THE LIBRARY
OF
THE UNIVERSITY
OF CALIFORNIA
LOS ANGELES
DISSERTATIONS
IMPRESSION
Two Hundred and Fifty Copies
No.Z.fa...
DISSERTATIONS
BY EMINENT MEMBERS OF
THE ROYAL MEDICAL SOCIETY
PRINTED FOR THE SOCIETY
EDINBURGH
DAVID DOUGLAS
1892
W6
PREFACE
THE ROYAL MEDICAL SOCIETY, not unmindful of the
excellent work which it has done, and the advan-
tages which it has, for more than a century and
a half, bestowed on the students of Medicine in
Edinburgh, and justly proud of the long roll of
illustrious names which are to be found in the
records of its membership, has resolved to publish
a selection from the Dissertations which have been
read at its meetings by members now deceased.
The technical expression Dissertation calls for
little explanation from those who have in any
way taken an interest in the Edinburgh School
of Medicine, and none from those who have enjoyed
the advantages and these are manifold of the
membership of the Society. For those, however,
who are not conversant with the Medical Educational
Institutions of Edinburgh a short explanation of the
working ways of the Royal Medical may not be
inappropriate.
When a student of Medicine, or it may be a
newly fledged member of the profession, desires to
a 2
vi PREFACE
enjoy the privileges of the Society, after the usual
preliminaries of proposal and ballot, according to
the laws, he takes his seat as an ordinary member.
He is bound to attend the meetings, and is fined
for absence so long as he continues to reside in
Edinburgh. After a due lapse of time, varying
according to the number of those who have preceded
him in election, he is called upon to read to the
Society an essay on some subject connected with
the healing art or some of the ancillary sciences,
which is called his Dissertation. The paper is open
to the criticism of the members, and on many occa-
sions has given rise to debates which have had an
important effect in extending the knowledge and
influencing the future opinions and practice of those
who have had the benefit of hearing or taking part
in them. The member who has read the Disserta-
tion, and almost of necessity taken part in the
discussion thereof, is entitled to become an Extra-
ordinary Member, and is now freed from compulsory
attendance and fines.
The Honorary Members are those members of
the profession or men of science whom the Society,
by the votes of the attending members, desire
to honour on account of scientific reputation or
professional esteem.
It is essentially to the list of Extraordinary
Members that the Society has had to look for the
PREFACE vi
authors of those Dissertations which it is selecting
for publication, and there is an abundant series at
command. It is to be noted, however, that there
are several names, and some of them among the
most illustrious, of whom there are no Disserta-
tions extant. Of these may be mentioned William
Cullen, one of the founders of the Society, Joseph
Black, Haller, the Monros, Oliver Goldsmith, Mark
Akenside, Mungo Park, Sir Charles Hastings,
Thomas Addison, and Charles Darwin.
It is not to be supposed that even the latest of
these selected Dissertations will add much that is
new to our knowledge of Medicine, theoretical or
practical. To expect this would be to cast a slur
on the majestic steps in advance which our profes-
sion has made in recent years ; but the writings
temporis acti are still of much value. They form
important additions o the history of Medicine a
study too much neglected ; they, in many instances,
reveal to us the embryonic state of opinions which,
by a process of evolution, have come to dominate
the scientific world ; they furnish us with interest-
ing additions to the biographies of men whose
memories we delight to honour ; and lastly, though
not least, they furnish, in their rough and ready
ways of working, and their imperfect means of ob-
servation, a salutary lesson to the enthusiastic dis-
coverer of the present day, armed with all his
yiii PEEFACE
modern refined appliances that vixere fortes ante
Agamemnona multi.
The present members of the Society desired that
the Preface to this issue of selections should be
written by one of the older members. Gratitude
for the benefits which I derived from it in my
student days, for the honour of occupying its Chair,
and for the honorary membership which it bestowed
on me, were sufficient reasons for my acceding to
the ' request that I should write the Preface. It
is not, however, without misgivings that I have
assented, because I know that there are many, both
among the past and present members, who could
have written a better Preface than myself. But as
regards the being an old member, I fancy that I am
sufficiently qualified, as I have been in its ranks
now for sixty-two years, and have never lost any-
thing of my interest in the Royal Medical, or my
desire for its continued prosperity.
DOUGLAS MACLAGAN.
March 1892.
CONTENTS
i
DANIEL RUTHERFORD
PAGE
Of Apoplexy ....... 1
The Modus Operandi of Oleum Eicini. In what Diseases is it
Useful? 9
III
GILBERT BLANE
What is the Nature of Antiseptics, and how do they Operate ? 15
IV
ROBERT JAMESON
Is the Huttonian Theory of the Earth consistent with Fact ? . 32
An Inquiry into the Nature and Origin of the Passions in their
Relation to the Intellect and Bodily Economy of Man . 40
VI
RICHARD BRIGHT
On Gangrene .... 64
x CONTENTS
VII
MARSHALL HALL
PAOI
On the Dispersive and Refractive Powers of the Human Eye,
and on some Motions of the Iris .... 84
VIII
EGBERT LISTON
On Fracture of the Neck of the Femur ... 95
IX
JAMES SYME
On Caries of the Bones ..... 104
X
EGBERT CHRISTISON
On the Contagious Nature of the British Continued Fever . 118
XI
WILLIAM SHARPEY
On Cancer of the Stomach . . . . .140
XII
ALLEN THOMSON
On the Formation of the Egg, and the Evolution of the Chick . 158
XIII
JAMES YOUNG SIMPSON
On the D^eases of the Placenta . . . .173
XIV
JOHN EEID
Can acquired Habits and Physical Configuration of Body
descend to the Offspring ? . . . 197
PAGE
CONTENTS
XV
MARTIN BARRY
On the Unity of Structure in the Animal Kingdom . . 215
XVI
WILLIAM BENJAMIN CARPENTER
On the Physiological Inferences to be deduced from the Struc-
ture of the Nervous System in Invertebrata . . 237
XVII
JOHN BROWN
On the Adaptation of the Eye to Distances . . . 254
XVIII
JOHN GOODSIR
On Continued Fever ...... 268
XIX
CHARLES MURCHISON
On the Red Corpuscles of the Blood .... 280
>
XX
JAMES MATTHEWS DUNCAN
Reflections on the Duration of Pregnancy, with Remarks on
the Calculation of the Date of Confinement 300
EDITORIAL NOTE
THE Editorial Committee desires to state that in many
cases the Dissertations published in this volume, as originally
written were too long for reproduction in extenso. They have
been abbreviated by the omission of such matter as lengthy
quotations from other authors, detailed clinical histories and
bibliographical references ; but in no case has the writer's text
been interfered with. Many of the original MSS. contained
plates and diagrams, which it was found impossible to repro-
duce.
The Committee has to express its indebtedness to PROFESSOR
SIR DOUGLAS MACLAGAN, PROFESSOR CHIENE, and DR. JOHN
WYLLIE for their kind assistance and advice in the selection,
from among several thousand Essays, of those contained in this
volume.
MEMBERS OF EDITORIAL COMMITTEE. Convener ALEXANDER
MILES, M.D. ; Secretary A. B. GILES, M.B. ; R. J. A. BERRY, M.B. ;
GERALD FITZGERALD, M.B. ; E. BARNARD FULLER, M.B. ; A. N. S.
CARMICHAEL ; R. P. COCKBURN, M.B. ; D. C. BREMNER ; LIM BOON
KENG ; J. R. HIGSON ; G. L. K. PRINGLE ; ROBERT HUTCHISON ; S. G.
DAVIDSON ; R. M. LESLIE.
DANIEL RUTHERFORD
1749-1819
OF APOPLEXY
Read 1770
A GENTLEMAN about sixty years of age, of a sanguine
temperament and very corpulent, subject to attacks
of the gout and nephritic affections, otherwise
healthy, though accustomed to a full rich diet, yet
of late has indulged more freely in the use of wine
than formerly, having for some days now and
then complained of headache and vertigo, suddenly
while at table dropped down from his chair and lies
as if in a profound sleep, without appearance of
sense or motion, at least of the left side for this
cannot be made to contract by the application of
severe stimuli, though the part shows some degree
of feeling. His breathing is natural, pulse full and
strong, though slow, has been in the above state
above a quarter of an hour.
