may

Sect. XVII. 2. 5.
485
ROOTS AND BARKS.
may be preferved from any degree of cold or of warmth much above
or below that of the internal parts of the earth, in which feeds are
known to continue for ages even without germination or decay.
It is nevertheleſs neceſſary to dry many palmated roots, when they
are taken out of the ground, either becauſe they will not continue to
live in our barns or ſtore-rooms, like the bulbous roots, or becauſe
they require to be kept for ſome years in the ſhops of medicine.
Some of theſe roots, as thoſe of rhubarb, are ſaid like the bulbous
roots of fcilla or ſquill to contain five fixths of their weight of water,
and therefore require confiderable care in the method of drying them;
for unleſs they are properly dried, they are liable to contract mould
or mucor ; which is a vegetable production, which will grow on pu-
trefying materials without light or much air ; but might be prevent-
ed from growing by the vapour of perhaps a teaſpoonful of ſpirit of
wine, as mentioned in Sect. XV. 2. 3.
There is nevertheleſs ſome precaution neceffary in exhaling the
moiſture of theſe roots, as they ſhould be placed in a ſituation, where
they are ventilated as well as heated; for warmth alone is liable to
forward the tendency of the faccharine and mucilaginous parts of
them to paſs into fermentation or putrefaction, and thence to deſtroy
them; as the alburnum or fap-wood of timber trees is liable to de-
cay by what is termed the dry rot.
With this deſign drying houſes are conſtructed for the preparation
of madder, rubia tinctoria, as deſcribed in Miller's Dictionary; and
the rhubarb of the ſhops has frequently large holes bored through it;
which, it is ſuppoſed, were defigned to paſs cords through for the
purpoſe of fufpending it to dry, as it is conveyed on camels in a
warm climate.
5. The cultivation of muſhrooms, morels, and truffles, agaricus,
phallus, lycoperdon, ſhould be here mentioned ; as they are propa --
gated by their roots. The fungi ſeem to conſtitute an iſthmus be--
tween the two great continents of nature, the vegetable and animal
kingdoms.

486
SECT. XVII. 2. 5:
PRODUCTION OF
a
a
a
a
kingdoms. The odour of a fungus, when burning, approaches to that
of burning feathers; and all of them putrefy like animal fleſh; fome
;
of them as the phallus impudicus, ſtink-horn, emits ſuch a putrid
ſcent, as it grows, as to attract innumerable fleſh-flies to depoſit their
eggs or ſpawn in it. And thoſe muſhrooms, which are cooked at our
tables, as well as the catchup, made by preſerving their juices in ſalt
and water, poffefs an animal flavour. Of this laſt circumſtance I was
told a remarkable inſtance, where a cook-maid in a family of invalids,
who frequently wanted weak broth, perpetually deceived them by a
mixture of a ſmall quantity of good catchup with thin gruel, and
with only the addition of ſhred leaves of parſley, and a little falt.
Another thing in which the funguſes differ from vegetables, con-
ſiſts in their growing perfectly well without light, which is ſo ne-
ceſſary to the health of vegetables. The ſcarlet folds beneath the
head of the common eſculent muſhroom are ſo like the gills of fiſh,
that they have in our language obtained the ſame name. Theſe
folds beneath the hat of the agarics, the pores beneath the boletus,
and the thorny appearance beneath the hydnum, and the net-like
pores of phallus, are all different means of expoſing a larger ſurface
to the air; and therefore undoubtedly conſtitute the lungs of the
funguſes, as leaves conſtitute thoſe of vegetables, and not their organs
of reproduction, as ſome have ſuppoſed.
The chemical analogy, which exiſts between ſome of the muſh-
room tribe and animal matters, led Van Humboldt to inveſtigate
their conducting power of what he terms the galvanic fluid, which I
believe to be ſimply a minute ſhock of the electric fluid; and he
found, that morels and thoſe fungi, which in a ſtate of putrefaction
emit a cadaverous animal ſmell, are equally good conductors as real
animal ſubſtances. Annals of Medicine for 1798, Edinb. Van Hum-
boldt aſſerts further, that by chemical analyſis they approach like-
wiſe to animal ſubſtances, as they contain much azote and phof-
phorus. He alſo aſſerts, that he converted morels into fat by means
of

Secr.XVII. 2. 5.
487
ROOTS AND BARKS.
of ſulphuric acid diluted with water, which experiment he thinks is
analogous to that of Gibbes, and of the burying ground of the Inno-
cents, where fat was formed from muſcular fleſh. Journal de Phy-
fique, Vol. IV. p. 67.
The fungi would hence appear to be animals without locomotion,
whoſe lacteal veſſels are inſerted into the earth, like thoſe of vege-
tables; but whoſe gills or lungs are covered from the light, like
thoſe of animals, but expoſed to the open air like the leaves or lungs
of vegetables. Another curious occurrence, which ſeems to aſſociate
them with animals, if the truth can be depended upon, is that ſome
of them are of animal origin; as the common muſhroom is ſaid cer-
tainly to be procured from horſe-dung, as mentioned below; and
may therefore have its embryon or early ſtate in the inteſtines of ani-
mals, and its maturer ſtate in the ſoil or atmoſphere like other in-
ſects, as the bot-fly, and perhaps the tape-worm, and aſcarides? as
this production of muſhrooms is otherwiſe contrary to all known ana-
logy. Other fungi are found on the decayed parts of peculiar vege-
tables, from which they ſeem to take their origin, perhaps like
worms in the inteſtines of animals, as the agaric of the oak, of the
beech, of the elder ; the boletus of the beech, and of the willow;
and many others mentioned by Linneus.
The lycoperdon tuber, or truffle, grows under ground without
light, never riſing into day; and is propagated, I ſuppoſe, by only a
paternal or lateral progeny, like the polypus of our ditches, and not
by ſexual connexion, or feminal progeny. The truffle is hunted by
dogs probably from its poffefſing ſomewhat of an aniinal ſcent, like
the perfpirable effluvia left upon the ground, by which they hunt
their game or diſcover the foot of their maſter.
The phallus eſculentus, morel, and the agaricus, muſhroom of
various kinds, will grow without light in cellars, or on beds covered
with ſtraw; and are alſo, I ſuppoſe, propagated by a paternal or la-
teral progeny only, and not by a ſexual or ſeminal one.
7
The

488
Secr. XVII. 2. 5.
PRODUCTION OF
The roots, or ſpawn, or embryons, of the common muſhroom are
faid by Mr. Kenedy and others to be certainly procured from horſe-
dung laid unbroken in ſmall heaps under cover. It is aſſerted, that
in a few weeks during the ſummer months theſe roots will appear
like white threads; which on breaking the lumps have the muſh-
room ſmell. Theſe horſe-droppings are directed to be as little broken
as poſſible, and to be laid about three inches thick on a hot bed of
moderate warmth, conſtructed of alternate layers of tanner's bark
and horſe-dung, and whoſe uppermoſt ſtratum conſiſts of tanner's
bark about two inches thick. The bed is then to be covered with a
little manure, and about three inches of good foil, and finally with
a thick coat of ſtraw. The ſhed behind moſt hot-houſes is found
to afford a convenient place for a muſhroom bed; as no light is re-
quired, but only warmth, and occaſional moiſture. See Kenedy on
Gardening, Vol. II. for a particular account of this proceſs.
In the tanyards of Derby, I am well informed, that a production of
muſhroom ſpawn always occurs in the path, where the horſe walks,
which draws the rolling ſtone to grind the bark, which path conſiſts
of powdered oak-bark and horſe-dung trampled together. Of this I
was in one inſtance an eye-witneſs, but whether the embryons of
muſhrooms were derived from the oak-bark or horſe-dung was not
eaſy to determine.
Mr. Ferber, in his Travels through Italy, tranſlated by Raſpe,
mentions the muſhroom-ftone. He ſays " the pietra fungaia is a
white calcareous ſtalactite, or tuph-ſtone, dug in the limeſtone hills
bordering on Romagna, and endowed with the quality to produce in
any ſeaſon of the year eſculent muſhrooms, if kept in a moiſt cellar,
and now and then ſprinkled with water. This quality is owing to a
great many roots, or vegetable fibres, together with the muſhroom
feeds encloſed in its ſubſtance. They are uſed in ſome great houſes in
Naples and Rome. I ſaw an indurated mould from the ſame place
that
a

Secr.XVII. 2. 5.
ROOTS AND BARKS.
489
a
that had the ſame quality, which was uſed by Mr. Fabriani in the
mint of Florence.”
From this account the muſhroom-ſtone appears to conſiſt of a
porous tupha, like that with which the houſes are built at Matlock
Bath; and which has been depoſited from the water. But a later
writer has ſince analyſed one of theſe ſtones, but does not mention
how long it had been uſed for the vegetation of muſhrooms, which
might in great meaſure affect the reſults of his analyſis. Mr. Gadd,
in the Stockholm Tranſactions, ſays, that this pietra fungaia deſcribed
firſt by Ferber conſiſts of forty-five or forty-ſix hundredth parts of
filiceous earth, and twenty of a calx of iron, with a little magneſia
and vegetable alkali. Analytic. Review, Dec. 1798.
In this country the cellars would not be ſufficiently warm to pro-
duce muſhrooms at any ſeaſon of the year ; but as this muſhroom-
ſtone is of calcareous origin according to Ferber, it ſhews, that cal-
careous earth is friendly to the growth of muſhrooms; and a ſimilar
porous ſtone from the vicinity of Matlock Bath might probably be
permeated in a ſimilar manner with the roots of them, as a conve-
nient repoſitory of them to be raiſed into life occaſionally by warmth
and moiſture.
Some of the fungi are believed to poſſeſs an intoxicating quality,
and are eaten for that purpoſe by the peaſants in Siberia. One fungus
of the ſpecies agaricus muſcarum eaten raw, or a decoction of three
of them, produces intoxication for twelve or fixteen hours. Hift. of
Ruſſia, Vol. I. Nichols, 1780. The Oftiachs alſo bliſter the ſkin by
a fungus found on birch-trees, and uſe the officinal agaric for foap.
Other fungi poſſeſs a juice ſo acrid in their raw ſtate as immediately
to bliſter the tongue, as I once experienced on taſting a minute drop
of the juice of a large muſhroom, which on breaking the hat poured
out a yellow juice, which became purple or blue in a few ſeconds of
time on its being expoſed to the air ; which I believed to be the
fungus delicioſus of Linneus; the acrimony of which might never-
theleſs
a
a
3 R

490
Secr. XVII. 2. 5.
PRODUCTION OF
theleſs probably be deſtroyed by a boiling heat. And it is alſo probable,
that the common eſculent muſhroom may ſometimes diſagree from
their being not ſufficiently ſtewed, or by the incautious mixture of
ſome intoxicating fungi along with them.
Otherwiſe thoſe in common uſe at our tables appear to ſupply a
wholeſome and nutritive food, approaching towards an animal nature.
Two or three kinds are ſaid to be eaten in France beſides the red-
gilled ones which are eaten here; and it is probable many other
kinds of fungi might be found agreeable to the palate, and whole-
fome food, if well boiled, which might deſtroy their acrimony; and
eſpecially thoſe which when broken have fimply the agreeable ſmell
of the red-gilled ones in common uſe; and ſome of theſe, I ſuppoſe,
might be eaten raw without injury, as many people eat the red gilled
ones.
Beſides fome muſhrooms with white gills, which when broken
had the grateful ſcent of the common red-gilled muſhroom, and
which were ſaid to be more delicious, I have known the peziza au-
ricula, or ear-fungus, which was formerly an article of the materia
medica under the name of Jew's ear, to be ſtewed and eaten in con-
ſiderable quantity with impunity; and was eſteemed an agreeable ar-
ticle at the ſupper-table. And as this was eſteemed a pernicious genus
of fungi by Cluſins, it is probable, that many other funguſes might
loſe their acrimony by the heat of ſtewing, and become wholeſome
and agreeable food; which are at preſent in diſuſe from their dif-
agreeable acrimony in their raw ſtate, or from the bad character they
have accidentally acquired.
It ſhould be added, that though thoſe plants, which are ſuppoſed
to poſſeſs an alkaleſcent property, and to be liable to putrefaction
ſooner than other vegetables, loſe a part of their acrimony by a boil-
ing heat, as water-creſſes, cabbages, onions; yet that plants, whoſe
acrimony is of a different kind, as ginger, capficum, arum, do not
become much milder by boiling. I this morning directed ſome leaves
of

SECT. XVII. 3. I.
491
ROOTS AND BARKS.
of common ſpotted arum, and of arum ariffarum to be boiled, and on
taſting them found my tongue and lips almoſt excoriated. The na-
ture of this kind of acrimony has not been ſufficiently inveſtigated
by the chemiſts, but probably depends on a fixed eſſential oil.
| III. Barks.
a
1. The barks of the trunks of trees are ſimilar to thoſe of their
roots, and may be eſteemed a part of them, as they conſiſt of an in-
tertexture of the veſſels, which deſcend from the plume of each in-
dividual bud to the radicle of it, and conſtitute its caudex. The
bark nevertheleſs of the root is furniſhed with lymphatics to abſorb
water and nutritious juices from the earth, and is covered with a
moiſter cuticle; while the bark of the ſtem is furniſhed with lym-
phatics to abſorb moiſture from the air, and is covered with a drier
cuticle; the latter reſembling the external ſkin of animals, and the
lymphatics, which open upon it; and the former reſembling the
mucous membrane of the ſtomach, and its lacteals.
As the fap-juice riſes in all deciduous trees during the vernal
months to expand their foliage, though probably in greater quantity
in ſome trees than in others, it muſt conſiſt not only of ſugar and
mucilage, as in the maple and birch, but of various other ingredi-
ents in different trees, which have not been attended to; as appears
from the taſte of their young leaves, as of oak or aſh. And as ſome
of theſe materials reſide in the roots and ſap-wood or alburnum, ſo
others of them may perhaps reſide in the bark, where they have been
depoſited during the preceding ſummer, and become lignified by the
warmth of the ſpring, or diffolved by the moiſture abſorbed from
the earth and air, and conveyed upwards to the opening buds ;
whence it is evident, that the barks of trees ſhould be taken off for
uſe in winter or in early ſpring, before their buds begin to expand;
as then a part of theſe nutritious juices, or of the other materials,
which are required for medicines, or in the arts of dying and tan-
3 R 2
ning,
3 R

492
Secr.XVII. 3. 20
PRODUCTION OF
a
9
ning, are in part expended on the young leaves; which generally
poſſeſs the taſte and qualities of the bark, though in a leſs degree.
It may nevertheleſs be obſerved, that all theſe aſtringent, or other
materials, may reſide in the alburnum of the trunk or roots of all
perennial vegetables, as well as in their barks; becauſe the young
leaves, which pullulate on decorticated oaks, have the ſame bitter
flavour as the leaves on thoſe, which have not been decorticated
which may in part be derived from the bark of the root, which is ſtill
in the ground, and be carried up the veſſels of the ſap-wood to the
new buds.
2. Hence the bark of oak-trees ſhould be taken off during the
winter ; but when the ſap-juice reſiding or aſcending in the veſſels
of the alburnum becomes more liquefied by the warmth of the ſpring,
or is mixed with more moiſture, and puſhed up with great force by
the abſorbent veſſels of the roots, it oozes out in ſome degree be-
tween the alburnum and the bark; and thus the bark becomes fo much
more readily ſeparated from the fap-wood; whence this buſineſs is
generally done early in the ſpring, and ſhould be performed as foon
as this facility of detracting the bark appears, as mentioned in Sect.
III. 5 ; becauſe this proceſs of the germination of the buds continues
.
to injure the bark, whether the tree be cut down or not; as the buds
expand their foliage on new felled trees, as they lie on the ground.
3. The interior barks of ſome trees, like the alburnum or roots
above deſcribed, contain much mucilaginous or nutritious matter ; as
the bark of elm, ulmus, and of holly, ilex; and probably of all thoſe
trees or ſhrubs which are armed with thorns or prickles, which are
deſigned to prevent the depredations of animals on them, as the haw-
thorn, gooſeberry, and gorſe, cretægus, ribes groſſularia, ulex. The
internal barks of theſe vegetables may be conceived to be their albur-
num leſs indurated, and might probably all be uſed as food for our-
felves or other animals in years of ſcarcity, or for the purpoſe of
fermentation ; as I doubt not but the inner bark of elm-trees, ul-
4
mus,

SECT. XVII. 3. 3.
493
ROOTS AND BARKS.
mus, detracted in the fpring by being boiled in water might be con-
verted by the addition of yeft into ſmall beer, as well as the albur-
num of the maple and birch, acer et betula; all which are now ſuf-
fered to be eaten by infects when thofe trees are felled,
For the fugar, which is extracted from the vernal fap-juice of the
maple and birch, as well as that found in the manna-aſh, fraxinus
ornus, ſeems to reſide during the winter months in the root or albur-
num, rather than in the bark properly ſo called; and to become li-
quefied, as above mentioned, by the warmth of the fpring, or diffolved
by the moiſture abforbed from the earth, and conveyed to the open-
ing buds; but reſides ſolely in the roots of perennial herbaceous
plants; and in the economy of graffes, and I ſuppoſe of the ſugar-
cane, it is depofited at the bottom of each joint, which is properly
the root of the ſtem above it, as ſhewn in Sect. IX. 3. I.
Of theſe the bark of the holly not only yields a nutritious muci-
lage, and thus ſupplies much provender to the deer and cattle in
Needwood-foreſt by the branches being cut off, and ſtrewed upon
the ground, in ſevere ſeaſons of froſt and ſnow; but contains a re-
finous material, which is obtained by boiling the bark, and waſhing
away the other parts of it. This reſinous material poſſeſſes a great
adheſivenefs to feathers and other dry porous bodies, and has hence
obtained the name of bird-lime, and much reſembles the caoutchouc
or elaſtic reſin brought from South America, and alſo reſembles a
foffil elaſtic bitumen found near Matlock in Derbyſhire, both in its
elaſticity and inflammability. Hollies may be worth cultivating for
this material beſides the ufes of their wood, as I was informed, that
thirty years ago a perſon, who purchaſed a wood in Yorkſhire, ſold to
a Dutch merchant the bird-lime prepared from the bark of the numer-
ous hollies for nearly the whole ſum given for the wood; which if it
could be hardened might probably be ſold for the elaſtic reſin above
mentioned. Whether this reſembles the nutritive reſinous material
found
a

494
Sect, XVII. 3. 4.
PRODUCTION OF
found in wheat flour, when the mucilage and ſtarch are waſhed from
it, might be worth inquiry, as mentioned in Sect. VI. 8.5.
4. Other barks contain bitter, reſinous, aromatic, or acrid materials,
which ſupply the ſhops of medicine, as peruvian bark, cafcarilla,
cinnamon,and were deſigned by nature to protect thoſe vegetables from
the depredations of quadrupeds or inſects. Hence many trees, and
even the wood of them, after it is dried, and made into domeſtic fure
niture, is never devoured by worms, as the mahogany, cedar, cy-
preſs; and hence many plants, as the foxglove, digitalis, hounds-
tongue, cynogloſſum, henbane, hyoſciamus, and many trees, are not
devoured by any animals; as their juices would be poiſonous to
them, or much diſagree with their ſtomachs, if their diſguſtful fla-
vours to the noſe or palate did not prevent their eating them. The
ſame defence of the vegetable kingdom from human digeſtion, except
thoſe which have in long proceſs of time been ſelected and cultivat-
ed, appears from the relation of ſome unfortunate ſhipwrecked tra-
vellers, who have paſſed ſome hundred of miles along uninhabited
countries almoſt without finding an eſculent vegetable production.
5. Other barks contain reſtringent or colouring particles, employed
in the arts of dying and tanning, as berberry, oak, and afh, berber-
ries, quercus, fraxinus. The art of tanning conſiſts in filling the
pores of the animal mucous membrane with theſe reſtringent par-
ticles found in ſome vegetables, which are believed to poſſeſs a qua-
lity of ſhortening animal fibres. Thus when a long hair is immerſ-
ed ſome time in a ſolution of the bark of oak, or of the galls pro-
duced on its leaves by the punctures of inſects, the hair is ſaid to be
ſhortened. Whether this proceſs be occaſioned by chemical coagu-
lation of the mucus, of which theſe fibres totally or in part conſiſt,
or by capillary attraction tending to diſtend theſe fibres in breadth,
and thus to ſhorten them, as a twiſted ſtring is ſhortened by moiſ-
ture, has not yet been well inveſtigated. By thus impregnating the
pores of animal ſkins with vegetable particles, they become leſs
7
liable

Sect. XVII. 3. 6.
495
ROOTS AND BARKS.
a
a
liable to putrefaction, as conſiſting of a mixture of animal and vege-
table matter, as well as much better adapted to many domeſtic or me-
chanical purpoſes.
The art of dying confifts likewife in impregnating the pores of
dry ſubſtances with a ſolution of the colouring matter extracted from
vegetables by the capillary attraction of thoſe pores to the coloured
ſolution. And ſecondly, by a chemical change of thoſe colouring
particles after they have been imbibed, and the water of the ſolution
exhaled, by again ſteeping them in another folution, which may
chemically affect the former. Thus as green conſiſts of a mixture of
blue and yellow, it may be beſt produced by boiling the material de-
ſigned to be dyed firſt in a decoction of one of theſe colours, as of in-
digo; and then in that of another, as of the bark of berberry. And
as a ſolution of iron becomes black when mixed with a decoction of
oak-galls, by being in part precipitated; it is probable, that the par-
ticles of this combination of a ſolution of iron with reftringent matter
may be larger than either of thoſe particles ſeparately; and there-
fore that, if a dry porous ſubſtance be immerſed firſt in a decoction
of oak-galls, and after being ſuffered to dry, is then immerſed in a
ſolution of iron, the black tinge will penetrate into minuter pores,
and thus become more intenſe, than if the ſubſtance had been im-
merſed in the black dye already prepared.
6. Other barks are uſed for apparel, paper, cordage, and for
many 'mechanical purpoſes, owing to the ſtrength and tenacity of
their fibres, or to the fineneſs of them; as hemp, cannabis; flax,
linum; for the purpoſes of ſpinning and weaving; an art invented by
Iſis, queen of Egypt, who feems firſt to have cultivated flax ; which
was brought into Europe from the banks of the Nile. The bark or
leaves of the papyrus, a flag of the Nile, was firſt uſed for paper; and
the bark of the mulberry-tree is ſtill made into cloth at Otaheite and
other ſouthern iſlands.
The art of ſeparating the fibres of the bark of plants, as they con-
fift
3
1

496
3.7.
PRODUCTION OF SECT. XVII.
a
liſt of the caudexes of buds, or the connecting vefſels between the
plumules and the radicles of them, is performed by ſoaking them ſome
weeks in ſtagnant water ; till the mucous membranes, which con-
nect theſe fibres, are deſtroyed by putrefaction ; and afterwards by
;
drying them, and beating off with hammers, what may ſtill adhere.
Theſe fibrous parts of the barks of trees, as they contain no fac-
charine matter, like the alburnum, are much leſs liable to decay than
the ſap-wood, or perhaps than any part of the timber. Mauper-
tuis, who went to Lapland to meaſure a degree of the meridian, ſays,
that among the numerous trees which lay upon the ground deſtroy-
ed by age, or blown down by the winds, many birch trees appeared
whole, owing to the undecayed ſtate of their bark; but crumbled
into powder on being trod upon; and that the Swedes took the prac-
tice from this of covering their houſes with this unperiſhable bark,
on which they ſometimes lay foil, and thus poffefs aerial gardens.
Voyages by Mavor, Vol. XII.
7. To increaſe the quantity of bark it muſt be remembered, that
the leaf-buds, or viviparous offspring of trees, as they form new buds,
acquire new caudexes extending down into the ground, and thus in-
creaſe the bark of the ſtem in thickneſs; but the flower buds acquire
no new caudexes, but die, as ſoon as they have ripened their feed,
and conſequently do not increaſe the thickneſs of the bark. Whence
one method of increaſing the quantity of the bark is to increaſe the
number or vigour of the leaf-buds in contradiſtinction to the flower-
buds, which may be done by pinching off the flowers as ſoon as they
appear; and as the bark becomes gradually changed into wood, this
may be one method alſo of forwarding the growth of timber trees, as
mentioned in the next Section.
8. The method of preſerving the bark of trees from moſs conſiſts
in rubbing off that paraſite vegetable in wet weather by means of a
hardiſh bruſh; which is ſaid to be uſed with advantage on the apple-
trees in the cyder countries; and may at the ſame time give motion
to

SECT. XVII. 3.9.
497
ROOTS AND BARKS.
to the vegetable circulation, or forward the aſcent of their juices ab-
ſorbed by the radical or cortical abſorbents. In dry weather the bruſh
ſhould be frequently dipped in water. Waſhing the barks of wall-
trees by a water-engine may alſo facilitate the protruſion of their
buds in dry ſeaſons; and might poſſibly prevent the canker, if appli-
ed to dwarf or aſpallier apple trees. Other paraſite vegetables muſt
be occaſionally deſtroyed, where they occur, as the lichens, fungi,
milletoes; with the ivies and other climbers, as ſome kinds of lo-
nicera, clematis, and fumaria, woodbine, virgin's bower, and fumi-
tory.
When a wound is made in the bark ſo as to expoſe the albur-
num to the air, the upper lip of the wound is liable to grow faſter
downwards, than the lower one is to grow upwards, owing to the
former being ſupplied directly with nutritive juices ſecreted from the
vegetable blood, after its ventilation, and conſequent oxygenation in
the leaves; whereas the lower lip only receives thoſe juices laterally
by inofculation of veſſels. Over theſe wounds the cuticle is liable to
project, and to ſupply a convenient hiding place for inſects, which
either eat the new fibres of the growing bark, and perforate the al-
burnum; or by their moiſture, their warmth, and their excrements,
contribute to the decay of the alburnum, and prevent the healing of
the wound. Theſe dead edges of the projecting bark or cuticle
ſhould be nicely cut off, but not ſo as to wound the living bark.
Plaſters of lime, or of tar with ſublimate of mercury, have been
recommended to preſerve the wounded parts from the air, and from
moiſture, and from inſects; but as all theſe materials are injurious
to the fibres of the living bark, they ſhould be uſed with caution, fo
as not to touch the edges of the wound, but only to cover the al-
burnum ; for this purpoſe white lead and boiled oil, mixed into a
thick paint, or with the addition of fublimate of mercury, or of ar-
ſenic, or of ſpirit of turpentine, may probably anſwer the purpoſe;
and may be of real utility on the wounds of thoſe trees, whoſe wood
3 S
contains

498
PRODUCTION OF Sect. XVII. 3. 10.
contains leſs acrimony, and is therefore more liable to be bored into
and eaten by a large worm or maggot almoſt as thick as a gooſe-
quill : which I have ſeen happen to a pear-tree, ſo as to conſume the
whole internal wood, till the tree was blown down.
In reſpect to the caution neceſſary to be obſerved in not touching
the living edges of the wounded bark with ſuch materials as may in-
jure the tree by their abſorption, I remember ſeeing ſeveral young
elm trees, which died by their boles having been covered, as I was
informed, by quick-lime mixed with cow dung to prevent their be-
ing injured by horſes; and I have ſeen branches of peach and nec-
tarine trees deſtroyed by ſprinkling them, when in leaf, with a ſlight
ſolution of arſenic, and others with ſpirit of turpentine.
10. A more curious method of cure is ſaid to have ſucceeded,
where the bark of a tree has recently been torn off even to great
extent, and that is by binding the ſame piece of bark on again, or
another piece from the ſame tree, or from one of a ſimilar nature,
nicely adapting the edges of the bark to be applied to the edges of
that, which ſurrounds the wound of the tree, which it is ſaid will
coalefce in the ſame manner, as the veſſels of the bark of an ingraft-
ed ſcion unite with thoſe of the bark of the ſtock ingrafted on;
which is ſtrictly analogous to the union of inflamed or wounded parts
of animal bodies, as in the cure of the hare-lip, or the inſertion of
the living tooth from one perſon into the jaw of another, or the fac-
titious noſes of Talicotius.
If the bark over the cankered parts of apple-trees could be thus re-
newed by paring the edges of the mortified bark to the quick, and
then nicely applying a piece of healthy bark from an apple-tree of in-
ferior value, and ſecuring it with an elaſtic bandage, as a ſhred of
flannel, it would be a very valuable diſcovery.
Another method, where a branch of a valuable tree is in the
pro-
greſs of being deſtroyed by canker, might be by incloſing the can-
kered part, and ſome inches above it, in a garden-pot of earth pre-
viouſly

Secr.XVII. 3. 10.
499
ROOTS AND BARKS.
viouſly divided, and ſupported by ſtakes, and tied together round the
branch; which might then ſtrike roots in the earth of the garden-
pot, and after ſome months might be cut off, and planted on the
ground, and might thus be preſerved, and produce a new tree;
which experiment I have this ſummer tried on two apple-trees, and
believe it will ſucceed.
3 S2
SECT.

500
SECT. XVIII
PRODUCTION OF
SECT. XVIII.
PRODUCTION OF LEAVES AND WOOD.
1. 1. Leaves are the lungs of vegetables. Graſſes propagated by their roots. Some
are viviparous. Joints of graſſes are ſucceſſive vegetables. And their roots. Ex-
tract roots of twitch-graſs by a ſcarifier with inclined teeth. Produce root-leaves
for grazing, and ſtem-leaves for bay. Eat down the firſt ſtem. Cut graſs young
for hay. Why young hay is liable to take fire. How to prevent it by ſtraw. Eat
low meadows late. Sow rye-graſs, trefoil, white clover, for ſucceſſive herbage.
Other graſs Seeds. Roll them in Spring. Effeets of frost. Uſe more water as in
rice grounds. Sow thick. Heavy cattle ſhould be ſtall-fed. How to deſtroy tuf-
ſocks. How to make hay. 2. Some root-leaves eaten raw.
Others previouſly
boiled. Upper part of ſome roots and of ſome ſtems eſculent. Aſparagus. Art of
cultivation of root-leaves and ſtem-leaves. Of mulberry-leaves. 3. Etiolation of
leaves leſſens their acrimony. Etiolated flowers. Etiolated ladies. 4. Aromatic
and bitteriſh leaves uſed as tea, as of fage. When to be gathered. Tea recom-
mended. 5. Leaves uſed in medicine. Bog-bean inſtead of hops. Others for
tonning, as oak, aſh, and alder leaves. Others for dying, as indigo and woad.
6. Leaves will ferment and may make a kind of beer. II. 1. Wood is produced
from leaf-buds. To increaſe wood moiſten the trees. Scratch the bark. How to
ſtraighten crooked trees. Pinch off the flowers. 2. To render timber trees tall with-
out knots, or crooked for ſhip-timber. Willows. Oziers. Sugar-maple. Scotch
firs. 3. Preſerve wood from lightning, and from wood-peckers. 4. Woods differ
in colour. Uſed in dying. Differ in medical and chemical properties. 5. Oak
corrodes lead. Sap-wood rots under lead. How prevented. Whence the myſ-
teries of Free Maſonry. 6. Woods differ in their hardneſs and ſmoothneſs. Blocks
for printing. 7. In their durability as cypreſs. Alder for piles. 8. In lateral
coheſion. Hygrometer. Pendulum. 9. In Specific gravity. Rafts of hollow
trunks. 10. In elaſticity. Bows, 11. How to tranſplant large trees.
How
to

Secr. XVIII. 1.1. LEAVES AND WOOD.
501
to prop them.
12. Time of felling timber after barking it. The concentric rings
of timber.
13. Pith is brain. Does not communicate from bud. to bud. Sa-
goe from artichoke. From elder. 14. Boundary to the growth of trees. Not
to coralline rocks.
I. Of Leaves.
1. The buds of plants have already been ſhewn to be individual
vegetable beings, and the leaves to conſtitute the lungs of each in-
dividual bud. And laſtly, that the new bud in the boſom of each
leaf is the offspring from the caudex of that old bud, of which the
leaf conſtitutes the lungs.
The leaves of graſſes are of great conſequence, as they nouriſh
many of our domeſtic quadrupeds; the cultivation of graſſes has
therefore been much attended to. Many of theſe propagate them-
ſelves more by their roots than by their feed; eſpecially where their
ſtems are perpetually deſtroyed by the grazing of cattle, ſheep, or
geeſe ; and ſome of them are ſaid to be viviparous, as the feſtuca
dumetorum, or feſcue graſs ; that is, that they bear bulbs on their
ſtems after flowering inſtead of ſeeds, which in time drop off, and
ftrike root into the ground, like the polygonum viviparum, and the
allium magicum; which circumſtance is ſaid to obtain in many al-
pine graſſes, whoſe ſeeds are annually devoured by ſmall birds.
The ſtems of the graſſes conſiſt in general of joint above joint
without lateral branches; each joint of which ſeems to be a ſuccef-
five plant growing on the preceding one, and generated in the boſom
of the leaf, which ſurrounds it; the ſtem may therefore be eſteemed
a ſucceſſion of leaf-buds, till at length a flower-bud is produced on
the ſummit, as thewn in Sect. IX. 3. 1. In ſome graſſes, as the
agroſtis canina, or triticum repens, dog's-graſs, twitch-graſs, or
couch-graſs, the root conſiſts of joints as well as the ſtem ; which
may be conſidered as ſeparate individual plants, like the bulbs of po-
tatoes, as every joint of theſe roots will grow into a new plant to the
great

502
PRODUCTION OF
Sect. XVIII. 1. 1.
great annoyance of the agricultor, which, when the ground is not
hard, may be beſt, I believe, drawn out by a deep harrow, or by
Mr. Cook's ſcarifier; as a plough turns them over under the foil, as
it breaks them, and thus much increaſes their number by in a man-
ner tranſplanting them. The teeth of the harrow, or ſcarifier, ſhould
be inclined forwards towards the horſe for the purpoſe of lifting up
the roots, and that it may not too eaſily riſe out of the ſoil; and it
ſhould be fixed by wedges or ſcrew-nuts to the wooden frame for the
purpoſe of occaſionally lengthening them to adapt them to different
ſoils, as the roots pierce deeper into leſs tenacious foils than into clayey
ones.
Hence it appears, that a plant of graſs conſiſts not only of a tuft
of leaves ſurrounding the root, but that the three or four lower joints
of the ſtem, as of a wheat-ſtraw, are ſo many ſucceſſive leaf-buds,
which are generated by the caudex of the leaf, which ſurrounds each
joint, and precede the flower-bud at the ſummit; and that hence
with the deſign of producing much herbage for cattle, the propagation
of new leaves from the root is principally to be attended to; but with
the deſign of producing hay, or winter fodder, the leaf-buds of the
Nem are principally to be attended to.
For the former of theſe purpoſes the ſtem of graſs ſhould be eaten
down as ſoon as it riſes ; whence more graſs leaves will ariſe from
the root; as is well known to thoſe who eat down the firſt ſtem of
wheat, when it is too luxuriant. For the ſecond purpoſe the leaf-
buds, which conſtitute the ſtems of graſs, ſhould be cut down, be-
fore the flower-ſtem at the ſummit has begun to ripen its feeds; as
at that time the ſweet juice lodged in the joint below the flower-ſtem
becomes expended on the feed; and the ſtem becomes converted into
ſtraw rather than into hay.
From hence it is readily underſtood, why thoſe paſtures, which are
perpetually grazed, are ſo much thicker or cloſer crowded with graſs
roots than thoſe, which are annually mowed ; and why graſs cut
young
I