MR. PRESIDENT,
From the symptoms of the above
case I think it is evident our patient is affected
with a stroke of the apoplexy, one of the most
A
2 DISSERTATIONS [OF APOPLEXY
dreadful diseases in its manner of attack and event
of any that befall the human body.
It is comprehended by Dr. Cullen under the
first order of Neuroses, the Comata, and is thus
defined, Motus involuntarii fere omnes imminuti cum
sopore plus minus pro/undo.
, Sauvages distinguishes it from the Cams and
Cataphora by the stertor or respiratio sonora which
enters his definition of apoplexy. Dr. Cullen with
great propriety omits this symptom, and considers
them as species of the same genus.
It is known from epilepsy by the relaxation
of the muscles, for though there are sometimes
convulsive motions of the muscles of one side in
apoplexy, yet they are to be considered as entirely
accidental, and are never so violent as those which
happen even in a slight epileptic fit.
It differs from syncope in the way it attacks,
which is for the most part very sudden, whereas in
syncope the strength more gradually fails, with
excessive sickness, tinnitus aurium, cold sweats,
etc., besides, the pulse is for the most part always,
in the sanguine apoplexy, fuller and stronger than
in syncope.
It has a much nearer affinity with paralysis
than any other disease indeed, they commonly run
into each other. I know no certain symptoms by
which they can be distinguished at the first attack ;
the most likely are the almost universal and entire
loss of sense and motion, and profound sleep that
attend apoplexy.
It has been alleged by some that apoplexies are
vastly more frequent now than they were anciently.
This notion arose from a passage in Celsus, whence it
RUTHERFORD] ROYAL MEDICAL SOCIETY 3
might be concluded that the ancients considered a
resolution of the nerves rather as a case which could,
but never did happen ; but by comparing this with
other passages from Celsus, and other authors either
before or after his time, there is the greatest reason
to believe the whole spurious, and the opinion quite
without foundation. It is true that apoplectic and
sudden deaths have been much more frequent at
one time than at another, but at the same time it
seems certain that these occur under atmospheric
circumstances which are universally allowed to be
the occasional causes of apoplexy, such as sudden
changes in the temperature of the air, etc.
Physicians have commonly marked two cases of
apoplexy, very different from each other, both with
respect to the subject, the attack, and more especially
with regard to the method of cure the sanguine and
serous. The first, those of plethoric habit, have
short necks and signs of topical determination to the
head. During the fit the face is flushed, the pulse
full and strong. The serous, on the other hand,
attacks those of a lax phlegmatic habit, and who
seem more disposed to dropsy. Besides, there is a
third kind, that may attack all temperaments indis-
criminately, which proceeds from the introduction or
application of matters which seem to destroy the
nervous power itself without any sensible effect
upon the state of the body, such as some poisons,
mephitic air, e.g. ; we can even imagine the state of
the nervous power which induces sleep, carried to a
higher degree, occasion all the symptoms of apoplexy.
But as my patient's disease is entirely of the first
kind, viz. the sanguine, I shall confine myself solely
to that.
4 DISSERTATIONS [OF APOPLEXY
Though we must suppose the proximate cause
of all apoplexies to be one and the same, as it seems
to be purely an affection of the nervous fluid, there
is little hope of our ever determining with precision
what that may be, since people are cut off by par-
ticular apoplexies where we cannot observe the
smallest deviation from the natural texture of the
brain ; we must be contented to take the preter-
natural appearance within the cranium for the
proximate cause of sanguine apoplexy. There are
few diseases that afford so good an opportunity for
discovering the causes by dissection as the present.
There is commonly found an effusion of blood or
serum between the meninges of the brain, into the
ventricles or some preternatural cavity in the sub-
stance of the brain, though in some few cases there
is nothing uncommon to be observed, except an im-
moderate distension of the vessels, and accumula-
tion of blood in them. I would therefore assign as
the proximate cause of the apoplexy an accumula-
tion or effusion of blood within the encephalon, and,
from thence, compression of the brain.
A very great many cases may contribute to
produce this effect. They seem to be referable to
two heads : first, whatever tends to increase the
quantity or accelerate the motion of the blood in
general, or particularly in the vessels of the brain ;
second, whatever retards the free return of the blood
by the veins from the brain.
To the first head belong all the causes of ple-
thora, and particularly high living and indolence, as
in the present patient ; compression of any of the
large arteries on any other part of the body ; parti-
cular conformation of the body to favour the ascent
RUTHERFORD] ROYAL MEDICAL SOCIETY 5
of blood to the brain, as a large head, short neck.
In people who have died of apoplexy there have
been only six cervical vertebrae found, unnatural
division of the arteries, as the vertebral coming
from the aorta in place of the subclavian.
Those which belong to the second head are more
frequently the causes of apoplexy. The particular
distribution of the veins of the brain may by itself
perhaps tend to produce accumulations in them,
since by the firm texture of the sinuses and the
tendinous threads which run across and connect
their sides together, these cannot suffer any dilata-
tion. The smaller veins which run throughout the
brain must be more subject to it.
The advanced stage of life to which our patient
has arrived comes under this head, for at this time
congestion in the veins, or venous plethora, is most
apt to take place.
Obstructions to the motion of the blood through
the right ventricle of the heart belong thus likewise
to this head.
Also any obstructions to the free passage of the
blood through the lungs, as happens commonly in all
cases of difficult respiration ; hence whatever hinders
the descent of the diaphragm, as a great accumulation
of fat in the abdomen, as is probably the case in our
patient. The over-distension of the stomach proves
a cause of apoplexy. Violent strainings, in which
we commonly make a full inspiration, and then
confine the air for a long time, sometimes occasion
it. Cold air, by repelling the blood from the sur-
face, and accumulating it in the lungs, and thereby
obstructing respiration ; and, on the other hand,
the air becoming hot of a sudden, by rarefying and
6 DISSERTATIONS [or APOPLEXY
expanding the blood, are also mentioned as causes
of it.
Compression of the jugular veins, or lying with
the head very low, are apt to bring it on, for by
barely stooping for a short time headache, sidomia,
and other symptoms that commonly precede an
apoplectic fit, are induced.
The causes that for the most part more imme-
diately excite it are those which occasion an in-
creased action of the heart and arteries, such as
anger, hard drinking, etc.
The symptoms are all easily explicable from the
supposition of a diminution, almost a cessation, of
motion in the nervous fluid. The only difficulty is
to explain how the heart and arteries continue to
act when the rest of the body is almost inanimate.
Some have attempted to account for this by deriving
the nerves of the heart from the cerebellum, which
they say is never affected in apoplexy. But I think
we can scarcely subscribe to this opinion when we
observe that other organs supplied with branches of
the same nerves are equally deprived of sense and
motion with the rest of the body. Nor is it a fact
that the cerebellum is never affected. It seems more
probable that this phenomenon is caused by the
greater quantity or greater power of the vessels,
inside of the vital organs, than of the other parts
of the body, by which they are enabled to perform
their functions for a long time, though in a great
measure deprived of the vis nervea.
With respect to the prognosis, the apoplexy is
for the most part fatal, and always dangerous.
There are no symptoms, as far as I know, that
certainly prognosticate a cure ; the danger is chiefly
RUTHERFORD] ROYAL MEDICAL SOCIETY 7
to be estimated according to the degree and univer-
sality of the loss of sense and motion. When these
are great, and the faeces voided, it is commonly fatal
in a few minutes.
The apoplexy agrees so very much with active
hemorrhages, that the cure of the present fit, and
the preventing a return of it, are conducted upon
the same plan in both diseases.
The recovery from a fit is attempted by taking
off the congestion from the head. It is evident that
blood-letting is the only means that can be employed
here, for any other evacuations, as by vomiting or
stool, however desirable they may seem, by the
straining that attends their operations, are likely
to aggravate the cause of the disease.
A great quantity of blood should be taken, and
that speedily too. Authors have differed with regard
to the vessels from whence it should be drawn.
Arteriotomy would answer very well in this case,
were it not that the evacuation is very slow this
way. Opening the jugular vein seems to be the
most proper, and it ought to be performed on the
soundest side of the body, if there be any difference,
as most nearly connected with the side of the brain
that is compressed, for whichever side of the body
is chiefly struck, the opposite side of the brain
is found to be affected. Mead and some others
strongly recommend the application of cupping-
glasses to the occiput, having previously taken
care to make the scarifications very deep.
If the patient is not roused from his fit by the
blood-letting, there will be very little chance for a
cure. We should then try blisters applied to the
head, and some purgative either by the mouth or
8 DISSERTATIONS [RUTHERFORD
by way of clyster. Hot, stimulating applications
are manifestly improper in such a case, yet if death
seems inevitable otherwise, these must also be tried.
Perhaps pediluvia might cause a revulsion from the
head.
Were we so fortunate as to restore him to his
senses, I think small doses of tartar emetic, so as to
procure a diaphoresis, would be the most effectual
means of carrying off the remainder of the fit.
From this time his diet ought to be extremely
poor, and every means used to keep him very low ;
upon the slightest attack of headache, etc., it would
be proper to take a little blood. He ought to abstain
entirely from wine, and use a great deal of exercise,
though very cautious not to fatigue or overheat
himself, lest that might occasion a relapse.
II
JAMES GREGORY
1753-1821
THE MODUS OPERANDI OF OLEUM EICINI.
IN WHAT DISEASES IS IT USEFUL?
Read 17-72
MR. PRESIDENT,
The medicine of which I am now to
treat has of late been pretty generally used
where a very mild laxative was required, for
which purpose it has been found to answer very
well. As I have had but little opportunity to
observe its effects myself, I must content myself
with relating what I have learnt concerning it
from others. In particular, I think it proper to
declare that what I have to say concerning it is
almost entirely taken from a dissertation of Dr.
Canvane of Bath, written expressly on the virtues
of the Oleum Hieing. Perhaps he is too great an
enthusiast in behalf of his favourite medicine, and
ascribes virtues to it greater than many would be
disposed to allow. But I must observe that few
can be so well qualified to judge of its virtues as
he is, for he says he used it constantly for seven
years in the West Indies, and very frequently for
twelve years after he returned to England.
10 DISSERTATIONS [OLEUM mem
This oil is obtained by expression from the kernel
of the fruit of the Palma Christi, as it is commonly
called. This plant Linnaeus has placed in the 9th
Order (Monadelphia) of his 21st class (Moncecia).
As I never yet could learn anything from a
botanical description myself, I despair of being able
to give such a description of this plant as may be
of use to others ; and if I could, I believe it would
hardly be worth my while, as many members of this
Society have seen a specimen of this plant already,
and those who have not may see it whenever they
please. The specimen I mean is that in the Botanic
Garden, which is perhaps the finest in Europe.
Dr. Hope, I believe, has procured a considerable
quantity of the oil from the seeds of this plant. The
tree has obtained the name of Palma Christi from a
fancied resemblance between the palm of the hand
and its leaves. It was called Bicinus by the
Romans because its seed resembles an insect of that
name which infests horses and other cattle. The
French in the West Indies gave it the name of
Agnus Cast us, from a supposed virtue of moderat-
ing venereal appetite, which they ascribed to it ;
and that name of Agnus Castus was corrupted by
the English into that of Castor Oil, by which it is
now very commonly known. It is said that this
plant was known to the ancient Jews under the
name of Keh, and to the Greeks under the name
of Kporuv, but it does not appear exactly in what
manner they used it. In modern times it was first
used in the island St. Christopher's, I believe after
the example of the Indians. It is now very com-
monly used, and Dr. Canvane very strongly re-
commends it in all cases where a mild laxative is
indicated.
GREGORY] EOYAL MEDICAL SOCIETY 11
In Fevers. It is said to answer very well as a
laxative in all fevers where it is required to keep
the belly open, and at the same time where it
would be improper or dangerous to use any stimu-
lating medicine. It is recommended particularly in
the yellow fever of the West Indies after premising
an emetic. Dr. Oanvane gives us a caution in
respect to its use in the nervous fever, where he
says it did not answer.
Colica Pictorum or Dry Belly-ache. It is said
to be a very valuable remedy in this disease, and to
remove the constipation and consequent symptoms
easily, safely, and effectually. It is said in par-
ticular that those cured by this remedy had no
paralytic affections of their extremities ; which, as
is well known, used frequently to follow on the cure
of the original disease.
Bilious Disorders. It is said to be of consider-
able service in carrying off and clearing the primes
vies from a load of bile which is sometimes poured
upon them, as in cholera. Where the bile is ob-
structed, as in jaundice, it is of use as a laxative to
remove the costiveness which attends that disease.
Arthritis. As a mild laxative it may often be
used with propriety in this disease.
Nephritis and calculous complaints in general.
In the nephritis it may be used to considerable
advantage as a, mild laxative. But Dr. Canvane
observes that it has an effect in promoting the
discharge of gravelly matter, and preventing the
formation of calculus. He observes : 1st. That as
often as he has taken this oil it occasioned a dis-
charge of sandy matter ; 2nd. That by the use of this
oil he has continued free from nephritic complaints,
12 DISSERTATIONS [OLEUM EICINI
to which he was formerly subject; 3d. That in these
islands where this oil is much used, the inhabitants
in general are not so subject to calculous complaints
as in other places ; 4th, That though it generally
acts as a purgative, yet it sometimes fails of that
effect, and proves a very powerful diuretic ; 5th.
That its colour and smell are sometimes communi-
cated to the urine of those who take it.
Dropsy. It is said to be useful in this disease,
and to have occasioned a great and sudden dis-
charge of urine when well rubbed over the ab-
domen. Dr. Can vane thinks it useful in the tetanus,
in the gonorrhoea and fluor albus ; but as he used
other more powerful medicines along with it, it is
difficult to determine how far the good effects were
owing to the oil.
Aphthce. The Oleum Ricini is said to be of con-
siderable service when given occasionally in the
course of this disease.
Dysentery. The importance of mild laxatives
in this disease is well known, and perhaps none bid
fairer to be of use than the Oleum Bicirii.
It is to be observed that the effects of the oil
differ greatly from those of the kernel from which
the oil is expressed, which is generally the case
with expressed oils. The Oleum Ricini is of a mild,
unctuous, nauseous taste, but may be taken in-
ternally to the quantity of two or three ounces
without its producing any other effect but that of an
easy laxative. The kernel, too, is very mild to the
taste, but if taken internally, even though in very
small quantities, occasions sometimes violent vomit-
ing and purging. On this account an emulsion of
these kernels, if it is to be used at all, must be
GREGORY] ROYAL MEDICAL SOCIETY 13
exhibited very cautiously. It is said that an emul-
sion of one kernel only will occasion vomiting and
purging. Perhaps if the oil could be obtained
perfectly pure, and without any mixture of the
other parts of the kernel, it might have no more
cathartic property than oil of olives or oil of almonds.
At least it appears clearly that the chief activity
does not reside in the oil. Perhaps, too, from this
circumstance, the oil may be of very different degrees
of strength and efficacy, as greater or less force has
been used to separate it from the kernel. As we
have it here, it may be given from a half to two
ounces for a dose. Its taste is not disagreeable to
some people, but with many it is apt to excite
nausea ; to such therefore it may be disguised with
a ^sufficient quantity of peppermint- water or brandy
(which last I am informed answers the purpose very
well), or honey or sugar in the form of an oleo-
saccharum or emulsion, or with gum-arabic, etc.
These mixtures would perhaps be rendered more
agreeable by the addition of any aromatic essential
oil.
It may be given with advantage in clysters to
the quantity of three ounces. To children it may
be applied in the way of friction or embrocation.
It is said that when rubbed on the abdomen of
children it will exert its cathartic effects.
I forgot to mention that this oil seemed to be
one of the best remedies to prevent habitual costive-
ness, even when not attended with any other disease.
It may seem somewhat extraordinary that I have
taken no notice of the first part of the question, to
wit, the modus operandi of castor-oil. I have all
the inclination in the world to give a good account
14 DISSERTATIONS [GREGORY
of this, but must confess it is beyond my abilities.
I believe it acts by stimulating the intestines like
other cathartics, but I do not know by what peculiar
property it produces that effect more than other
expressed oils.
Ill
GILBERT BLANE
1749-1834
WHAT IS THE NATURE OF ANTISEPTICS, AND
HOW DO THEY OPERATE 1
Read 1775
MB. PRESIDENT,
This question is both curious as a
subject of natural inquiry, and important as an
object of the Medical Art. I shall endeavour to
consider it in both views, at as great length as the
extent of a paper of this kind will allow.