Secr. XVIII. I. I.
503
LEAVES AND WOOD.
a
young makes ſo much ſweeter and more nutritive hay-than that,
which has ripened and ſhed its feed. And laſtly, why the hay from
graſs cut young is ſo much more liable to take fire, if ricked too
moiſt; becauſe the greater quantity of ſugar in the joints of the ſtems
produces ſo violent a fermentation, when it has ſufficient water to
diſſolve it, that it generates ſo much heat as to burſt into flame.
This might beſt be prevented, where chopped Atraw is deſigned to be
given to horſes along with their hay, by laying alternately in the hay-
ftack a ſtratum of new hay and a ftratum of ſtraw, or of clover and
ſtraw ; whence the rapid fermentation, which occaſions combuſtion,
may be prevented, and the ſtraw may be rendered eafier of digeſtion
by being impregnated with the fermentative infection, or yelt, of the
fermenting hay.
The art of increaſing the quantity of leaves round the roots of
graffes conſiſts in eating off the central ſtems by ſheep, or horſes, or
cattle, early in the ſeaſon, as above mentioned; whence new ones
are produced around the firſt joint of the ſtem thus bitten off, and
from the diſtant horizontal root-wires of ſuch graffes, as produce
them. In low meadows it is hence doubly profitable to eat down the
early graſs till about the middle of May, as in moiſt ſituations there
is no danger but a crop of hay will ſucceed; which by this me-
thod will be finer and more copious; and at the ſame time fome
weeks provender of hay will have been ſaved by the uſe of the early
grafs.
On land intended for paſture, as for theep, many people adviſe to
fow three kinds of vegetables, which may in ſome meaſure ſucceed
each other in their growth. Mr. Parkinſon ſows four buſhels of the
ſeed of rye-graſs, lolium perenne, ten pounds of trefoil ſeed, trifo.
lium pratenſe, and ten of white clover, trifolium repens, ùn every
acre; and adds, that the rye-graſs ſhould be eaten early, while the
white clover is ſtill concealed in the ground, and the trefoil makes
only ſome ſmall appearance. That when the rye-graſs is eaten down
the

g04
SECT. XVIH, 1.1.
PRODUCTION OF
the trefoil ſprings up, and becomes food for the ſheep; after which
the white clover ſucceeds; and after this is conſumed, the rye-graſs
again ſprings up, and ſupplies food during the winter months, if the
weather proves tolerably mild ; and he further aſſerts, that a third
more of ſheep at leaſt may be thus nouriſhed than by any other
means. Experienced Farmer, Vol. I. p. 88.
For the production of a meadow much ſuperior to thoſe commonly
ſeen Mr. Curtis recommends ſix kinds of graſs and two of clover to
be fowed; the feeds are to be mixed together in the following pro-
portions. Meadow foxtail, alopecurus pratenſis, one pint; meadow
feſcue, feſtuca pratenſis, one pint; ſmooth ſtalked meadow-grafs,
poa pratenſis, half a pint ; rough ſtalked meadow-graſs, poa trivialis,
half a pint; creſted dog's-tail, cynoſurus criſtatus, a quarter of a
pint; ſweet-ſcented vernal graſs, anthoxanthum odoratum, a quarter
of a pint; Dutch clover, trifolium repens, half a pint ; red clover, tri-
folium pratenſe, half a pint; theſe ſeeds are to be mixed together,
and about three buſhels to be fown on an acre in rows for the con-
venience of hoeing them. About the end of Auguſt or beginning of
September they ſhould be occaſionally weeded and thinned, and roll-
ed in the ſpring, to preſs down into the ground ſuch roots as may
have been raiſed by the froſt.
Mr. Curtis thinks that meadow foxtail and rough ſtalked meadow-
graſs ſuit moiſt ſoils the beſt ; and that the ſmooth ſtalked meadow-
graſs and creſted dog's-tail ſuit dry paſtures ; and laſtly, that the
meadow feſcue, and the ſweet-ſcented vernal graſs, ſuit land either
moiſt or moderately dry; and gives the following order of their
times of flowering. 1. Sweet-fcented vernal. 2. Meadow foxtail.
3. Smooth ſtalked meadow-graſs. 4. Rough ftalked meadow-graſs.,
5. Meadow feſcue. 6. Creſted dogs-tail. See Hall's Encycloped.
Art. Agriculture.
Not only new ſown graſſes deſigned for meadows, but the larger
graſſes, which have the names of corn, as wheat, oats, barley, may be
advantageouſly rolled, when dry, after froſt, which by expanding the
water

SECT. XVIII. I. I.
505
LEAVES AND WOOD,
a
water in moiſt ſoils leſſens the cavities, which are occupied by roots;
and as roots or their branches are in general conical, they become
puſhed upwards; and ſuch as are looſe riſe quite out of the ground,
as is often feen to happen to the roots of the ſtrawberries, when a
froſty night has occurred foon after their being tranſplanted. After
a ſlight froſt the larger pebbles of a gravel walk are ſeen below the
furface, as if they had funk downwards during the night ; whereas
this is owing to a ſimilar cauſe, the expanſion of the moiſt ſoil or
gravel an inch deep; but as the froſt had not penetrated ſo low as to
ſwell the ground beneath the large pebbles, theſe had not been lift-
ed up like the ſmaller ones, or the wet fand.
Secondly, both to increaſe the quantity of leaves round the root,
and to increaſe the ſize or vigour, as well perhaps as the number, of
leaf-buds on the ſtem, a greater ſupply of water than uſual, where it
can be done, would be advantageous; as is done to the rice-grounds
in warm countries in the early part of its growth, and as in flooding
our own meadows occaſionally in the vernal months. Thus very
moiſt ſeaſons are well known to forward the luxuriant growth of the
herbage, and ſtems, in the cultivation of wheat, and to render the
ears later, and leſs prolific.
Where plants are fown for the purpoſe of conſuming the firſt fo-
liage, as graſſes or ſaint-foin, the feed ſhould be fown thicker, than
where the plant is grown for the purpoſe of producing ſeeds, as in
wheat or peas; becauſe the quantity of the firſt foliage will be greater
in reſpect to number; and the central parts of the tuſſocks, as is of-
ten ſeen in wheat and peas, when ſown too thick, will riſe two or
three inches higher in their conteſt for light and air, like the trees of
thick planted woods; and will hence produce a forwarder paſture as
well as a more copious one.
To which ſhould be added, that the plants with ſucculent ftems,
as faint-foin, lucern, red clover, receive ſo much injury from the
trampling of heavy cattle, that they ſhould be mowed, and given to
COWS
3 T

506
PRODUCTION OF
Secr. XVIII. 1. 1.
a
cows and horſes in their ſtalls; which ſhould nevertheleſs have a
yard or fold occaſionally to run into with the convenience of water
and if ſtraw be chopped along with this green food, it might be
cheap and a falutary addition.
Where a piece of graſs land is overrun with tufſocks of ſour graſs,
which often happens near towns, I have been informed, that lime or
coal-aſhes ſpread on them would render the graſs ſweeter, ſo that
horſes or cattle would eat it. But I ſuppoſe the more certain and
advantageous management would conſiſt in mowing it frequently,
and giving it to the horſes or cattle in the ſtable or ſtall; as I believe
they will eat it greedily after it has been a few hours withered, and
thus the land will not only yield more provender at preſent, but af-
ter a few mowings a ſweeter graſs will riſe in the place of that which
was of a bad kind, or of too luxuriant growth; for which purpoſe it
ſhould be mowed as near the ground as may be ; or if it be frequent-
ly mowed during the ſummer, and left on the ground, ſome cattle
will eat it, when it is withered to a certain degree; by which the
diſagreeable flavour of it is probably leffened or deſtroyed.
The art of making hay conſiſts in evaporating about two thirds of
the weight of it, as obſerved by Young and Ruckert. Dr. Hales
found a fun-flower plant, which weighed forty-eight ounces to loſe
thirty-ſix ounces by drying in the air during thirty days; and con-
ſequently to have loſt three fourths of its weight. Vegetables to ap-
pearance perfectly dry contain three fifths or three fourths of their
weight of water ; a part of which water Mr. Kirwan thinks is not in
its liquid ſtate, but that it is by a loſs of much of its ſpecific heat in
a great meaſure folidified. Kirwan on Manures, p. 37. Thus when
water is thrown on freſh quick-lime, a part of it unites with the
lime, and becomes folid, giving out much heat; which converts
another part of it into ſteam, as mentioned in Sect. X. 4. 4.
There are two methods of making hay practiſed in different parts
of
3

Sect. XVIII. 1. 1. LEAVES AND WOOD.
507
a
of the country. In the more ſouthern counties the ſwarths are not
turned over or ſcattered for a day, or two, or three, but remain as
they were left by the ſcythe. In the more northern counties the
hay-makers follow the mowers, and ſcatter the graſs immediately,
or on the ſucceeding day. Perhaps a method between theſe may in
general better ſuit this climate.
Herbs collected for medicinal purpoſes, as well as flowers, ſhould
be dried in the ſhade ; otherwiſe they become bleached, and loſe
both their colour and their odour, by too great inſolation, and exha-
lation. Now if the ſwarth of cut graſs be only turned over once a
day for three or four days, the internal parts of it may be ſaid to be
dried in the ſhade ; and afterwards if it be ſpread over the ground for
only a few hours on a fine day, I ſuppoſe it would become dry enough
to ſtack, and have loſt conſiderably leſs of its nutritive quality. Some
adviſe a chimney to be left in the center of a ſtack to prevent the
hay taking fire, but there ſhould then alſo be culverts under the
ſtack to ſupply that chimney with air ; which may be made by cut-
ting three or four trenches in the earth, and covering them with
boards or ſticks with their apertures expoſed to the wind in all di-
rections. Perhaps the beſt way would be to make the ſtack narrow
and long, and bent into a ſemicircle or creſcent to enable them the
better to reſiſt the winds, inſtead of round or ſquare, though a greater
ſurface would indeed be afterwards expoſed to the weather, and in
ſome degree injured, by this mode of conſtruction,
When the graſs is ſpread uniformly over the whole meadow,
which is called tedding, it will ſooner dry, as ſo much larger a ſur-
face of it is expoſed to the wind and ſun; but it ſhould certainly be
put into ſmall cocks or wind-rows at night, eſpecially'if the weather
be moiſt; becauſe it will otherwiſe receive much dirt and ſlime from
the innumerable worms, which riſe out of the ground always in moiſt
warm nights, and generally when the ſurface is covered with moiſt
grafs
3 T 2

508
Sect. XVIII. 1. 2.
PRODUCTION OF
graſs at all ſeaſons; and when they retreat into their ſubterranean
manſions in the morning, they are liable to draw in the ends of the
graſs to ſtop up the apertures of their holes, and by that means pre-
vent the centipes from following them into their homes, and deſtroy-
ing them. See Zoonomia, Vol. I. Sect. XVI. 16. Whence much of
the new hay becomes injured by the ſoil, they previouſly puſh before
them out of their mines, and by that which adheres to the graſs,
which was drawn in to ſtop the apertures of them, as well as by the
ſlime, which they leave behind them on the new hay, which they
paſs through or over.
On this account hay-cocks ſhould be made as high as may be in
proportion to their baſe, that leſs ſurface may be in contact with the
ground, as well as that a greater ſurface may be expoſed to the air
for a quicker exhalation of its moiſture, and for the purpoſe of the
better ſecuring it from accidental ſhowers.
In wet ſeaſons, I ſufpect, the beſt method muſt conſiſt in turning
over the rows of ſwarth every day or every alternate day, or making
it into ſmall cocks, and turning them over in the ſame manner, that
the rain may not injure the whole of it by paſſing perpetually through
it, and waſhing away its faccharine and mucilaginous fluids; and
alſo that the part next the ground, and the central parts of the cock
or ſwarth, may not paſs into fermentation and putrefaction. And
laſtly, when it can be put into tall cocks, as the weather becomes
drier, it will not only ſooner exhale its moiſture by the contact of
the atmoſphere, but a beginning fermentation will ſet at liberty fome
degree of heat, and thus contribute to dry it by increaſing the eva:
poration ; as the great heat generated in hay-ſtacks which have been
finiſhed but one day or two, aſſiſts much to dry the whole ſtack, in
moiſt ſeaſons, as is ſeen by the denſe ſteam, which ariſes from them.
2. Many root-leaves are conſumed at our tables either in their raw
ftate, as thoſe of water-creſs, fifymbrium nafturtium, lettuce, lactuca
fativa, muſtard, finapis, celery, apium ; many others are previouſly
boiled

Sect. XVIII. I. 2. LEAVES AND WOOD.
509
boiled to diminiſh their acrimony, and to coagulate their mucilage,
as the root-leaves of ſpinach, ſpinacia, of cabbage, braffica oleracea,
and even of turnips, braſſica rapa ; along with theſe ſtem-leaves of
many plants the flower-buds at their ſummits are eaten, as thoſe of
mercury, mercurialis, and of ſome of the cabbage kind called bro-
coli, braſſica italica.
Many of theſe leaves not only conſiſt of a reſpiratory organ, but
at the lower parts of them eſpecially, or in their ſtalks, there exiſts
a reſervoir of nutriment for the riſing flower-ſtem or for the ripening
feed, as in rhubarb leaves, and in cabbage leaves, which is ſimilar to
that in the roots of other herbaceous plants, and which renders them
both palatable and nutritive. Moſt of theſe concentric leaves are
ſituated in contact with the earth, as thoſe of lettuces, lactuca, and
falſafi, tragopogon. But others of them, as the cabbages, are placed
on a ſtem at ſome diſtance from the ground; in the former the up- *
per part of the root or caudex is palatable and nutritious, as well as
the lower part of the leaves ; and ſome of them are of ſuperior fla-
vour when boiled. In the latter the refervoir of nutriment for the
future flower-ſtem and feed conſiſts in the lower part of the ribs of
the concentric foliage, as in the concentric leaves or lamina, which
cover the bulb of the onion, or even in the ſtalks, as in cabbages,
and artichoke, which are therefore not only eſculent, but palatable.
and nutritive.
Other leaves are eaten in their early ſtate along with the ſtem,
which they ſurround, as aſparagus, and the young ſhoots of ſpinach,
and of ſome kinds of brocoli, and of mercury; which laſt are fome-
times ſuffered to thew their flowers before they come to our tables,
and are then treated of in Sect. XIX.
The art of cultivating all theſe conſiſts in ſupplying them with
abundant carbonic earth, and with abundant moiſture, as theſe are
more friendly to the luxuriant growth of root-leaves or ſtem-leaves,
than to the production of the fowers, or ripening of the ſeeds, as ap-
pears

$10
Sect. XVIII, 1.3.
PRODUCTION OF
pears by the too luxuriant growth both of herbaceous plants and of
fruit trees in moiſt ſeaſons.
Another method of forwarding the growth of the new leaves and
ſtem-ſhoots of perennial herbaceous plants, as of aſparagus, is an-
nually to looſen or turn over the earth around and above the roots,
for the purpoſe of admitting air into its cells or cavities to convert a
part of the manure or carbonaceous ſoil, with which they have been
ſupplied, into ammonia, or into carbonic acid, and thus both to af-
ford them warmth and nutriment.
Add to this, that the leaves of trees may be increaſed in ſize by lop-
ping off the branches, by which means the remaining buds acquire
more nutriment; the black mulberry tree is thus kept low, and
formed into extenſive ſhrubberies in China for the purpoſe of feeding
filkworms, as obſerved by fir G. Staunton, who thinks the leaves
are thus rendered both larger and more ſucculent; and adds, that the
afh-tree is alſo ſometimes uſed for the ſame purpoſe.
3. Another method of deſtroying the too great acrimony of leaves,
beſides that of boiling them, conſiſts in fecluding them from light,
and is termed etiolation. This is chiefly practiſed on cellery, apium,
by earthing it up nearly to the top of the plant ; and on ſea-kale,
crambe maritima, by covering the plant entirely with horſe-litter or
ſtraw, as deſcribed in Sect. XIV. 3. 3; and on lettuces, and endive,
by tying together the root-leaves with a bandage.
In many plants the central bud during its early growth ſeems to
be naturally in a ſtate of etiolation, as it is excluded from the light
by the curvature of the ſurrounding foliage, as in cabbages, and par-
ticularly in ſome fpecies of aloe, which are ſaid to conſume nearly
a century in opening their numerous concentric foliage. Theſe etio-
lated leaves, like flowers before the calyx is opened, are white ; and
the leaves become green, or the flowers of many other colours, when
expoſed to the light, as explained in Sect. XIII. 1. 3. It is probable
that the foliage of many other plants might be rendered eſculent by
а.
4
thus

SECT. XVIII. 1.4.
512
LEAVES AND WOOD.
thus deſtroying their acrimony, and decreaſing the tenacity of their
fibres by etiolation, as well as the leaves of celery, apium; and car-
doon, cinara; and of endive, cichorium endivia.
A ſecluſion from the ſun's light and from air has an effect fome-
what ſimilar on animal bodies, rendering them pale and weak, as
may be ſeen in the etiolated young ladies of ſome boarding ſchools;
and in thoſe who paſs their waking hours in unventilated parlours
during more than half the night.
4. Other vegetable foliage has been brought into very extenſive
uſe infuſed in hot water for its agreeable aromatic or bitteriſh fla-
vour, as thoſe of foreign tea, thea ; and of the aſh, fraxinus, of our
own iſland, the leaves of which were collected, before they became
expanded, and ſold after being dried for the inferior kind of Bohea
tea in ſo great quantity as to occaſion an act of parliament to be paff-
ed about forty years ago to lay a fine on any one, who ſhould have
accumulated more than fifty pounds of aſh leaves, which were not the
produce of his own trees. The leaves of many other of our domeſtic
vegetables, as of mint, balm, and fage, mentha, meliffa, ſalvia, have
been infuſed in hot water as an agreeable diluent beverage both in
health and fickneſs; the laſt of which, the ſage, poſſeſſes a very
pleaſant aromatic flavour ; and if the infufion be poured from the
leaves, before it has acquired too much of the bitter flavour, it is very
grateful to the palate or ſtomach, and has been eſteemed falubrious
from high antiquity to the preſent times, whence the line of Ho-
race.
Cur moriatur homo, cui falvia creſcit in horto ?
All theſe infuſions become nutritive, when drank with cream and
ſugar, and have certainly contributed to the health of the inhabi-
tants of this iſland by decreaſing the potation of fermented or ſpiritu-
ous liquors; and to their morality by more frequently mixing the
ladies and gentlemen in the fame ſociety.
The

512
SECT. XVIII. 1. 5.
PRODUCTION OF
The leaves of theſe plants, as well as the aromatic or balſamic buds
of ſome other plants, as of myrica, gale; of tacamahaca, populus
balſamifera ; of balm of Gilead, amyris giliadenſis, and many others,
ſhould be gathered at the time of their greateſt fragrance, as the ef-
ſential oils, which conſtitute their odorous exhalation, perpetually
evaporate, as our ſenſe of ſmell informs us; and were apparently for
the purpoſe of defending the plants from the depredation of inſects in
their ſtate of infancy.
5. Other leaves have been uſed for medicinal purpoſes, and for the
arts of dying and tanning, like the barks before mentioned; as the
leaves of carduus benedictus, cnicus acarna, as an emetic; thoſe of
foxglove, digitalis purpurea, as an abſorbent in anaſarca ; thoſe of
bog-bean, menyanthes trifoliata, as a corroborant ; which laſt might
probably ſupply the place of hops, humulus lupulus, in the brewe-
ries of malt-liquors; and as it might be plentifully cultivated on
boggy grounds, which are not at preſent uſed for other purpoſes,
might be a cheaper bitter to the conſumer, and ſave to the public
much more fertile foil for the cultivation of corn or other valuable
vegetables.
The leaves of teucrium ſcorodonia, wood-ſage, are as bitter as
thoſe of menyanthes, bog-bean, and have been uſed with ſucceſs, as
I have witneſſed, in the cure of agues ; and, as it grows on dry barren
ſoils, might poſſibly be cultivated to ſupply the place of peruvian bark
in ſome diſeaſes, or to ſupply the uſe of hops in the breweries of
malt-liquor.
The leaves of oak-trees, quercus robur, and of aſh-trees, fraxinus
excelſior, and of alder, betula alnus, even after they drop ſpontane-
ouſly in the autumn, are ſaid to ſerve the purpoſe of tanning animal
membranes, like the barks of the ſame trees ſpoken of in Sect. XVII.
3.5; and for the purpoſes of dying, the leaves of indigo, indigofera
tinctoria ; and of wood, iſatis tinctoria ; and of weld, reſeda luteola,
8
have

SECT. XVIII. 1.5.
LEAVES AND WOOD.
513
have been much cultivated, and extenſively uſed; and a ſpecies of
polygonum is ſaid to be much cultivated in China for the ſame pur-
poſes as indigofera by fir G. Staunton; to which may be added the fo-
liage of lichen fruéticoſus, or archil, a whitiſh lichen brought from
the rocks of the Canary Iſlands, which gives a beautiful bloom to
other colours, but is itſelf very fugitive. Linneus aſſerts in the
Swediſh Tranſactions, that this archil mofs is to be found on the
weſtern coaſts of England ; and it is ſaid, that the archil is now pre-
pared by Meffrs. Gordens at Leith near Edinburgh from a ſpecies
found in the Highlands of Scotland. Encyclopedia Britannica. Art.
Archil. The manner of cultivation and of the extraction of the co-
louring matter from the leaves of theſe plants may be alſo ſeen in
Bomare's Dictionaire Raiſonne, and in Chambers's Encyclopedia. It
it probable, that many other plants, as hedyfarum, ſaintfoin, or the
broad thick leaves of phytolacca, might yield a ſimilar material to that
of indigo, woad, and weld, if properly cultivated and prepared, as well
as other kinds of moffes or lichens to that above mentioned.
The green colour of perhaps all vegetables, as well as of thoſe
from which indigo and woad are produced, is owing to the blue fe-
cula, which has been obtained for the dyers principally from thoſe
plants; and to a yellow material, which is more fugitive or more ea-
ſily decompoſed, which yellow may poſſibly be owing to iron. This
blue fecula is ſimply obtained from indigo, as it ſubfides from the
fluid, in which the plant is ſuffered to ferment; and is obtained from
woad along with the cellular parts of the leaves during their fermen-
tation in water, and beaten into a maſs. It is probable that the blueſt
kinds of vegetables may contain the moſt of this fecula.
For domeſtic purpoſes the juice of the fage-leaf, ſalvia officinalis,
has been uſed both to give colour and flavour to cheeſe ; and the
juice of ſpinach is employed, I am informed, to colour the
green
uf-
quebaugh, a favourite dram with the Iriſh vulgar. And it is proba-
ble, that the leaf of the vine, which bears purple grapes, might give
a ſimilar
3 U

514
Secr.XVIII, 2. I.
PRODUCTION OF
a ſimilar colour and aſtringent taſte to our domeſtic wines, as the
ſkin of the ſame grape gives to the foreign wines made from it;
ſince the leaves of this vine always become quite red in autumn, be-
fore they fall, probably by the concentration of their acidity, as
their water evaporates unſupplied; as all blue vegetable juices be-
come green by an admixture of alkali, and red by that of an acid.
6. Another uſe for which leaves are collected by ſome gardeners,
as they fall in autumn from any kinds of trees, is for the production
of heat by fermentation in hot-houſes, or melon-frames, inſtead of
oak-bark, after its bitter particles have been much extracted by the
tanner; and it is probable, that many leaves might be ſelected, as they
will thus undergo fermentation, which might afford a ſpirituous
drink like ſmall beer without any diſagreeable flavour, or unwhole-
ſome material, which now ſerve only for manure when gathered.
into heaps, or by their flow decay on arable lands; or encumber the
graſs lands, they fall upon.
II. Of Woods.
1. The leaf-buds of trees producing a viviparous offspring acquire
new caudexes, extending from the branches to the ground, and the
intertexture of theſe caudexes forms the new bark over the old one.
But the flower-buds acquire no new caudexes down the bark, as.
their oviparous progeny does not adhere to the fide of the parent
bud, but falls down when mature, and ſtrikes root into the ſoil.
Now as the bark of trees is thus produced along with the leaf-
buds, and as it annually becomes alburnum or ſap-wood; and that
ſap-wood gradually loſes all vegetable life, and becomes heart-wood,
it follows, that the art of forwarding the growth of the wood of
trees muſt conſiſt in producing and nouriſhing the leaf-buds.
For this purpoſe the roots of trees ſhould be ſupplied with rather
more water, than they generally poſſeſs in their moſt natural ſtate, or
the branches ſhould be ſprinkled by a water-engine; as moiſture fa-
cilitates

Sect. XVIII. 2. 1. LEAVES AND WOOD.
515
cilitates the production of the new caudexes of the leaf-buds proba-
bly by leſſening the coheſion of the cuticle, or mechanically relax-
ing it, like the cuticle of our hands when long ſoaked in water, as
well as by ſupplying them with more nutriment.
It may ſometimes occur, that the cuticle of trees, or exterior bark,
may adhere too ſtrongly, and by not opening in cracks confine the
growth, or prevent the production of the caudexes of the new buds.
There is annually a new cuticle produced beneath the old ones, as
well as a new bark above the old ones; hence ſome trees have as
many cuticles as they are years old, others caſt them more eaſily, as
a ſnake caſts its cuticle. When a number of cuticles thus exiſt one
over another, it is uſeful to ſcratch them longitudinally, which will
admit the new bark beneath, conſiſting of the caudexes of the various
buds to ſwell out, and form a line more prominent than the other parts
of the trunk of the tree. If crooked young trees be thus ſcratched in-
ternally in reſpect to the curvature, and this repeatedly, I am in-
formed, that they will gradually become ſtraight, by thus encourag-
ing the growth within the curvature more than on its convex fide.
Another method of increaſing the number and vigour of the leaf-
buds, and in conſequence of enlarging the wood of a tree, conſiſts in
pinching off the flowers, as ſoon as they appear; as the nouriſhment
is thus ſupplied to the leaf-buds by the inoſculation of the veffels of
the bark, which otherwiſe would have been expended on the flowers,
fruit, and ſeeds. The truth of this circumſtance is not only coun-
tenanced by gardeners, who pull off the flowers of fruit-trees lately
planted to encourage their growth, but alſo from the appearance of
ſickly trees; which are liable to periſh, when in flower. In this caſe
it often happens, that, after the flowers fade, ſome of the leaf-buds
continue to expand, or new ones put out, owing to the ſupply of
nutriment not being now expended on the flowers.
2. As tall timber trees without branches, and conſequent knots in
the timber, are moſt valuable except for thip-building, this may be
3 U 2
certainly
2

516
PRODUCTION OF Sect. XVIII. 2, 2.
certainly effected by planting them near each other; as then the
powerful conteſt with each other for light and air propels them up-
wards, inſtead of producing many lateral branches; as may be ſeen
in many woods, which have not been too much thinned. For this
purpoſe ſome have planted trees of leſs value though of quicker
growth, as pines, amongſt oaks; which may be pruned or lopped,
if they ſhade the oaks too much, and may be finally removed, when
the oaks are crowded by them; whence ſingle trees ſeldom grow fo
tall as thoſe in woods, and appear ſtunted, as it is called; which is
generally aſcribed to the cold ſeaſons, or to their being expoſed more
to the winds; which may perhaps ſometimes happen in this nor-
thern climate; or where trees are expoſed to infalubrious air, as near
the ſea; or exiſt in colder ſituations, as on the ſummits of moun-
tains.
Something ſimilar to this may be feen in tuffocks of graſs, or
where too many feeds of wheat have been fown near together. The
central part of the knot of wheat or graſs grows much taller than the
external part, ſo as to give it a conical figure ; which has been by
fome aſcribed to the central part having been ſheltered from the cold
by the external ring, but is more generally owing to the ſtruggle of
the internal ſtems for the acquiſition of light and air.
The Society of Agriculture at Copenhagen has propofed prizes
concerning the cultivation of timber for ſhip-building. One queſtion
is, whether the neceſſary form and degree of flexion can by any means
be given to growing timber without injuring it? This I imagine
may be done by annually fcratching the external bark or cuticle ei-
ther longitudinally or horizontally on the ſouth ſide of the part of a
tree, which is wiſhed to be curved, as the ſouth ſide of trees are
known to grow fafter annually than the north ſide, as is ſeen by the
greater thickneſs of the concentric rings of a tree, when felled and
fawed into blocks; and becauſe the cuticle bounds the lateral growth
of the trunks of trees, as the ſkin of animals bounds the growth of
the

Sect. XVIII. 2. 2.
517
LEAVES AND WOOD,
the cellular parts beneath it ; and hence that ſide of the tree, where
the cuticle or exterior bark is frequently ſcratched through, will be-
come larger than the other ſide of the tree, and tend to bend it into
a curve with the ſcratched fide outwards. Trees alſo on the outfide
rows of woods will ſpontaneouſly bend outwards for light and air,
and may I ſuſpect be more eaſily formed into proper curves by the
method above propofed. And where trees in a wood are at a proper
diſtance from each other, they may forcibly be bent by cordage to-
wards each other, and then by wounding the exterior and interior
bark longitudinally, or perhaps horizontally alſo on the exterior fide
of the curved part of the tree, they may be brought into almoſt any
degree of flexure, which they will afterwards preſerve as the tree
advances.
Some of the quicker growing trees may be more valuable to the
planter than oaks, and ſome in different foils are more valuable than
others; as willow-trees in the hedge-rows in moiſt grounds are ſaid,
if headed once in ten years, on an average to produce each of them
one thilling a year. Perhaps the ozier for baſket making may be ſtill
more advantageous in low grounds; there is a valuable paper on the
planting of them and the choice of the kinds of them in the Tranſ-
actions of the Society of Arts, Vol. XVI. p. 129, by Mr. Phillips.
p
Perhaps the ſugar-maple may alſo be cultivated in this climate to ad-
vantage on many barren commons, as on Cannock Heath. And cer-
tainly pines, as Scotch fir, might in theſe ſituations ſucceed aſtoniſh-
ingly, as appears by the plantations of Mr. Anſon on the barren moun-
tains near his ſeat in Staffordſhire ; and alſo from the plantations of
the marquis of Bath at the foot of Wiltſhire Downs near War-
minſter, whoſe ſteward, Mr. Davis, has given a valuable account of
the profit of planting Scotch fir in preference to other timber trees;
and finally aſſerts, “ that although fir-timber is worth individually
more per tree than oak or beech of the ſame ſize, theſe trees will ne-
vertheleſs grow faſter and thicker together than any other trees. Four
firs
a

518
SECT. XVIII. 2. 3.
PRODUCTION OF
firs will grow, where but one oak or beech will grow ; for firs are
the better, and deciduous trees the worſe, for being crowded.” I fup-
poſe becauſe the branches of the latter are valuable, but the former is
injured by the knots left in the trunk, where large branches have
exiſted. Tranſ. of Society of Arts, Vol. XVI. p. 126.
p.
Mr. Davis adds further, I ſuppoſe from his own obſervation, that
“ the chalk-hills in Hampſhire are peculiarly proper for beech; the
flinty loams and clays of the ſame county for oaks and aſh; the
mofly ſteep ſides of the Wiltſhire Downs for hazel; the rugged and
almoſt naked rocks of Mendip in Somerſetſhire near Chedder pro-
duce the lime-tree and the walnut in the greateſt luxuriance; and
on the higheſt parts of the ſame Mendip hills, where no other tree
can ſtand the ſea-breeze, fycamore flouriſhes as well as in the moſt
fertile vallies. But taking into conſideration the general demand of
countries, and the peculiarities of different ſoils, no kind of wood is
ſo generally profitable for planting in coppices as afh." Ib.
3. Another thing concerning timber-trees, which ought to be at-
tended to, is the injury, they are liable to receive from lightning;
which, I am informed, is much more frequent than is generally ſup-
poſed; infomuch that in felling moſt woods, eſpecially thoſe which
grow in wet ſituations, very many of the trees are found to be crack-
ed longitudinally to the great injury of the timber ; to prevent this,
pointed wires, as thick as a gooſe quill, ſhould be attached to a few
of the talleſt trees of all flouriſhing woods reaching above their ſum-
mits, as conductors of lightning. Add to this that the holes made by
wood-peckers, I am told, are very numerous, and do much injury to
the timber of our foreſts, which can only be prevented by deſtroy-
ing that beautiful and ingenious bird.
4
Woods differ from each other in many reſpects, and are there-
fore uſed for many other purpoſes beſides mechanical ones; as in
colour; whence particular woods are choſen for their beauty in the
conſtruction of the furniture of houſes, as roſe-wood, aſpalathus ;
others
3

Sect. XVIII. 2. 5. LEAVES AND WOOD.
519
others are uſed in the art of dying, as the Campechy wood, hæma-
toxylum, and ſaunders, ſantalum, and pterocarpus ; and ſeveral
others. Other woods differ in their medicinal properties, as guaicum,
quaſlia, Campechy wood, and faſſafras. Others differ in their che-
mical properties, affording eſſential oils, as oleum rhodii, and
turpentines or balſams, and tar; and in their reſtringency, as the
oak.
5. The oak probably contains much gallic acid, ſuch as has been
extracted from the galls occaſioned on their leaves by the punctures
of inſects; whence oak boards are ſaid to corrode the ſheets of lead,
which are laid on them, and are hence believed to be improper for
the gutture-boards on the roofs of houſes. But the ſap-wood, or ex-
ternal part of all timber, I ſuſpect, muſt be improper for this pur-
poſe on another account; as, when confined from much air by the
ſheet of lead over it, it muſt lie for many months in the year in
that ſtate of moiſture, which will favour the fermentation of the
ſaccharine matter, which all ſap-wood contains; and will thence be
fubject to the dry rot, as it is called by architects. This may be long
prevented by leaving proper holes in the walls on all ſides the build
ing immediately under the roof, as has been generally done by thoſe
itinerant bodies of architects, who ſhewed ſuch prodigies of genius in
the conſtruction of cathedrals in this iſland, and all over Europe; and
whoſe ſecret identifying words, and confederate ſigns, which were
neceſſary to them in foreign countries, whoſe language they had not
time to acquire, ſeems to have given origin to the modern myſteries,
of Free-maſonry.
The rot of wood might probably be entirely prevented by ſoaking
dry timber firſt in lime-water, till it has abſorbed as much of it as
may be; and then after it is dry. by ſoaking it in a weak folution of
vitriolic acid in water, which will unite with the lime already de-
poſited in the pores of the timber, and convert it into gypſum ; which
I ſuppoſe will not only preſerve it from decay for many centuries, if
its