By antiseptics are meant substances that retard
or prevent the progress of putrefaction, or correct it
when it has taken place. The progress of putrefac-
tion is one of the most important operations in the
economy of nature. The life of all organic beings,
according to the present constitution of the world,
is circumscribed within certain limits of duration.
The scheme of nature requires that when deprived
of life their organisation should be broken down,
both to free the surface of the earth from the incon-
venience that would arise from their accumulation,
and to afford matter for a new succession of the
same forms. All vegetable and animal matter has
16 DISSERTATIONS [ANTISEPTICS
a decay and a revival, and putrefaction is the middle
stage through which they must all pass, and to
which they are all spontaneously prone. But how-
ever useful an instrument this may be in nature, it is
often a desirable object, both in the economy of life
and in medicine, to prevent and arrest its progress,
since it disqualifies alimentary substances . for the
purpose of food, and in the living body is altogether
incompatible with health and life. Of however
much consequence it may be in all these views, it
was long before it was attended to as it ought.
Lord Bacon saw the importance of it, and recom-
mended it to the inquiry of physicians. It has
accordingly been prosecuted lately by some of the
ablest hands, and we have a considerable collection
of facts and reasonings upon the subject. Of these I
shall endeavour to give a synoptical view, as concise
as the great extent of the subject will admit.
In the inquiry I shall observe the following
method. I shall first consider the nature and cir-
cumstances of putrefaction. Secondly, the' means
of correcting and preventing it in the dead body.
Lastly, the means of preventing and correcting it
in the living body.
I. NATURE OF PUTREFACTION.
In treating of the first article it may be observed
that in order that putrefaction take place, it is
necessary that a certain degree of moisture, heat,
and air be present. These are circumstances that
usually occur in nature, and therefore putrefaction
is nevertheless called a spontaneous operation.
That moisture should be necessary is what we
should naturally expect, for no chemical change
BLANE] ROYAL MEDICAL SOCIETY 17
can take place among bodies that are absolutely
solid. It is necessary that their aggregation be
broke either by solution or fusion, that the elemen-
tary particles may be free to unite or separate in
order to form new combinations ; for in this we
suppose putrefaction as well as every other change
in the forms of matter to consist.
Heat is no less requisite, for it is the great
principle of activity in nature, and is particularly
favourable to chemical attraction. It favours putre-
faction according to its intensity from the freezing-
point to 100 or 110. From this to the boiling
heat it has less and less effect in promoting this
process. We may perhaps affirm the same from
this to the degree in which the substance is de-
compounded. All other chemical processes are
promoted in proportion to the degree of heat ;
and why this should be an exception is what I
cannot perhaps explain satisfactorily, and will not
detain you with conjectures.
The third requisite to putrefaction is air. It
seems to be necessary to this operation on the same
foundation that it is necessary to combustion. How
it is so in either case is a difficult question. It
seems to be by its affinity with some of the principles
of the body, by its attraction for which, it facilitates
the decomposition of the substance. The fact here
has been a matter of some dispute, but it is now
beyond a doubt that putrefaction does not proceed
in a receiver that is absolutely exhausted. It has
been objected indeed that it proceeds fastest in
close vessels. But there is a fallacy here, for though
it proceeds faster at first, it is found to be sooner
at a stand than if it had been exposed to the free
B
18 DISSERTATIONS [ANTISEPTICS
air ; and the hasty progress at first is owing to the
putrid effluvia being retained, and acting as a ferment
on the rest of the substance. But when the air
enclosed conies to be thoroughly charged with these
effluvia the putrefaction is stopped, notwithstanding
of the increased force of the ferment. The exhaust-
ing of air in part, does indeed promote it, and the
condensation of air retard it, but this is to be
ascribed merely to the diminution and increase of
the incumbent weight.
These three circumstances may in some sense be
called the causes of putrefaction. But they are
so only in a secondary and remote manner, and we
would choose to inquire more closely into this
operation in order to understand its nature. It is
seldom however we can carry our researches so far
with success, for the intimate nature of bodies, and
the minute motions taking place among the ultimate
indivisible particles in producing the various forms
of things, is all an unknown world to us. It is upon
such minute changes that the great operations of
nature depend ; but the shape, arrangement, and
various affinities of the primitive particles of matter
are slight and impalpable, and only their distant
effects are the objects of our senses. The doctrine
of corpuscular attraction does indeed carry us a
certain length in explaining the phenomena of
chemistry, and we may apply this to the present
subject. There is in the formation and dissolution
of organic bodies, a separation and combination of
particles that seems referable to the various affinities
of constitutional parts, in like manner as the
mixtures and precipitations of chemistry. There are
however in these processes several peculiarities that
BLAKE] KOYAL MEDICAL SOCIETY 19
seem hardly referable to other chemical changes, as
we shall see in the sequel of our reasonings.
Animal bodies are substances of a peculiar nature,
and seem to be the most elaborate and exquisite of
nature's works. Organs, in order to answer their
purposes, must possess a certain degree of hardness
or softness, flexibility, and elasticity, according to
their use in the system, and these varied and ad-
justed with a nicety that is not required in the
other parts of nature. In order to perfect this, very
subtle principles must be combined in the most art-
ful and delicate manner in the stomach, intestines,
and blood-vessels, and again unite by accretion into
various forms of aggregation in the fibres forming
bone, muscles, and membranes. The constituent
parts of the animal mixt being thus nicely ad-
justed, are in a continual effort to separate, and
are held together by an unknown and wonderful
power peculiar to life. The natural heat of the
body is about that degree which is most favour-
able to putrefaction, yet it resists it ; but as soon as
life is gone, runs into it in a much lower temperature.
The excretion of effete and putrid matter by the
skin and lungs, the constant repair from aliment,
and the constant motion from the contraction and
dilatation of vessels, go a certain length in account-
ing for this antiseptic power of life.
There is nothing more evident than that putrefac-
tion consists in decomposition, for all the elementary
principles in nature appear in the course of it. The
aqueous, the saline, the inflammable, the aerial, and
the earthy principles are severally evolved. The
evolution of water is evident from the greater
fluidity of putrefying substances. As to the saline,
20 DISSERTATIONS [ANTISEPTICS
there is some doubt of the presence of an acid, but
that of the volatile alkali cannot be denied. I think
it highly probable that an acid is also sometimes
at least extricated. 1. It is presumable, because
vegetables are the nourishment of animals, and they
are well known to be acescent. 2. Decoctions of
the flesh of young animals have been observed to
turn sour. 3. It is now proved that animal matter
is subject to the various fermentations, for the in-
habitants of Siberia and the north of Tartary have
a method of making an intoxicating liquor by the
maceration of fish in holes dug in the earth. It is
probable, therefore, that such substances may pass
through the other stage of fermentation when in
proper circumstances. Lastly, I conclude that an
acid is generated from the septic power of ab-
sorbents. As to the aerial principle, it is proved
by the experiments of Cavendish and Pearson that
both fixed and inflammable air are extricated. The
residuum, after the putrid process is complete, and
ah 1 the volatile parts exhaled, is purely earthy ;
for putrefaction volatilises the salts more than
even fire, converting the fixed alkaline into the
volatile, and the acid into that of the phosphoric
kind.
A gentleman, to whom we are indebted for
several ingenious suggestions relating to the present
subject, has supposed that the cohesion depended
on the fixed air. But I apprehend that the mode
of aggregation in all mixed bodies is the result of an
habitual relation subsisting between all the principles,
whereby the attraction on which cohesion depends is
mutual, and that as soon as a body is decompounded
by losing any one of its principles, its properties as
an aggregate and its nature as a mixt is destroyed.
BLANE] ROYAL MEDICAL SOCIETY 21
If air was the principle first extricated, or the only
one, there might be some appearance of foundation
for this opinion. But it is proved by the experi-
ments of my ingenious friend Dr. Pearson, that the
saline and inflammable principles are as soon extri-
cated as the fixed air. Dr. Alexander has even
found that putrefaction can take place without any
extrication of air at all.
It has been doubted by some if putrefaction
could properly be called fermentation. But it is
so analogous to what is called fermentation in
vegetables that it seems unnatural to deny them
the same appellation. They are both instances of
the dissolution of organic bodies ; and, what is more
essential, they are both excited by ferments. It is
this that most distinguishes these processes from all
others in chemistry, and there seems hardly any-
thing less understood than their mode of operation.
I am one of those who think that fermentation is
a process very analogous to inflammation. 1. The
principal phenomenon in both is an evolution of
phlogiston. 2. The presence of air is necessary to
both, and seemingly for the same reason. 3. They
both resolve bodies into much the same principles.
4. They both produce actual heat. Lastly, I would
infer this analogy from the nature of ferments. For
in like manner as inflammable bodies are put into
a state of combustion by the application of another
body in the state of ignition, we may conceive
a fermentable substance to be put into intestine
motion by the application of a small quantity of
matter actually in a state of fermentation.
They are, in short, both active conditions of
matter communicable from the smallest masses to
the greatest.
22 DISSERTATIONS [ANTISEPTICS
II. ANTISEPTICS IN RELATION TO INANIMATE
MATTER.
Having said so much of the nature of putre-
faction, I proceed now to consider the means of
counteracting it. These are either such as prevent
putrefaction, or such as restore soundness. It is
the former that have been commonly understood by
antiseptics, since it is but lately we are brought
acquainted with the latter. Concerning them I will
venture to advance a proposition more general than
has hitherto been offered on the subject, in saying
that everything with which water can be impreg-
nated is of an antiseptic nature. We have men-
tioned before that moisture is an indispensable
circumstance in putrefaction, and it would appear
that pure water is the fittest for this purpose. This
is, indeed, what we would expect from the general
analogy of chemistry, where we find that changes
can take place only in bodies that are in some
degree of fusion or solution. Now, it is well known
that water unimpregnated with anything is the
best menstruum for those bodies for which it has
an attraction ; and it is proved by the experiments
of Dr. Robinson that pure water has a stronger
affinity with the animal fibre than any impregna-
tion of it. By being the solvent of the animal
mixt, therefore, it gives the elementary particles
of the constituent parts that free motion upon each
other, which is necessary to the various attractions
and repulsions resulting from their several affinities
with each other. It is true there are some corrosive
salts that seem to possess a solvent power superior
to pure water. Of this kind are the simple salts
BLASB] ROYAL MEDICAL SOCIETY 23
and some metallic salts. But these seem to act by
decomposition, in consequence of a particular affinity
with some of the constituent parts, and not by an
attraction for the impregnated parts, as is the case
with pure water. Though they have a solvent
power, therefore, yet they are at the same time
antiseptic, by changing the relation of the con-
stituent parts to each other, by supporting what
may be called the equilibrium of attraction, and
thereby taking off that proneness to separate which
they have in the state of the animal mixt.
Having thus stated the arguments a priwi in
favour of this opinion, let us next see how far it is
supported by fact. It is now sufficiently proved by
the experiments of Sir John Pringle, who has en-
larged our ideas upon this subject, that all saline
bodies in some quantity or other are antiseptic.
Alkalies from their solvent power, and because
they were the product of putrefaction, were supposed
to be septic, but this has been clearly disproved
by the above-mentioned experiments. It is well
known that all impregnations of vinous spirits are
antiseptic, and it has been found by a number of
experiments that all vegetable decoctions and in-
fusions are so. All the different species of factitious
air have been found to possess this power. From
this induction of facts we seem sufficiently justified
in the proposition before laid down, ' that every im-
pregnation of water is antiseptic.' It need hardly
be mentioned that ferments and fermentable bodies
themselves are excepted from the general rule. If
the impregnation be of a fermentable nature it is
itself a subject of putrefaction, and will communicate
this state to the mass with which it is in contact.
24 DISSERTATIONS [ANTISEPTICS
It will do so much more if it be applied in this
state. But if the intestine motion has ceased, and
the putrid process be complete, it will even have an
antiseptic effect. It is the want of attention to
this last circumstance that has produced some fallacy
in Dr. Alexander's inferences from these experiments.
Those putrid substances which he found antiseptic
were such as had undergone the complete putrefac-
tive process, and his facts do not invalidate the
common opinion of the septic power of putrefying
bodies. We must distinguish therefore between the
putrefying and the putrid states.
What we have hitherto said relates only to the
matter of antiseptics. We may also take some
notice of the means. These are chiefly suggested
by the circumstances necessary to putrefaction,
which we have before enumerated, and are therefore
the want of the requisite degrees of heat, moisture,
and air. We have an example of both the two first
in the practice of cold climates, where they preserve
their meat from corruption by allowing it to freeze
in the open air. We have an instance of the effect
of drying in portable soup, and many other culinary
preparations. As to the third circumstance we have
already mentioned the effects of a vacuum. But
this is not applicable to any useful purpose in life.
There are other methods, however, of excluding the
air, which may be turned to use, such as the pouring
wax or grease about substances we wish to preserve.
To this also may be referred the well-known method
of preserving eggs. To the head of means we may
add compression, which Dr. M'Bride has found to
be strongly antiseptic. The division of a substance
into small masses is another means of preventing
BLASE] ROYAL MEDICAL SOCIETY 25
fermentation. We have a familiar instance of this
in the juice of an orange, which is preserved long
from corruption in the small vesicles of the fruit,
but soon ferments when effused. Does not this
show that the sphere of the corpuscular attraction
is of a very sensible extent ?
The other class of antiseptics is of those that
restore sweetness. They may be divided into two
orders : those that remove the fcetor and prevent
farther intestine motion, and those that restore
firmness and soundness. Of the first kind are the
simple salts, and of the other kind is fixed air. The
former seems to act by uniting with the volatile
phlogistic principle upon which the fcetor depends,
and they check the farther evolution of it by their
common antiseptic power. The other seems to act
by restoring a principle which had escaped during
the septic process.
I would willingly enlarge on this subject, and
also enter into the consideration of septics. But
the limits of a paper of this kind will not admit it,
and the most important part of the subject yet
^ceraains to be considered. With regard to septics,
I shall satisfy myself with saying that they may be
reduced to three classes, small quantities of some
neutral salts, absorbent earths, and putrid ferments.
I shall only add that these salts alone seem to be
septic which have an earthy basis ; for Dr. Percival
has found that Epsom salt is the most septic of all,
and that sea salt is only septic in so far as it contains
a portion of that salt.
26 DISSERTATIONS [ANTISEPTICS
III. ANTISEPTICS IN RELATION TO THE
LIVING BODY.
We proceed to consider what are the antiseptics
of the living body, and what is their manner of
operating. In order to be intelligible on this sub-
ject, I must premise some general considerations
from the animal economy. I need not mention to
gentlemen so enlightened in the doctrines of physic,
how much pathology, as well as the other branches of
medicine, has been enlarged and improved of late by
attending to the powers peculiar to life in opposition
to those of a chemical and mechanical nature, which so
long occupied the attention of physicians. Nor need
I mention to whom, we are indebted for so great an
improvement. It is to him whose name I foretell
will make an era in the history of our art for the
many new and important truths he has established,
and for the singular success with which he has
applied them to the practice of medicine. Let us
keep constantly in view that the human body is an
animated system, subject to laws totally different
from those of a mere automaton or of a chemical
compound. To be sensible of this we need only
reflect on the various phenomena of sense and
motion, the irritable contractility of fibres, the
generating power of heat, circumstances in common
with no other matter. Let us not be rash there-
fore in applying what has been said in the former
part of this paper to the cure of diseases. We
shall find that the principles laid down are in some
degree applicable, but that in general we must
conduct ourselves by an experience of a different
kind, considering how fallacious it is, however
BLASE] ROYAL MEDICAL SOCIETY 27
plausible it may be, to transfer to the living body
those experiments and reasonings that are instituted
on dead matter. The power of resisting putrefac-
tion is as distinguishing a peculiarity in the animal
economy as any we have mentioned. We would
naturally expect that the causes of putrid diseases
would, in many cases at least, operate on this anti-
septic power of life independent of any direct effect
on the matter of the body itself. We shall find in
the nature of this inquiry that there are causes of
both kinds, though very different in their power
and their mode of operation.