520
Secr. XVIII. 2. 6.
PRODUCTION OF
.
it be kept dry, but alſo render it lefs inflammable, a circumſtance
worthy attending to in the conſtruction of wood-built houſes. I alſo
conceive that beams ſo impregnated would be leſs liable to ſwag,
and boards fo prepared leſs liable to warp. In the immenſe ſalt-
mines of Hungary many large wooden props, which ſupport the roof,
and are perpetually moiſtened with ſalt-water trickling down them,
are ſaid to have ſuffered no decay for many centuries.
6. Woods alſo differ from each other in their hardneſs, or the
general coheſion of their particles, whence one kind of timber has
obtained the name of iron-wood, fideroxylum. Others differ in the
fineneſs of their conſtituent fibres, which ſhew a beautifully ſmooth
poliſh, when planed, as roſe-wood, aſpalathus.
Where theſe two properties of hardneſs and finoothneſs exiſt to-
gether, as in box, buxus ſempervirens, the wood muſt be peculiarly
valuable for the purpoſe of making wooden printing blocks, ſo well
managed at this time by Mr. Bewick of Newcaſtle in his books of
Natural Hiſtory of Quadrupeds and Birds.
7.
Other woods differ in their durability, as cypreſs, cedar, maho-
gany, are ſaid to be indiſtructible by time, or by the depredation of
inſects. The wood of the cedar of Bermudas, Juniperus Bermu-
diana, in which black-lead pencils are incloſed, is ſaid not to be eaten
by either aerial, terreſtrial, or marine inſects, and is thence uſed in
the Weſt Indies for building veſſels, whoſe bottoms are not pene-
trated by ſea-worms. The unperiſhable cheſts, which contain the
Egyptian mummies, were of cypreſs, as well as the coffins in which
the Athenians are ſaid by Thucydides to have buried their heroes.
The gates at St. Peter's at Rome, which had laſted from the time of
Conftantine to that of Pope Eugene the fourth, that is eleven hun-
dred years, were of cypreſs, and had at that time ſuffered no decay.
Of theſe ſome are believed to endure longer in water than others,
as alder, betula alnus, and is therefore eſteemed preferable for piles
to guard the banks of rivers. But Mr. Brindly, the conductor of the
grand
I

Sect. XVIII. 2. 8.
521
LEAVES AND WOOD.
>
grand trunk canal, aſſured me, that he believed from obfervation,
" that red Riga deal, or pine-wood, would endure as long as oak in
all fituations," owing perhaps to its being fo full of reſin or turpen-
tine.
8. Other woods differ in the degree of the lateral adheſion of their
longitudinal fibres, as the fir-wood, or deal, pinus, whence the tim-
ber readily ſplits by wedges. As the moiſture of the atmoſphere is
abſorbed into the pores of the dry cellular membrane, whch connects
the longitudinal fibres of theſe woods, more than into thoſe of the
longitudinal fibres themſelves, they become much more dilated la-
terally than extended longitudinally, by the change of a dry atmo-
ſphere to a moiſt one; whence by joining pieces of deal cut croſs-wiſe
into a rod of ſome feet in length, a very ſenſible creeping hygrome-
ter was made by Mr. Edgeworth, deſcribed in the Botanic Garden,
Vol. II. note on Impatiens. And as this wood is not liable to be
much extended by low degrees of heat, when it is impregnated with
boiling oil, or covered with varniſh, to prevent the acceſs of aerial
moiſture, the pendulums of time-keepers have been conſtructed of
it, which have not perceptibly lengthened in any variations of the
heat or moiſture of the atmoſphere.
9. Another circumſtance of great conſequence, in which woods
differ, is their ſpecific gravity, as many of them will fink in water,
as oak after it has been long moiſtened; and others will ſwim with
much of their contents above water, as deal, and hence have been
uſed for the conſtruction of rafts for the purpoſes of rude naviga-
tion; and which are now ſaid to be conſtructed in France as engines
of war, probably for the deſign of ſuddenly landing troops, horſes,
artillery, and proviſions, from the ſhips of invading armies on danger-
ous ſhores, and for the certainty of re-embarking them. Theſe ne-
vertheleſs can not carry great burthens ſimply by their ſpecific le-
vity ; but if each piece of timber could be made hollow, and rendered
water-tight, ſo as to contain air, which might probably be done by
boring
3 X

522
PRODUCTION OF Sect. XVIII. 2. 10.
boring them, and plugging up the ends ; or by joining thick boards
together by means of paint and flannel, or caoutchouc, ſo as to con-
ſtruct long ſquare wooden troughs filled with air, perhaps eight
or ten inches diameter within, and twenty or thirty feet long. If the
Ĉtions of theſe could be rendered water-tight, and a number of
ſuch hollow trunks could be chained looſely together, and laid
croſs-wiſe three or four times over each other, they might carry very
large burthens, not eaſily to be deſtroyed by ſtorms, or funk by can-
non ſhot.
10. Another difference of the longitudinal fibres of timber conſiſts
in their degree of elaſticity, a circumſtance of much greater conſe-
quence to our anceſtors in reſpect to the art of war than to the pre-
ſent generation; as their bows for dicharging arrows, and the cata-
pulta, or engine for throwing ſtones, depended on the recoil of rods
or beams of timber forcibly bent into a curve. For the conſtruction
of bows the yew-tree, taxus, was uſed in this iſland, and was plant-
ed in church-yards, probably for the purpoſe of ſupplying the youth
of the pariſh with bows, that they might become expert in the uſe
of them; many of which have acquired extreme old age, and remain
to this day.
11. When tall trees are deſigned to be tranſplanted for the pur-
poſe of ornamenting a pleaſure-ground, it is proper to dig a circular
trench round them two or three feet deep in the early ſpring;
whence many new roots will ſhoot from thoſe, which have their
ends cut off, and thus the ball of earth will be better held together,
when the tree is removed in the ſucceeding autumn, and the tree
by having previouſly produced ſo many more fine abſorbent radicles
will be more certain to grow in its new ſituation.
Hence when new grafted fruit-fcions on young ſtocks are deſigned
to remain a few years in the nurſery, before they are deſigned for
fale, fome provident gardeners I am told tranſplant them every two
years, that the root-fibres may be more numerous in a ſmall com-
paſs,

Sect. XVIII. 2. 12.
523
LEAVES AND WOOD.
paſs, which occaſions them to grow, when finally tranſplanted, with
more certainty, and with greater vigour.
As tranſplanted trees ſhould not be ſet too deep in the ground,
as their growth is then always much checked, as explained in Sect.
XV. 2. 4. they generally require ſome kind of props to prevent
them from being overturned, or much ſhook by the winds, before
they have ſufficiently extended their roots. As the bark is the only
living part of the tree, it is liable to receive much injury from its
contufion by the preſſure of the props againſt it, or by the ſtrangu-
lation of the bandage which holds it to them. Hence as the inter-
nal wood of a tree is not alive, I remember many years ago, that I
faſtened one prop by a ſtrong nail to each fruit-tree of a ſmall or-
chard, which I then planted ; and found the tree fupported with
much leſs apparent injury than in the uſual manner by three props
and adapted cordage.
12. The time for felling timber has generally been in the winter
ſeaſon, when labourers could beſt be ſpared from other rural em-
ployments, and from the architecture of towns; but it was long
ago obſerved by Mr. S. Pepys in a paper publiſhed in the Philoſoph.
Tranſact. Vol. XVII. p. 455, that the beſt time for felling oaks for
ſhip-building was after having taken off the bark in the early ſpring,
and having ſuffered the new foliage to put forth and die. For by
the pullulation of the new buds the faccharine matter in the ſap-
wood or alburnum is expended, and it then becomes nearly as hard
and durable as the heart-wood, being both leſs liable to decay, or to
be penetrated by inſects; which was a curious and ingenious diſco-
very at that time, though the theory was not well underſtood; the
truth of which has now been eſtabliſhed, I believe, by the experi-
ence of a century.
As the bark of trees annually changes into alburnum or fap-wood,
ſo the alburnum annually changes into lifeleſs wood; whence the
concentric rings, which are ſeen in the trunks of trees, when they
3 X 2
X2
are

524
SECT. XVIII. 2. 13.
PRODUCTION OF
are felled, are annually produced ; and are ſaid generally to be thicker
on that ſide of the trunk, which grows towards the fouth, than on
the northern fide, and thicker in the ſummers moſt favourable to ve-
getation than the contrary. Theſe rings, as they loſe their vege-
table life, and at the ſame time a part of their moiſture by evapora-
tion, or abſorption, gradually become harder and of a darker colour ;
infomuch, that by counting their number, it is ſaid, that not only
the
age
of the tree, but that the mildneſs or moiſture of each fum-
mer during the time of its growth may be eſtimated by the reſpec-
tive thickneſs of the rings of timber.
13. In the ſame manner the central pith alſo loſes its vegetable
life, probably after the firſt year; and then gradually becomes ab-
forbed, or ſo impregnated with ligneous particles, as not to be diſtin-
guiſhed from the ſurrounding wood. The pith of a young bud fo
reſembles the brain and ſpinal marrow of animals in reſpect to its
central ſituation, that it probably gives out nerves to every living
fibre of the bud; though theſe have yet eſcaped our eyes and glaſſes;
and thus furniſhes the power of motion, as well as of ſenſation, to
the various parts of the vegetable ſyſtem. One curious fact, which
I have obſerved, ſeems to countenance this conjecture; which is,
that the pith of a laſt year's twig communicates to the leaves on each
ſide of it, but not to the new buds in the bofoms of thoſe leaves ; be-
cauſe thoſe new buds are each an individual being, generated by the
caudex of the leaf, and muſt therefore poſſeſs a ſenſorium of its own.
See Sect. I. 8. and IX. 2. 4.
The pith of trees contains much mucilage, as well as the ſtalks
of annual and perennial plants, whether they are hollow or not; the
pith of a palm-tree, cycas circinalis, is ſoftened with water, and
paſſed through fieves, and thus forms the fagoe of our ſhops; it is
poſſible the large pith of the ſtalks of artichokes, cinara ſcolymus,
might be manufactured into a ſimilar kind of taſteleſs mucilage ; and
the pith of the young ſhoots of elder, ſambucus nigra, might alſo
poſſibly
a

Secr. XVIII. 2. 14.
525
LEAVES AND WOOD.
poſſibly be made into taſteleſs mucilage, if previouſly agitated in cold
water to waſh away any acrid material, as in the preparation of
ftarch.waha
14. When we contemplate the manner of the production of the
internal wood of trees from the induration of the ſap-wood, and the
annual increaſe of the fap-wood from the bark, which was previouſly
generated by the caudexes of the numerous buds; there would ap-
pear to be no natural boundary to the growth of trees. But that
their trunks, though a mile diſtant from each other, might be en-
larged, till they meet together, and cover the whole earth with lig-
neous mountains, conſtructed by fucceffive generations of vegetable
buds; as ſome parts of the ocean are crowded with calcareous rocks,
fabricated by the ſucceſſive generations of coralline inſects !
A very large tree is deſcribed by Mr. Adanſon in Africa, which is
called by Linneus Adanſonia, in honour of that philoſopher; of
which he ſays the diameter of the trunk frequently exceeds twenty-
five feet, and the horizontal branches are from forty-five to fifty-five
feet long, and ſo large, that each branch is equal to the largeſt tree
in Europe. The breadth of the top is from 120 to 150 feet; and
one of the roots bared only in part by the waſhing away of the earth
by the river, near which it grew, meaſured 110 feet long, and yet
theſe ſtupendous trees do not exceed 70 feet in height. Voyage to
Senegal.
And in this country, when the internal wood is gradually detach-
ed from the alburnum, as it decays, as in ſome old hollow oaks and
willows, ſo that it does not deſtroy the tree by the putrid matter
being abſorbed, there ſeems to be no termination of the growth of
the external remains of the tree, till the wind blows it down from its
want of ſolid wood to ſupport it. Of this kind of hollow tree-a re-
markable inſtance remains in Welbeck Park in Nottinghamſhire,
through the middle of which a coach is ſaid to have been driven. There
is another oak of uncommon dimenſions in the foreſt of Needwood,
called
а
4

526
PRODUCTION OF SECT. XVIII. 2. 15.
called Swilcar oak, celebrated in an unpubliſhed poem by Mr. Mundy,
on his leaving that foreſt, and is there ſaid to be 600 years old.
But the caudexes of buds, which compoſe the barks and afterwards
the timber of trees, differ from the neſts or cells of the coralline in-
ſects, which compoſe their calcareous rocks beneath the waves, in
this circumſtance. The cells of the coralline infects, like the ſhells
of other ſea-animals, become harder by time, changing by flow de-
grees the phoſphoric acid, which they contain, for carbonic acid ; and
ſome of them afterwards for filiceous acid, and are thus converted
into limeſtone and fint, and remain eternal monuments of departed
animal life.
Whilſt the remaining vaſcular ſyſtem, after the death of vegeta-
ble buds, like the fleſh of animals, undergoes in proceſs of time a
chemical decompoſition, and loſes by fermentation and putrefaction
both their carbonic and phoſphoric acids, which probably gave them
their ſolidity, and crumble into duſt; which is ſeen in the rotten
trunks of trees, which loſe ſo much of their carbon as they decay ;
and alſo become luminous, when expoſed to the air by the eſcape or
production of phoſphoric acid. And finally, their other component
parts are ſeparated by elutriation, and form moraſſes ; whence coals,
iron, clay, and ſandſtone ; all which are found on the lime-rocks,
which were previouſly generated in the ocean, and remain eternal
monuments of departed vegetable life. Whence it appears, that a
boundary is ſet to the ſize of trees by their internal decay, but none
to the growth of coral-rocks, which are ſo formidable in the navi-
gation of the ſouthern ocean.
15. Queſtion on the cultivation of Timber.
The political advantage or diſadvantage of cultivating timber in
this iſland ſhould be here conſidered. In the preſent inſane ſtate of
human

ECT. XVIII. 2. 15. LEAVES AND WOOD.
527
human ſociety, when war and its preparations employ the ingenuity
and labour of almoſt all nations, and mankind deſtroy or enſlave
each other with as little mercy, as they deſtroy and enſlave the be-
ftial world ; and may in time, for what appears to the contrary, re-
turn to their favage ſtate, and begin to eat each other again, as
ſeems to have occurred at or before the commencement of almoſt all
civil ſocieties; the firſt political attention ſhould certainly in this pe-
riod of human infatuation be employed to ſtrengthen the country,
to enable it to repel the invaſion of foreign enemies, and to defend
its natural rights, when they are infringed by them; but not to
attack or invade other nations for any predatory or ambitious pur-
poſe. The next important thing ſhould be for this nation to ſet a
great example of juſtice and humanity to all contending nations, and
thence again to introduce truth and virtue into the world with peace
and happineſs in their train.
Now as the power to reſiſt invafion, and to defend our natural
rights, when infringed by foreign enemies, muſt depend more
on the number of men than on the number of trees; there need be
no heſitation in determining, that thoſe lands, which can be employ-
ed in the preſent production of vegetable or animal food, ſhould not
be occupied in the tedious cultivation of future timber.
But that, as the ſummits of this country conſiſt principally of a
ridge of mountains extending from ſouth to north between the eaſt-
ern and weſtern ſeas, as thoſe of the Peak of Derbyſhire and the
Mocrlands of Staffordſhire, which are ſo bleak or ſo barren as to be
totally unfit for the plough or for paſturage, and yet might be em-
ployed for raiſing variety of timbers; which from our great ſucceſſes
in naval engagements may be termed with great propriety, when
employed in building ſhips, the wooden walls of this iſland: All
thoſe unfertile mountains from the extremity of Cornwall to the ex-
tremity of Scotland, ſhould be covered with extenſive foreſts of
fuch

/ 528
PRODUCTION OF
Secr. XVIII. 2. 16.
ſuch kinds of wood, as experience has ſhewn them to be capa-
ble to ſuſtain, and which may be beſt adapted to the conſtruction of
ſhips.
16. The following addreſs to Swilcar oak in Needwood foreſt,
a very tall tree, which meaſures thirteen yards round at its baſe,
and eleven yards round at four feet from the ground, and is be-
lieved to be fix hundred years old, was written at the end of Mr.
Mundy's poem on leaving that foreſt, and may amuſe the
weary
reader, aud conclude this Section.
91
ADDRESS TO SWILCAR OAK.
a
Gigantic OAK! whoſe wrinkled form hath ftood,
Age after age, the Patriarch of the wood ! -
Thou, who haſt ſeen a thouſand ſprings unfold
Their ravel'd buds, and dip their flowers in gold;
Ten thouſand times yon moon relight her horn,
And that bright ſtar of evening gild the morn! -
Erſt, when the Druid-bards with ſilver hair
Pour'd round thy trunk the melody of prayer;
When chiefs and heroes join'd the kneeling throng,
And choral virgins trill'd the adoring fong;
While harps reſponſive rung amid the glade,
And holy echoes thrill'd thy vaulted ſhade;
Say, did ſuch dulcet notes arreſt thy gales,
As Mundy pours along the liſtening vales ?
Gigantic Oak!- thy hoary head ſublime
Erewhile muft periſh in the wrecks of time;
Should round thy brow innocuous lightnings ſhoot,
And to fierce whirlwinds ſhake thy ſteadfaſt root;
Yet ſhalt Thou fall !-thy leafy treſſes fade,
And thoſe bare ſhatter'd antlers ſtrew the glade;
Arm

Secr.XVIII. 2. 16.
529
LEAVES AND WOOD.
Arm after arm ſhall leave the mouldering buſt,
And thy firm fibres crumble into duft!-
But Mundy's verſe ſhall conſecrate thy name,
And riſing foreſts envy SwilcAR's fame;
Green ſhall thy gems expand, thy branches play,
And bloom for ever in the immortal lay.
2016
TO AD
M
Cold
3 Y
SECT.

530
SECT. XIX.
PRODUCTION
blood and
sele
SECT. XIX.
PRODUCTION OF FLOWERS.
water.
I. Flowers from feeds. 1. Double flowers from ſeeds. Hereditary diſeaſes in
plants. Full flowers have no ſtamina. Three kinds of double columbine. Vege-
table monſters analogous to animal mules. The ſtomen, piſtil, and calyx, are the
moſt unchangeable parts. Double flowers diſtinguiſhed by the calyx, are mucha
more durable than ſingle ones. Double poppies yield more opium. Annual infeEts.
2. The colours of ſingle flowers from ſeed how varied. Variegation of foliage.
Vegetable juices are hyper-oxygenated. This fluid oxygen is converted into gas by
the ſun's light; which therefore colours living vegetables, and bleaches dead ones.
II. 1. Flowers from buds. Double ones how cauſed. Surround the bud with
Oil, and conſerve of roſes. Their double flowers. Acquired habits.
2. How to vary the colour of ſingle forub-flowers, by anther-duſt, by inocula-
tion. Trees how variegated by ingraftment, or made into evergreens. 3. How
to increaſe the number of flowers. III. 1. Flowers from roots. Bulb-rooted
flowers. To cauſe their duplicature, break off the flower, raiſe them out of the
ground. 2. Single bulb-rooted flowers. To increaſe them in ſize or number,
take away offsets, crowd their roots. Propagation by offsets. By feeds. How
broken into colours. Plant them in different foils. Tulips break into colours from
age. 3. Perennial branching roots. Duplicature of their flowers, propa-
gated by offsets, by ſeeds. Ibeir ſingle flowers. How broken into colours. By
feeds, by tranſplaniing. IV. Eſculent and medicinal flowers. Vegetable mu-
cilage coagulated by boiling in water, in ſteam. They loſe their green colour in
ſteam, Why? Artichoke-ſtalks. 2. Cultivation of brocoli. Knobs on its roots.
3. Hop. Camomile. Their duplicature. V. Flowers uſed in the arts. For
dying, ornotto. For ſpinning, cotton, cotton-ruſh, cat's-tail. VI. Nutritious
parts of vegetables. 1. Muſhrooms. Gluten of Wheat. Oils. 2. Sugar.
Mucilage. Oil. 3. Starch. Meal. 4. Alburnum, Barks. Roots of fern
and

SECT, XIX. I. I.
531
OF FLOWERS.
and of bryony. 5. Immature flowers. Honey. Leaf-ſtalks. Leaves. Re-
ſervoirs of nutriment. VII. Happineſs of organized nature. 1. Seeds and
eggs have not ſenſitive life. Milk gives two-fold pleasure. Dull animels and
diſeafed vegetables periſh, and give life to more ſenſible ones. Old age unknown
before ſociety. Miſery is not immortal. 2. Animal abſorption and ſecretion is
attended with agreeable ſenſalion. Renders matter more ſolid. The ſame in ve-
getables. 3. Strata of limeſtone formed from animal ſhells. Thoſe of coal, clay,
Jand, from vegetable ſecretions, gave pleaſure at the time of their production, and
are monuments of paſt felicity, and of the benevolence of the Deity. VIII. Cul-
tivation of brocoli, a poem.
The beautiful colours of the petals of flowers with their poliſhed
furfaces are ſcarcely rivalled by thoſe of ſhells, of feathers, or of
precious ſtones. Many of theſe tranſient beauties, which give fuch
brilliancy to our gardens, delight at the ſame time the ſenſe of ſmell
with their odours ; yet have they not been extenſively uſed as ar-
ticles either of diet, medicine, or the arts. For the purpoſe of cul-
tivation they may be divided into thoſe immediately derived from
feeds, thoſe from buds, and thoſe from roots; to which may be
added the efculent and medicinal ones, and thoſe uſed in the arts.
sro
1. Flowers from Seeds.
a
1. The eye of the floriſt is frequently delighted with double
flowers, which ſhew a greater blaze of colour in a ſmall ſpace, and
continue fome weeks longer in blow than ſingle ones; and, though
they are properly called vegetable monſters by the botaniſts, may
give information to the philoſopher in reſpect to the ſexual genera-
tion of vegetables. The method therefore of producing double
flowers from ſeeds is a matter of importance, as well as the art of
giving to both theſe and the ſingle flowers their moſt healthy ex-
panſion, and the greateſt brilliancy and variety of their colours.
3 Y 2
Though

532
PRODUCTION SECT. XIX. I.I.
Though thoſe multiplied flowers, which are ſaid to be full, pof-
feſs no ftamens, or piſtils, and conſequently can produce no feeds;
yet are they frequently raifed immediately from ſeeds ; for thoſe
flowers, which are cultivated with more manure, moiſture, and
warmth, than is natural, become more vigorous and larger, and at
the ſame time are liable to ſhew a tendency to become double, by
having one or two ſupernumerary petals in each flower, as the ſtock
July-flower, cheiranthus, and anemone. And what is truly curi-
ous, this tendency to duplicature is communicated to the ſeeds of
od
thoſe individual bloſſoms; inſomuch that floriſts are directed to tie a
thread round ſuch flowers, which have a ſupernumerary petal, to
mark them, and to collect their feeds ſeparately; which are ſaid uni-
formly to produce double or full flowers, if cultivated as above with
rather more manure, moiſture, and warmth, than thoſe plants have
naturally been accuſtomed to be more and
.
The analogy of this circumſtance with the hereditary diſeaſes of
animals is truly wonderful; as the children of thoſe parents, who
have acquired the gout or dropfy by intemperance in the uſe of fer-
meited or ſpirituous potations, become afflicted with thoſe diſeaſes,
as I have frequently obſerved, in a much greater degree by the fame
quantity of intemperance, which originally produced them in their
parents; or they acquire the ſame quantity of thoſe diſeaſes by a leſs
degree of intemperance, than occaſions them in others, whoſe
parents
have not uſed fermented or fpirituous liquors to exceſs.
ST
The luxuriance of flowers, which is believed to ariſe from their
cultivation in more nutritive ſoils with greater moiſture and
warmth, conſiſts in the increaſe of ſome parts of the flower, and
the conſequent exclufion of others; and is diſtinguiſhed by Linnæus
into the multiplication and plenitude of flowers, and into proliferous
ones. Multiplied flowers conſiſt of double, triple, or quadruple co-
rols; but full flowers are ſo multiplied as to exclude the ſtamina ;
while in proliferous ones other flowers ariſe from within the
odo
principal
a

Sect. XIX. I. I.
533
OF FLOWERS:
principal flower, and frequently from its center. Philof, Botan.
p. 80.
It is ſuppoſed that the ſtamina of ſome double flowers are con-
verted into petals ; but on examination, I ſuſpect that the number
of petals is increaſed, and the ſtamina prevented from growing by
being compreſſed by them in their nafcent ſtate ; as in
many
of
them, I believe, the rudiments of ſome ſtamina may be ſeen, as in
ranunculus. So when a new flower riſes in the center of the old
Wom
one, it is ſuppoſed, that the piſtillum is converted into the ſtem of a
new flower, as in proliferous daiſy, bellis prolifera; but I ſuſpect,
that the piſtillum is prevented from riſing by the immoderate growth
of the new flower-ftem ; as in ſome of them, I am told, the rudia-
ment of the piſtillum may be perceived.
Thus monopetalous flowers are doubled or multiplied by the in-
creaſed diviſions of the limb, as obſerved by Linnæus, Philof. Botan.
p. 83, who adds, that the metamorphoſis of Engliſh foapwort is very
fingular, as its five petals are transformed into one petal, and that in
opulus flore globofo the central florets become ſimilar to thoſe of the
circumference, acquiring wheeled corols, and being barren: in
theſe caſes the ſtamens cannot be changed into corols, as the num-
ber of corols is not increaſed. Afterwards, in p. 84, the fame il-
luſtrious author obſerves, that in double lychnis the rudiment of the
common piſtil is preſent.
The luxuriance of flowers therefore conſiſts in the multiplica-
tion of the corols or nectaries, which laſt are properly an appendage
to the former; and the prevention of the growth of the male and
female organs is the conſequence. Thus the flower of aquilegia,
columbine, has three kinds of plenitude: 1. the petals become mul-
tiplied, and the nectaries excluded; 2.. the nectaries are multiplied,
and the petals excluded; 3. the nectaries are multiplied, the petals
remaining. So that there are five petals, and between each of theſe
three nectaries, which exiſt within each other.
ou as
A curious

534
PRODUCTION
Sect. XIX.
A curious analogy here alſo exiſts between theſe vegetable
monſters and thoſe of the animal world; as a duplicature of limbs
frequently attends the latter, as chickens and turkeys with four legs
and four wings, and calves with two heads. And in mules the
parts fubfervient to generation become deficient, whence they can-
not propagate their ſpecies; exactly as in theſe full flowers, which
can thence produce no feed. And in reſpect to botanic ſyſtems, it
may be obſerved from theſe vegetables of luxuriant growths, that
the ſtamens and piſtils are leſs liable to change than the corols and
nectaries, and are therefore more proper parts for the claſlification of
plants; on which idea Linnæus has conſtructed his unrivalled
fyftem. And laſtly that the calyx, or perianth, is the next moſt
unchangeable part of the flower, as this is ſeldom doubled or multi-
plied; and that hence by inſpecting the calys the genera of many
double flowers may be detected ; thus the double ranunculus poſſeſſes
a calyx, but the double anemone is without one, like the fingle ones
of thoſe genera.
The greater duration of double flowers than fingle ones is ſo re-
markable in fome poppies, that their ſingle flowers loſe the corolla
in a few hours, while in the double ones it continues ſeveral days:
this circumſtance is well worthy the attention of thoſe, who cultivate
poppies for the purpoſe of wounding the head, which incloſes the
ſeeds, for the opium, which thus exſudes. As poppies with double
flowers may probably be capable of yielding opium, before they ſhed
their flowers, and as long as other poppies, after they ſhed them,
Dr. Smith aſcribes this event to the organs of reproduction being
obliterated, and the confequent want of impregnation ; by the great
ſtimulus of which he thinks the vegetable irritability may be fooner
exhauſted in ſingle flowers: and adds, “ that on the ſame account
many plants refift a greater degree of cold for feveral winters before
flowering; but after that event they perilh at the firſt approach of
cold, and can by no art be preferved ſo as to ſurvive the winter."
I
And

SECT. XIX. 1.2.
535
OF FLOWERS.
And repeats an obſervation from Linnæus, that the piſtilla of the
female hemp, cannabis, continued much longer to exiſt when not
expoſed to the male pollen, than thoſe piftilla on which the pollen
had been effuſed. Tracts on Nat. Hiſt. p. 177.
It may be obſerved, that many inſects may be called annual ones
as well as many vegetables, and die, as ſoon as they have provided the
eggs or feeds for the reproduction of their ſpecies, as the filkworm,
and, I ſuppoſe, all the kinds of moths and butterflies; many of
which take no food at all, after they have acquired their organs of
generation and their amatorial paſſion, and yet appear fat and active;
and others live only upon honey, and ſeem to die as ſoon as that
paſſion is gratified, probably from having no further pleaſureable fti-
mulus to excite the animal power into activity, rather than from its
total exhauſtion; becauſe other animals, whoſe exiſtence is not na-
turally ſo ſhort, are not injured or deſtroyed by the moderate uſe of
the powers of reproduction; and that power leaves them long before
their death. An experiment to ſhew, whether the moths of filk-
worms would live longer if deprived of their paramours, might be
worth the attention of naturalifts; and alſo, whether the butterflies
of our climate might not be preſerved during the winter, if fed with
honey like bees, and kept from exceſſive cold. I directed ſome honey
to be offered to the filkworm-butterflies, which they would not
attend to, though they may probably ſeek for it in their native
climates.
2. Varieties in the colours of fingle flowers raiſed from ſeeds
may probably be generally acquired by fowing near together thoſe
of the fame ſpecies, which already poffefs different colours; fo that
during the difperfion of their anther-duft by the wind, or otherwiſe,
they may izatermix and adulterate each other. Or this
Or this may be more
certainly effected by bending the flowers of one colour, and ſhaking
the anther-duſt over thoſe of another colour. In this manner, I
fuppoſe,

536
SECT. XIX. 1.2.
PRODUCTION
ſuppoſe, it happens, that the beds of centaurea cyanus become of
fuch various and beautiful ſhades of blues, purples, and whites.
Another method of giving variety of colours to feedling flowers
conſiſts in fowing them on natural foils, or on factitious compoſts,
which differ much from each other in reſpect to vegetable nu-
triment, and perhaps in reſpect to their colour, as ſome ani-
mals change their natural colours when in different ſituations of
Toil. As frogs much reſemble the colour of the foil on which
they live, and our domeſticated horſes, dogs, cats, rabbits, pigeons,
and poultry, change their colours into endleſs varieties, owing to
the difference of their nutriment or ſituation. But obfervations and
experiments are wanting on this ſubject in reſpect to the colours of
ſeedling flowers, as well as in reſpect to the variegation of the leaves
of ſhrubs and trees; which laſt originates probably from foil or ſitua-
tion, and may be propagated by ingrafting.
As the origin of double flowers is believed to reſult from the lux-
uriant growth of the plant, owing to too much nouriſhment, moiſ-
ture, and warmth, ſo the origin of new colours in flowers, and of
variegated foliage, is thought to occur from the innutrition of the
ſoil, on which they grow, compared to that which they have na-
turally been accuſtomed to, or from defect of moiſture and of heat;
which is countenanced by the dwarfiſh ſize of ſuch plants in general,
and eſpecially by the leſſened ſtature of tulips, when their petals
break into variety of colours.
The proximate cauſe of the change of colours in flowers or foliage
muſt be ſought from the modern acquiſitions of aerial chemiſtry.
The preſence of oxygen gas deprives dead vegetable fibres, as cotton-
wool and the threads of flax, of their colour; that is, it bleaches
them; which is probably owing to its uniting with the colouring
matter and forming a new acid, which is tranſparent. Thus the
hyper-oxygenated muriatic acid almoſt inſtantaneouſly deprives cote
ton and linen of their colour; and the ſun's light on moiſtened
linen

SECT. XIX. 1. 2. OF FLOWERS.
537
linen ſpread upon the ground ſeems to decompoſe the water, and
the oxygen thus detached whitenis the linen. The etiolation or
blanching of living vegetables on the contrary ſeems to originate
from the want of the ſun's light to convert into gas the fluid oxy-
gen; which, by diffolving their colouring matter, and forming
new and perhaps taſteleſs acids, deprives them of colour. Hence
the water, which vegetables perſpire in the ſunſhine, becomes hyper-
oxygenated, which has much puzzled philoſophers to account for ;
and the oxygen riſes from it without decompoſing it; which laſt
circumſtance is evinced by the total abſence of the ſmell of hydro-
gen, which ſo powerfully affects our noſtrils, when a ſpoonful of
water is thrown on burning coals.
Now as plants, which grow leſs vigorouſly from defect of nutri-
ment, moiſture, air, or warmth, may acquire or poſſeſs leſs
oxygen
to diffolve their colouring matter, their ſtructure may approach to-
wards that of dead vegetables ; and hence they may become bleached
inſtead of coloured by the influence of the ſun's light, eſpecially in
thoſe parts where their vital functions are performed with leſs vi-
gour; ſo an etiolated vegetable, as a blanched plant of celery, apium
graveolens, becomes green in a few days, when expoſed to the light
and air; and white again, if deprived of life, and expoſed to the
ſunſhine and dews.
The immediate cauſe of the various colours of ſome flowers, as of
poppies, might be a ſubject of curious inveſtigation. I once fup-
poſed, that the thinnefs of the pellicle of ſome flowers might occa-
fion them to reflect different colours, as is ſeen on dropping a drop
of oil from a bridge on the water below on a bright day. But co-
lours thus produced vary with the ſituation of the obſerver, in reſpect
to the obliquity or angle of reflection, in which they are ſeen ; and
are thence variable with every motion of them, as thoſe colours ſeen
on ſoap-bubbles, and on mother-pearl, and on the Labradore-ſtone,
and on ſome filks. For thoſe colours depend on the thinneſs of the
reflecting
a
3 Z

538
Sect. XIX. 2.1.
PRODUCTION
reflecting ſurface, which when ſeen more obliquely become thicker ;
and then reflects thoſe colours, which paffed through thinner plates;
in the ſame manner as the red light of the ſetting fun is reflected
from glaſs windows, feen very obliquely by the obſerver.
The colours of flowers therefore, as they are not variable by the
obliquity, with which they are ſeen, like thoſe of mother-pearl card-
fiſh, do not depend on the thinneſs of their pellicle ; but, I ſuppoſe,
to the greater facility that ſome parts of them poſſeſs in parting with
their oxygen, when expoſed to the ſun's light, than other parts of
them; for_all flowers are more or leſs etiolated, before they firſt
open. In the filk manufactory a variable colour is produced by
making the warp of one colour and the woof of another ; perhaps
the variable colour of a peacock's tail may be owing to a mixture of
different coloured down placed in lines near each other,
a
II. Flowers from Buds.
sittel
Slod
1. The flowers ariſing from the buds of ſhrubs or trees are liable
to become double or full by the multiplication of their petals, as
thoſe of roſes, cherries, hawthorn, peach, roſa, prunus, ceraſus, cra-
tegus oxyacantha, amygdalus perſica. Which tendency to duplica-
ture, as in the flowers of annual plants, is probably owing to the
too vigorous growth of the bud from a too nutritious foil, or the
combination of abundant moiſture and warmth, and would probably
be forwarded by ſurrounding the bud itſelffrequently with water;
as is ſo beautifully ſeen in thoſe plants, which have a cup round
their joints to preſerve for a time the rain, which falls upon them,
as round the joints of dypſacus, teafel, filphium, tillandſia, and ne-
penthes.
It is remarkable, that though the duplicature of many flowers is
believed to have been owing to the more nutritious foil, in which
they
a

SECT. XIX. 2. 2.
539
OF FLOWERS.
they have been cultivated, yet that, when tranſplanted into leſs fer-
tile ſoils, or ingrafted on leſs luxuriant trees, they ſtill retain their
tendency to duplicature; which can only be aſcribed to the continu.
ance of an acquired habit, or to the ſucceſſion of hereditary diſeaſes,
ſo frequently obſerved in the animal ſyſtem.
This duplicature of flowers from buds is generally propagated by
ingrafting the ſcions of ſuch, as bear multiplied petals, on fimilar
plants, which bear ſingle flowers; and may be of ſervice not only for
beauty, but for the purpoſe of increaſe in thoſe plants, the petals of
whoſe flowers are conſumed for any purpoſe, as the leaves of roſes.
A gentleman at Nottingham annually diſtils a profitable quantity
of effential oil of roſes, by collecting all of them he can purchaſe in
the neighbourhood during the ſeaſon ; and this by the uſual proceſs,
which is not difficult though tedious. And a ſurgeon at Stafford
has introduced an agreeable and profitable kind of agriculture, by
planting half an acre of ground with red roſes, and converting the
flowers into conſerve with ſugar, or by ſimply drying them for the
London market.ee
Jono
a
2. It is probable, that numerous varieties of colour in the fingle
flowers of ſhrubs, as well as thoſe of annual plants, might be ob-
tained by ſhaking the anther-duſt of one variety over the ſtigma of
another, where any difference of colour already exiſts in the ſame
ſpecies. And perhaps ſome changes of colour of the flowers might
be produced by inoculating the buds of a ſhrub, whoſe flowers are of
one colour, into the branches of another variety of the ſame ſpecies
or ģenus; as the variegation of the foliage of plants is ſaid to have
been produced in this manner, according to the affertions of Mr.
Bradley and Mr. Laurence, who budded a ſpotted paflion-flower and
a ſtriped jaſmine on thoſe, which were not variegated, and produced
a fimilar variegation of them, as related in Sect. V.1. This has been
aſcribed to the abſorption of ſome infectious matter from the inocu-
lated bud, which propagated a fimilar diſeaſe to the whole tree; and
has
3 Za

540
SECT. XIX. 3. 1.
PRODUCTION
an
has thence been uſed as an argument in favour of a vegetable circu-
lation of juices.com oglasa
10
A fimilar fact is alſo aſſerted by Mr. Milne. He ſays, that "
evergreen tree ingrafted on a deciduous one determines the latter to
retain its leaves ; this obſervation is confirmed by repeated experi-
ments, particularly by grafting the laurel, lauroceraſus, an ever-
green, on the common cherry, ceraſus; or the ilex, an evergreen
oak, on the common oak.” Botanical Dict. Art. Defoliatio All
theſe ſeem to want further experiments to authenticate the facts fo
delivered on the authority of ingenious men.
3. To increaſe the number of the flowers of ſhrubs, all thoſe arts
are applicable, which are deſcribed in Sect. XV. 2. for the production
of fruit on wall trees; which, when the tree is of a proper age,
confift, 1. in bending down the viviparous branches to the horizon,
which renders them oviparous; 2. by twiſting a wire, or tying a
cord round the viviparous branches; 3. by wounding or cutting
away a narrow cylinder of the bark; 4. by tranſplanting or cutting
off ſome of the roots; 5. by cutting away the central or viviparous
branches; 6. by ingrafting.
do od del
Selain at no III. Flowers from Roots.
10 15 noh
1. Many bulb-rooted flowers are deſervedly in great eſtimation by
floriſts, as the tulip, hyacinth, lily, colchicum, crocus, fritillary, &c.
and of thoſe many are liable to become double, which adds in gene-
ral ſo much to their ſplendour and to their duration, as narciſſus,
hyacinth, colchicum, tulip.
The immediate cauſe of duplicature or multiplication of the pe-
tals of theſe flowers is probably ſimilar to that of thoſe above men-
tioned, and originates from their luxuriant growth, owing to the
fertility

SECT. XIX. 3. 1.
54!
OF FLOWERS.
fertility of the ſoil, and the abundance of moiſture and of warmth in
combination.
Other circumſtances, which may add to their luxuriant growth,
may
alſo contribute to their duplicature; ſuch as by breaking off
the flower as ſoon as it begins to fade; and thus, by preventing the
nutritious vegetable juices from being expended in the growth of
the feeds, more of it may be derived to the principal ſucceeding
bulb.
Thus it is aſſerted, that the preventing ſome annual plants from
flowering lengthens their lives, which it may effect by occafioning
them to produce new root-ſcions, and thus to become perennial ve-
getables. The very ingenious Mr. Bogle, in the papers of the Bath
Society, believes that wheat, oats, and barley, may be made peren-
nials, if they are eaten down by cattle or ſheep, or cut by the ſcythe
or fickle, ſo as to prevent them from producing ears.
As tulip-bulbs raiſed from ſeed produce a larger bulb the ſucceed-
ing year, and'again a larger with a different leaf on the third year,
and ſo on till the fifth or fixth, the bulbs thus annually improving
till they flower; and even after they flower they are believed to
continue to improve for ſome years, till the colour of the petals be-
come ſtriped : I ſuſpect that the art of procuring a great duplica-
ture of the petals of theſe flowers conſiſts in breaking off the flower-
ſtem on the fifth, fixth, and ſeventh years, from the fowing of the
feed; that is, for a year, or two, or three, after the flower-ſtem
firſt appears, as noted in Sect. VIII. 1. 3. And that the tendency to
duplicature will continue in the ſucceeding bulbs by the acquired
habit, as in the hereditary diſeaſes of animals.
And ſecondly, theſe flower-roots become more luxuriant by raiſ-
ing them out of the ground, as ſoon as the leaves wither, which are
the parents of the new bulbs ; and then by taking away the ſmaller or
collateral new bulbs from the principal one, which might otherwiſe
incommode its growth by their vicinity, and conſequent compreſo
fion,

542
SECT. XIX. 3. 2.
PRODUCTION
9
fion, both theſe methods are of equal uſe to enlarge and render more
vigorous the fingle flowers of bulb-roots, as well as to increaſe their
tendency to duplicature.
2. The fingle flowers of ſome of theſe plants may be probably not
only enlarged, but ſo ſtrengthened as to ripen their feeds in this cli-
mate, by nicely laying bare the root, and taking from it the new
progeny; whether a fingle new bulb, as in orchis mafcula, or the
numerous ones of hyacinth, tulip, or lily of the valley; as by theſe
means the vegetable nutriment is not expended on the new bulbs,
and probably more of it may thence be derived to the flower. See
Sect. XVII. 1. 3.
Another method of increaſing the bulb-rooted flowers in ſize or
number confifts in crowding their roots in garden-pots, or by not
annually tranſplanting them; and thus by preventing their offsets
from being formed, or by decreaſing the number or vigour of them;
thus lily of valley, and jonquil, ſeldom afford large or numerous
flowers, till they have remained three or four years in the ſame ſitua-
tion; but muſt nevertheleſs be then occaſionally in part tranſplant-
ed, leaſt the roots ſhould die from being ſo crowded as not to form
each of them one annual new bulb, which is their mode of reproduc-
tion.
The uſual method of propagating bulbous roots has been by the
ſmaller offsets, which are formed annually round the principal or
central new bulb, as in tulips; which central new bulb has com-
monly been miſtaken for the old root ; by this mode of propagation
the ſimilarity of the new progeny to the parent is nicely preſerved ;
and on that account ſome of theſe new roots of tulips and hyacinths
have been ſold at extravagant prices. For the circumſtance of this
mode of reproduction fee Sect. IX. 3. 2.
But in reſpect to producing variety of colour in the fingle flowers
of bulbous roots, the moſt effe&tual method, I ſuppoſe, muſt be by
fowing their feeds, and waiting a few years, till their ſucceſſive bulbs
at

Sect. XIX. 3. 2.
OF FLOWERS.
543
at length produce flowers, as deſcribed in Sect: XVII. 1. 2. and par-
ticularly if the anther-duft of one variety in reſpect to colour be ſhed
on the ſtigma of another variety.
Another method of producing a change or variety of colours in
bulb-rooted flowers may be by planting them every year, till they
flower, on very nutritious foil, with an abundant combination of
moiſture and of heat, as theſe two elements ſhould exift together
to effect the moſt luxuriant growth of vegetables. And after they
have flowered, or on the year in which they are expected to flower,
they ſhould be tranſplanted on a leſs nutritive foil, with leſs heat
and moiſture. Or probably this lefs quantity of nutriment, heat, and
moiſture, might be uſed at the commencement of their growth, or
even at fowing their feed, with ſimilar effect of ſooner breaking into
variety of colours.
The beauty of the double yellow tulip, and its greater longevity,
much recommend it to common eyes; but the endleſs variety in the
colours of fingle tulips has long and deſervedly been the admiration
of floriſts. The curious event of their breaking into various colours
from an uniform purple, a year or two after their firſt flowering,
and at the ſame time of their lofing nearly one third of the height of
their ſtems, ſeems to indicate, that this effect reſults not from the
debility of age, but from the acquiſition of hereditary diſeaſes, as theſe
new colours, into which they break, afterwards remain for uncount-
ed generations, and may in this reſpect be compared to the canker
in apple-trees, mentioned in Sect. XIV. 1. 3.
This change of colour from darker to lighter in tulips may proba-
bly be accelerated or increaſed by keeping the roots long out of the
ground in dry or warm apartments, ſo as to harden their fibres, and
diminiſh the diameters of their ſecreting veffels, and thereby 'hin-
dering their abſorption of colouring molecules, ſimilar to grey hairs
produced on animals by age or external injury of the part. This
would ſeem to obtain in tulips, as when they break into colours,
they
1

544
Secr. XIX. 3. 3.
PRODUCTION
a
they loſe one third of their fize, and conſequently the diameters of
their ſecretory and of their abforbent veſſels muſt be much di-
miniſhed.
New kinds of varieties in the ſituations or production of white
parts of the petals of flowers might be cauſed, I ſuſpect, by com-
preſſing ſome parts of them before the flower opens, by tying fine
threads round the calyx, which incloſes them; as many darker co-
loured cats and dogs have all thoſe parts lighter or quite white, which
have been compreſſed together, as they lay in their fetus ſtate in the
uterus; an inſtance of which exiſts in a black male cat, which now
lies upon the hearth, and an inſtance of a black terrier bitch is de-
ſcribed in Zoonomia, Vol. II. Claſs I. 2. 2. 11. This may be worth
the attention of floriſts and flowerfellers; and it is probable, that the
white ſtreaks in dark flowers may have been thus produced by their
greater compreſſion in the calyx, before the flower opens.
3. The cauſes of duplicature in perennial flowers with branching
roots, as ranunculus, caltha, hepatica, anemone, cheiranthus, dian-
thus, filene, wallflower, carnation, catchfly, are probably ſuch as
afford a general luxuriancy of growth to thoſe vegetables, and may
be certainly propagated by offsets from thoſe roots, or by laying
their branches in the ground, ſo as to exactly reſemble their parents.
Many of theſe double flowers may alſo be procured by collecting the
ſeeds from ſuch ſingle flowers of the ſame ſpecies, as poſſeſs a ſuper-
numerary petal; which, if ſowed on fertile ground, will preſent us
with double or multiplied flowers, as the anemone and july-flower
mentioned in No. I. 1. of this Section.
The effect of breaking the fingle ones into varieties of colour,
which, in anemones and poppies as well as in tulips, are uncom-
monly beautiful, is probably owing to the leſs fertility of the ſoil,
or leſs ſupply of heat and moiſture, where they have happened to
reſide, and that more effectually if they were removed from more
favourable ſituations.
The

SECT. XIX. 4. 1.
545
OF FLOWERS.
The varieties of the ſingle flowers alſo of thoſe roots may be
pro-
pagated unchanged, as well as the double ones, by dividing the
roots or tranſplanting the offsets, or by laying their branches in the
ground, as of pinks and carnations. Other varieties may be
pro-
cured by collecting ſeeds and fowing them in diffimilar ſoils and
ſituations; and ſuch flowers as are of approved beauty, may pro-
bably be occaſionally ſtrengthened and enlarged by depriving them
in part of their offsets early in the ſeaſon; or may be broken into
colours by keeping the roots ſome weeks or months out of the
ground in the autumn in dry or warm apartments.
The colours of flowers of this kind, I believe, are frequently
changed by ſituation ; in my garden ſome roots of comfrey, fym-
phytum, with purple flowers had long exiſted on a moiſtiſh border;
and laſt year other roots, I ſuppoſe from the ſeeds of the former,
grew in a dryer ſituation, and bore white flowers. And Mr. Brad-
ley aſſerts, in his Philof. Account of Nature, p.71, that ſome roots
of purple hepatica, which were removed from Tothill-fields to Hen-
ley on the Thames, became white; and became purple again, when
they were returned to their native ſituation,
IV. Eſculent and Medicinal Flowers.
1. The eſculent flowers moſt in uſe at our tables have their mu-
cilage in ſome degree coagulated by boiling them in water or in
ſteam, and are conſumed before their maturity, as thoſe of arti-
choke, cinara ſcolymus ; of mercury, mercurialis ; of ſea-cale,
crambe maritima; and of brocoli and cauliflower, braſſica oleracea,
italica and botrytis. The flowers of the naſturtion, tropeolum ma-
jus, poſſeſs an agreeable acrimony, and are eaten raw, ſhred with
the freſh leaves of lettuce, young muſtard plants, or red cabbage.
Other flowers are uſed for domeſtic or medicinal purpoſes, as thoſe
4 A
of

546
SECT. XIX. 4. 1.
PRODUCTION
of hops, humulus lupulus, camomile, anthemis nobilis, roſes, carda-
mine, violets.
The three foremoſt of theſe, the artichoke, and mercury, and
ſea-cale, are perennial plants; and, as they put forth numerous root-
ſcions or offsets, may have their principal ftem much invigorated,
and will conſequently produce larger flowers, by taking away many
of theſe offsets, ſo as to leave but two or three on a root. And as
the ripening of the feed is no object, a greater abundance of moiſture,
than theſe plants have been naturally accuſtomed to, with propor-
tional increaſe of warmth in reſpect to fituation, will forward their
growth, and increaſe their fize.
A great part of the nutritious mucilage in the artichoke is placed
in the upper part of the ſtem, as well as in the pericarpium of the
flower, which ſhould therefore be boiled along with it for the pur-
poſe of coagulation; and might then probably be managed ſo as to
reſemble fagoe, if granulated by paſſing it through ſieves.
The art of boiling vegetables of all kinds in ſteam inſtead of in
water, might probably be managed to advantage, as a greater degree
of heat might be thus given them, by contriving to increaſe the heat
of the ſteam after it has left the water; and thus the vegetable mu-
cilage in roots and feeds, as in potatoes and flour-puddings, as well
as in their leaves, ſtems, and flower-cups, might be rendered pro-
bably more nutritive, and perhaps more palatable.
But many of the leaves of vegetables, ās the ſummits of cabbage-
ſprouts, loſe their green colour by being boiled in ſteam, and look
like blanched vegetables. This etiolation of ſome vegetables by
ſteam is probably owing to its diffolving their colouring matter,
which may then become decompofèd ; and may render them leſs
agreeable to thoſe who chooſe by the eye rather than by the palate;
which green colour is however heightened by boiling them in
ſome hard waters, which contain diſſolved lime or ſea-falt, or by a
fight admixture of common ſalt with ſoft water. An effect which
is

Sect. XIX. 4. 2.
547
OF FLOWERS.
is owing to the evaporation of a part of the marine acid, and to the
remaining alkali, which was the baſis of it, when applied to bluiſh
vegetables converting them into green, as in the common experi-
ment of adding falt of tartar to ſyrup of violets; or, according
to the cuſtom of ſome cooks, who add a little potaſh, or fixed ve-
getable alkali, to the water, in which young peas are boiled to
make them green, and afterwards a very little ſugar to fweeten
them.
The ſame effect of making vegetables green, when boiled in other
kinds of hard waters, is probably produced by the lime, which
abounds in them; and which like the vegetable alkali when the
aerial acid, which was united with it evaporates, is ſaid to convert
bluiſh vegetable colours into green ones.
i
The nutritious mucilage reſides likewiſe in the young ſtems of
mercury, which ſhould therefore be eaten before the flower begins
to open.
The ſtalks and immature flowers of fea-cale are fimilar to
good brocoli, if eaten young; though many gardeners prefer the
blanching them, which ſupplies an early and agreeable repaſt, de-
fcribed in Sect. XIV. 3. 3. Aſparagus does not perhaps properly
belong to this ſection, as the ſtem is eaten, before the flower becomes
viſible.
2. The cultivation of brocoli and cauliflower muſt be very fimi-
lar, except as to the ſeaſons of the year, as they are varieties of the
ſame ſpecies of plant of the cabbage family. The following direc-
tions for the cultivation of brocoli were ſent me by Edward Tighe,
Eſq. an ingenious gentleman of Ireland, along with an elegant Latin
poem on the ſame ſubject, a free tranſlation of which is placed at the
end of this ſection.
“ Brocoli may be ſo managed as to ſupply the table with a deli-
cious and falutary vegetable during the months of November, De-
cember, January, February, March, April, and May.
4 A 2
1. Pro-

548
SECT. XIX. 4. 3.
PRODUCTION
1. Procure prime feed from Rome or Naples both for early and late
ſowing.
2. Sow at the ceffation of the vernal ſnows, and repeat it once a
month till the end of May, or longer. .
3. When three leaves appear, tranſplant them; and when fix
leaves appear, tranſplant them again. Afterwards in June,
July, and Auguſt, tranſplant them two or three feet afunder,
to remain.
4. During September and October the ground muſt be looſened,
and repeatedly cleared from weeds and ſtones; and the plants
earthed up to preſerve their roots from the froſt, and to pre-
vent their being injured by the equinoctial winds.
5. Water them occaſionally with water impregnated with dung.
6. Sow and plant them far from hedges, trees, and walls.
The head is generally completed in five or ſix days from its firſt
appearance, and ſhould not remain much longer; the ſtalk ſhould
be boiled with the flower, and peeled in the kitchen, before it is
brought to the table.”
Some kinds of Italian brocoli are ſaid to produce ſome knobs or
bulbs at their roots, which are ſuppoſed to be for the purpoſe of
raiſing other ſtems; if this laſt circumſtance be aſcertained, they
ſhould be broken off, when the principal ſtem is tranſplanted; like
the new root of orchis to enlarge the flower, mentioned in Section
XV. 2. 4. But they may be fimply a reſervoir of nutriment for
the principal ftem, as in carrots and turnips; in that caſe they ſhould
certainly remain, and be tranſplanted along with the ſtem.
3. In reſpect to the flowers of hop, humulus lupulus; and cha-
momile, authemis nobilis ; as well as thoſe of roſes, violets, carda-
mine, and the nafturtion above mentioned ; as their petals only are
required, it would add much to their quality, if they could be cul-
tivated in their double or multiplied ſtate, as is generally indeed
practiſed

SECT. XIX. 5.1.
549
OF FLOWERS.
practiſed in reſpect to roſes and chamomile ; many acres of the lat-
ter of which are cultivated near Cheſterfield in Derbyſhire, and are
fold, I am informed, to mix with hops, when thoſe crops are de-
ficient, as well as for the purpofes of medicine. What might be the
effect of endeavouring to introduce a duplicature or multiplication of
the flowers of artichoke, ſea-cale, cauliflower, and brocoli, has not,
I believe, been experienced.
v. Flowers uſed in the Arts.
1. The beautiful membrane, which covers the feeds of euonymus,
or ſpindle-tree, and of the bixa of South America, is ſaid to be ma-
nufactured into the anotta, or arnotta, uſed in colouring cheeſe; but
I am told that madder, made from the root of rubia tinctoria, is fold
frequently in its ſtead, and may be readily grown by farmers in their
own gardens. Few flowers are uſed in the art of dying, their co-
lours are ſo fugitive, as they readily bleach when expoſed to the
light, and cannot be kept long even in the herbariums of botaniſts
without loſing their colours; which is believed to be owing to the
oxygen of the atmoſphere being ſeparated from the aerial water by
the ſun's light, and converted into a gas combined only with heat or
light, and in that ſtate more readily uniting with the colouring
matter of flowers, and producing a new acid, which is tranſparent,
colourleſs, or white, or is diſſolved and waſhed away by the dews
or rains.
The blue colour of the flowers of violets has been extracted by
water, and preſerved by the addition of ſugar converting it into fy-
rup for the purpoſes of medicine in part, but chiefly for thoſe of
chemiſtry, to ſhew the change of vegetable blues into greens by an
admixture of fixed alkali, as falt of tartar or potaſh; and into red
by
7

550
Secr. XIX. 6. I.
PRODUCTION
by the admixture of an acid, as thoſe of ſulphur, nitre, or marine
ſalt,
2. Another very important flower, which is ſuffered to grow to
maturity for the purpoſe of uſing the fine fibres which wing or in-
velope its feeds, is that of the cotton plant, goffypium ; which, as
it requires ſo much leſs preparation than the fibres of the ſtems of
flax and of hemp or nettles, is likely to become the principal cloth-
ing of mankind; and eſpecially ſince the art of ſpinning it was
brought to ſuch wonderful perfection by the genius of Sir Richard
Arkwright, who diſcovered that two ſets of rollers moving with dif-
ferent velocities would draw out the fibres of cotton into a fine
thread more accurately than could be done by the human hand,
as well as more expeditiouſly, along with much other very ingeni-
ous machinery
There are two bog or water plants in our moraſſes, which produce
much vegetable fibres attached to their ſeeds, one of theſe is the ty-
pha, or cat's-tail; and the other eriophorum, or cotton-ruſh. The
fibres of the former are ſhort and coarſe, but might ſerve perhaps to
ſtuff cuſhions, or even coarſe beds; thoſe of the latter are longer,
and perhaps fine enough to ſpin. And as both theſe only grow on
bogs or in water, where we at preſent cultivate no uſeful vegetables,
one, or both of them, might poſſibly be worthy the attention of
thoſe, who poſſeſs aquatic or marſhy ſituations. The cultivation of
the cotton plant belongs to warmer climates, and may probably re-
quire abundant water for its vigorous -growth, as well as the typha
and eriophorum of this country.
VI. Nutritious parts of Vegetables.
1. Having treated of the cultivation of fruits, ſeeds, roots, barks,
leaves, woods, and flowers, an important queſtion preſents itſelf;
which

SCET. XIX. 6. 2.
551
OF FLOWERS.
a
which of them may ſupply the moſt nutrition to mankind, or to
other animals?
It
may
be anſwered firſt, that thoſe vegetables, or parts of vege-
tables, which approach neareſt to the nature of animal bodies, are
moſt likely to ſupply them with the moſt nutriment; as the eſcu-
lent muſhrooms, and the gluten of wheat, and the oils of ſeeds and
kernels. The former claſs of plants ſeems to connect the animal
and vegetable kingdoms of nature, as ſpoken of in Sect. XVII. 2. 5.
and though many of them poſſeſs an acrid, and ſome of them an in-
toxicating quality, it is probable that the former might be deſtroyed,
and the latter diminiſhed, by the heat employed in cookery. This
ſhould nevertheleſs be attempted with due caution ; fince, though
one kind of vegetable acrimony, as that of water-creſſes and of cab-
bages, is much diminiſhed or deſtroyed by a boiling heat, yet that
of the leaves of arum maculatum, and of arum ariſarum, I found by
experiment, was not decreaſed by boiling. And a few grains of the
powder of lycoperdon, puff-ball, have lately been recommended in
epileptic fits, and may thence poſſibly poſſeſs a powerful narcotic
quality. The gluten of wheat is ſuppoſed to approach towards the
coagulable lymph of animal bodies, as referred to in Sect. XVI. 7. 1.
and was once, I believe, advertiſed as an alimentary powder, and
recommended as a nouriſhment of the moſt portable kind for the
ſuſtenance of marching armies. And laſtly the oils of vegetables
approach much to a fimilitude with thoſe of animal bodies.
2. Secondly, it may be anſwered, that ſince the chyle of all red-
blooded animals is believed to be nearly fimilar, and to conſiſt prin-
cipally of ſugar, mucilage, and oil; the laſt of which ingredients
renders it white by its inſolubility in water, and thence diſtinguiſhes
it from the vegetable chyle or fap-juice of trees, which is tranſparent,
and is believed to conſiſt principally of ſugar and mucilage without
oil; thoſe parts of vegetables which contain the greateſt quantity of
theſe
I

552
Sect. XIX. 6. 2.
PRODUCTION
theſe ingredients which compoſe animal chyle, or are convertible
into them by the power of digeſtion, may be ſuppoſed to contain the
moſt nutriment for red-blooded animals.
To this may be added, that the nutritive quality of ſugar is in-
conteſtably evinced from the known fact, that the ſlaves in the ſugar
iſlands become in better condition during the ſugar ſeaſon, though
they are compelled to labour harder. The nutritive quality of fimple
mucilage was ſhewn in a remarkable inſtance on record; where a
caravan by ſome misfortune had conſumed or loſt all their other
proviſions, and lived many weeks on the gum arabic alone, which
conſtituted their principal merchandiſe. The nutritive quality of
oil is obſervable in the proceſs of feeding cattle with oil-cake, and
in the habits of the natives of the northern latitudes, who uſe the oil
of fiſh for both meat and drink, and derive from it their principal
nouriſhment.
Sugar is known to be the ſame, from whatever vegetable it is ex-
tracted, whether from the fruit of the vine or apple-tree, from the
joints of the ſugar-cane, from the ſap-veſſels of the maple, from the
alburnum of the manna aſh, from the ſeeds of germinated barley and
rice, from the roots of beets, carrots, and potatoes, or, laſtly, from
the nectaries of flowers. The expreſſed oils of vegetables are alſo
believed not much to differ from each other in reſpect to the nutriment
they contain, though ſome of them may approach nearer to the na-
ture of animal fat ; as the painters diſtinguiſh them by their greater
aptitude to dry, when mixed with their colours and expoſed to the
air.. But the word mucilage has been uſed for ſtarch, which will
not diſſolve in cold water, as well as for gum arabic, and other mu-
cilages properly ſo called, which will diſſolve in cold water, and even
for the gluten of wheat, which will not diffolve in either hot or
cold water. We may therefore conclude, that thoſe parts of vege-
tables, which contain the moſt of theſe materials, are the moſt
nutritive,
14

SECT. XIX. 6.3.
553
OF FLOWERS.
nutritive, if they do not contain along with them fome noxious
materials united with their ſalutary ones, and which cannot be
readily ſeparated from them.
3. Though the parts of vegetables, which poſſeſs much oil, ſugar,
or mucilage, may afford more expeditious nutrition, as they con-
ſtitute the ingredients of the chyle of all red-blooded animals; yet
there are other materials, which appear to be fo readily convertible
into ſugar or into mucilage, as perhaps nearly to ſupply an equal
quantity of nutriment. Thus by the proceſs of germination, as
when ſeeds of barley are converted into malt, and when roots pullu-
late in our ſtore-rooms, as of onions or potatoes; the farina, con-
fiſting of meal or ſtarch, is in part converted into fugar, and in part
into mucilage; ſimilar to this procefs of germination appears to be
that of ripening, by which the auſtere juices of fruits are tranſmuted
into ſweet ones; and alſo the culinary proceſſes of baking or boiling,
by which the auftere juices of unripe pears are changed into ſweet
ones by the application of heat, as mentioned in Sect. VI. 5. But
another more expeditious converſion of vegetable materials into fugar
is by the digeſtion of animals, which may be truly termed a ſaccha-
rine, proceſs; as appears in thoſe, who labour under diabates, as by
evaporating the urine of one of theſe patients, fixteen ounces of im-
pure ſugar were daily extracted for ſome time. Zoonomia, Vol. I.
Sect. XXIX. 4.
Hence, though the oily kernels of nuts, walnuts, almonds, and
the oily ſeeds of flax, hemp, rape, may contain moſt expeditious nu-
triment; and next to theſe the faccharine fruits of figs, dates, rai-
fins, and the ſweet roots of beet, mungel-worfal, ground artichoke,
helianthus tuberoſus, parſnip, carrot, may contain expeditious nu-
triment. Yet the more farinaceous feeds, as of wheat, peas, rice,
barley, oats, and buck-wheat, polygonum fagopyrum, and the roots
of potatoes, which contain ſtarch, and flour, and mucilage, which
are convertible into ſugar in the ſtomachs of animals, and are pro-
bably
а
4 B

PRODUCTION Sect. XIX. 6.4.
554
bably by that digeſtive proceſs, and their previous maſtication in the
mouth, mingled with more animal coagulable lymph, as the ſaliva,
gaſtric, and pancreatic juices, and may thus ſupply a more animal-
ized nutriment than the former; and may on that account con-
tribute more to ſtrengthen the ſyſtem. Of theſe ſeeds and roots it
appears probable, that thoſe, which contain the moſt ſtarch or gluten,
as wheat, afford the moſt nouriſhment, as they are believed to make
the beſt bread.
4. The alburnum, or fap-wood, of moſt trees in the winter
months probably contains much nutritious matter; whence it is ſo
foon deſtroyed by fermentation or putrefaction when deprived of life;
and by inſects, when it is deprived of its protecting bark. This nu-
tritious matter might be obtained by grating, or raſping, or pounding
it, and boiling the powder or faw-duft thus procured. The bark
of all thoſe vegetables, which are armed with thorns or prickles, is be-
lieved to contain much nutritious matter, which their armour was
deſigned to protect; as the inner barks of elm, holly, gooſeberry,
whin or gorſe, contain much nutritive mucilage; thus the deer in
Needwood Foreſt greedily peel the bark from the branchies of holly,
which are cut from the ſummits of thoſe trees, where they have no
prickles, as mentioned in Botanic Garden, Vol. II. note on Ilex.
And horſes are ſaid to be well nouriſhed by gorfe, if the prickles are
previouſly deſtroyed by rolling a ſtone over it, as the tanners bruiſe
their oak-bark; and ſome horſes are ſaid to be ſo fond of it, and ſo
wiſe, as to bruiſe young gorſe-buſhes with their feet, and then to
eat them.
Fern roots are ſaid to be eaten by the natives of New Holland,
and in other countries in times of ſcarcity ; but as their farinaceous
or mucilaginous matter is included in ligneous fibres too hard for
maſtication, the method of cooking it is faid to conſiſt in boiling the
root, and then extracting the fibres by hammering it to pieces. The
root of white bryony, which grows to a great fize in our hedge-bot-
toms,

Sect. XIX. 6. 5.
555
OF FLOWERS.
toms, is ſaid, by M. Permentier, to poſſeſs a quantity of ſtarch,
which was capable of being waſhed from the acrid mucilage by grat-
ing it into cold water, and of being manufactured into an agreeable
and ſalutary bread ; like the bread made from the caſſava, which is
ſaid to undergo a ſimilar proceſs, by expreſſing ſome of the acrimo-
nious mucilage previous to the application of the heat of cookery.
Which however not only deſtroys the acrimony of many vege-
tables, as of water-creſſes, cabbages, and the ſkins of potatoes, but is
alſo believed to render fome of them more nutritive by coagulating
their mucilage, which was previouſly combined with too great a
proportion of water.
5. It would appear therefore in general, that the feeds or kernels
of vegetables afford the moſt nutriment; next to theſe their fruits
and roots; and afterwards the alburnum or bark. Some of the
flowers alſo in their early ſtate before impregnation, as thoſe of
artichoke, cinara, and cauliflower, braffica, are nutritious from the
mucilage, which they poffefs; and ſome feeds already impregnated,
but ſtill in their immature ſtate, along with their huſks or capſules,
as thoſe of kidney-bean, phaſeolus, and of very young peas, afford a
falutary nutriment. And laſtly all flowers after the expanſion of
their corols ſecrete honey ; which ſupplies food to innumerable in-
ſects, who plunder it, as well as to mankind. In the baſes of many
leaves another faccharine or mucilaginous juice is ſecreted, as at the
joints of graſs, on the bulbs of onions, and at the lower parts of the
leaves of cabbages, and around the ſtems of aſparagus, mercury, and
hop-buds, during the early ſtate of their flowers; but the leaves
themſelves, like the lungs of animals, ſeem to poffefs leſs nutritious
aliment than many other parts of their ſyſtem.
3
4 B 2
VII. The

556
,
PRODUCTION
XIX. 7.1.
SECT. VII. The Happineſs of Organic Life.
All organized nature may be divided into ſtationary organizations,
and locomotive organizations; the former of which are called vege-
tables, and the latter animals. All thoſe parts of vegetables, which
are moſt nutritious to animals, confift, as obſerved above, of aliment
fecreted from the vegetable blood, and laid up in reſervoirs for the
future ſuſtenance of their embryon or infant progeny; which re-
ſervoirs are plundered by locomotive animals, and devoured along
with the progeny, they were deſigned to ſupport! add to this, that
the ſtronger locomotive animals devour the weaker ones without
mercy. Such is the condition of organic nature ! whoſe firſt law
might be expreſſed in the words, " Eat or be eaten !" and which
would ſeem to be one great ſlaughter-houſe, one univerſal ſcene of
rapacity and injuſtice !
1. Where ſhall we find a benevolent idea to conſole us amid fo
much apparent miſery? I hope the ſympathizing reader will not
think the following account of the happineſs, which organized beings
acquire from irritation only, impertinently inſerted in this place;
their happineſs derived from imagination and volition may be treated
of in ſome future work.
It may firſt be obſerved, that the feeds of plants and the eggs of
animals, when they have left the pericarp or uterus, and have not
yet commenced their new growth upon the ſoil, or beneath the
wings of the mother, exiſt in a torpid ftate, not poſſeſſed of ſenſitive
life; and cannot therefore, at this time be ſuppoſed to ſuffer pain,
when they are deſtroyed by other animals; though thoſe animals
obtain pleaſure from the activity, into which their vaſcular ſyſtems
are excited by the ſtimulus of the aliment thus ſupplied.
Secondly, that the young of lacteſcent animals both acquire and
communicate pleaſure to the enamoured mother, from whom they
receive

SECT. XIX. 7.1.
557
OF FLOWERS.
receive their nutriment, as mentioned in Botanic Garden, Vol. I.
Canto 1. 1. 278, note; which conſtitutes the moſt beautiful and moſt
benevolent part of the great ſyſtem of nature.
Thirdly, all animals, and, I ſuppoſe, vegetables, receive pleaſure
in the reproduction of their ſpecies; and where ſeeds are diſperſed
on the ſoil, and the.eggs of ſome animals and of many inſects are
buried beneath it, to be revived and hatched by the warmth of the
ſun; there can be no pain in theſe caſes inflicted on the mother, when
they are deſtroyed by animals or by inſects, as ſhe is unconſcious of
their deſtruction.
Fourthly, as all animal exiſtence muſt periſh in proceſs of time,
by the inirritability and conſequent debility occafioned by the repe-
tition of ſtimulus, which is termed habit, and appears to be an uni-
verſal law of nature: it is ſo ordered, that as ſoon as any organized
being becomes leſs irritable and leſs ſenſible, and in conſequence
feeble or fickly, that it is deſtroyed and eaten by other more irritable
and more ſenſible, and in conſequence more vigorous organized
beings; as inſects attack the weaker vegetable productions in pre-
ference to the healthy ones; and beaſts of prey more eaſily catch and
conquer the aged and infirm, and the young ones are defended by
their parents. By this contrivance more pleaſureable ſenſation exiſts
in the world, as the organized matter is taken from a ſtate of leſs ir-
ritability and leſs ſenſibility, and converted into a ſtate of greater ;
that is in other words, that the old organizations, whether ſtation-
ary or locomotive ones, are tranſmigrated into young ones: whence
it happened, that before mankind introduced rational ſociety, and
conquered the ſavage world, old age was unknown on earth!
Finally, the aged and infirm, from their preſent ſtate of inirrita-
bility and inſenſibility, loſe their lives with leſs pain, and which
ceaſes inſtantly with the ſtroke of death; infomuch that death
cannot ſo properly be called poſitive evil, as the termination of
good.
To
a