Putrid diseases are either chronic or acute. By
the first we mean the scurvy, and under the other
we comprehend putrid fevers and gangrene. The
scurvy arises from such causes as we might
naturally expect to affect the fluids, and it is perhaps
the only disease whose proximate cause consists
primarily in an affection of the fluids'. The occa-
sional causes of it are, an excessive quantity of
animal food, or a vitiated state of it, and a cold and
moist atmosphere. The first tends to dissolve the
texture of the blood, the other suppresses the ex-
cretion by the skin, which is one of the principal
outlets to the effete and putrid matter continually
generating in the mass of fluids.. We can make
some application of what has been said in the first
part of this paper to the cure of this disease. There
are, however, many of the antiseptic substances
there enumerated which are unavailing, and many
of them hurtful. It is only those that restore
sweetness which have been found of any service.
From these the alkalies must be excepted, as they
are highly noxious, both by their stimulant and
28 DISSERTATIONS [ANTISEPTICS
dissolving power. Acids are exceedingly useful,
especially as preservatives. Their use, however, has
been magnified beyond what experience warrants.
As in this disease there was supposed to be an
alkali present, it was imagined that acids must be
infallible by neutralising it. But it is more probable
that they operate, either by coagulating the bile, as
ingeniously explained by Dr. M'Lurg, or by becom-
ing a constituent principle in the gluten of the
blood. This last opinion seems to be confirmed by
the superior efficacy of the vegetable acid to any
other, for it is well known that this can enter into the
mixture of the animal fluids. It is found that nothing
will cure this disease but fresh vegetables, or ferment-
able substances analogous to them. We cannot
sufficiently applaud the ingenuity and humanity of
Dr. M'Bride in discovering and confirming this
practice. He has pointed out a succedaneum to
fresh vegetables which bids fair to be of the most
extensive use in preserving the life and health of
seamen. Such substances seem to operate merely
as aliment in producing a total change in the crasis
of the fluids. Their effect seems to depend on a
particular mode of fermentation in the stomach,
consisting in the easy extrication and reabsorption
of fixed air. This has appeared so probable that
Dr. Priestley and Dr. Percival have proposed -to sub-
stitute water impregnated with fixed air. The
particular advantage of this is that the materials
for producing it are very portable, and of an incor-
ruptible nature. Experiments are now making
under public authority to determine the expediency
of this practice, and we shall suspend our judg-
ment till the result of these appear.
BLANE] ROYAL MEDICAL SOCIETY 29
We come now to consider the acute putrid
diseases ; but as I am already beginning to exceed
the usual limits of exercises of this kind, I must
satisfy myself with a few general observations,
nowise proportioned to the difficulty and importance
of the subject. Putrid fevers belong chiefly to
warm climates and seasons, and it has been im-
agined that heat produced them in the living body
as it does putrefaction in the dead body. But it is
found, by observations on the thermometer, that the
heat of the body is the same in all climates. It
-acts in a more indirect manner, by producing a
debility and relaxation which predisposes to disease
by carrying off the more fluid part of the blood by
perspiration, and by generating more copiously those
human and marsh effluvia which are the remote
causes of fever. It can, indeed, be pretty clearly
evinced that the putrid state is a consequence and
not a cause of such fevers. This appears not only
from the general doctrine that all fevers are
primarily affections of the nervous system, but from
the absence of putrid symptoms in the beginning
even of putrid fevers. We are to ascribe the
putrid state, therefore, either to the sedative power
of the remote cause, concurring with the debili-
tating and relaxing power of external heat, in
diminishing that energy of the vital motions which
enables the body to resist the spontaneous tendency
to putrefaction ; 1 or to the contagious matter acting
as a ferment, and multiplying itself by assimilating
the fluids to its nature. The existence of this last
is sufficiently proved by the multiplying of contagion,
but the first has probably a greater share in the
putrid symptoms ; for, in the remittent fevers of
30 DISSERTATIONS [ANTISEPTICS
warm climates, proceeding from marsh effluvia,
and in tropical gangrenes, the putrefaction advances
very fast without any suspicion of a ferment. For
this, as well as other reasons, I cannot help disagree-
ing with so great an authority as Sir John Pringle,
who thinks that in putrid fever, as in scurvy,
there is a primary affection of the fluids, that these
diseases only differ in the putrid acrimony being
more slowly generated in the latter than the former,
and that the latter assumes a chronical form by the
symptoms being gradually habituated to this
vitiated state of the fluids. The purpose of this
reasoning is to show that few indications in putrid
fevers are to be drawn from what has been said
concerning the antiseptics of dead animal matter.
Since the morbid condition of the system depends pri-
marily on the state of motion, it is to this the means
of cure must be directed. This theory is confirmed
by experience, which ought to be the touchstone of
all our reasonings ; for those antiseptics which are
at the same time tonic have been found most
serviceable in the diseases in question. The bark
and other tonics do indeed possess a strong anti-
septic power in relation to dead matter ; but this is
not to be wondered at, since every impregnation of
water does so. If the effect of medicines in putrid
fevers was in proportion to their simple antiseptic
powers, we should find camphor, ardent spirits, and
essential oils preferable to all others, and alkalies
would be as useful as acids. But the contrary of
all this is known by experience. The operation of
acids seems indeed to consist, in a considerable
degree, in a purely antiseptic power ; but this
chiefly by sweetening the putrid contents of the
BLANE] ROYAL MEDICAL SOCIETY 31
intestines. Much may depend also on their effects
on the bile, which is remarkably acrid and copious
in putrid fevers. The vegetable acid, as a nutritious
substance, may, as in scurvy, have a good effect in
correcting the crasis of the fluids. I need not insist
on their refrigerent and diaphoretic powers, which
render them applicable in all fevers.
I should now proceed to consider gangrene, but
I find I have grasped a too extensive subject, and
must leave this part altogether untouched. My
unexpected attendance this session has obliged me
to give in this dissertation at a much earlier period
than I thought of, having intended to reduce it to a
more concise form, and to have determined some of
the ambiguous points by experiment. I have
now only to crave indulgence for the crude form
in which it appears, sensible that it is not answer-
able to the expectations of those who may know that
the subject was assigned me at my own particular
desire.
IV
ROBERT JAMESON
17/4-1854
IS THE HUTTONIAN THEORY OF THE EAKTH
CONSISTENT WITH FACT?
Read 1796
MR. PRESIDENT,
The celebrated theory of Doctor Hutton
has, for several years, attracted the attention of
geologists, not more from the ingenuity with which
it is supported, than the vast collection of facts
which it contains, rising in this respect far superior
to all former conjectures. His arrangement is exten-
sive, and would require more time than the Society
could spare, for a complete examination would in-
clude a thorough review of the most interesting
mineral phenomena. It would be preposterous then
to investigate all the general principles he has laid
down ; I shall therefore only examine that position
which appears to me to be the basis of the theory ;
that is, that all the strata of the globe have been
consolidated by means of heat, and hardened from a
state of fusion.
To explain this position two principles have been
assumed, viz. Insuperable Compression and Slow
Cooling. The consideration of these will conse-
JAMESON] DISSERTATIONS 33
quently contain what I have to say in these few
notes with regard to this theory.
INSUPERABLE COMPRESSION.
This wonderful principle of compression, we are
told, prevents the escape of elastic vapours, fuses
silex, etc. And, in proof of this, various mineral
phenomena are produced, which are said to be in-
explicable upon any other principle. Thus, silex
is said to be insoluble in water, consequently, must
have been crystallised, etc., from fusion. All this,
however, must be rejected, when we find that silex
is soluble in water, and that it is probable it can
form crystals, by extremely minute division, as is
the opinion of Kirwan, Macie, and Chaptal. We are
next told that the flinty nodules, found in chalk-
beds, have been in a state of fusion, and ejected
from some other place to their present situation,
then the strata have been raised from the bottom
of the sea. Unluckily, in this instance, he allows,
notwithstanding immense compression, that these
flinty nodules can be tossed from one place to
another.