558
PRODUCTION
Secr. XIX. 7.1.
To this ſhould be added, that a long continued or a great exceſs
of pain cannot afflict an organized being; as fyncope or ſudden
death, and conſequent decompoſition, attends very violent pains;
and a lingering deatli attends the continuation of leſs violent ones.
Hence it becomes a conſoling circumſtance, that miſery is not im-
mortal.
A philoſopher, whom I left in my library, has peruſed the above
paragraphs, and added the ſubſequent one to my manuſcript. 6. It
conſoles me to find, as I contemplate with you the whole of orga-
nized nature, that it is not in the power of any one perſonage, whe-
ther ſtateſman or hero, to produce by his ill-employed activity fo
much miſery, as might have been ſuppoſed. Thus, if a Ruſſian
army, in theſe inſane times, after having endured a laborious march
of many hundred miles, is deſtroyed by a French army in defence of
their republic, what has happened ? Forty thouſand human crea-
tures dragged from their homes and their connexions ceafe to exift,
and have manured the earth; but the quantity of organized matter,
of which they were compoſed, preſently revives in the forms of mil-
lions of microſcopic animals, vegetables, and infects, and afterwards
of quadrupeds and men ; the ſum of whoſe happineſs is perhaps
much greater than that of the haraſſed ſoldiers, by whoſe deſtruc-
tion they have gained their exiſtence !-Is not this a confoling idea
to a mind of univerſal ſympathy?'
“ I well remember to have heard an ingenious agricultor boaſt,
that he had drained two hundred acres of moraffy land, on which he
now was able to feed a hundred oxen; and added, "is not that a me-
ritorious thing?'. True,' replied one of the company, 'but
for-
get, that you have deſtroyed a thouſand free republics of ants, and
ten thouſand rational frogs, beſides innumerable aquatic inſects, and
aquatic vegetables.
Having written the above, I fear you may think me a miſan-
thrope, but I aſſure you a contrary ſenſation dwells in my boſom ;
a
but you
7
and

Sect. XIX. 7. 2.
OF FLOWERS.
559
and though I commiſerate the evils of all organic being, Homo ſum,
humani nihil a me alienum puto.”
2. The vaſcular ſyſtems of animal bodies are excited into action
by the ſtimulus of the fluids, which they abſorb, circulate, and ſe-
crete; and when this action is exerted in its natural or moſt uſual
quantity, it is attended with agreeable ſenſation, which conſtitutes
the pleaſure of organized exiſtence. Theſe vaſcular actions of ani-
mals, which perform digeſtion, fanguification, and ſecretion, convert
the aliment, after its ſolution in the ſtomach, into more compounded
and more ſolid materials; as into muſcles, membranes, nerves,
bones, and ſhells; at the ſame time that pleaſurable ſenſation attends
this activity of the ſyſtem. The vaſcular actions of vegetables,
which perform their digeſtion, fanguification, and ſecretion, convert
the elements of air and water, or other aliments, which they receive
from organized matter decompoſing beneath the ſoil, into more com-
pounded or more folid materials, as into vegetable vefſels, muſcles,
membranes, nerves, and ligneous fibres; and a degree of pleaſure-
able ſenſation muſt be ſuppoſed from the ſtrongeſt analogy to attend
this activity of their ſyſtems.
3. Many of the materials, which have been thus produced by the
digeſtion and ſecretion of organized beings, and have given pleaſure
in their production, have been flow in their decompoſition after the
death of the creature; as the ſhells of fiſh were originally thus
formed, and were left at the bottom of the ocean, till they became
wonderfully accumulated, were afterwards elevated by ſubmarine
fires, and conſtitute at this day the immenſe rocks and unmeaſured
ſtrata of limeſtone, chalk, and marble. As mentioned in Sect. X.
10. 1.
The ſtrata, which are incumbent on the calcareous ones, which
conſiſt of coals, ſand, iron, clay, and marl, are all of them be-
lieved to have been originally the products chiefly of vegetable orga-
nization ; whatever changes they have ſince undergone in the long
progreſs

560
PRODUCTION Sect. XIX. 8.
progreſs of their decompoſition, and that all thoſe folid parts of the
earth have been thus fabricated from their ſimpler elements by vege-
table and by animal life, and have given pleaſure to thoſe organized
beings, which formed them, at the time of their production.
We hence acquire this ſublime and intereſting idea ; that all the
calcareous mountains in the world, and all the ſtrata of clay, coal,
marl, ſand, and iron, which are incumbent on them, are Monu-
MENTS OF THE PAST FELICITY OF ORGANIZED NATURE!
-AND
CONSEQUENTLY OF THE BENEVOLENCE OF THE DEITY!
VIII. The Cultivation of Brocoli.
Tranſlated in part from an elegant Latin poem of Edward Tighe, Eſq.
There are of learned tafte, who ſtill prefer
Cos-lettuce, tarragon, and cucumber;
There are, who ſtill with equal praiſes yoke
Young peas, aſparagus, and artichoke ;
Beaux there are ſtill with lamb and ſpinach nurs’d,
And clowns eat beans and bacon, till they burſt.
This boon I aſk of Fate, where'er I dine,
O, be the Proteus-form of cabbage mine!
Cale, colewort, cauliflower, or ſoft and clear
If Brocoli delight thy nicer ear,
Give, rural Muſe! the culture and the name
In verſe immortal to the rolls of Fame.
When the bright Bull aſcending firſt adorns
The Spring's fair forehead with his golden horns ;
When the bright Bull, 19th of April.
Italian

Secr. XIX. 8.
561
OF FLOWERS.
Italian feeds with parſimonious hand
The watchful Gardener ſcatters o'er his land;
Quick moves the rake, with iron teeth divides
The yielding glebe, the living treaſure hides ;
O'er the ſmooth foil, with horrent thorns beſet,
Swells in the breeze the undulating net;
Bright ſhells and feathers dance on twiſting ſtrings,
And the ſcar'd Finch retreats on rapid wings.
Next when the Twins their lucid forms diſplay,
And hand in hand falute the lord of day;
When climbs the Crab the blue ethereal plain,
Or ſhakes the Lion his refulgent mane ;
Each paſſing month renew the grateful toil,
Upturn with ſhining blade the fertile ſoil;
New feeds inſert, whoſe vegetable birth
May riſe ſucceſſive from the womb of earth.
So ſhall hibernal hours on frozen wing
View the green products of the breezy ſpring :
Admiring nymphs the genial banquet ſhare,
Smile on thy labours, and reward thy care.
But when three leaves the young Aſpirer ſhoots,
To other foils tranſplant the ſhorten'd roots ;
Where no tall branches form a vaulted glade,
Nor ivy'd tower projects a length of ſhade;
There in wide ranks thy verdant realms divide,
Parting each opening file a martial ftride.
There with charm'd words of ſome poetic ſpell
Call the blue Naiads from their ſecret cell;
From filver urns in lucid circles pour
Round each weak ſtem the falutary ſhower.
a
Pants thy young heart to graſp the laureld prize,
And ſwell thy Brocoli to gigantic fize?--
The Twins, 20th of May.
The Crab, 20th of June.
The Lion, 22d of July,
4 С
Soon

562
SECT. XIX. 8.
PRODUCTION
Soon as each head with youthful grace receives
The verdant curls of fix unfolding leaves ;
O, ſtill tranſplant them on each drizzly morn,
Oft as the moon relights her waining horn;
Till her bright veft the ſtar-clad Virgin trails,
Or corn-crown'd Autumn lifts his golden ſcales.
Then ply the ſhining hoe with artful toil,
Ere the grey night-froſt binds the ſtiffen'd ſoil;
And, as o'er heaven the riſing Scorpion crawls,
Surround the ſhuddering ſtems with earthen walls.
So ſhall each plant erect its leafy form,
Unſhook by Autumn's equinoxial ſtorm ;
And round and ſmooth, with ſilvery veins emboſs'd,
Repel the dew-drops, and evade the froſt.
Thus on the Stoic's round and poliſh'd brows
Her venom'd ſhafts in vain misfortune throws;
By virtue arm’d, he braves the tented field,
The innocuous arrows tinkling on his ſhield.
Hence when aſcendant rules the watery Star,
Or the celeſtial Fiſhes ſwim in air,
Thy guarded ſtalks ſhall lift their curled heads,
And fringed foliage ſhade thy ample beds,
Gem with bright emerald Winter's trackleſs ſnows,
Or bind with leafy wreaths his icy brows.
When leads the Spring amid her budding groves
The laughing graces, and the quiver'd loves;
Again the Bull ſhall ſhake his radiant hair
O'er the rich product of his early care;
The ftar-clad Virgin, 22d of Auguſt.
Golden fcales; 22d of September.
Scorpion, 22d of October. Evade the froſt. One advantage, which vege-
tables receive by repelling the water by the upper ſurfaces of their leaves, is, that it
may not incommode their reſpiration; but another is, that by not being thus moiſtened
they are lefs injured by froſt.
Watery Star, 19th January. Celeſtial Fiſhes, 17th February. The Bull, 19th April.
With

Secr. XIX. 8.
563
OF FLOWERS.
With hanging lip and longing eye ſhall move,
And Envy dwell in yon blue fields above.
Oft in each month, poetic Tighe! be thine
To diſh green Brocoli with ſavory chine;
Oft down thy tuneful throat be thine to cram
The ſnow-white cauliflower with fowl and ham!
-Nor envy thou, with ſuch rich viands bleft,
The pye of Perigord, or Swallow's neſt.
The pye of Perigord was made of the red-legged partridges before the French revolu-
tion ; and was ſold in London at the price of a guinea for each bird it contained.
Swallow's neſt. There is a ſpecies of ſwallow, that builds a neft on the banks of
the Nile and Ganges, which conſiſts of iſinglaſs ; which the bird collects from putrid
fiſh left on the ſands; and which is eſteemed a great delicacy, and enters the most
coſtly ſoups at the luxurious tables of the eaſt.
402
SECT.

564
Secr. XX. 1.
NATURAL CLASSES.
SECT. XX.
PLAN FOR DISPOSING PART OF THE VEGETABLE SYSTEM OF LINNEUS
INTO MORE NATURAL CLASSES AND ORDERS.
1. The claſſes of plants diſtinguiſhed by the proportion of ſituation of the ſtamina are
more natural than thoſe diſtinguiſhed by their numbers. Many Linnean claſſes
thus diſtinguiſhed. Many of the orders are natural claſifications. Uſe of natural
claffes. 2. The ſituation and proportion of the ſexual organs are leſs liable to ve-
riation than their numbers. Great variation in reſpeet to number of the ſtamina.
From luxuriant growth. Some ſpecies have but half the number. Others have
part of them without anthers.. The number of piſtilla varies in different ſpecies of
the ſame genus. Progreſs of nature to greater perfeétion. Of the claſs Syngeneſia.
3. Immutable parts diſcovered by reaſoning as well as by obſervation. Filaments
of Meadia unchangeable, and of hemerocalis fulva, nigello, collinfonia, Spartium.
4. Some natural orders might become claſſes. As the graſes, and the umbellatæ,
and ſtellatæ, Forms of the filaments, and of the anthers, as well as their fitua-
tions, leſs variable than their numbers. 5. Claſic characters. From ſhort and
long filaments. From their unequal beights. From their different infertions. From
their reſpective ſituations. From their adheſions to each other. Or to the corol,
or ſtyle. From their exiſtence in different flowers. From the connexion of the an-
thers, or from the forms of the filaments and anthers. 6. Uncertainty of the num-
ber of piſtilla. Their proportions and figures leſs variable. And would define
more natural orders. 7. Characters of orders from the length of the ſtyle. The
curvature of it. The attitudes of it. Diviſions of the ſtigma. Abſence of the ſtigma.
Adheſions of the ſtyle. 8. Concluſion.
1. OFTEN as I have admired the claſſification of vegetables by
the great Linneus deduced from their ſexual organs of reproduction,
ſome

Secr. XX. I. NATURAL CLASSES.
56.5
ſome of the claffes have appeared to me to be more excellent than
others, as they ſeemed to approach nearer to natural ones. On fur-
ther attention to this ſubject, I perceived that thoſe claſſes, which
I
were deduced from the proportions or ſituations of the ſtamina, or
which included the number of the ſtamina along with their propor-
tions and fituations, were more natural claſſes than thoſe, which were
diſtinguiſhed fimply by the number of them.
Thus the claſſes termed Dydynamia and Tetradynamia, which
are derived from the proportions and ſituations of the ſtamina as well
as their number, are wonderfully natural ; to which may be added
the claſſes Icofandria, and Polyandria, as their diagnoſtic character
conſiſts in the ſituation of the ftamina on the calyx or petals in the
former clafs, and on the receptacle in the latter, though the names
of theſe claſſes are not ſo happy, as they ſimply refer to their num-
bers, which are unfortunately very variable.
Some other of the Linnean claſſes are diſtinguiſhed by the fitua-
tion of the filaments, as the Monadelphia, Diadelphia, Polyadelphia,
and Gynandria ; all which approach towards natural claſſes ; and the
Syngeneſia, which is diſtinguiſhed by the adheſion of the anthers, is
a claſs beautifully natural, except the laſt order.
Many of the orders alſo in the fexual ſyſtem are natural claſſifica-
tions, as the graſſes in the claſs Triandria, the umbellated plants in
the claſs Pentandria, and perhaps the cruciform plants in the claſs
Tetandria ; with many amongſt thoſe which are termed natural
orders at the end of the Genera Plantarum ; all which might proba-
bly be diſcriminated by ſome ſituation, or proportion, or form, of
their reſpective ſtamina.
As the claffes deduced from the proportions or ſituations of the
ſtamina alone, or conjointly with their reſpective number, appear
thus to produce more natural diſtributions of vegetables, than thoſe
derived fimply from their number; it might have been more fortu-
nate for the ſcience of Botany, if the great author of the ſexual
ſyſtem

566
Sect. XX. 2.
NATURAL CLASSES.
ſyſtem had turned his mind to have claffed all of them from the pro-
portions, ſituations, and forms of the ſtamina alone, or from theſe
conjointly with their number, and to have diſtinguiſhed the orders
according to the proportions, ſituations, or forms of the piſtilla alone,
or conjointly with their numbers.
The great uſe of diftributing plants into natural claffes is not only
for the purpoſe of more readily diſtinguiſhing them from each other,
and diſcovering their names, but alſo for that of more readily detect-
ing the virtues or uſes of them in diet, medicine, or the arts; as for
the purpoſes of dying, tanning, architecture, fhip-building; which
has already been happily experienced in attending to the genera or
families of plants, which are all natural diſtributions of them, whence
the ſame virtues or qualities generally exiſt among all the ſpecies of
the ſame genus, though perhaps in different degrees.
2. But another great advalitage would probably occur from deduc-
ing the characters of the claſſes of vegetables from the ſituations,
proportions, or forms of the ſexual organs rather than from their
number; which is, that theſe criterions of the claſſes and orders
would be much leſs ſubject to variation.
The variation of the number of ftamina not only frequently oc-
curs from the too luxuriant growth of many cultivated flowers, or
by the duplicature or multiplication of their petals, or nectaries, which
is liable much to inconvenience the young botaniſt; but ſeveral of
the ſpecies of plants have but half the number of ſtamina, which
other ſpecies of the ſame genus poſſeſs. This occurs ſo frequently,
that the defect of number is expreſſed as an eſſential character of the
ſpecies in many inſtances. Thus the ceraſtium pentandrum, and ſper-
gula pentranda, diſtinguiſh thoſe ſpecies from the other plants of the
genus, which poſſeſs ten ſtamens; ſo tamarix floribus pentandris,
tamarix floribus decandris, falix floribus diandris, falix triandra, ſalix
pentandra, valeriana floribus monandris, valeriana floribus diandris,
verbena diandra.
I
So

SECT. XX. 2. NATURAL CLASSES.
567
So the vernal flowers of the corchorus filiquoſus have but four
ſtamina, but the autumnal ones have numerous ſtamina. The linum
flax of this country has but five perfect ſtamina, and five without an-
thers on their ſummits; whereas the linum luſitanicum, Portugal
flax, poffefſes ten complete ones. The verbena, vervain, of our coun-
try has four ſtamina, that of Sweden but two; the genus albuca,
bignonia catalpa, gratiola, and hemlock-leaved geranium, have only
half their filaments crowned with anthers; all which and many
others evince the uncertainty of depending on numbers alone for
diftinguiſhing the claſſes of plants.
Nor are the number of piſtilla more certain as a criterion of the
orders. Thus there is nigella pentagyna, and nigella decagyna;
hypericum floribus pentagynis, trigynis, and digynis, with innu-
merable other ſimilar inſtances, as mentioned in No. 6 of this Sec-
tion. Which evince, that great confuſion muſt be occafioned by a
reliance fimply on the number of the piſtilla for defining the orders
of plants.
I contend, that the number of the ſexual organs in flowers is more
liable to change by the influence of foil or climate, or by the pro-
greſs of time, than their fituations or proportions, or forms, and might
therefore probably be more advantageouſly employed in diſtinguiſhing
their claſſes and orders from each other, as well as in rendering them
more natural combinations.
This mutability or uncertainty of the number of the organs of re-
production belonging to individual flowers, would ſeem to ariſe from
an attempt of all organized beings towards greater perfection.
Whence as the ſucceſs of the proceſs of reproduction becomes more
certain from the greater perfection of the vegetable being, the organs
for the purpoſe of reproduction ſeem to become fewer. Whence
ſome flowers have loſt half the ſtamina, and in others the anthers
of thoſe ſtamina are yet only deficient, and in others the piſtilla are
deficient; all which in proceſs of time may gradually become leſs
numerous,

568
Secr. XX. 3.
NATURAL CLASSES.
numerous, or ſeparate themſelves from hermaphrodite flowers into
ſexual ones, as in the claſſes of monæcia and diæcia ; and all of
them finally, after a long proceſs of ages, become of the orders mo-
nandria and monogynia of thoſe claſſes ; whilſt new kinds of vege-
tables may begin a ſimilar progreſs from leſs to greater perfection.
So in animals, the leſs perfect ſeem to poſſeſs organs for a more nu-
merous reproduction, as fiſh and infects. Such would ſeem to be
the perpetual progreſs of all organized being from lefs to greater per-
fection exiſting from the beginning of time to the end of it ! a power
impreſſed on nature by the great Father of all.
Thus in the claſs fyngeneſia, the tendency of theſe vegetables
from more numerous to a more ſimple organization for the purpoſe of
reproduction is wonderfully conſpicuous. In the order polygamia
æqualis, all the florets are furniſhed with male and female organs.
In the order polygamia fuperflua, the florets in the centre have both
male and female organs, thoſe in the circumference have only fe-
male ones; and of thoſe ſome have loſt the corol of the floret. In
the order polygamia fruſtranea the florets in the centre poſſeſs both
male and female organs, but thoſe in the circumference have nei-
ther; though at the ſame time the corols of thoſe florets remain.
And laſtly, in the order polygamia neceffaria the central florets are
ſimply male florets, and thoſe in the circumference ſimply female
ones; and thus approach to the claſs of monoecia, having the male
and female organs in ſeparate florets; and may in proceſs of time
exiſt in ſeparate flowers, and afterwards in ſeparate plants, like the
two ſexes of the more perfect animals. Something ſimilar to this
ſeems already to have occurred in the plant phytolacca, of the claſs
decandria decagynia; which poſſeſſes one ſpecies with twenty males,
another with ten, another with only eight males and eight females,
and laſtly one of the claſs diccia, or two houſes.
3. In many flowers fome circumſtances of the ſituations or pro-
portions or forms of the filaments or anthers may be ſhewn, by rea-
4
foning

SECT. XX. 3.
569
NATURAL CLASSES.
foning as well as by obſervation, to be leſs mutable than others; as
the ſhortneſs of the filaments of dodecatheon meadia, cyclamen, fo-
lanum, borago, fuſchia, and others. As mentioned in Botanic Gar-
den, Vol. II. note on Meadia. Thus in the flower of meadia the
filaments are exceedingly ſhort compared to the ſtyle, and ſeem to
have been in that circumſtance immutable. Whence it became ne-
ceſſary, firſt to furniſh them with long anthers, which ſtand pointed
towards the diſtant ftigma apparently endeavouring to reach it. Se-
condly, it was neceſſary to bend the flower-ſtalks, when the corols
open into thoſe graceful curves, which conſtitute the uncommon
beauty both of this flower and of the fuſchia ; that the ſtigma by
hanging down immediately beneath the anthers might thus receive,
as it falls, the prolific farina. And that this was the evident deſign
of the curvature of the flower-ſtalk appears from its riſing again, and
becoming quite erect, as ſoon as the impregnation of the pericarp is
accompliſhed. Thirdly, as the flower thus becomes perpendicularly
pendent, it was neceſſary to reflect the petals for the purpoſe of ad-
mitting light and air to the ſexual organs.
We
may
reaſon from this ſtructure of the meadia, that all this
ap-
paratus of long erect anthers to approach the ftigma; of bending the
flower-ſtalk, that the ſexual organs might become pendulous; and
then of reflecting the petals to give light and air ; might have all
been ſpared, if the filaments alone could have grown as long as the
ſtyle; as occurs in moſt other flowers. And that therefore in theſe
flowers the filaments are the moſt unchangeable parts of them; and
that hence the comparative length of the filaments in reſpect to the
ſtyle would afford the moſt immutable mark of their efſential cha-
racter, or for the purpoſe of claſſification.
Another apparent inſtance of the great unchangeableneſs of the
length of the filaments exiſts in the hemerocallis fulva, tawny day-
lily, in which I obſerve the ſtyle is crooked, or bent into a zigzag,
about the middle of it, evidently for the purpoſe of ſhortening it,
that
3
4 D

670
NATURAL CLASSES. Secr. XX. 4:
that the anthers might approach the ftigma ; the ſtalk of the flower
not being ſo flexible as to allow it to become pendent, as in the he-
merocallis flava, or yellow day-lily.
In nigella, devil in the buſh, the ſtyles are very long compared
with the filaments, and bending down their ftigmas over the an-
thers in curves, give the flower a reſemblance to a regal crown;
which need not to have occurred, if the filaments could more eaſily
have been lengthened.
In collinfonia the two anthers ſtand widely diverging on ſhort
filaments, and the tall capillary ſtyle bends its ſtigma into contact
firſt with one of them, and afterwards with the other. In the ſpar-
tium ſcoparium, common broom, the long ſtyle bends round into a
circle to accommodate the ſtigma to the ſhort ſet of anthers, which
great curvature need not have exiſted, if the filaments could more
eafily have grown longer. Other inſtances of ſimilar ſtructure are
related in Sect. VII. 2. 2. of this work.
It is probable, that fimilar obſervations, and a conſequent reaſon-
ing on them, might be applied to many other kinds of flowers ſo as
to detect the moſt unchangeable parts of them: but great time, la-
bour, opportunity, and ingenuity, would be required to eſtabliſh
from them the moſt invariable and moſt natural claſſes of vege-
tation.
4. Many different proportions and ſituations and forms of the fila-
ments are enumerated in the Philoſophia Botanica of Linnæus ;
Some of which might poſſibly have become claſſical characters, if he
had turned his attention to them, and given them adapted names;
as he has done to thoſe claffes, which he has derived from the fitu.
ations of the ſexual organs, as didynamia, tetradynamia, fyngeneſia,
and others, which approach nearer to natural claſſes, and are ſubject
to leſs variation than the numerical ones.
Some of thoſe collections of plants, which Linnæus has termed
natural orders, and ſome of thoſe of Ray, and Tournefort, might
perhaps
ndare
4

Sect, XX. 4
571
NATURAL CLASSES.
perhaps have had names affixed to them, denoting the ſituations or
proportions or forms of their ſtamina, and have thus conſtituted na.
tural claſſes in the Linnæan ſyſtem. Thus for example the natural
order of graffes might perhaps have had a name denoting their
long capillary filaments. The natural order of graſſes is ſo conſpi-
cuous, as to have ſtruck all beholders; they conſtitute, it is ſaid,
nearly a fixth part of the vegetable kingdom, eſpecially in open
countries; the leaves are not eaſily broken by being trampled on,
but die in winter, becoming yellow and dry ; but what is wonder-
ful, they are ſaid to revive in the ſpring, and become green again.
This natural order of plants has been divided into cerealia and gra-
mina, corn and graſſes; which however only differ in reſpect to the
ſize of the ſeeds. It is much diſunited by the numerical diſtinctions
of the ſexual ſyſtem, as ſome graffes belong to the claſs monandria,
diandria, triandria, and hexandria ; and thoſe of the triandria, and
hexandria, are either hermaphrodite, or monecious, or polygamous
plants. Of theſe a very curious and extenſive table is given in the
Prælectiones in Ordin. Natur. a Gifeke Hamburg. 1792, p. 138.
A great part of the natural order of caryophyllei, in which the
number of the ſtamina is very variable, are obſerved by Mr. Milne
to have their filaments alternately attached to the claws of the petals
and to the receptacle, and might poſſibly have a claſſical denomina-
tion from that circumſtance. Botan. Dic. Art. Caryophyllei.
The five ſtamina of the umbellated plants in the claſs of pentan-
dria digynia, with five petals, two feeds, above; which are term-
ed umbellatæ in the natural orders of Linnæus; as they diverge from
each other, might perhaps be called five ſtarred, or cinque-pointed
ftamina from this ſituation. And in part the natural order of plants
termed ſtellatæ by Linnæus, as galium, and aſperula; which belong
to the claſs tetandria monogynia with one petal, two berries, above;
the four diverging ſtamina might perhaps be termed cruciform, as
they oppoſe each other. And thus theſe natural collections of vege-
4 D 2
tables
a

NATURAL CLASSES.
572
SECT. XX. s.
.
tables might acquire a claſſical denomination from the fituations
of their ſtamina, or perhaps from the form of their filaments or
anthers.
To theſe fituations and proportions of the ſtamina, with many
others, might be added the form of the filaments, as capillary, ftat,
wedgeform, ſpiral, awled; and alſo the forms and ſituations of the
anthers, as globular, oblong, arrowy, angular, horned. Which
may be ſeen in the Philoſophia Botanica of Linnæus, p. 65; or a
tranſlation of them in Miln's Botanical Dictionary, under the titles
of filament and anther. All which, I ſuppoſe, are much leſs vari-
able by ſoil or climate, than the numbers of their reſpective ſexual
organs, and would in the hands of an ingenious botaniſt form more
natural claſſifications.
5. Claſſical characters might perhaps be taken from the length of
the filaments compared to that of the ſtyle, with ſome other con-
comitant circumſtances; as firſt where they are ſomewhat ſhorter
than the ſtyle, as in the pendent bell-flowers of lily, fritillaria, cam-
panula. Secondly where the filaments are more than twice as ſhort
as the ſtyle, as in meadia, cyclamen, ſolanum, borago, fufchia.
Or thirdly where the filaments are more than twice as long as the
ſtyle, and in the natural order of graffes.
Secondly, the unequal heights of the filaments at the firſt opening
of the corol. In many flowers the inferior ſet of ſtamina riſe up to
the ſtigma, when the higher fet have diſcharged their pollen. To
theſe ſituations of the ſtamina may alſo be added their number, as in
the two very natural claſſes of Linnæus, the didynamia and the te-
tradynamia. One of theſe might be termed two higher than two;
the other four higher than two. To which might perhaps be added
a third claſs, of many higher than many; as fix above fix in lithrum
falicaria, five above five in lychnis.
Thirdly, the different inſertions of the filaments, as firſt on the
calyx, which principally diftinguiſhes the claſsicofandria of Lin-
6
næus,

Secr. XX. 5.
573
NATURAL CLASSES.
a
a
næus, and which thus approaches towards a natural claſs. Secondly
on the receptacle, which diſtinguiſhes the claſs polyandria of Lin-
næus, which alſo approaches toward a natural claſs. And thirdly,
the inſertion of the filaments alternately to the claws of the petals,
and to the receptacle; which diſtinguiſhes a part of the natural
order of the caryophyllei, in which the number of the ſtamina is
very various
Fourthly, the ſituation of the filaments in reſpect to each other;
-as firſt in the natural order of Linnæus termed ſtellatæ, or a part of
the tetrandria monogynia ; the diverging filaments oppoſe each other,
and might be termed cruciform, as in galium, afperula. Or ſe-
condly, where five diverging filaments aſſume the appearance of a
ftar, as in the natural order of umbellatæ, or a part of pentandria di-
gynia, and might have a name borrowed alſo from their number,
like five-ſtarred, or cinque-pointed, applied to the filaments, as men-
tioned above.
Fifthly, the adheſions of the filaments to each other at their baſe.
This has given names to three claſſes of the Linnæan ſyſtem, which
approach to natural ones, under the term of brotherhoods; as firſt,
where the filaments all adhere at their baſe, as in the claſs monadel-
phia ; ſecondly, where they adhere in two ſets, as in the claſs dia-
delphia ; and thirdly, where they adhere in many ſets, as in the
claſs polyadelphia.
Sixthly, the adheſions of the filaments to the corol, as where
they adhere more than half their length to the internal part of it,
as in many monopetalous flowers, as primula, auricula ; or where
the filament ariſes from the petal, or where the anthers adhere to the
margin of the petal, as in many of the natural order of ſcitamineæ,
as obſerved in the Prælect. in Ord. Natur, a Giſeke, p. 189.
Seventhly, where the filaments adhere to the ſtyle, as in the claſs
gynandria, which approaches to a natural one.
Eighthly, the ſituations of the ſtamina not in the ſame flowers
with

:574
NATURAL CLASSES. SECT. XX. 6.
with the piſtillum. This has alſo given names to three claſſes of the
Linnæan fyftem, monccia, diccia, polygamia.
Ninthly, the connexion of the anthers, which has given the name
to the claſs fyngeneſia, which excepting the laſt order, is a wonder-
fully extenſive and natural clafs.
To theſe varieties of ſituation, proportion, and adheſion, of the
filaments, may be added thoſe of the anthers on their ſummits;
which to an attentive obſerver may perhaps be as numerous as thoſe
of the filaments, and to theſe may again be added the various forms
of the filaments, as capillary, flat, wedgeform, ſpiral, feathered, &c.
and alſo the various forms of the anthers, as oblong, globular, ar-
rowy, angular, horned. All which are deſcribed in the Philoſophia
Botanica. And by an adoption of ſome of theſe ſeparately or in
conjunction for claſſical characters, I ſhould hope that new claſſifica-
tions might be diſcovered inſtead of thoſe, which are ſimply numeri-
cal. Which might be more natural ones, leſs ſubject to variation,
eaſier to be diſtinguiſhed from each other, and more ſimilar in their
good or bad qualities; and might thus add to the great beauty and
utility of the preſent wonderful arrangement of ſo many thouſand
vegetables in the Linnæan ſyſtem.
6. The ſame obſervations and mode of reaſoning are applicable to
the various orders of the ſexual fyftem. Which if the great Lini-
næus had fortunately deduced them from the proportions, ſituations,
or forms of the ſtyles and ſtigmas, the characteriſtic ſigns might
have been leſs liable to change by ſoil or climate, and many of the
orders have been more natural collections of vegetables, than thoſe
are, which he has derived fimply from their number,
The uncertainty of the number of piſtilla, and the confuſion,
which might be occaſioned by a reliance on it, was mentioned in
No. 2 of this fection; there is a nigella pentagyna, and a nigella
decagyna; there is an hypericum floribus pentagynis, trigynis,
and digynis; and in the whole order of fruſtraneous polygamy in
the

SCET. XX.7.
575
NATURAL CLASSES.
the claſs ſyngeneſia the florets of the ray are furniſhed with a ſtyle
and no ſtigma, as in the ſunflower.
The flowers of the polygonum, whoſe claſſical character is oc-
tandria, and its order trigynia, affords many inſtances of the uncer-
tainty of the number of the ſexual organs, both in reſpect to the
ſtamina and piſtilla. Thus the ſpecies 4, 5, 6, 7, poffefs but five.
ftamina in each; the ſpecies 8, 9, 10, have each of them fix
ſtamina, and the eleventh ſpecies has ſeven ſtamina. And laſtly the
fpecies 4, 5, 6, 8, 9, 11, 12, have each of them but two piſtilla,
and all the reſt three piſtilla.
From theſe and other innumerable inſtances there is reaſon to con-
clude, that the proportions, ſituations, and forms of the ſtyle and
ſtigma, to which might be added their number conjointly, would
have made eſſential characters for the orders, which would have been
leſs variable than thoſe derived only from the number of them, and
would have rendered them more natural collections.
7. The characters of the orders might be deduced firſt from the
length of the ſtyle compared with that of the filaments; as where
the ſtyle is more than twice as long as the filaments, as in meadia,
cyclamen, ſolanum, fuſchia. Secondly, where the ſtyle is about
,
one third longer than the filaments, as in lilium, fritillaria, cam--
panula, and many other bell-flowers. Thirdly, where the ſtyle is
very ſhort compared to the filaments, as in poppies.
2. The characters of the orders might be deduced from the cur-
vatures of the ſtyle. As firſt, where the ſtyle bends into a curve
over the anthers to bring the ftigma into contact with them, as in
nigella, devil in the buſh. Secondly, where the ſtyle bends into a
circle like a french-horn to accommodate the ftigma to two ſets of
ſtamina in ſucceſſion, firſt the lower, and then the higher, as in
ſpartium fcoparium, common broom. Thirdly, where the ſtyle is
crooked in the middle of it, making a kind of zigzag, to lower the
ſtigma
a

576
Secr. XX. 7.
NATURAL CLASSES.
a
ſtigma to the anthers beneath it, as in hemerocallis fulva, tawny
day-lily.
3. Characters might be deduced from the attitude of the ſtyle; as
where it is pendent, that the ſtigma may be accommodated to the
anthers above it, as in many bell-flowers. Secondly, where it is
inclined at a conſiderable angle to accommodate the ſtigma to the in-
clined anthers, as in epilobium, willow-herb, and glorioſa ſuperba.
Thirdly, where the ſtyle is erect, to adapt the ſtigma to the upright
anthers, as in many flowers.
4. Where the diviſions of the ſtigma expand, and bend down to-
ward the anthers beneath them, as in ſome kinds of dianthus, pink,
and in epilobium.
5. The total abſence of the ſtyle might mark an order.
6. The total abſence of the ſtigma, which is a characteriſtic mark
of the florets of the ray in the order fruſtraneous polygamy of the
claſs fyngeneſia.
7. Where the ſtyle adheres to the ſtamina, as in the natural order
of Linnæus termed calamariæ, as obſerved in Philof, Botanica, No.
102, on the Piftilla, p. 68.
8. Where the ſtyle ſupports the ſtamina as in the claſs gynan-
dria.
9. Where the ſtyle appears to exiſt both above and below the
germ, as in capparis, euphorbia.
10. The lateral adheſion of the ſtyle to the germ, as in one of
the natural orders of Linnæus, which he has termed fenticofæ, or
briers, which includes the roſe, raſpberry, ſtrawberry, agrimony, al-
chemilla, and many others, which might be named from the lateral
adheſion of the ſtyle to the germ, which Linnæus aſſerts to exiſt
both in the natural order above mentioned, and in the order Icofan-
dria polygyna. Philof. Botan. p. 67.
If to theſe proportions or ſituations of the ſtyle were added the va-
rieties

Sect. XX. 7. NATURAL CLASSES.
577
rieties of its figure, as cylindrical, angular, awled, capillary; and to
theſe were again added the diviſions of the ſtigma, as convolute, re-
volute, fix-parted, many-parted. And to theſe were again added
the various forms of the ftigma, as globular, egged, end-nicked,
cruciform, feathery, &c. which are enumerated in the Philoſophia
Botanica; there is great reaſon to believe, that characteriſtic marks
of all the orders of plants might be deduced and named from ſome of
thoſe circumſtances ſeparately or conjointly; which might diftin-
guiſh them from each other with greater eafe and certainty, and by
marks leſs variable by ſoil or climate, than by the number alone
and by rendering them more natural add to the beauty and utility of
the Linnæan ſyſtem.
Concluſion.
Nevertheleſs I am well aware of the great general inconvenience.
of altering fo extenſive a ſyſtem once eſtabliſhed, and am ſorry to ſee
ſome idle efforts to add the claſſes already deduced from ſituation or
proportion to thoſe, which are fimply numerical ; and thus rather to
deteriorate than to improve the preſent ſyſtem of the great maſter.
I profeſs myſelf incapable to execute the plan, which I have here
ſuggeſted, as it would require a moſt exact knowledge of the detail of
botany, as well as of the outline; would require many years of un-
remitted application, with every opportunity of viſiting botanic gar-
dens, or examining dry collections, and inſpecting prints and draw-
ings of vegetables; and would demand a genius, which few poſſeſs,
capable of reducing the complex and intricate to the ſimple and ex-
plicit.
But if the ſyſtem of the great Linnæus can ever be intrinſically
improved, I am perſuaded, that the plan here propoſed of uſing the
ſituations, proportions, or forms, with or without the numbers of
the
4 E

578
Sect. XX. 7
NATURAL CLASSES,
the ſexual organs, as criterions of the orders and claſſes, muſt lay the
foundation ; but that it muſt require a great architect to erect the
ſuperſtructure. And my principal deſign in adjoining this imperfect
ſketch at the end of this work was to warn thoſe botaniſts, who have.
began to interweave ſome of the Linnæan claſſes deduced from fitu-
ation or proportion of the ſexual organs into thoſe diſtinguiſhed fim-
ply by number, that they ſo far contribute to deteriority the great
ſyſtem, which they mean to amend.-At the fame time I much ap-
plaud, and beg leave to recommend to the attention of the public, the
ſuperb pictoreſque botanical coloured plates now publiſhing by Dr.
THORNTON, which I ſuppoſe have no equal.
ADDITIOTAL

ADDITIONAL NOTES.
1. To be inſerted before the laſt paragraph of Sect. IV. 2. 1. at p. 45,
line 22.
In the preſent year 1799, Auguſt 18, there was an uncommon
ſummer-food on the Derwent, which covered my garden above
three feet deep with muddy water. Many plants of the rheum hy-
bridum, mule rhubarb, which were tranſplanted in the ſpring, and
had not flowered, had their large pointed leaves covered with mud,
ſo as to render the green colour totally inviſible after the water ſub-
fided. They appeared ſtrong as before for a day or two, and then
every one withered and dropped down. The ſame happened to
the leaves of many other vegetables, and to eſpallier apple-trees, as
high as they were immerſed ; which was doubtleſs owing to their
reſpiration being precluded by the veil over them of a fine tenacious
mud. See Sect. VII. 2. 6.
a
2. To be inſerted in Sect. VII. 2. 6. at p. 115, after line 23.
The rheum hybridum, mule rhubarb, deſcribed in Murray's Syf-
tema Vegetabilium, -edition the fourteenth, I believe to be produced
between the palmated rhubarb, and the common rhubarb of our gar-
dens, or rheum rhaphonticum; as it appeared both in my garden
4 E 2
and

580
ADDITIONAL NOTES.
and my neighbours amongſt a mixture of thoſe two kinds of rhu-
barb, without being previouſly placed or fown there. The leaf is
very large and pointed, without being palmated, and is a week or
two forwarder in the ſpring than either of the other rhubarbs, and
the peeled ſtalks are aſſerted by connoiſſeurs in eating to make the
beſt poſſible of all tarts, much ſuperior to thoſe of the palmated or
raphontic rhubarb; and are ſo much more valuable as a luxury, as
a
they precede by a month the gooſeberry and early apple ; and may
be well propagated by dividing the roots, as they do not produce
feed in all ſummers. See Sect. IV. 2. I.
3. To be inſerted at the end of Sect. X. 4. 9. p. 207.
a
Mr. Ruckert planted two beans in pots of equal ſize filled with
garden-mould ; the one was watered almoſt daily with diſtilled wa-
ter, and the other with water impregnated with carbonic acid
gas,
in
the proportion of half a cubic inch to an ounce of water; and both
of them were expoſed to all the influence of the atmoſphere except
to the rain. The bean treated with the carbonic acid water appeared
above ground nine days ſooner than that moiſtened with diſtilled wa.
ter, and produced twenty-five beans; whereas the other pot pro-
duced only fifteen. The ſame experiment was made on ſtock-july
flowers, and other plants with equal ſucceſs. An. Chym. 1788.
J
4. To be inſerted at the end of Sect. X.7.7. p. 228. .
Beſides which the vitriolic acid abounding in many clays, when
brought into contact with mild calcareous earth, by the various opea
rations of agriculture, muſt unite with it, and ſet at liberty the car-
bonic acid either in a fluid form, or a gaſſeous form beneath the ſoil ;
4
which
a

ADDITIONAL NOTES.
581
which is known to be ſo friendly to vegetation, when applied to the
roots of plants; and at the ſame time a gypſum will be produced,
which is now alſo believed to be uſeful in agriculture.
Mr. Kirwan aſſerts, " That the gypſum uſed with ſucceſs in agri-
culture is of a fibrous texture; and that clay lands, he believes, to
be more improved by it than calcareous ones. The time of ſpread-
ing it is in February or March, and it is then to be thinly ſtrewed
on graſs-land at the rate of about eight buſhels to an acre; as more
he ſays would be hurtful. He further adds that the theory of its
effects is to be deduced from its extraordinary ſceptic power; as it is
found to accelerate putrefaction in a higher degree than any other
fubſtance, (Hiſtoire de Putrefaction, p. 36), whence it is not to be
ploughed in, but barely to be ſtrewed on the ſurface of the land in
the month of February, to convert the old graſs quickly into coal to
nouriſh the young growths.'
I have tranſcribed the above from Mr. Kirwan's Treatiſe on Mae-
nures, but am liable to doubt the experiments concerning bodies
promoting putrefaction; as the progreſs of that proceſs has generally
been only judged of by the odour; which may poſſibly be altered or
deſtroyed by many bodies, by their uniting with it without other
wife affecting the tendency to diſſolution. Add to this another cir-
cumſtance, ſhewing the uncertainty of theſe deductions, that ſome
of theſe antiſeptic materials, as ſea-falt, and lime, are ſaid to pro-
mote putrefaction, when uſed in ſmall quantities; and to ſuppreſs
it, when uſed in large ones..
s. To be inſerted in Se&t. XIII. 2. 2. at the end of the paragraph which
mentions Mr. Lawrence's letter to Mr. Bradley.
Another thing, which renders low ſituations leſs
for
proper gar-
dens, is, that I believe them to be much more liable to be, infeſted
by

582
ADDITIONAL NOTES.
9
;
by the aphis; as leaves of the nut-trees in my garden on the banks
of the Derwent are every year crowded with innumerable aphiſes
on their inferior ſurfaces, and yet I have ſeen few, if any of them, on
nut-trees in ſome higher fituations, which I happened to inſpect. Add
to this, that the great honey-dew, mentioned in Sect. XIV. 1.7.
was produced on a row of willows by the fide of water. This may
nevertheleſs be in part afcribed to ſome other local circumſtance; as
I this year obſerved numerous large black aphides round the ſtalks of
garden-beans on a clayey foil, which did not exiſt in my garden,
which may be called a carbonic, foil. Though on the peach and nec-
tarine trees, againſt the walls in my low garden, and on ſome plum-
trees, the aphides exiſt almoſt every year in ſuch deſtructive mul-
titudes as to prevent the fruit from ſucceeding, and thence to render
them not worth cultivation ; and to render the leaves of the nut-
trees leſs in ſize, and leſs prolific than other nut-trees on a more ele-
vated and clayey ſoil, with which I this year compared them.
Why the aphis ſhould be ſo much more numerous in moiſt fitua-
tions is a curious ſubject of inquiry, but is ſo fimilar to another ani-
mal fact, that they may illuſtrate each other. The cough and con-
ſequent conſumption of ſheep, which occurs annually in moiſt fitua-
tions, is owing to an inſect called a fleuk-worm, about the ſize and
ſhape of a child's finger-nail, which creeps up the gall-ducts from the
inteſtines, and preys upon the livers of ſheep; as may be ſeen in
moiſt ſeaſons in our ſhambles. This ſeems to occur from the bile
becoming too dilute from ſo much watery nouriſhment in thoſe ani-
mals, and that thence it does not poſſeſs ſufficient bitterneſs or acri-
mony to prevent the depredation of theſe inſects, as in drier ſeaſons.
On the ſame account I ſuſpect the juices of nut-trees and of willows
planted in very moiſt ſituations may be rendered too dilute ; but that
in higher ſituations they may poſſeſs ſufficient acrimony or bitterneſs
mixed with the fap-juice to prevent the depredations of the aphis.
See Sećt, XIV. 2. 8.
a
6. TO

ADDITIONAL NOTES.
583
6. To be inſerted at the end of Seat. X. 5.3.
Phoſphorated lime is ſaid to be found in the greateſt quantity in
wheat, where it contributes to the formation of the gluten, which
is thence not improperly denominated by ſome writers animal glu-
ten; which in rainy years has been obſerved by Witwer to be in
ſmaller quantity. Diſſert. II. p. 103. Hence the uſe of bone-aſhes as
a manure for wheat, as obſerved by Mr. Kirwan. Eflay on Manures;
P. 53
7. To be inſerted at the end of Seet. VI. 10.-
Beſides the various ſecretions above deſcribed Brugmanns is ſaid
by Humbolt to have ſhewn, that plants void an excrement like ani-
mals, which might be noxious to them, if retained ; that he put
the plant, lolium, ray-grafs, into a glaſs of water, and obſerved daily
at the extremities of the roots a ſmall drop of a viſcous material ;
which he detached and found to be renewed on the next day. But
this I ſuſpect to have been produced by the death and conſequent
decompoſition of the extremities of the roots in their unnatural fitua--
tion. Journ. de Phyſique Delametherie, T. IV. p. 388.
8. To be inſerted at the end of Sect. XIV. 4. 2.
In the Tranſactions of the American Philoſophical Society there
is a paper ſhewing, that the water-rats of that part of the country are
ſo liable to be affected with tape-worm, as is ſuppoſed much to dia
minifh their numbers. In this country many animals, as I believe
dogs, cats, and geefe, as well as the human ſpecies, are afflicted with:
this inteſtine enemy.. Could ſome of theſe diſeaſed American rats be:
imported
6.

584
ADDITIONAL NOTES.
imported into this country, and propagate their malady amongſt the
native rats of this climate ?
9. To be inſerted at the end of Seet. X. 7. 8. p. 228.
Having now ſpoken of carbon, of lime, and of clay, which with
Giliceous fand conſtitute the principal ingredients of fertile foils, ſome
rules may be required for diſtinguiſhing the goodneſs of ſoils by the
purchaſer, as well as by the poffeffor. For this purpoſe the chemical
analyſis would firſt preſent itſelf, as attempted by Fordyce, many
years ago, and lately by Giobert, Bergmen, Kirwan, and others.
M. Giobert found, that one pound of a fertile ſoil in the vicinity of
Turin contained of carbonic matter, which would burn and flame,
about twenty-five grains, of flinty fand about 4400 grains, of clay
about 600 grains, of lime about 400 grains, and laſtly, of water about
70 grains. The fame author found that one pound of ſome barren
ſoils was compoſed of filiceous earth about 3000 grains, of argillace-
ous earth about 600 grains, and of calcareous earth about 400 grains,
and I ſuppoſe without any carbonic matter.
Mr. Kirwan ingeniouſly obſerves, that the quantity of moiſture,
which ſome countries are more liable to than others, ſhould be nicely
attended to, at the ſame time that you eſtimate the fertility of land
by its analyſis, as moiſt climates or ſituations may require more fand
than drier ones; and therefore the ſame component parts of ſoil
would not be the'moſt fertile, on both the weſtern and eaſtern coaſts
of this iſland; as the former experiences more rain than the latter;
nor on the ſummit, declivity, and baſe of moſt mountains, which
differ in their degree of moiſture.
It appears from hence, that the chemical analyſis of ſoils is not yet
arrived at ſufficient accuracy to be depended upon with certainty to
diſcover their degrees of fertility. But as the carbonic part of ſoil
probably

Sect. XV. 2. 3.
401
OF FRUITS.
ftate; and conſequently the parts beneath will poffefs more of it;
and alſo becauſe theſe new buds are generated from a lower part of
the caudex, and will thence be a few years before they will acquire
that maturity, or puberty, which is neceſſary for the generation of
flower-buds, or the production of a ſexual or ſeminal progeny;
whence by ſtrangulating or decorticating the alternate branches of a
pear-tree they will bear for fix or eight years; and the other alternate
ones will become in the ſame time ſtrong and vigorous, ready to un-
dergo a ſimilar operation, when the former ceaſe to be of further uſe;
but
the fruit will become ſmaller in ſize, though in greater number,
and ripen earlier in the ſeaſon.
In the ſame manner new root-ſcions are ſaid to be produced by
ſtrangulating a branch of a root near the ſurface with a tight ſtring,
or by ſitting a root near the trunk, Evelyn's Sylva; as in theſe caſes
the aſcent of the ſap-juice is impeded, and the part below becomes
viviparous, or produces new leaf-buds for the reaſons mentioned in
the laſt paragraph ; as is frequently ſeen where the end of a branch
is lopped, or beneath the ſcar of the junction of an ingrafted ſcion.
On the ſame account it is not uncommon to ingraft with ſucceſs on
roots taken out of the ground, and afterwards replanted; as the ro-
binia on the root of acacia, and any other apples on the roots of the
ſuckers of bur-apple, or codling, mentioned in Sect. IX. 3. 5.
For the ſame reaſon the roots of ſome plants, which are otherwiſe
not eaſily propagated, will ſhoot up buds; if a part of them next the
ſtem of the plant be half cut through, or raiſed out of the ground,
and expoſed to the air ; as in pyramidal campanula, and geranium lo-
batum. And for the ſame reaſon the lateral branches of numerous
ſhrubs, as well as of herbaceous plants, will put forth roots, when
they are bent down into the ground, if they are previouſly wounded
to prevent the free ſupply of the vegetable nutriment in its uſual
courſe, as in laying carnations, dianthus.
A method of converting the viviparous branches of pear and apple
trees
3 F

402
PRODUCTION
SECT. XV. 2. 3.
trees into oviparous branches is deſcribed by Mr. Fitzgerald in the
Philofph. Tranfact. Vol. LII. and ſeems to be fuperior to the exſec-
tion of a cylinder of the bark above mentioned ; as the alburnum is
not left naked after the operation. In the month of Auguſt he made
a circular incifion round the principal branches of ſeveral pear-trees,
apple-trees, plum-trees, and cherry-trees, near the ſtems of each,
quite through the bark. About three or four inches higher he then
made another inciſion round the bark, and then a perpendicular one,
joining theſe two circular ones, and ſeparated the cylinder of bark
nicely from the wood, covering it, and the bare part of the wood,
from the air for about a quarter of an hour, when the wound began
to bleed. He then replaced the bark with great exactneſs, and bound
it round rather tightly with baſs, ſo as to cover the wound entirely,
and half an inch above and below the circumcifions.
In about a month the bark began to ſwell above and below the
bandages, he then unbound them, and found the parts quite healed.
He rebound them ſlightly with baſs, and let them remain ſo till the
beginning of the next ſummer, when he again took off the bandages,
and found them all healthy, and every one of them bore plentifully
that ſeaſon, though it was in general reckoned a ſcarce fruit year.
He treated two young pear-trees in this manner, which never had
yet had any bloom; on one of them he operated on the main arms,
and on ſeveral of the lefs branches from thoſe main arms; and on
only one of the main arms of the other. The firſt, he ſays, bore a
ſurprizing quantity of fruit in the next ſummer; and the circumciſed
arm of the other bore a moderate quantity; though no other part of
the tree had any appearance of bloom.
Mr. Fitzgerald afterwards took a cylinder of the bark from the
branches of two young apple trees about the ſame fize, as exactly as
he could by meaſure; and changing them, bound them each on the
other tree. The bark of one had a leaf-bud and two apples growing
on it; the barks of both of them healed perfectly, the leaf-bud put
forth
a
;

Sect. XV. 2.4.
403
OF FRUIT S.
forth leaves, and the apples remained on and ripened; and both the
branches bore ſo plentifully, that one broke with its load, and it
was neceſſary to prop the other.
The theory of the ſucceſs of theſe curious experiments confirms
that delivered above concerning the ſcars made by the junction of
ingrafted ſcions with the ſtocks; and it is probable, that three or
four circular inciſions through the bark on viviparous pear or apple
trees, or a ſpiral inciſion, as deſcribed in Sect. IX. 2. 8. might anſwer
the purpoſe without detracting and replacing the bark; as ſcars or
callous circles would be thus produced, which might render it more
difficult for the new caudexes of the embryon leaf-buds to be gene-
rated, or their parts united, and conſequently increaſe the number of
flower-buds.
Mr. Fitzgerald further obſerves, that he changed cylinders of the
bark with equal ſucceſs of nectarine and peach trees; and that the
branches thus operated upon were retarded in their general growth;
which coincides with the idea of repeatedly grafting one ſcion above
another on the apple-trees deſigned for dwarfs to be ſet in garden
pots, as deſcribed in No. 2. 2. of this Section.
4. The tranſplanting a viviparous fruit-tree, or deſtroying ſome of its
roots before Midſummer, or the confining its roots in a garden pot, or
on a floor of bricks beneath the ſoil, will induce it to become oviparous.
Mr. Knight, in his treatiſe on the Culture of the Apple and Pear,
p. 83, has the following paffage. “ In the garden culture of the
apple, where the trees are retained as dwarfs or eſpaliers, the more
vigorouſly growing kinds are often rendered unproductive by the ex-
ceſſive, though neceffary, uſe of the pruning knife. I have always
ſucceeded in making trees of this kind fruitful by digging them up,
and replacing them with ſome freſh mould in the fame ſituation.
The too great luxuriance of growth is checked, and a diſpoſition to
bear is in conſequence brought on.” The ſame obſervation was made
by Mr. Lawrence, who took up trees which were too vigorous ;
that
3 F 2

404
SECT. XV. 2.4.
PRODUCTION
3
that is, which produced viviparous buds inſtead of oviparous ones,
and replanted them to render them fruitful. Art of Gardening. Lond.
1723
In tranſplanting trees for any purpoſe it may be obſerved, that
they ſhould not be replanted deep in the ſoil, fince the moſt nutri-
tive or falubrious parts of the earth are thoſe within the reach of the
ſun's warmth, of the deſcending moiſture, and of the oxygen of the
atmoſphere. And as the root-fibres of trees, like thoſe of ſeeds, al-
ways grow towards the moiſteſt part of the ſoil, as the young ſhoots
and leaves grow towards the pureſt air and brighteſt light; it fol-
lows, that the root-fibres ſeldom riſe higher in the ground than they
were originally ſet, and ſeldom elongate themſelves even perfectly
horizontally; ſo that when a fruit-tree is planted too deep in the
earth, it ſeldom grows with healthy vigour, either in reſpect to its
leaf-buds or its flower-buds.
This curious effect cannot be produced by generally debilitating
the tree from its want of due nouriſhment ; becauſe it is ſaid to fuc-
ceed beſt in very good foil, or by the addition of new garden mould,
as before directed ; but by rendering more difficult the production
of radicles from the caudexes of the embryon leaf-buds; which de-
fcend to the fineſt ramifications of the old roots, and elongate them-
ſelves beyond the extremities of their ultimate fibrils ; a great num-
ber of which roots being torn off by tranſplantation, or compreſſed
in a garden pot, the production or progreſs of many of the new radi-
cles muſt be impeded or prevented ; and the numerous caudexes of
new leaf-buds be in conſequence formed with greater difficulty,
whence an increaſed tendency to generate flower-buds.
For the ſame reaſon if beans, vicia faba, which are but a few
inches high, be tranſplanted; they do not become ſo tall, but they
flower and ripen their feeds ſooner; becauſe they can not ſo eaſily
generate new leaf-buds. The ſame occurs in frequently tranſplant-
ing brocoli, braſſica; the plant does not grow ſo tall, but has earlier
flowers,
ފް

Sect. XV. 2. 4.
405
OF FRUIT S.
a
a
a
flowers, and in greater number ; and it is hence better to pluck them
up, than to dig them up, for the purpoſe of replanting them; as by
that means more of the root-fibres are torn off, and the plants be-
come almoſt totally oviparous.
It is well known, that the veſſels of animal bodies are leſs liable to
bleed, when they are torn afunder, than when they are cut with a
ſharp inſtrument; as their diameters are contracted, or their internal
ſurfaces brought into contact with each other, in the act of extend-
ing them, till they break. Thus if the navel-ſtrings of new born ani-
mals are cut inſtead of torn, they are liable to bleed to death; and
there is a remarkable caſe of a miller's ſervant, who had his arm and
ſhoulder bone, or ſcapula, torn off in a windmill without much loſs
of blood. This is mentioned to ſhew, that it may alſo be better to tear
up roots, which are tranſplanted for this purpoſe, than to dig them
up; as they may thence effuſe leſs vegetable blood, and in conſe-
quence be leſs weakened by the operation.
In tranſplanting ſtrawberries many of the roots being torn off, fewer
leaf-buds, and conſequent wires, are produced from the difficulty,
which their embryon caudexes find in producing new radicles over
the old ones to ſupply nutriment to the wires, till they bend down
and protrude roots into the ground at their other extremities; whence
a greater number of flower-buds are generated'; on this account the
roots of ſtrawberries ſhould generally be tranſplanted, or new ones-
from the wires ſhould be cultivated, every third or fourth year; to pre-
vent the too luxuriant growth of their wires; or a ſimilar difficulty,
of producing wires or leaf-buds may be effected by crowding the
roots of ſtrawberries together, as ſome gardeners recommend; but:
I ſuppoſe by theſe means the fruit may become ſmaller from ſcarcity
of nutriment, though more numerous.
A floor of bricks, or of ſtone, extended about two feet deep be-
neath the roots of wall trees, has been practiſed in ſome gardens from
an idea, that the roots-ſhot themſelves too deep into ſome unwhole-
fome:

406
Sect. XV. 2. 5.
PRODUCTION
;
ſome ſtratum of earth; and it has been obſerved, that the trees be-
came better fruit-bearers. In ſome ſituations it is poſſible, this might
be the cauſe of the new prolific property of the trees; but I ſuſpect
it has occurred generally from the difficulty oppoſed to the number
and elongation of the root-fibres, and conſequently to the generation
of the new caudexes of the embryon leaf-buds; whence a greater
production of flower-buds enſued.
In fimilar manner it is aſſerted by one of the Linnean ſchool in the
Amanitates Academicæ, that ſome bulbous rooted plants, which
ſeldom produce ſeeds in Sweden, will produce prolific feeds, if their
roots be confined in a garden pot, till they crowd each other; as
thoſe of the lily of the valley, convallaria. And that the orchis will
bear prolific ſeeds, if the new root early in the ſeaſon be ſevered from
the old one, which has put up the flower-ſtem. This muſt occur
in the former caſe from the difficulty, which the plants find to ge-
nerate new offsets at their roots, which are their viviparous progeny;
and in the latter cafe from the new offset being deſtroyed ; whence
in both ſituations more nutriment is expended on the flower.
On the ſame account it is probable, that confining the roots of cu-
cumbers and melons in ſmall garden pots would ſtop the too lux-
uriant growth of their leaf-buds, and render them ſooner oviparous,
if care was taken to ſupply them with water more frequently, and
with ſufficient nutriment by mixing with the water ſome of the car-
bonic black fluid, which has drained from a manure heap.
5. If the central viviparous branches of a plant be cut away or ſhort-
ened, the lateral ones will ſooner or more completely become oviparous.
1. There are many very ſmall buds on the lower parts of large
branches, which do not ſeem to grow to maturity, and in confequence
produce neither new leaf-buds nor new flower-buds. There are other
lateral ſhoots on many trees, which only puſh out a few inches, and
are called ſpurs, and which bear fruit the ſucceeding ſummer at their
extremities. In many other plants the lateral branches are oviparous,
6
except
)
a

SECT. XV. 2.5.
407
OF FRUIT S.
W
except at the extremity, which is terminated with a viviparous bud;
while the central branches continue long to generate only a vivipar-
ous progeny, as in vines and melons.
The firſt of theſe, or the unprolific exiſtence of the buds at the
bottom of large branches, may be owing in part to their feebler ef-
forts of pullulation from the want of ſufficient funſhine and venti-
lation ; and alſo in part, like the ſpurs, and other lateral branches, to
the difficulty they encounter in producing the embryon caudexes of
new leaf-buds along the trunk; which is already occupied by thoſe
of the more vigorous vegetation of the central branches, which poſ-
ſeſs a greater ſhare of ſunſhine and ventilation.
But the principal cauſe, which renders the ſpurs and lateral branches
oviparous, reſults from the reſiſtance the embryon caudexes of leaf-
buds experience by the curvature of the lateral branch, where it joins
the trunk, and the conſequent coarctation of its veſſels, added to the
difficulty every lateral bud has to encounter from its own curvature
at its exit from the parent twig; on which laſt account the central
bud a: the extremity of an oviparous branch is generally viviparous,
becauſe it has not any curvature at its exit. All this correſponds with
the fact above deſcribed, that when the viviparous arms of wall-trees
are bent down to the horizon, they become oviparous. See No.2. 1.
of this Section.
2. What then happens in all theſe ſituations when the central parts
are 'cut away or ſhortened? Firſt the dwarf buds at the bottom of
theſe large viviparous branches, which are in part cut away, will find
more room to puſh down the embryon caudexes of new leaf-buds ;-
and will produce a viviparous progeny; and thoſe at the bottom of
oviparous branches, which are ſhortened by cutting off their vivipar-
ous extremities, will alſo now pullulate, and produce flower-buds for
the ſucceeding year, owing to the derivation of fome of that nouriſh-
ment to them, which would otherwiſe have been expended on the
fummit-bud. Secondly, the ſpurs will generate an oviparous pro-
geny,

408
PRODUCTION
SECT. XV. 2. 5.
geny, but will acquire more nutriment, becauſe all the veſſels of
plants inofculate, as mentioned in Sect. IX. 2. 10. and will thence
produce larger fruit, and more certainly ripen it. Thirdly, the other
lateral branches will receive more nouriſhment, and become more
vertical, and will thence find leſs oppoſition to the production of the
caudexes, both of their flower-buds and leaf-buds; either of which
may become ſtronger or more numerous according to the greater or
lefs inclination of the branches to the horizon; and both of them
may be more vigorous properly ſpeaking ; that is, they may become
larger leaf-buds, or larger flower-buds, than others of the ſame tree.
3. Thus in the management of MELONS, which would grow into
branches much too extenſive for the artificial glaſs-frames of our
climate, and would not have time to ripen their later fruit in our ſhort
fummers; it is neceffary firſt to check the vigour, properly ſo ſpeak-
ing, of the whole plant. This is done by waſhing the feed from the
ripe fruit, which ſhould naturally contribute to nouriſh it; and by
keeping the ſeed four or five years, that the mucilaginous nutriment
depoſited in the cotyledons may alſo be in ſome degree impaired; it
is alſo probable, that confining the roots of melons and cucumbers
in garden-pots, if they were well ſupplied with nutriment, warmth,
and water, might be advantageous for this purpoſe. wobn16
Secondly, as ſoon as the leaf appears an inch in diameter, experienc-
ed gardeners pick out the central bud, which cauſes an oviparous,
tho gh a more vigorous, lateral ſhoot; which therefore ſooner bears
fruit, and that of a larger kind; as it acquires more nouriſhment
from the deſtruction of the central one.
And as theſe lateral branches are liable to produce other viviparous
ſhoots at their extremities, after they have generated lateral flower-
buds, it again becomes neceſſary to pinch off the viviparous extre-
mities of them, not only to accommodate them to the ſize of the
glaſs-frame, but alſo to ſupply them with more nutriment, which
would otherwiſe have been expended on the viviparous ſummit.
The

ADDITIONAL NOTES.
593
of alluvial limeſtone, like Ketton limeſtone, which they do not burn
for ſale, over the bed of the calcareous limeſtone, which they get
from beneath the former, and calcine for ſale. It is probable, that
the ſuperior bed may contain magneſia, which has rendered it not ſo
uſeful in agriculture.
It is more probable, that alluvial limeſtone has acquired its mixture
of magneſia from the ſea-water; as magneſia in its uncalcined ſtate
will precipitate lime from water, as obſerved by Dr. Alfton ; who
thence propoſes to render water pure and potable, which has been
long kept at ſea free from putridity by having lime mixed with it, by
precipitating the lime by the addition of mild magneſia; which is a
ſubject now perhaps worthy the attention of the court of admiralty,
ſince magneſian limeſtone appears to be ſo plentifully diffuſed over
the earth. See Dr. Black's Exper. on Magneſia in the Effay Philoſ.
and Literary, Edinb.
The lime from Breedon is magneſian, that from Ticknal (which
is fold) is calcareous lime I believe ; and ſome farmers in the vicinity
of Derby aſſert, that two loads of Breedon lime will go as far, that
is will apparently do as much ſervice to their land as three loads of
Ticknal lime. Breedon lime, I am alſo informed, is preferred in ar-
chitecture, and is ſaid to go further in making mortar; which I ſup-
poſe means, that it requires more ſand to be mixed with it. Mr.
Marſhall in his account of the agriculture of the Midland counties
ſpeaks of lime made at Breedon near Derby as deſtructive to vegeta-
bles when uſed in large quantities. And in Nottinghamſhire it is af-
ſerted, that the lime from Critch in Derbyſhire is ſo mild, that thiſtles
and graſs ſpring up through the edges of large heaps of it, when laid
in the fields. Dr. Fenwick of Newcaſtle obferves, that the farmers
in that country divide lime into hot and mild; which Mr. Tennant
believes to mean magneſian and calcareous lime.
By experiments which were made by Mr.Tennant by ſowing ſeeds
of colewort on various mixtures of calcined magneſia with foil, and
of
4. G

594
ADDITIONAL NOTES.
of calcareous lime with ſoil, he found that thirty or forty grains of
lime did not retard the growth of ſeeds more than three or four of
calcined magneſia; from hence what can we conclude? but that, as
they both injure vegetation in large quantities, they may both affift
vegetation in ſmall ones ? and that this is more probable, as the far-
mers believe, that they find both of them uſeful, though in different
quantities; and as the magneſia would form Epſom ſalt, if it meets
with vitriolic acid, which Dr. Home found from his experiments to
be friendly to vegetation, when uſed in very ſmall quantities. More
accurate obſervations and more numerous experiments on this ſub-
ject are required, which this important diſcovery of Mr. Tennant's
will I hope foon occaſion.
13. To be inſerted at p. 286, l. 16, at the end of No. 2 of Sect. XII.
a
Another method has been attempted by ſome for the purpoſe of
ameliorating clayey lands, which were unfit to be turned up deeper
than they had been accuſtomed to be ploughed, on account of their
acidity or tenacity being very injurious to vegetation ; as the white
faggar clays over many coal countries ; or ſome very tenacious red
clays, which may contain a vitriol of iron; not an oxyde, or oxy-
genated calx of it.
con our country
The method I allude to confifts in firſt turning over a ridge of
earth, as in common ploughing; and then with a plough, made on
purpoſe, to penetrate ſome inches deeper into the clay fo injurious to
vegetation ; this plough is to be ſo contrived, as to raiſe up the
clayey ſoil about the breadth of the furrow recently made, and three
or four inches deep, or more ; but not to turn it over, ſo that it may
ſtill lie under the fertile ſoil, which is to be turned over it with the
common plough, in making the adjoining furrow. So that this
plough

ADDITIONAL NOTES.
595
plough is only to paſs under the ſoil, and thus looſen it, and mix it
with atmoſpheric air without turning it over.
.
By this maneuvre the clay a few inches deep beneath the fertile
foil becomes broken in its texture, and obtains ſome air intercepted in
its pores; from the former circumſtance it may contribute to retain
the vernal ſhowers, which would otherwiſe run off over the clayey
ſurface beneath the more fertile one, and might thus in drier ſeaſons
prevent the upper ſurface from being ſo much indurated, and might
gradually become leſs injurious by the frequent admixture of atmo-
ſpheric air, and at length even ſalubrious to the roots of vegetables.
4 G 2
APPENDIX

SODIO 102
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Cort
2 bocor
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2010
om
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തിരി
2dira att den
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sanoa
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in novo sjaol 16 C

TOYOTE
APPENDIX.
bomotor
IMPROVEMENT OF THE DRILL PLOUGH.
10 siis
The firft experiment I tried to improve this valuable machine was.
that mentioned in Sect. XIL 5. of this work, by enlarging the axis
of Mr. Tull's feed-box into a wheel of fixteen inches diameter, with
excavations in the rim to raiſe portions of the corn above the ſurface
of that in the ſeed-box. But I found to my ſurpriſe the friction of
the corn to be ſo much greater than expected, when fix fuch large
wheels were immerſed in it, that an additional hopper became ne-
ceſſary to deliver the ſeed flowly into the ſeed-box, as in Mr. Cook's
drill plough ; which, as it would add much to the intricacy and ex-
pence of the machinery, and to the inaccuracy of the quantity of feed
delivered, occafioned me to relinquiſh that idea, and after many de-
ſigns and many experiments to conſtruct the following machine,
which I believe to be more fimple, and conſequently leſs expenſive
to conſtruct, and leſs liable to be out of order, and to deliver the ſeeds-
of all kinds with greater accuracy than any drill plough at preſent in
uſe; and that it poffeffes every other advantage that they can boaſt.
The ſcale of the three following plates is half an inch to ten inches
Conſtruction of the Carriage Part.
tao
Plate X. Fig. 1. a a, are the ſhafts for the horfe, which are fixed
to the center of the axle-tree by a ſimple univerſal joint at %, whence,
if