The only other fact I shall consider is the petri-
faction of wood. This, we are informed, is produced
by the liquid flint being injected into the body of
the wood under immense compression. To this
curious piece of hypothesis I may answer by referring
to the consideration of specimens of petrified wood,
where one half is silicified, the other in its natural
state. What becomes of the vegetable matter that
disappears ? It must be converted into carbonic
acid ; and this, we are told, cannot take place under
insuperable compression.
c
34 DISSERTATIONS [HUTTONIAN THEORY
These facts militate against this opinion more
than the Doctor appears to have been aware of, and
are more supported from the consideration of the
phenomena that must have occurred in the consoli-
dation of the globe. Thus, he tells us that this
world is the ruins of a former, which had gradually
been deposited at the bottom of the sea in a loose
form, but, by the application of heat; under immense
compression, was hardened. Here then the particles
are much approached to each other, and the solid
materials are formed, consequently air and water
must be separated. This being allowed (which, I
think, cannot be denied) it follows that all crystal-
lised bodies should be destitute of water of crystal-
lisation ; in short, that all the materials of the globe
should be in a glassy form.
From what has been now said, it appears that
notwithstanding insuperable compression, carbonic
acid can be formed, flints tossed from one part to
another, and immense quantities of air and water
separated. All these, according to the Doctor's own
statement, must have occurred ; therefore, it will not
be thought presumptuous if the idea of insuperable
compression be rejected till further proof be brought
of its existence. This being set aside, the whole
theory appears to fall to the ground. I am, however,
aware of the possibility of considerable controversy
about this ; I shall therefore examine the theory a
little further, to endeavour to discover something
satisfactory. In doing this, I am naturally led to
the consideration of the second principle, that is,
SLOW COOLING.
This idea was first started by the ingenious Sir
JAMESON] KOYAL MEDICAL SOCIETY 35
James Hall, one of the most able advocates for this
theory. In reflecting upon the formation of granite
by fire, it immediately occurred to him that al-
though insuperable compression was present, yet
still it followed that the quartz and felspar would
form a homogeneous mass. Much about this time a
curious appearance was observed in the cooling of
glass, which he mentions in the following terms :
' A quantity of common green glass having been
allowed in a great mass to cool slowly, it was found
to have lost all the properties of glass, being opaque,
white, very hard and refractory, and wholly composed
of a set of crystals which shot into some cavities
in a determinate form. When a piece of this sub-
stance was melted by the violent heat of a blow-pipe,
and was allowed to cool instantly, it recovered all
the properties of glass. We may conclude from this
example/ says he, 'that if the glass produced by
the fusion of granite had been allowed to cool with
sufficient slowness, it might have crystallised, pro-
ducing a granite similar to that which was originally
melted.'
Even reasoning a priori from such a phenomenon,
I should never have adduced it as an irrefragable
proof of the Huttonian theory ; for the term slow
cooling is here evidently another way of expressing
a chemical change ; if so, it cannot be applied to
explain the formation of granite. That this is the
true explanation we find from his own words, when
he tells us that the glass had lost all its properties,
was opaque, white, very hard and refractory. Will
any peculiar arrangement of particles cause a sub
stance to lose all its properties, and assume new
ones ? If not, it follows that this change must
36 DISSERTATIONS [HUTTONIAN THEORY
depend upon the abstraction, or addition, of some
matter ; consequently this explanation must be
rejected.
To be convinced more certainly of the truth of
what I have now said, I made the following experi-
ments :
Experiment 1st. Exposed a quantity of green
glass to a strong heat, in a wind-furnace, for some
hours ; suddenly exposed it to the cold air, and
found that it was completely converted into a
whitish mass.
Experiment 2nd. Exposed equal quantities of
green glass, and what Sir James Hall calls slowly
cooled glass, to heat in a smith's forge ; when I
observed that the slowly cooled glass (as it is called)
required greater heat to fuse it.
Experiment 3rd. Exposed a quantity of green
glass to a strong heat, fused it, then cooled it
suddenly ; and observed the surface to have some-
what of a zeolitiform appearance.
Experiment th. Melted a considerable quantity
of green glass in a large crucible, and allowed it to
cool slowly (that is, by allowing the fire to be
gradually extinguished) ; when I observed several
zeolitiform masses, which were slightly opaque, had
the usual hardness and fragility of glass, with the
same glassy fracture.
Experiment 5th. Filled several crucibles with
green glass, then put them into a wind-furnace,
continued the application of heat for several hours,
taking out the crucibles at different periods to
observe the successive changes of the glass at dif-
ferent temperatures ; when I found that as the heat
was continued the glass grew opaque, hard, and at
JAMESON] ROYAL MEDICAL SOCIETY 37
last was reduced to a substance much resembling
frit, being the siliceous matter combined with a very
small proportion of alkali.
After having made these experiments, I was told
by a gentleman that glass made from metallic oxides,
would, by slow cooling, become opaque, etc. To
ascertain the truth of this, I made the following
experiment :
Experiment 6th. Took certain proportions of pure
silex and red oxide of lead, and melted them to-
gether ; allowed the materials in one crucible to
cool slowly ; but the other was instantly immersed
in cold water : both presented the same transparent
orange-coloured glass.
These experiments show us that the change of
the properties of glass does not depend on slow
cooling, but upon the application of certain degrees
of heat, which extricates from it some substance,
in greater or less quantity, according to the con-
tinuance of this heat. The nature of this substance,
I apprehend, is at once evident : it is plainly the
alkali of the glass, which is demonstrated from its
opacity and infusibility. This is also further proved
from the experiment with the glass made of lead,
where no such change could be produced.
To all this it may be objected, as is done by
several eminent chemists, that opaque masses are
found in the centre of masses of glass, where the
alkali possibly could not be separated. In answer
to this it must be inquired : Are these masses always
of the same nature ? If they are not (which is the
case), it follows that the explanation of their forma-
tion must be different. That these masses are some-
38 DISSERTATIONS [HUTTONIAN THEORY
times crystallised cannot be disputed ; but have they
lost any of their properties ? Have they not the
same fragility as glass ? The same fracture and
degree of fusibility ? They have, however, very
different appearances ; sometimes they are the
neutral salts used in the formation of glass, which
have been prevented from rising to the surface ;
they may be what the workmen call tears, which
are part of the pots vitrified ; or particles of sand,
which, in the operation of fritting, have been pre-
cipitated by the too sudden application of heat, and
consequent separation of alkali. What conclusion,
then, are we to draw with regard to this slow-
cooling ? I apprehend it is this : That the opacity,
infusibility, etc., of the glass does not depend at all
upon slow cooling ; but, on the contrary, it depends
on the continued application of a certain degree of
heat, which favours the escape of the alkali, thus
changing the chemical nature of the glass.
It appears, then, that immense compression and
slow cooling are, as yet, wanting of proof; conse-
quently the pillars of the Huttonian conjecture are
not well founded.
P.S. I omitted to mention the account which
Dr. Hutton has given of Natron. He tells us that
' it is a solid crystalline salt, with a structure which,
upon fracture, appears to be sparry and radiated,
something resembling zeolite. It contains no water
of crystallisation, but melts in a sufficient heat
without any aqueous fusion.'
To this account the celebrated Kirwan answers
by producing specimens which contain water of crys-
tallisation. The Doctor, however, is so little satis-
JAMESON] ROYAL MEDICAL SOCIETY 39
fied with this sort of explanation, that he questions
whether or not he is to consider that the author is,
on this occasion, consistent with himself? I can
only say that from the opportunities I have had in
examining this substance, which have been very
considerable, I have often observed saline efflor-
escence, demonstrating to a certainty the presence
of water.
V
HENRY HOLLAND
1788-1873
AN INQUIRY INTO THE NATURE AND ORIGIN
OF THE PASSIONS IN THEIR RELATION TO THE
INTELLECT AND BODILY ECONOMY OF MAN
Read 1810
MB. PRESIDENT,
It was not without hesitation that I
made choice of the subject which this title purports.
To any prominent novelty in its discussion I cannot
lay claim, but at the same time, by a new arrange-
ment and method of inquiry, I may possibly succeed
in furnishing some deductions which have not before
been expressly pointed out. In metaphysical, still
more than in physical science, improvements are
often the result simply of a new process of investi-
gation applied to objects which before have been
differently examined.