598
IMPROVEMENT OF
a
if the horſe ſwerve from a ſtraight line, or is purpoſely made to paſs
obliquely to avoid treading on the rows of corn in hoeing; the per-
fon, who guides the plough behind, may keep the coulters of the
plough or hoe in any line he pleaſes; which is thus performed with
much ſimpler mechaniſm, than that uſed in Mr. Cook's patent
plough for the fame purpoſe, which has many joints like a parallel
rule.
bb are the horns or ſhafts behind, for the perſon who guides the
drill coulters or hoes; they are fixed to the axle-tree before, and
have a croſs piece about fix inches from it at g g for the purpoſe of
ſupporting the ſeed-box deſcribed below. Behind this about a foot
diſtant from it is another croſs piece at c.c, called the coulter-beam,
which is fifty inches long, fix inches wide, and two inches thick ;
it is perforated with two ſets of ſquare holes, fix in each ſet, to re-
ceive the coulters in drill-ploughing, and the hoes in horſe-hoeing.
The fix light ſquare holes are nine inches from each other, and are
to receive the coulters or hoes in the cultivation of wheat, the rows
of which are deſigned to be nine inches from each other, and the fix
dark ſquare holes are placed ſeven inches from each other to receive
the coulters or hoes for the cultivation of barley, the rows of which
are deſigned to be but ſeven inches diſtant from each other.
Beſides theſe there are fix round holes through this coulter-beam
at one part of it, and fix iron circular ſtaples fixed into the edge of
the other part of it; theſe are to receive the ends of the tin Alues,
which croſs each other, and convey the feed from the bottom of the
feed-box into the drills or furrows, when the coulters are diſpoſed
the ſquare perforations before them.pl
Theſe coulters or hoes the perſon, who guides the machine, can
raiſe out of the ground in turning at the ends of the lands, or in paff-
ing to or from the field, and can ſuſpend them ſo raiſed on the iron
ſprings dd, which at the ſame time fo fixes the ſhafts to the axle-
tree

THE DRILL PLOUGH.
599
tree that the wheels will then follow in the ſame line with the
horſe.
ee are wheels of four feet in diameter, the nave of one of which
has on it a caſt-iron wheel at ff, for the purpoſe of turning the axis
of the feed-box, which has a ſimilar wheel of one fourth its diame-
ter; whence the axis of the feed-box revolves four times to one re-
volution of the wheel.
a
و
Conſtruction of the feed-box. Plate XI. Fig. 2.
Sao
This conſiſts of boards about an inch in thickneſs, is forty-eight
inches long within, twelve inches deep, twelve inches wide at top,
and fix inches wide at bottom; it is divided into fix cells, in which
the corn is to be put, as repreſented in Plate XI. Fig. 2. and ſhould
alſo have a cover with hinges to keep out the rain, and is to be plac-
ed in part over, and in part before, the axle-tree of the carriage, at
gg: Plate X. Fig. 1.
Beneath the bottom of the ſeed-box paſſes a wooden cylinder, at
bh, Plate XI. Fig. 2. with excavations in its periphery to receive the
grain from the ſix cells of the ſeed-box, l m n o p q, and to deliver it
into the fix oblique flues ii, which are made of tin, and croſs each
other, as repreſented in the plate. The uſe of the ſeed-flues thus in-
terſecting each other is to increaſe the length of the inclined ſurface,
on which the ſeed deſcends, that if fix or eight grains be delivered
together, they might ſo ſeparate by their friction in deſcending, as
not to be fown together in one point, which might be liable to pro-
duce tuffocks of corn.
As theſe ſeed-flues croſs each other, before they paſs through the
coulter-beam at cc, Plate X. Fig. 1. it was neceſſary to make three
of the round holes of the coulter-beam at one end backwarder than
thoſe at the other end; and on that account to uſe iron ftaples or
୨
rings

600
IMPROVEMENT OF
rings at one end inſtead of perforations, as at ww, Plate X. Fig. 1.
Theſe tin flues deliver the ſeed at the time of ſowing into the ſmall
furrows or drills, which are made by the coulters before them.
Theſe feed-flues have a joint at % %, where one part of the tin
tubes ſlides into the other part, and they by theſe means can be occa-
fionally ſhortened or lengthened to accomodate them to the coulters,
when placed at ſeven inches diſtance for fowing barley, or at nine for
ſowing wheat.
At the bottom of this feed-box are fix holes, one in each cell, to
deliver the corn into the excavations of the cylinder, which revolves
beneath them. Theſe holes are furniſhed on the deſcending ſide, as
the cylinder revolves, with a ſtrong bruſh of briſtles about three
fourths of an inch long, which preſs hard on the tin cylinder. On
the afcending ſide of the revolving cylinder the holes at the bottom
of the feed-box are furniſhed with a piece of ſtrong ſhoe-ſoal leather,
which rubs upon the aſcending ſide of the cylinder. By theſe means
the corn, whether beans or wheat, is nicely delivered, as the axis re-
volves, without any of them being cut or bruiſed.
Conſtruction of the iron axis and wooden cylinder beneath the ſeed-box.
Plate XI. Fig. 3.
0
An iron bar is firſt made about four feet fix inches in length, and
an inch ſquare, which ought to weigh about fifteen pounds; this bar
is covered with wood, ſo as to make a cylinder four feet long, and
two inches in diameter, as at k k, Plate XI. Fig. 3. The uſe of the
iron bar in the centre of the wood is to prevent it from warping,
which is a matter of great conſequence.
This wooden cylinder paſſes beneath the bottom of the feed-box,
and has a caſt-iron cog-wheel at one end of its axis, as at rr, which
is one fourth of the diameter of the correſpondent caſt-iron wheel,
a
a
which

THE DRILL PLOUGH.
601
.
which is fixed on the nave of the carriage-wheel, as in Plate X.
Fig. 1. ff, ſo that the axis of the feed-box revolves four times dur-
ing every revolution of the wheels of the carriage.
In the periphery of this wooden cylinder are excavated four lines
of holes, fix in each line, as at n n nnnn. A ſecond line of excava-
tions is made oppoſite to theſe on the other ſide of the cylinder, and
two other lines of excavations between theſe ; ſo that there are in all
twenty-four excavations in the wooden part of this axis beneath the
feed-box, which excavations receive the corn from the ſeed-cells, as
the axis revolves, and deliver it into the flues ſhewn in Plate XI.
Fig. 2. ooii, not unſimilar to the original deſigu of the ingenious
Mr. Tull.
alioggeadigai sot si al d 1
The ſize of theſe excavations in the wooden cylinder to receive the
feed are an inch long, half an inch wide, and three eighths of an
inch deep; which are too large for any feeds at preſent employed in
large quantities except beans, but have a method to contract them to
any dimenſions required, by moving the tin cylinder over the wooden
one, as explained below in Plate XI. Fig. 4.
201
lo que
iubit
a
1750
Conſtruction of the Tin-cylinder. Plate XI. do
Lexu endt vion. Tous
A B at Fig. 4. repreſents a cylinder of tin an inch longer within
than the wooden cylinder on the iron axis at Fig. 3. and is of two
inches diameter within, fo as exactly to receive the wooden cylinder,
which may ſlide about an inch backwards or forwards within it. CD
are two ſquare tin ſockets fixed on the ends of the tin cylinder to fit
on the ſquare part of the iron axis, which paſſes through the wooden
cylinder at ll, Fig. 3. on which they flide one inch backwards or
forwards.otod
Olio su Daily aboov
The following directions in making the holes in this tic cylinder,
and
on which
4 H

602
IMPROVEMENT OF
and thoſe in the wooden cylinder, which are to correſpond with
them, muſt be nicely attended to.
Firſt, when the tin-cylinder is foldered longitudinally, and one end
of it ſoldered on, as at A, fix holes through it muſt be made longi-
tudinally on four oppoſite fides of it, each hole muſt be exactly half
an inch wide, and five eighths of an inch long, the length to be parallel
to the length of the cylinder.
The centre of the firſt of theſe holes muſt be five inches diſtant
from the cloſed end A, the centre of the ſecond hole muſt be eight
inches diſtant from the centre of the firſt, and fo on till fix holes are
made longitudinally along the cylinder. Then another ſuch line of
fix ſimilar holes is to be made on the oppoſite ſide of the cylinder, and
then two other ſuch lines between the former, in all twenty-four;
and the ſize of all theſe holes muſt be nicely obſerved, as well as their
diſtances.
Secondly. The wooden cylinder fixed on the axis is now to be in-
troduced into the tin cylinder, but not quite to the end of it, but ſo
as to leave exactly one inch of void ſpace at the cloſed end A, and
then the ſize of all theſe apertures through the tin cylinder, each of
which is exactly half an inch wide, and five eighths of an inch long,
are to be nicely marked with a fine point on the wooden cylinder,
which muſt not previouſly have any excavations made in it.
Thirdly. The twenty-four holes thus marked on the wooden cy-
linder are now to be excavated exactly three eighths of an inch deep,
but with an addition alſo of three eighths of an inch at that end of
every one of them which is next to A ; ſo that, when the wooden
cylinder is again replaced in the tin cylinder as before, with one inch
of void ſpace at the cloſed extremity of it, the excavations in the
wooden cylinder will be three eights of an inch longer, than the per-
forations in the tin cylinder over them. Theſe excavations in the
wooden cylinder muſt alſo be rather narrower at the bottom than at
coobga
the

THE DRILL PLOUGH.
603
a
a
the top, to prevent with certainty any of the grain from ſticking in
them, as they revolve.
Fourthly. A ſcrew of iron about three inches long, with a ſquare
head to receive a ſcrew-driver, is to paſs through the end A of the
tin cylinder on one ſide of the axis, as at x, Fig. 4. The ſcrew part
of this is to lie in a hollow groove of the wooden cylinder, and to be
received into a nut, or female ſcrew, which is fixed to the wooden
cylinder. The head part of the ſcrew, which paſſes through the end
A of the tin cylinder at x, muſt have a ſhoulder within the tin cy-
linder, that it may not come forwards through the end of it; and a
braſs ring muſt be put over the ſquare end of the fcrew on the out-
ſide of the tin cylinder, with a pin through that ſquare end of the
ſcrew to hold on the braſs ring.
Thus when the ſquare head of the ſcrew is turned by a ſcrew-
driver, it gradually moves the tin cylinder backwards and forwards
one inch on the wooden one, ſo as either to preſs the end A of the
tin cylinder into contact with the end of the wooden cylinder within
it, or to remove it to the diſtance of one inch from it, and leave a
void ſpace at the end A.
Fifthly. The ends of all the holes of the tin cylinder, which are
next to the end A of it, are now to be enlarged, by flitting the tin
three eighths of an inch towards A, on each ſide of the hole; and
then that part of the tin, included between theſe two flits, which will
be half an inch wide, and three eighths of an inch lengthways in re-
ſpect to the cylinder, is not to be cut out, but to be bent down into
the excavations of the wooden cylinder beneath, ſo as to lie againſt
that end of the excavation which is next to A.
But theſe projecting bits of tin, before they are bent down into
the excavations of the wooden cylinder, muſt be filed a little leſs at
the projecting end, which is to be bent down, than at the other end;
as the excavations of the wooden cylinder are to be rather narrower
4 H 2
at

604
IMPROVEMENT OF
на нас
at the bottom than at the top, and theſe pieces of tin, when bent
down, muſt exactly fit them.
Laſtly. When all theſe holes through the tin-cylinder are thus en
larged, and the bits of tin filed rather narrower at their projecting
ends, and then bent down into the excavations of the wooden cylin-
der, the other end of the tin eylinder with its ſquare focket may be
foldered on.
And now when the end of the tin cylinder at A is preſſed forwards
upon the wooden cylinder towards B, by turning the ſcrew at x
above deſcribed ; every excavation of the wooden cylinder will be
gradually lefſened, and finally quite cloſed ; by which eaſy means
they may be adapted to receive and deliver ſeeds of any ſize from
horſe-beans and peas to wheat, barley, and to turnip-feed, with the
greateſt accuracy, fo as to low four, five, or fix pecks, on an acre,
or more or leſs, as the agricultor pleaſes, by only turning the ſcrew
a few revolutions one way or the other,
ho dos
tidsin bu boot and brood ni
។
albos moitia toosib silat
Obſervations. Ab
Com
1. In the conſtruction of the tin and wooden cylinders beneath the
feed-box another ſmall improvement may be neceſſary in ſowing very
ſmall feeds, which is this : As the ſcrew at the end A is turned, ſo
as to contract all the excavations of the wooden cylinder, the ſurface
of the wooden cylinder for one inch from the end of each excavation
towards the end B, Plate XI. Fig. 4. will become bare without being
covered by the tin cylinder ; and on theſe bare parts of the wooden
cylinder, which will be one inch long, and half an inch wide, ſome
ſmall feeds may chance to ſtick, and evade the bruſhes, which ſhould
prevent them from paffing, as the cylinders revolve.
To prevent this, when the wooden cylinder is ſo placed within the
tin cylinder, that all the holes are quite open, let a piece of the tin
cylinder

THE DRILL PLOUGH.
605
cylinder about an inch and a half long, and half an inch wide, be cuo
out from the extremity of each hole next to the end B, and let this
piece of the tin cylinder thus cut out be fixed by a few ſprigs on the
wooden cylinder exactly in the ſame place, which it covered before:
it was cut out of the tin one, by which contrivance, when the tin
cylinder is afterwards puſhed forwards by turning the ſcrew at its
end, ſo as to contract the excavations of the wooden cylinder be-
neath, the bare parts of the wooden cylinder will exiſt an inch and
a half from the extremities of the excavations next to the end B, and
thus will not paſs under the bruſhes, and in conſequence no ſmall
feeds can lodge in them.
2. Some kind of iron ſtaple ſhould be fixed at each end of the feed-
box on the outſide, which when the hinder part of the carriage is
raiſed up by the perſon who guides it, might catch hold of the two
iron ſprings at dd in Plate X. Fig. 1. for the purpoſe of ſuſpending
the coulters out of the ground, and connecting the hinder part of the
machine with the ſhafts before ; that in turning at the ends of the
lands, or in paffing from or to the field, the wheels may not ſwerve
at the joint Z, at the centre of the axle-tree, but may follow in the
ſame line with the ſhafts.
3. The feed-box muſt alſo be ſupported on upright iron pins paff-
ing through iron ftaples, with a lever under the end of it next to
the wheel rr, Plate XI. Fig. 3. for the purpoſe of eaſily lifting that
end of the feed-box about an inch high, to raiſe the teeth of the iron
cog-wheel on its axis out of the teeth of the correſpondent iron
wheel on the nave of the carriage-wheel.
4. The conſtruction of the coulters, which make the drills, and
of the rakes, which again fill them, after the feed is depoſited, and
alſo of the hoes, are not here delineated; as they are ſimilar to thoſe
ſo often deſcribed or uſed by Mr.Tull and his followers.
5. When the lower ends of the ſeed-Alues are placed through the
holes in the coulter-beam, Plate I. Fig. 1. at nine inches diſtance
from

606
IMPROVEMENT OF
from each other, the rows of wheat or beans will then be fown nine
inches from each other; and as the wheels of the carriage are four
feet in diameter, and therefore travel about twelve feet at each revo-
lution; and as there are four excavations round the axis of the feed-
box, which revolve four times for one revolution of the carriage-
wheels; it follows, that the feeds contained in the excavations of
the cylinder beneath the feed-box will be fown at nine inches dif-
tance in each drill or furrow, as the plough proceeds; and as theſe
rows are nine inches afunder, any deſired number of ſeeds
may
be
depoſited in every ſquare of nine inches, which are contained in the
ſurface of the field.
6. Mr. Coke of Norfolk acquainted me, that on his very exten-
five farm the wheat fown on an acre was fix or ſeven pecks by the
Rev. Mr. Cook's drill plough, which was about half the quantity
generally uſed in broad-caſt fowing. If the wheat was nicely depo-
fited in the drills, I ſuſpect one buſhel would be quite ſufficient for
an acre, as the rows are at nine inches diſtant from each other; for
there would in that caſe be about eight grains or nine grains depo-
ſited in every nine inches of the drill-furrow; that is, in every
ſquare of nine inches contained in the ſurface of the land ſo cul-
tivated.
Which may be thus eſtimated. Mr. Charles Miller, in the Philo-
fophical Tranſactions, Vol. LVIII. p. 203, has eſtimated the num-
ber of grains in a buſhel of wheat to amount to 620,000 ; and Mr.
Swanwick of Derby has lately eſtimated them to be-645,000. We
may ſuppoſe therefore, that a bufhel may at an average contain
635,000 grains of wheat. Now as a ſtatute acre contains 4840
ſquare yards, and there are ſixteen ſquares of nine inches in every
fquare yard, 4840 multiplied by 16 gives 77,440, which is the
number of ſquares of nine inches in ſuch an acre. If 635,000 grains
in a buſhel be divided by 77,440, the number of ſquares of nine
inches in an acre, the quotient will thew, that rather more than
eight

THE DRILL PLOUGH.
607
eight grains of wheat will thus be depoſited in every nine inches of
the drills.
7. Now if eight or nine grains were dropped altogether in one
inch of ground, they would be too numerous, if they be all ſup-
poſed to grow, and would form a tuffock ; but by making them
ſlide down an inclined plane, as in the tin-flues, from the ſeed-box
to the coulters, which are croſſed for the purpoſe of lengthening
them, as ſeen in Plate XI. fig. 2. fome of the feeds will be more de-
layed by their friction in deſcending than others, and the eight or
nine ſeeds will thence be diſperſed over the whole nine inches of the
drill; which renders drill-fowing ſuperior to dibbling, as in the
latter the ſeeds are dropped all together.
8. When the holes in the wooden cylinder are completely open,
they are about a proper ſize for fowing horſe-beans or peas : when
they are completely cloſed, there will remain a ſmall niche at the end
of the excavation in the wooden cylinder next to B, Plate XI. fig. 4.
for turnip-ſeed, or other ſmall feeds.
For wheat and barley and oats, a wooden wedge ſhould be made
of the exact ſhape of the area of the hole, which the director of the
plough requires; who will occaſionally inſert it into the holes, when
he turns the ſcrew at the end of the cylinder to enlarge or to leffen
them to theſe exact dimenſions.
Theſe wedges ſhould be written upon with white paint, wheat,
barley, oats, &c. which will much facilitate the adapting the ſize of
the excavations to each kind of grain, and may be altered, if required,
to ſuit larger or leſs feeds of the ſame denomination.
9. In ſome drill-ploughs, as in Mr. Cook's, there is an additional
machinery to mark a line, as the plough proceeds, in which the
wheel neareſt the laſt fown furrow may be directed to paſs at a pro-
per diſtance from it, and parallel to it. But in fowing wheat or peas
and beans this may be done by making the wheels, as they run upon
the ground, to be exactly fifty-four inches from each other; and
6
then

608
IMPROVEMENT OF
then at the time of ſowing to guide the wheel next to the part laſt
ſown exactly in the rut, which was laſt made; by which guide the
rows will all of them be accurately at nine inches diſtant from each
other.
sam od
bomo
ofitelight to
ab sin The Simplicity of this Drill-Plough.
a
100
this
1. The fimplicity of this machine conſiſts firſt in its having only
a ſeed-box, and not both a hopper and a ſeed-box, as in the Rev.
Mr. Cook's patent drill-plough. olish
2. The flues, which conduct the feed from the bottom of the
ſeed-box into the drill-furrows, are not disjoined about the middle of
them to permit the lower part to move to the right or left, when
the horſe ſwerves from the line, in which the coulters paſs, as in
Mr. Cook's patent drill-plough; which is done in this machine by
the ſimple univerſal joint at %, Plate I. fig. 1.
3. In this machine the horns or ſhafts behind, between which
the perſon walks, who guides the coulters, are fixed both to the coul-
ter-beam, and to the axle-tree; whereas in Mr. Cook's patent plough
theſe are all of them moveable joints like a parallel rule, for the pur-
poſe of counteracting the ſwerving of the horſe ; which in this ma-
chine is done by the ſimple univerſal joint at z, fig. 1, Plate I. before
mentioned.
4. The altering the dimenſions of the holes in the axis of the
ſeed-box by only turning a ſcrew, ſo as to adapt them to all kinds of
ſeeds, which are uſually ſown on field-lands.
5. The ſtrong bruſh of briſtles, which ſweep over the excavations
of the cylinders beneath the feed-box, ſtrickle them with ſuch ex-
atneſs, that no ſupernumerary ſeeds eſcape, and yet none of them are
T
in

THE DRILL PLOUGH.
609
in the leaſt braiſed or broken, as I believe is liable to occur in Mr.
Tall's original machine.
Laſtly it ſhould be obſerved, that the leſs expence in the conſtruc-
tion, the leſs propenſity to be out of repair, and the greater eaſe of
underſtanding the management of this machine, correſpond with its
greater fimplicity; and will, I hope, facilitate the uſe of the drill-
huſbandry.
b. Mr. Swanwick's Seed-Box.
As the dibbling of wheat, deſcribed in Sect. XVI. 2. 2. is a very
flow and laborious method of depoſiting the corn), and is yet coming,
as I am informed, more and more into faſhion in ſome counties, I
fufpect this muſt be owing to the expence of procuring, and the
difficulty of managing the drill-ploughs now in uſe, or to the greater
inaccuracy, with which they deliver the ſeed. I flatter myſelf there-
fore, that I am doing a benefit to fociety in endeavouring to fimplify
this machine, and to increaſe its accuracy as much as poſſible: and
ſhall therefore here deſcribe another method of delivering the feed
from the feed-box, which was invented by Mr. Swanwick, an inge-
nious teacher of writing and arithmetic, with ſome branches of na-
tural philoſophy, in Derby; and who will not be averſe to ſhew
the working models of the feed-boxes, or to give aſſiſtance to any
one,
who wiſhes to conſtruct either this drill machine, or the pre-
ceding one.
Mr. Swanwick's ſeed-box is forty-eight inches long within, is di-
vided into fix cells for the purpoſe of ſowing fix rows of ſeeds at the
ſame time, like that above deſcribed. And at the bottom of each
cell is a hole a, a, &c. Fig. 1. Plate XII. for the ſeed to paſs
through
41

610
IMPROVEMENT OF
a
through into the feed-flues, as in the machine before deſcribed :
but in this there is no revolving axis, but a wooden or iron bar BB,
fig. 3. Plate XII. about two inches broad, and about four feet eight
inches long, and exactly three eighths of an inch thick. Through
this bar there are fix perforations, e e e, &c. which are each of them
exactly one inch long, and half an inch wide ; and three eighths of
an inch deep, which is the thickneſs of the bar. The centres of
theſe holes are exactly eight inches diſtant from each other, corre-
ſpondent to the holes at the bottom of the ſeed-box; over which it
is made to ſlide backward and forwards in a groove. By this ſliding
motion it paſſes under ſtiff bruſhes, which are placed over it on each
end of the holes at the bottom of the feed-box, and ſtrickle off the
grain, as the holes in the ſliding-bar paſs under them, which thus
meaſure out the quantity with conſiderable accuracy.
In order to increaſe or diminiſh the quantity of grain delivered,
the ſlider is covered with a caſe of tin CC, fig. 4, Plate XII. which
has fix perforations exactly correſponding with the holes in the flider;
but inſtead of the bit of tin being cut out the whole length of the
hole, part of it is left at the end i, fig. 6, equal to the thickneſs of
the ſlider, and is bent down as at b, after the ſlider is put into the
caſe, like the tin cylinder in the preceding machine. This cafe is
moveable about one inch backward and forward by turning the finger
ſcrew s, fig. 4 and 5; and thus the holes are made larger or leſs to
fuit various forts of grain, or different quantities of the fame fort, ex-
actly as in the wooden and tin cylinders in Plate XI. The flider is
moved forwards by a bent iron pin h attached to it, which paſſes
into a ſerpentine groove Y, fig. 5, fixed to the nave of the wheel :
and backwards by a ſteel ſpring at the other end of the feed-box,
which is not repreſented in the plate.
Fig. 5 is a bird's eye view of the parts before deſcribed : E E the
feed-box divided into cells by the partitions dd, &c.--ccc the flider,
I
with

THE DRILL PLOUGH.
611
a
a
with a part of the apertures feen juſt appearing from under the bruſhes.
X the axis of the wheel.
Fig. 6 is a drawing of part of the tin cafe, nearly of the full dia
menſions as to breadth and thickneſs, but only a ſmall portion of the
length; and is intended to ſhew more diſtinctly the conſtruction
of it.
Fig. 2 repreſents a fide-view of one of the fix bridges lying over
the holes at the bottom of the ſeed-box, on each ſide of which the
bruſhes are fixed, which ſtrickle the holes, when they are full of
corn, as the bar ſlides backwards and forwards.
The ſimplicity of this ſlider at the bottom of the feed-box may be
in ſome reſpects greater, than that of wooden and tin cylinders in
the former machine; as this has but fix holes to meaſure out the
corn, and the other has twenty-four. But perhaps in other reſpects
lefs ſo; as in this twelve bruſhes are uſed, one on each ſide of each
of the fix holes; whereas there are only fix bruſhes rub upon the
tin cylinder in the former machine. And the reciprocating motion
of this ſlider muſt be quick, as it muſt act once every time the pe-
riphery of the wheel of the carriage has paſſed nine inches forward;
which may not be ſo eaſy to execute as the cog-wheel, and unin-
terrupted movement of the axis and cylinder in the preceding
machine.
I have only to add, that the facility of adapting the holes to the
dimenſions required in both theſe machines, and their not bruiſing
or breaking the grain in their operation of delivering it, as well as
their not being encumbered with an additional hopper, which muſt
deliver the quantity of ſeed with great inaccuracy from the unequal
ſhaking of the machine, adds much to the excellency and ſimplicity
of them both. And I hope will render more general the uſe of the
drill huſbandry invented by the ingenious Mr. Tull; who was on
that
4 1 2

612
IMPROVEMENT, &c.
a
that account an honour to this country, and ought to have a ſtatue
erected to his memory, as a benefactor of 'mankind, like Ceres and
Triptolemus of old.
Ille Ego, qui quondam gracili modulatus avena
Carmen, et egreſſus ſylvis vicina coegi,
Ut quamvis avido parerent arva colono,
INDEX.

Ι Ν D Ε Χ.
3.2.
3. 2.
A.
Alum reſiſts putrefaction, x, 7. 8.
Ammonia, X. 2. 6. x 7.8.
ABSORBENT veſſels of vegetables, ii. Animals diſtinguiſhed from vegetables, x. I. -
have rigid coats, ii. 3. 4. X. 12. 4.
conſiſt of a ſpiral line, Animalcules microſcopic, xiv.
ii. 5, and 7
Annuals converted into perennials, xix. 3.1.
act direct or retrograde, Anthers and ſtigmas live on honey, iv. 5.6.
ii. 6.
hend' to the ftigmas, vii. 2. 2.
abſorb poiſons, ii. 9. Aorta of plants, y. I.
their force ſtronger than Appetencies and propenſities, vii. 3. 7.
the heart, v. 3. and 5.
formative and nutritive, vii.
Acid muriatic oxygenated, xv. 3. I. X. 2: 8. 3.7.
vegetable, vi. IO.
Aphis, iii. 2. 8. vii. I. s. ix. 3. 1. xiv. I.
Acrimony vegetable, xvii. 2. 5.
7. and 3. 2. add. note v.
of two kinds, xvii. 2. S: xix. Apple four on one ſide, xv. 1. 1. XV. 1.4.
6. I.
tree ſpread horizontally, xv. 2. 2.
Adanſonia the largeſt tree, xviii. 2. 14. Archil, xviii. 1. 5.
Adultery vegetable, viii. 8.
Armour of vegetables acquired, xiv.
Agriculture ſuperior to paſturage, xvi. 9. I. Arnotto, xvii. 2. 2.
Agroſtis canina, xviii. 1. I.
Artichoke ground, xvi. 3. 4. xvii. 1. 3.
Air atmoſpheric, X. 2.
Arſenic to poiſon flies and waſps, vi. 6.
... buried beneath the ſoil, xii. I.
... heats hot-beds, x. 8. 2. X. 11. 5: Affociation vegetable, viii. 5.
its ſurface over ridges and furrows, x. Afh-tree uſed to feed filkworms, xviii. 1. 2.
Aſh-leaves uſed for tea, -xviii 1. 4.
3. 7:
Air-veſſels of vegetables, ii. 4. ill. 2. 6.
Afhes of plants contain phoſphorus, x. 5.6.
Alburnum contains fugar, ill. 2. 3.
of bones, X. 5. 4.
acts ſometimes as capillary tubes, Aſparagus, xviti. 1. 2.
ix. 2.10
Attractions and aptitudes, vii. 3. 6.
ſometimes as capillary fyphons, Azote forms ammonia, x. 2.6.
iii. 2. 4.
Azotic
Alum, uſe of it in bread, vi. 3. I.
in ſpring water, X. 35:
how detected in bread, vi. 3. 2.
falutary in the bread of London, vi.
B
uſe in making hair-powder, vi. 3.
.. unfriendly to vegetation, x. 7. 8. Barks, xvii.
3.
wounds of, xvii. 3. 10.
X. II. 9.
Barks
3.
xiv. 3. 3:
.
gas, X. 2. 8.
3. 2.
>

1 N D E X.
.
Barks yeffels of inofculate, ix. 2. 10.
Calcareous earth. See Lime, x. 6.
.... exterior annually renewed, ii. 4. Calender of Flora, xvi. 8. 1. add. note ix.
interior of elm, xvii. 3. 3,
Canker, xiv. 1. 6.
ſcratched longitudinally, xviii. 2. 1.
propoſed cures of, xvii. 3. 10.
unperiſhable, xvii 3. 6.
Caoutchouc, vi. 8. 5. xvii. 3. 3.
Barley ſteeped in dunghill water, xvi. 8.3. Capillary attraction in alburnum, ix. 2.10.
three buſhels and an half on an acre, XV. 2. 3:
xvi. 8. I.
Caprification, xiv. 2. 9.
Beans uſed for provender, xvi. 6. 2.
Carbon, X. 4.
injured by cold water, xi. 3. 4.
diſſolved by lime, X. 4. 7.
injured by too much water, xvi. 1.4.
by ammonia, X. 4. 3.
enrich clayey foils, x. 7.7.
Carbonic acid, x. 2. 5.
Bees injure vegetation, vi. 6.3. xiv. 3. 7.
7
incompaſſes the earth, x. 4. 1.
how to ſave thein when attacked, xiv.
.
..
compoſes mountains, X. 4. I.
3. 7.
Caterpillars in apple-bloſſoms, xiv. 3. 3.
how to place their hives, xiv.3.7.
to deſtroy, xiv. 3. 3.
Beetles, xiy. 3. 5.
... efculent and poiſonous, xiv. 3.6.
Bird-lime, xvii. 3: 3.
Caudex of a bud, i. 2.
Bitter juices of plants, vi. 9. 1. xvii. 3. 1.
of buds of trees, vii. 1.7. xv. 2. I.
9
Blofſoms whiter as fruits become ſweeter,
multiplied by dividing, vii. 3. 4.
XV. I.4.
buds from every part of, vii. 1.7.
Bogbean uſed for hops, xviii. 1. 5. xi. 2. 5. triple, vii. 3. 1.
3
Bone-afhes, uſe of, x. 5.4.
Charcoal injected with quickſilver, v. 4.
Bounties on exportation of corn, xvi. 9. 1.
to preſerve feeds, xvi. 7. 6.
Bows from yew, xviii. 2. II.
Chick in the egg, iii. 1.4. vii. 1. 2.
Brain of vegetables, viii. 1. and 9.
Chorion of the chick, iii. 1. 4.
Branches, lower ones firſt in leaf, in. 5. Chyle of animals, x. 1.
Bread and beer made froin hay, x. 9.4. Circulation of vegetables, v. I. xix. 2.2.
Bredon-lime is half magneſia, x. 6. 8.
without a heart, V.2.
Briſtles on moſs-roſes, uſe of, xiv. 3. 2.
in fiſh, v. 2.
in the veins, v. 3.
.... on young ſhoots of nut-trees, xiv.
by abſorption and by ſpiral veſ-
Brocoli, cultivation of, xix. 4.2.
fels, v.5.
Clavus or ergot, xiv. 1.4.
Broth from muſhrooms, xvii. 2. 5.
Clay, x. 7. Add. note xii.
Buds, parts of, ix 2. 12.
efferveſces, x. 7. 2.
of different maturity, xv. 1. 3.
has a ſmell when breathed on, x. 7. 3.
lateral and ſummit ones, xv. 2. 5.
burnt for manure in coal countries, x,
converted into each other, ix. 2. 11. 7.4.
Budding on roots, ix. 3. 5.
.... is condenſed by froſt, xv. 4. 1. xiii. 2.
Bulbs, ix. 3.
2. X. 7. I.
produce other bulbs, ix. 1.5.
acidity of, injurious, xiv. 2. 5.
Bunium pignut, xvii. I. 3.
Coals, origin of, vi. 8. 2.
Burying-grounds, x. ii. 3.
Coke, his drill huſbandry, xvi. 2. 2..
Butomus flowering ruſh, xvii. 2. 3. xi. Colchicum autumnal, iv. 5. 4.
2. 5.
Cold after heat more injurious, xiii. 2.4.
C.
xiv, 2. 2.
exceſs of, xiv. 2. 2.
Cain and Abel, xvi. 9. I.
Colouring, matters of, xviii. 1, 5. xvii. 2.
Calamine for manure, x. 7. 1, X. 94.
1. xvii. 3.5
Colouring
6
3.2.
poem on, xix. 8.
.-...
. a

I N D E X.
xii. 5.
.
Colouring for cheeſe, xvii. 2. 1.
Drill-huſbandry, advantage of, x. Y2. 2.-
Colours of flowers, xix. 1. 2.
.. how to change, xix. 3. 2.
... for turnips, xiv. 3. 5.
white owing to comprelliən, xix. Dry-rot of timber, to prevent, xviii. 2. 5.
3.2.
Dunghill water, xvi. 8.
3.
Condiments, xiv. 2: 8.
Dwarf fruit-trees, xv. I. 3. XV. 2.2.
Congelation condenfes clay, xv. 4. E. K. Dyeing matters, xvi. 3. 5. xvii 2. 1.
ſeparates fluids, xv. 4. Li Xi
7. I.
7. I.
2. 2.
II. 1.
..
2 3
repels-mucilage, xv. 4. I.
Coping of ſtone, x. 3. 8. xv. 3. 6. xiii. Ear-fungus,"xvii. 2.57
Egypt, its fertility from want of rain, Xo
.. temporary of boards, xv. 3. 6.
6
Coralline rocks, xviii. 2. 14.
wheat from, xvi. 2.2.
Corn ripened in froſt, xvi. 3. 2.
Elaſtic reſin, vi. 8. 5.
ripened ſooner by lime, xv. 3. 3: Electricity, xiii. 3.
Corols are reſpiratory organs, iv. 5. 1. vii.
affects plants, viii. 1. xiv. 2.3.
points to precipitate dew, xiii.
Cotyledons of ſeeds, ix. I. 3.
4. I.
3.4.
Couch-grafs, xviii. 1. I.
... pendulum doubler of, xiii. 3. 58
Crambe ſea-cale, xiv. 2. 4. xviii, 1. 3. xix, Elm-tree, bark of, xvii. 3. 3.
Ergot, clavus, xiv. 1.4.
Crooked trees to ſtraighten, xviii. 2. I. Evyſiphe; mildew, xiv. 1. 2.
Cuticle, or exterior bark, xviii. 2. I. Eſpallier, horizontal, xv. 2. I.
may be ſcratched, xviii. 2. I. Etiolation of leaves, xiii. 1. 3. xiv. 2.-4.
Cyder, xiv. 2. 9. additional note xi.
of flowers, xviii. 1. 3.
of ladies, Xviii. 1.3.
D.
... of roots, xvii. 1. 2. xvii. 2: 2.
Evaporation of water injurious, x. 3. 8.
Deity, benevolence of, xix. 7. 3.
Evergreens have no bleeding ſeaſon, ix. 2.26
Degeneracy of grafted trees, vii.
1. 3. XV. I.
made by ingraftment, xix.2. 2.
4. xiv. 1 6.
Excrement of plants, add. note. vii.
Dew-drops, form of, xiii. 1. 5.
Exportation of grain, xvi. 9.1.
Dibbling wheat, xvi. 2.2.
Exſudatio miliaris, xiv, 1. 8,
Digeftion, experiment on, xvi. 6. 2.
Difeaſes of plants, xiv.
hereditary, xv. I. 4.
E.
Dogs, experiment on their digeſtion, xvi.
6. 2.
Fallowing, uſe of, xii. 3.
Double flowers, duration of, xix. 1. I. Faſt-says, uſe of, xvi. 9. I.
to produce, vii. 1. 3. xix. Fatneſs, how to produce, xiv. 2. 8.
3.1.
Fermentations, x. 8. 2. xvi. 3. 4.
Draught, exceſs of, xiv. 2. 1.
Figs fall off in flower, xv. 3. 4.
Draining lands, xi. 1.
... pinch off their fummits, xvi. 1.4.
Drill-machine improved, xii. 5. and Ap- .. compreſs them with wire below, xv.
pendix.
3 4.
print of, "Appendix at the end wound them with a ſtraw, xv. 3.4.
of the work
Fire-flues in garden walls, xv. 3. 6.
Drill-huſbandry, ix. 3. 7. xvi. 2. 2. Fiſh propagated for manure, X. 10.4.
Flax

IN DE X.
xvi 7.3
xvi. 7. 3:
iv. 5. 4.
3. xix. 6. I.
3: 6.
Tlax, linum, xvii. 3. 7.
1. Fruit wounded, ripens ſooner, x. 8.1. xv,
Flewk-worm in ſheep, xiv. 2. 8. additional 3. 7. xiv. 2.9.
note v.
.... to preſerve in ice-houſes, xvii. 2. 4.
Flies, how to poiſon, vi. 6. 3. xiv. 3. 3.
Floods injurious, x. 3. 7,
.... to raiſe good from ſeed, xv. 1, 1.
Flooding meadows, art of, xi. 3.
.... to preſerve by heat, xv. 4. I.
Flower-buds terminal, ix. 2. II.
....when ripe, to diſcover, Add. note x.
converted into leaf-buds, ix. deſtroyed by hafty thawing, why?
2. II.
Flowers require leſs water, x. 3.9. xvi. 1.4. Fungi, xvii. 2. 5.
enlarged by deſtroying the leaves,
.... grow
without light, xii. 1. 4. xv. 3.
..... cauſes of their colours, xix. 1. 2. .... are of animal origin, xvii. 2.5.
to render double, xix. 3. I.
.... are animals without locomotion, xvii.
double ones from feeds, xix. I. I. 2.5. xiii. 1.4.
Fluor, cubic ſpar, x. 5. 3.
.. are nutritious, xix. 6. I.
uſeful in agriculture, X. 5. 4.
Furrows and ridges, xvi. 2. 2.
Fluxus umbilicalis, fap-flow, Hi. 2. 2.
diſeaſe of, xiv. I. 9.00
Fogs injurious, xv. 3.6.
G.
daſhed againſt trees, xv. 3.6.
Food of plants or manures, X.
Gangrena, canker, xiv. 1. 6.
of young vegetables, X. 1. 3.
Garden, bett ſituation of, xii. 2. 2. XV.
of adult vegetables, X.-1.4.
Fowls, how fattened, xiv. 2.8.
Garden-walls with flues, xv. 3.6.
Free-maſons, xviii. 2. 5.
Garden-mould, X. 4:3
Froſt ripens corn, x. 3.9.
Generation, vegetable, vii. 3.
black or rimy, xiii. 2. 2.
lateral, vii. 1. I. vii. 3. 9.
deſtroys by expanding fluids, xiii. 2. 2.
ſexual, vii. 2. 1. vii. 3. 10.
by ſeparating fluids, xiii. 2. 2. xv. Glands of vegetables, vi.
4. I.
Glaſs, x. 7. 2.
by decreaſing irritability, xiji. 2. 2.
fine fand for, xi. 1. 3.
and 2. 3. xiv. 2. 2.,
Gluten of wheat nutritious, xix. 6.1.
ſtops the ſap juice, xiii. 2. 3.
deſtroyed by fermentation, xvi. 7.1.
deſtroys the old and infirm, xiii. 2. 2. Gooſeberry-trees, to protect, xiv. 3.3:
and the children of the poor, xiii.
to ſuckle, xv. 3. 5.
2.2.
Gout, xix. I. 1.
how to be ſaved in ſnow, xiii. 2. 2. Granaries, xvi. 7. I.
its effect on ſolutions, xv. 4. 1. xii. 2. Grain, preſervation of, xvi. 7
2. X. 7.1.
0
..
Grafts and ſtocks ſecrete from the fame
how it deftroys life, xv. 4. 1. xiii. blood, xv. I. 4.
2. 3
Graffes forwarded by flooding, xi. 3.
raiſes roots out of the ground, xviii. preſerved from froſt by flooding,
I. I.
... raiſes the ſmall pebbles of gravel walks,
when beſt for hay, xi. 3. 1.
xviii. I. I.
... ſtems and roots of, ix, 1. 6. ix. 3.1.
.. makes clay more folid, xv. 4. 1. X.
have no nectary, ix. 1. 6.
7. I.
fix kinds for ineadows, xviii. I.I.
prevented from injuring meadows, xi.
three kinds for paſtures, xviii. I.I.
ſeeds of, xvi. 2. 3. xviii. I. I.
Growth
xi..3
-
•
3.1.

I N D E X.
xii. 3.
I. I.
Growth of turnips does not impoveriſh land,
1. & J.
..... of trees, its boundary, xviii. 2. 14.
Incloſures if politically good ? xvi. 9. 1.
Gum, effuſion of, to prevent, xiv. I. IO.
Indigo, xviii. 1. 5.
Gypſum, x. 5. 3. 4. 5. 4.
Individuality of leaf-buds, i. 1.
with magneſia, x. 6. 8.
of flower-buds, i. 4.
how to be uſed, Add. note iv. Ingrafting, iii. 2. 7. XV. 1. 4.
why in ſpring, iii. 2. 7.
.. on roots, ix. 3. 5.
H.
ſtriped plants, v. 1. xix. 2. 2:
of different genera of plants, xv.
Habits of plants, xiv. 1. 1. xix. 2.1.
I. 4.
Hair-powder, vi. 3.
Inoculation, i. 3. ix. 2. 10.
Happineſs of organized nature, xix. 7. I.
why in ſummer? ii. 2. 7.
Harrogate water as a manure, X. 4. 7.
on roots, ix. 3. 5.
Harrow to extract roots, xviii. 1. I.
not by flower-buds, i. 4.
Harrowing wheat in ſpring, xii. 7.
with mature buds, xv. 1. 2.
Hawthorn-hedge from ſcions, i, 1. XV, 1.3. xv. I. 4.
Hay ſhould be cut young, xi. 3. 2. xvill. Inſects propagated for manure, X. Io. 3.
10.
depredations of, xiv. 3.
... loſes two thirds of its weight, xviii. 1. 1. generation of, ix. 3. I.
injured by worms, xviii. 1. I.
to destroy, xiv. 3. 3.
making, xviii. 1. I.
Joints of graſſes, ix. 3. I. xvii. 3. 3.
Heart-wood is lifeleſs, ix. 2. 10.
Jonquil, xix. 3. 2.
.. ſmall force of, v. 3.
Irritability, vegetable, viii. 2.
Heat, uſe of in vegetation, ix. 1. 3. xiii. 2.
diſeaſes of, xiv. I. I.
3. xiv. 2. 2.
internal of vegetables, xiii. 2. 3.
.... from dunghills, X. 2. 1.
L.
combined, xiii. 2. I.
variations of, wholeſome, xiv. 1.1. Land to eſtimate. See Soil.
.. above 212 preſerves fleſh, xvii. 2.4. Lateral progeny, vii. 1. I.
Hedgehogs ufeful in gardens, xiv. 3.6.
reſembles the parent, vii. 1. 3.
Helianthus tuberoſus, xvi. 3. 4.
degenerates, vii. 1. 3.
Hepar of carbon with lime, x. 4. 7. Lead corroded by oak-boards, xviii. 2. 5.
Hereditary diſeaſes of plants, xix. 1. 1. xix. Leaf-buds converted into flower-buds, ix.
Hills ploughed horizontally, X. II. I. X. Leaves are lungs,
3.7.
deſtroyed to produce flowers, ix.
Hoeing after the corn has bloſſomed, xv. 2. II.
... withered ones firſt eaten, xiv. 3. 2.
horſe-hoeing, ix. 3. 7. xii. 5.
enrich ſoil by carbonic acid, x. 7 7.
hand-hoeing, xii. 5. xvi. 2. 2.
... turn red in autumn, xv. 1.4.
Honey, vi. 6.
Lemon-trees ingrafted, xv. I. I.
differs from fugar, v. 6. 4.
Lichen rangiferinus, xiii. 2. 2.
food of anthers and ſtigmas, vii. 2.4. Light, uſe of in vegetation, xiii. I.
... dew, 111. 2. 8. xiv. 1. 7. xiv. 3. 2. exceſs of injurious, xiv. 2. 4.
Hops, bogbean inſtead of, xviii. 1. 5.
froin rotten wood, x. 2. I.
Hotbeds turned over heat again, x. 8. 2.
from reſpiration, X. 2.7.
Hydrocarbonate gas, x. 8. 3.
defect of, injurious, xiv. 2. 4.
Lightning
2. I:
2. II.
2. 3.
.
AK

IN DE X.
2.3.
2.5.
•
2.5.
..
Lightning injures wheat-fields, xiv. 2. 3. Marle, production of, x. 4. 3.
deſtroys by exceſs of ſtimulus, xiv.
ſhell, x. 5. 5.
... crumbles in the air, why? x.7. 3.
2. 3
by burſting vegetable veſſels, xiv. Marine acid, x. 7. I.
,
plants project a liquid, vii. 2. 2.
how to prevent, xiv. 2. 3. Maſonry, whence the myſteries of, xviii.
Lime, uſes of, x. 6. Add. note xi.
promotes putrefaction, x. 6. 5.
Meadows, flooding of, xi. 3.
... promotes the ripening of grain, x. 6. .... eat late in ſpring, xviii. 1. I.
7. xvi. 3.
Menyanthes uſed for bops, xviii. 1. 5. xi..
diſſolves carbon, X. 4. 7.
contains phoſphorus, x. 5. 5. x. 6. 3. Mice-field, xiv. 4. I.
uſe of burning it, X. 4. 8.
Michel's method of raiſing vines, xv. 1. 3.
...... emits heat, x. 4. 4.
4
Mildew, to prevent, xiv. 1. 2.
Naked with boiling water, x. 4. 4.
Miſery is not immortal, xix. 7. 1.
broken into powder by ſteam, X. 4. 4,
Miſts injurious, xv. 3. 6.
on new walls is long moiſt, why? x. daſhed againſt trees, xv. 3.6.
4. 5. X. 6.5.
Moiſture, uſe of in vegetation, ix. 1.3.
..... nouriſhes plants, X. 4. 6.
... exceſs of, xiv. 2. I.
approaches to fluidity, X. 4. 8. X. Moles, to deſtroy, xiv. 4. 3.
6. 6.
Mole-plough, xi. 1.7. Add. note xii.
of Breedon is half magnefia, x. 6. 8. Monſters, vegetable, ix. 2.11. XV. 1.4.
Add. note xi.
vegetable and animal, vii. 9. 8.
decreaſes the coheſion of clay, x. 7. 7.
xix. I.I.
Livers of geeſe, xiv. 2. 8.
Monuments of paſt felicity, xix. 7. 3.
Loamy ſoil, x. 4. 3.
of paſt animal life, xviii. 2. 14.
Lop nut trees early in ſummer, ix. 2.9.
of paſt vegetable life, xviii.
Lolium perenne, xviii. 1. I.
2. 14
Lycoperdon, puff-ball, xix. 6. 1.
Moraſſes, X. 4. 3.
Luxury in fleſh-food and ale, xvi. 9. 1. Morels approach to animals, xvii. 2. 5.
... converted into fat, xvii. 2. 5.
M.
Moſs-roſe, its armour, xiv. 3.2,
Mould, xiv, I. 2. See Mucor.
Machines for raiſing water, xi. 3.6. Mucilage, vi. I.
by Hiero's fountain, xi. 3. 6. Mucor, or mould, grows without light, xiv.
by new horizontal windmill, xi. I. XV. 3. 3
poiſoned by vinous fpirit, xv. 4. 3:
Madder for colouring cheeſe, xvii. 2. 2.
xvii. 2. 4
Magneſia with gypſum, X. 6.8.
Mulberry leaves, xviii. 1. 2
Malt, its goodneſs diſcovered, how? xvi.
fruit by ingrafting, xv. I. I.
Mule-beans, vii. 2. 6.
Manganeſe as a manure, X. 7. 2.
... cabbage, vii. 2. 6.
Manures, ſpontaneous, x. 8. 1.
....peas, xvi. 4. I.
chemical, X. 9. 1.
.. triple vegetable, vii. 3. 3.
by inſects, X. 10. I.
Mules, animal, vii. 2.7.
application of, X. 12. 1.
.. vegetable, vii. 2..6.
when to be applied, X. 12. 2. Muſcles of vegetables, viii. 1.
.... economy of its application, x. Muſhrooms, of animal origin, xvii. 2. 5.
.
.
3.6.
..
6. I.
.
.. approach to animal nature, xix.
which moſt nutritive, X. 12. 4.
Muſhrooms
12. 2.
6. I.

Ι Ν D Ε Χ.
Muſhrooms conduct Galvaniſm, xvii. 2.5.
. . ſtone, xvii. 2. 5.
Oxygen in vegetable Auids, whence ? x.
4. 8.
N.
Nerves of vegetables, viii. I.
Nevil-Holt water, x. 7. 8.
Nitre, production of, *.7. 4.
Nutritious parts of Vegetables, xix. 6. 1.
Nut-tree twigs their armour, xiv. 3. 2.
Nymphæa alba, ix. 2. 5. xvii. 2. 3.
nelumbo eaten in China, xi. 2.5.
.. from decompoſed carbonic acid, x.
4. 8. xiii. 1. 2.
from decompoſed water, x. 3. 3.
xiii. I. 2.
looſely combined in nitre, x. 8.4.
promotes vegetation, x. 2. 8.
abounds by etiolation, xix. I.
deſtroys plants by exceſs, xiv. 2.7.
.... as a cauſe of irritability, xiv. I. I.
Oxygenated muriatic acid, x. 2.8. xiv. 2.5.
perſpirable matter, xiii. 1. 2.
xiii. 1.4
.
0.
P.
Oaks and willows why barked in ſpring, iii.
5. xvii. 3. 2.
Papin's digefter, x. 9. 3.
ſhould be felled in winter, iii. 5. ix. 2. Papyrus, xvii. 3 7.
8. xviii. 2. II.
Paring and burning, x. 7.4.
.... barked produce more flower-buds, ix. Paſturage compared to agriculture, xvi. 9.1
2. 8. xv. 2. 3.
ix. 2.9
2.3.
.
.
Pauſe in vegetation at Midſummer, iii. 2.8.
planted with pines, xviii. 2. 2,
600 years old, xviii. 2. 16.
Pear-tree in part decorticated, ix. 2. 10. XV.
Oats leſs profitable provender than beans,
xvi. 6, 2,
compreſſed by wire, xv. 3.4.
improve by keeping, xvi. 6. 4.
bears at the extremities, why? ix.
Ochre red, as a manure, x. 7. I.
2. 7.
Oils eſſential, agreeable or poiſonous, vi.
ripens by baking, x. 8. 1.
8. 3.
Peas
grow
in water, xi. 3. 4.
.
... fixed in a boiling heat, xvii. 2 5. .... rows of from ſouth-eaſt to north-weſt,
uſed to poiſon weapons and pools of
xiii. 2. 2.
water, vi. 8. 3.
.... contain more meal than oats, xvi. 6.2.
expreſſed, not narcotic, vi. 4. 2. .... boil foft, xvi. 4. 2.
Old corn preferable to new, xvi. 6 4,
mule, vii. 2.6. xvi. 4. I.
Onions, roots of, ix. 3.2.
their pods nutritious, xi, 3. 2.
magical, ix. 3. 4.
... economical provender, xvi. 6. 2.
Orange bears by ingrafting, xv. 1. 1. Penetrability of foils, x. 3.6
Orchis for ſalep, xvi. 3. 4. xvii. 1. 5. Perſpiration vegetable oxygenated, xiii. 1. 4.
how to ripen the ſeeds, ix. 3.2. xi. Petals are reſpiratory organs, iv. 5. I. vii.
2. 4.
Organs of reproduction, vii.
Phoſphorus in rotten wood, x. 5.1.
lateral in buds, vii. I.
in all vegetables, x. 5. 3.
fexual in flowers, vii. 2.
hepar of, *. 6.3
x .
Owls ſhould be encouraged, xiv. 4. I.
gives folidity to timber, x. 5. 6.
Oxydes of metals, x. 2. 3. X. 7. 1.
Phoſphate of lime, x. 5. 5.X.7.6.
Oxygen, X. 2. X. 7: 2.
in the gluten of wheat. Additional
.. abounds in rain water and in ſnow,
note vi.
xiii. 2.2.
Pignut, bunium, xvii. 1. 3.
Pine.
2.3.
.
4 K 2

IN D E X.
2. I.
Ones, ix.
Pine-apple cultivated in water, xv. 3.4.
R.
Piping buds, ix, 2. '1.
Raddle as a manure, x. 7. 1.
Pith like brain or fpinal marrow, i. 8. ix, 2. Radiſhes to procure early, xvii. 1.1.
4. xviii. 2.13
Rafts of hollow timber, xviii. 2. 10.
Placental vefſels of buds, i. 4. 11. 2, 6. Rain contains oxygen, xiii 2. 2.
of feeds, iii. 1. 3.
injures the anther-duft, x. 3.9.
of eggs, ill. 1.4.
Rats to deſtroy, xiy. 4. 2.
Plants live longer if prevented from flower- .... are liable to the tape-worm, xiv. 4. 2.
ing, vii. 1.3.
Red leaves in autumn, xv. I. 4.
Plant trees ſhallow in the ſoil, xv. 2.4. Rein-deer moſs, xiii. 2. 2.
Plough for draining, xi. 1. 7.
Refin elaſtic froin bark of holly, xvii. 3. 3.
drill, xii. 5.
.... of wheat-flour, vi 8. 5. xvii. 3. 3.
.
mole, xi. 1.7. Add note xii. Reſpiration of animals, X. 2. 7.
Ploughing if in ridge and furrow, x. 3. 8.
of plants requires light, xiii. 1.4.
wheat in ſpring, xii. T.
of plants not in their fleep, iv. 5.
Plume of ſeed aſcends, why? ix. 1. 3.
5. xiii. I. 4.
Poems. See Verſes.
of glow-worms is luminous, X.2.7.
Points liberate air from water, xiii. 1. 5. Rheuin hybridum, niule rhubarb. Additional
Poiſon of yew leaves, xiv. 3. 2.
notes i, and ii.
of euphorbium, vi. 8. 3.
Rhubarb roots when to be taken up, xvii.
.
.... to vegetables, xiv. 2. 7.
Poiſonous exhalations, xiv. 2. 6.
leaves deſtroyed by inud. Additional
Polypus, ix. 3. I.
notei.
Potatoes, early ones, xvii. 1. 3.
Rice in Valencia, xi. 3. 4.
curled
3. 4. xvii. 1.2.
grounds, x. 3. 9.
aerial ones, xvii. 1. 2.
2
Ridges and furrows, X. 3. 7. xvi. 2. 2.
increaſed by trantplanting, ix. 3.7.. advantages of, xvi. 2. 2.
increaſed by pinching off the flow- Rime perpendicular or lateral, xv. 3. 6.
ers, ix. 3. 3. xvii. 1. 2.
.. froſts and black froſts, xiii. 2. 2.
better ſet in drills, xvi. 2. 2. Rings of timber concentric, xviii. 2. 12.
to ripen the ſeed, xvi. 3. 4.
Ripening of fruit by wounding it, xiv. 2.9.
how to improve, xvi. 5. I.
X. 8. I. XV. 3. 7.
to boil in ſteam, X. 9.2.
to diſcover. Additional note x.
to boil mealy, xvi. 4. 2.
Roll wheat in ſpring, xii. 8.
killed by drying on a kiln, x. 9.2. Roots deſcend, why? ix. 1. 3. xv. 2. 4.
xvii, 2.4
at Midſummer, ix. 2.9.
bread of, vi. 3.
decay internally, ix. 3. 5.
may be planted whole, xvii. 1. 2.
end-bitten, ix. 3.5.
Pottery, Breedon-lime for, x. 6. 8.
.. ſhould be plucked up for tranſplante
Preſervation of fruits, xv. 4. I.
ing, xv. 2.4.
of ſeeds, xvi. 7. 1.
from wounds of the bark, ix. 3.-7
of roots by cold and by heat, .... etiolation of, xvii. 2. I.
Root-grafting, ix. 3. 5.
Progreſs of nature to perfection, xx, 2. xiv. inoculation, ix. 3. 5.
propagation, ix. 3. 5.
Propagation of good trees, ix. 3. 7.
ſcions for planting, xv. 1. 2.
Props for tranſplanted trees, xviii. 2. II. Roſe plaintain, ix. 2. II..
Puberty of plants, ix. 3. I. XV.I.I.
Rofes to forward, xvi. 2. 5:
Pulmonary organs, iv.
double ones, xix. 2. I.
Putrefaction, X. 8. 3.
Rot of timber, iii. 2. 3. ix. 2. 8. xviii..
Putrid exhalations, X. 4: 3 %. 7.8.
2.5.
0
.
..
.....
xvii. 2. 4
...
3.2.
.
...
Rot
4

IN DE X.
..
.
Rot of theep, xiv. 2. 8. Additional note v. Seeds diſperſion of, vii. 2.5.
Rubia tinctoria to colour cheeſe, xvii, 2. 2. change of not neceſſary, xv. 5. 1.
Rubigo, ruft, a diſeaſe, xiv. 1. 3.
when ripe to diſcover. Add. note X.
Rye-graſs, xvi. 6. 1. xviii. 1.1.
.... how to preſerve, xvi. 7.6.
ſhould be fown ſoon after ploughing,
S.
x. 7. 5.
require oxygen, xiii. 1. 5.
Saccharine proceſs in malt, x. 8. 1.
Seedling trees, xv. I. I.
... may exiſt beneath the ſoil, x. Senſes of vegetables, viii. 6.
8. I.
Senſibility of vegetables, viii. 3:
in baked pears, x. 8. 1.
Sexual generation, vii. I. 7.
how haftened in fruit, xiv. 2.9.
progeny, vii. 2.
Sage-leaves for tea, xviii. 1.4.
of infects, ix. 3. 1.
Sagoe from the palm, xviii. 2. 13.
Sheep, flewk worm of, xiv. 2.8.
..... from artichoke ſtalks, xix. 4. I. Showers injurious, X. II. I.
Salep, orchis, xvi. 3. 4. xvii. 1. 5.
:
Shepherd kings, xvi. 9. 1.
Salt inarine as a manure, X. 7. 5.
Shrubberies of mulberries, xviii. 1. 2.
as a condiment, xiv. 2. 8.
Silkworms fed with aſh-leaves, xviii. I. 2.
Sand fine white near Derby, xi. 1. 3. Situation for a garden, xv. 3.5. xiii. 2. 2.
Sap-flow, a diſeaſe of, xiv. 1. 9.
Slaughter-houſe of nature, xix. 6.5,
... juice, great force of, v: 3.
Sleep of plants, iv. 5. 5.
flows in ſpring, iii. 2. 2. ix. 2. 8. Slugs, xiv. 3. 5.
... at Midſummer, iii. 2. 8.
Smoke and ſteam of poiſonous plants, xiv.
from herbaceous plants. Add. note X. 3. 2.'
.. component parts of, x. 1. I.
Smut of wheat, vii. 2. 2. xiv. 1. 5. xvi..
Scarcity, food in times of, x. 9.4.
Scarifier, xviii. 1. 1.
Smyrna wheat, xvi. 2. 2.
Scions from roots, xv. 1. 2.
Snails and Slugs, xiv. 3. 5.
for grafting, xv. 1.4.
Snow contains oxygen, xiii. 2. 2.
for planting, sv. I. 3:
Soap-ſtone ſteatites, x. 6.8.
Sea-cale, how to cultivate, xiv. 2. 4:
Soils to analize. Add. note ix.
Secretions of vegetables, vi.
by burning them. Add. note ix.
of the graft and ſtock different, .. by their ſpecific gravity. Add. note ix.
xy. I 4.
by their native plants. Add. note ix.
gum, a diſeaſe of, xiv. 1. 10. cracks in them, to prevent, xvi. 2. 2.
Secret concerning fruit-trees, ix. 3.2. Soup leſs nutritive than the folid meat, X.
Seeds before impregnation, vii. 2. I. vii.
9.4
Sour graſs, how to deſtroy, xviii. 1. I.
growth of, ix. I.
Sow thick for herbage, xviii. 1. I.
plume grows upwards, why? ix. 1. 3. ... early on wet foils, x. 3.6. xvi. 8. 1.
root downwards, why? ix. I. 3.
8. 2.
O..
...
of
2.5.
-
ſoon after the plough, x. 6. 5.
production of, xvi.
wet, xvi. 8. 4.
ſteeped in dunghill-water, xvi. 8.3. Spirituous liquors, xvi. 9. 1. Add. note xi..
of hay ſpoiled by fermentation, x.
from roots, xvii. 1. I.
from barks, xvii. 3. 3.
of wheat ſpoiled by fermentation, xv.
from leaves, xviii. 1.6..
7. I.
Springs, origin of, xi. 1. 2.
of wheat, how to preſerve, xvi. 7. I.
wall-ſprings and pipe-ſprings, xi.
of wheat, how improved, xvi. 5. 1.
of potatoes and orchis to ripen, Xvi, how to diſcover, xi, I. 12.
Spur
. .
.
II. 7.
O
.....
1. 3.
6-936
3:40

Ι Ν D Ε Χ.
Tranſplantation of trees at Midſummer, ix.
2.9.
.... of fruit trees, xv. 2. 4. xviii.
Spur of rye, ergot, xiv. 1. 4.
Stacks of hay, X. II. 7. xviii. 1. I.
of grain, to preſerve, xvi. 7. 1.
Starch, vi. 3. xvi. 3. ix. 1.4.
.
Steain, uſe of in cookery, xix. 4. 1.
etiolates ſoine vegetables, xix. 4. I.
Steatites ſoap-ſtone, x. 6. 8.
Stigma bends to the anther, vii. 2., 2.
Straw chopped with green food, xviii. 1. 1.
Strawberries, xv. 2. 4.
barren, ix. 3. 4. xv. 1.4.
Suffuſio mellita, honey-dew, xiv. 1.7.
Sugar, vi. 5. X. 8. 1. xix. 6. 2.
ſugar from fap-juice of herbs. Addi-
tional note xi.
may injure the teeth, vi. 5.2.
..... exiſts in malt.
exiſts in malt.Add. note x.
ſeparated from mucilage, vi. 5. 3. X.
8. 2.
from beats and carrots, xvii. 1. I.
converted into ſtarch, v. 5. 5.
preſerves ſeeds, xvi. 7. 6.
nutritious, xix. 6. I.
Sweat miliary, xiv. I. 8.
Swine-troughs moveable, x. II. 6.
Swilcar oak, xviii. 2. 16.
T.
2. II.
of timber trees, xviii. 2. II.
... not too deep, why? xv.
of turnips, ix. 3.5. xii. 6.
of brocoli, xv. 2. 4. xix.
2.4.
4.2.
of ſtrawberries, xv. 2. 4.
Trees crooked, how to ſtraighten, xviii.
2. I.
ſmeared with pitch die, iii. 2. 6.
do not bleed in ſummer, ini. 2. 5.
triple by ingraftment, vii. 3. I.
their fize bounded, xviii. 2. 14.
.... to make tall and ſtraight, xviii.
2. 2.
to make them crooked, xviii. 2. 2.
when to fell, iii. 2. 3. ix. 2. 8. xviii.
.
2. I 2.
tranſplanted when large, how, xviii.
2. II.
Tennant on limes. Add. note xi.
Tanning, xvii. 3. 5.
Tape-worm in water-rats. Add. note viii.
Tar-water deſtroys ſome inſects, xiv. 3. 5.
.
Tea recommended, xviii. 1.4.
Tellure or tiller, xvi. 2. 2. xvi. 2. 3.
..... tranſplanted, how to prop, xviii.
2. II.
Trefoil, xviii. 1. I.
Trifolium pratenſe & repens, xviii. 1. I.
Truffle, lycoperdon tuber, xvii. 2. 5.
Tulip,' xv. 1. 1.
feed is five
years
before it flowers, ix.
1. 5. ix. 3.1.
leſs when coloured, xix. 1. 2.
Tull's huſbandry, 9. 3. 7. xvi. 2. 2.
.. advantages of, xii. 5.
Turnips ſowed deep in drills, xiv. 3. 5.
do not impoveriſh the ſoil, why,
xii. 7:
xii. 3.
Teucrium ſcorodonia, wood - ſage, xviii.
I. 5.
Thiſtles, to deſtroy, xiv. 1.9. Additional
note xi.
Thunder ſhowers, xiii. 3. 3.
Tiller, or tellure, xii. 7. xvi. 2. 2.
Timber, concentric rings of, xviii. 2. 12.
rot of, to prevent, xviii. 2.5.
how decompoſed, xviii. 2. 14.
political to cultivate, xviii. 2. 15.
durability of, xviii. 2. 7.
See Trees.
Tranſplantation of wheat, ix. 3. 7. xii. 6.
tranſplanted, ix. 3.5. xii. 6.
affected by the fly, xiv. 3.5.
Turpentines, vi. 8.
Tuflocks of grafs, how to deſtroy, x. 6.7.
xvili. I.I.
of wheat, xii. 6. xiv. 4. I.
of trees, xviii. 2. 2.
Twitch-graſs, xviii. 1. I.
U. Umbilical

Ι Ν D Ε Χ.
U.
Umbilical veſſels of vegetables, iii.
in feeds, ill. I. 3
in eggs, iii. I. 3
of buds, iii. 2. 2.
of the alburnum, ix. 2.9.
live after the arterial ones, ix.
2. 10.
Uredo frumenti, xiv. 1. 3.
Ultilago, fmut, xiv. 1. 5.
V.
Variegation by ingrafting, v. I. XV. 1. 4.
xix. 2. 2.
Vegetables differ from animals, i. 5.
.
reſemble animals, i. 6.
how to boil them
green,
xix.
4. I.
Vegetation, pauſe of at Midſummer, iii. 2.8.
ix. 2.9
Verſes on ingrafting, xv. I. 5.
on producing flower-buds, xv. 2.6.
on cultivation of brocoli, xix. 8.
..... on pruning wall trees, xv. 5.
.... on pruning melons, xv. 5.
... on Swilcar oak, xviii. 2. 16.
Vigorous and weak trees, X. 2. I.
Vines, art of raiſing, xv. I. 3.
management of, xv. 2. 5.
..... to ripen the
grapes, xiv. 3.3.
leaves to colour wine, xviii. 1.-5.
Vitrification, X.7. 2,
Volition, vegetable, viii.4.
W.
......
Water is decompoſed in vegetables, x 3. 3:
of ſome ſprings contains limeſtone,
x. 6. 2. X. 3.5:
.
of rain contains oxygen, xiii. 2. 2.
poiſoned by euphorbia, vi. 8.4.
Watering meadows, xi. 3:-
plants, xv. 3. 4. xviii. 2. I.
.. not in ſunſhine, why, xi. 3.4.
.. nor in froſt, why, xv. 3. 4.
.. muſt be repeated, xi. 3. 4.
not ſo as to cover them, xi, 3.3.
Wax, vi. 7.
Weeds, to deſtroy. Add, note xi.
Wet ſeaſons injurious, x. 3.9.
.
injure wheat, vi. 7.1.
.... foils, ſow and reap early in, x. 3.6.
Wheat, ix. 1. 6. ix. 3. I. xii. 5.
with branching ears, xvi. 2. 2.
number of grains from one, ix.
3. 7
..... tranfplanted, xii 6. xvi. 1. 2. ix. I.
6. ix. 3. 7. xiv. 4. 1.
rolled in ſpring, xii. 8. xvi. 2.2.
xvi. 2. 5.
harrowed in ſpring, xii. 7.
conſiſts of feparate plants, ix. 3. 1.
gluten of, vi. 8. 5. xvi. 7. 1. xvii.
0
3-3. xix.
.
has no nectary, ix. 1. 6.
injured by wet ſeaſons, vi. 7.1.
fowed but one inch deep, xiv.
36.
how to diſcover its goodneſs, xvi.
6. 1.
fow two kinds of, xvi. 8. 2.
...... caudex of produces other ſtems, ix.
I. 6.
caudex injured by inſects, xiv.
3.6.
...
-..
Wall-trees horizontal, xv. 2. I.
Walls long in drying, why, X. 4. 4.
Walnut bears by ingrafting, xv. I. I.
Waſps, to poiſon, vi. 6.3.
Water, uſes of in agriculture, x. 3.
folidified, xviii. 1. I. X.4.4.
is an acid, X.-2.6.
dibbling of, xvi. 2. 2.
.. eaten down by ſheep, ix. 3. 7. xvi.
2. 3
dried on a kiln, xvi. 7. I.
hoarded by mice, xiv. 4. I.
White parts of flowers from compreſſion,
xix. 3. 2.
Willow-bark, ix. 2. 10.
Winds, ſouth-weſt ſalubrious, xv. 3.6.
north-eaſt injurious, xv. 3.6.
Wines,
6
.

Ι Ν D Ε Χ.
Worm of ſheep, xiv. 2. 8. Add. note v.
Wounds of trees bleed in ſpring, iii. 2. 2.
v. 3.
Wines, means to fine them, Add. note x.
Woad, xviii. I. 5.
Wood, to increaſe, xviii. 2. I.
durability of, xviii. 2.7. xviii. 2. 14.
triturated for food, x. 9.4.
Wood-fires impoveriſh a country, X. II. 5.
Wood-ſage, teucrium ſcorodonia, xviii. 1.5.
Woods ſhould be planted on hills, xviii. 2.
15.
imbibe fluids in ſummer, v. 3.
of the bark, xvii. 3. 10.
upper lip only grows, 3.
of fruit by inſects, xiv. 2.9.
by caprification, xiv. 2. 9.
i.
THE END.
ERRATA.
Page 139, line laſt but one, read diſtinguiſhes, for diſtinguiſh.
121, line 14, for from, read form.
528, line laſt but two, for ſo, read no.
DIRECTIONS TO THE BINDER.
Pleaſe to put Plate I, and the Explanation of it, facing each other,
at the end of Section I. between pages 8 and 9:
Plate II. at the end of Sect. II. between p. 18 and 19.
Plate III. at the end of Sect. III. between p. 38 and 39.
Plate IV. at the end of Sect. IX. between p. 182 and 183.
Plate V. VI. VII. at the end of Sect. XI. between p. 282 and 283.
Plate VIII. at the end of Sect. XIII. between p. 314 and 315.
Plate IX. at the end of Sect. XIV. between p. 372 and 373.
Plate X. XI. XII. at the end.
I
Printed by T. BENSLEY, Bolt Court, Fleet Street, London.

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