I am anxious that the object of inquiry should be
distinctly understood. My design is, not to give a
detailed account of the Passions and Feelings, or of
the sources whence these individually arise ; but to
consider the nature of Feeling or Passion as a dis-
tinct attribute of the mind ; and to survey the
HOLLAND] DISSERTATIONS 41
relations of this principle to the intellectual powers,
and to the bodily economy of man. In making use
of the word Feeling, I would be understood to refer
generally to all those affections of mind which we
term Feelings, in contradistinction to the acts of the
understanding or reason, and which are derived
directly from sensible perceptions, or more remotely
from sympathy and association of ideas. These
affections it will be my object to reduce to one
general principle, or faculty as it may be called, of
the mind ; a view of the subject which will appear
to have experienced too much neglect from meta-
physical philosophers when we consider its im-
portant relations to mental science.
The subject thus defined admits of division into
four sections, the first containing general con-
siderations of the argument ; the second discussing
the relation of the Feelings to the original constitu-
tion of the mind; the third their connection with the
intellect ; and the fourth their relation to the bodily
economy of man.
GENERAL CONSIDERATIONS ON THE SUBJECT.
A circumstance greatly impeding the formation of
general views on this subject has been the vague
and unphilosophical character of language in rela-
tion to the feelings. Not only are various propen-
sities and habits of action introduced into this class,
but the degree likewise and minute modifications of
feeling have received their distinctive appellations
and separate arrangement. All this may have its
convenience in matters of common life, but to the
metaphysical inquirer it enhances the difficulty of
obtaining general and systematic conclusions. It
42 DISSERTATIONS [THE PASSIOXS
\vill be sufficient to notice one of the many instances
which might be given of this want of precision,
arising from the defects of language.
The usage of words places before us anger and
revenge as two separate emotions of the mind. A
slight consideration will show that these are modi-
fications of the same feeling, and that the modifying
circumstance is simply the duration which the feel-
ing possesses. The action which proceeds directly
from a sense of injury we call the effect of anger or
passion ; that which results from a sense of injury
for some time retained we term the act of revenge.
In these two cases it is evident that the feelings
are identical in nature, and that the only distinc-
tive circumstance is their longer or shorter continu-
ance in the mind.
A simplification of the mental feelings might
evidently be carried to a great extent, and with
manifest advantage to the perspicuity of our know-
ledge on the subject. Though prevented by the
limits of my paper from following it further into
detail, it may still be proper briefly to consider
what method or basis of inquiry will best aid us in
attaining such simplicity and precision in the treat-
ment of the subject. Considering, as is our object,
the general nature and constitution of the passions
and feelings, and how we may best simplify an
inquiry into these, our first question must regard
their most general points of resemblance or differ-
ence as they appear in the mind. Is there any
circumstance affecting uniformly one class of these
feelings in contradistinction to another class ? This
question admits an affirmative answer. We may
observe one prominent distinction, affecting severally
HOLLAND] ROYAL MEDICAL SOCIETY 43
the nature or quality of all the feelings, and giving
to each its appropriate and decisive character. This
circumstance is the connection of a sense of pleasure
or pain with every act of feeling, a fact highly
important in its nature, and in its relation to the
present object of inquiry.
Whether this sense of pleasure and pain arises
from physical or other causes is a question at
present immaterial to our object : the point here to
be observed is its actual conjunction, in greater or
less degree, with every affection of mind which can
be classed under the name of passion or feeling.
We are unable to bring before our minds the con-
ception of a passion, without admitting at the same
moment the conception of a pleasure or pain, co-
existent and connected with it. Every mental
affection attended with an emotion of pleasure or
pain may, in propriety, be termed passion or feeling ;
if unattended by either of these emotions, it must
be referred to some other class of mental operations.
It may be a simple act of memory, a judgment, or
an association of ideas, but it cannot in philosophical
strictness be termed a feeling.
Here then we obtain a distinction highly useful
as a basis for inquiry, and which is founded not
merely upon the abstract nature of these mental
functions, but likewise upon the general, though not
strictly defined, sentiment of mankind. Its peculiar
advantages are, universality of application, and the
means it affords of distinguishing the feelings from
every other faculty or operation of mind a circum-
stance essential to the accurate discussion of the
subject. As it is our object to examine into the
general nature of mental feeling, the synthetical
44 DISSERTATIONS [THE PASSIONS
mode of inquiry is that we pursue, and hence the
more general the distinctions we assume, the more
important are they to our progress.
My limits prevent me from applying the charac-
teristic feature, just pointed out, to the individual
passions and feelings. The examination, however,
is open to every mind, and in its progress will con-
firm the remark I before made, that language has
had much effect in obscuring our knowledge of the
subject. We shall likewise be able, by attending to
the characteristics of pleasure and pain, to mark
the distinction between the feelings properly so
called, and those inclinations of habits of action, as
avarice, voluptuousness, which in common language
are often confounded with the former.
ON THE CONNECTION OF THE FEELINGS WITH THE
ORIGINAL CONSTITUTION OF THE MIND.
Dismissing these general considerations, I shall
proceed to the question respecting the origin of the
feelings ; not meaning, however, to investigate here
the cause by which they are drawn forth in life, but
to consider more especially their relation to the
nature and constitution of the mind. And here some
important inquiries offer themselves to our notice.
The question first occurs : Are the feelings, taken
generally, to be considered as innate in the human
being, as created and born with him ? Or are we to
regard the mind as devoid of original tendency
towards any particular passion or feeling as a
tabula rasa (to use the metaphor of Locke) upon
which these affections as well as ideas are after-
wards to be inscribed ?
To the latter opinion there can be little hesitation
HOLLAND] ROYAL MEDICAL SOCIETY 45
in giving an assent, and some reasons for this pre-
ference I shall briefly state.
First. I may remark that as every feeling has
some specific external object or cause, it would be a
strange paralogism to suppose that the feeling might
appear before its object or cause has any existence.
Secondly. It is a consequence of this argument
that those who consider the passions innate in the
mind are committing themselves to a doctrine of
innate ideas, such as was maintained in the
Academic school among the Greeks, by Descartes
and others in more modern times, and which has
since been generally discarded from the philosophy of
mind ; to suppose the passions innate necessarily
presumes these ideas to be so likewise. It would
be needless here to repeat all the arguments against
this doctrine of innate ideas. Suffice it to say that
they have induced the greater number of philoso-
phers to reject the opinion as untenable in itself,
and unnecessary in explaining the phenomena of
mind.
Thirdly. The gradual appearance and formation of
the feelings in the progress of life renders it impro-
bable that they are instinctive in the mind. Instincts
are at once perfect and complete the feelings sub-
ject to intimate varieties, according to the situations
in which the human being is placed.
Lastly. As the feelings are the great sources of
moral action, the idea that any of these are innate
in the mind supposes an influence of the Deity over
human conduct which is scarcely consistent with
the moral responsibility of man. It may be said
that this difficulty occurs to all who believe in the
necessity of human actions, and there is certainly
46 DISSERTATIONS [THE PASSIONS
some plausibility in the statement. Arguments,
however, may be adduced to prove that the cases
are not perfectly parallel. The rational advocate for
necessity supposes a present scheme, by which some
great future moral good is to be attained. He
regards as part of this scheme the direction of each
individual to particular modes of thought, feeling,
and action by the circumstances around him, and
considers the proposition of future rewards and
punishments as an exhibition of motives to modify
those which the events of life may create. The
advocate for the innate existence of the passions
adopts an idea little reconcilable with this system
of moral government. By giving to a superior
agency the formation of these affections, which de-
termine the whole course of action, he destroys the
relation of man, as a moral being, to the circum-
stances and events around him, and throws a shade
over the pleasing idea that rewards and punish-
ments are proposed simply as motive agents in a
great general system, and obscures our hope that
this system is tending forwards to some state of
more enlarged happiness and perfection. Such are
the apparent points of difference in the two cases.
But against the general position that the feelings
are not innate in the mind, may be urged the
instance of Conscience or the Moral Sense. Each
individual act of conscience consists, it may be said,
of certain emotions or feelings, the offspring of an
innate independent principle, common to all a
principle subject to none of the vicissitudes of life,
constantly watching over the actions of men, and
producing remorse or self-satisfaction, as these
actions are vicious or the reverse. That such is the
HOLLAND] ROYAL MEDICAL SOCIETY 47
voice of the world cannot be denied. The forum
conscientice is everywhere regarded as a divine
tribunal, infallible and certain in the dictates which
it pronounces to man. The sceptic, as to common
opinion, while admitting the general belief, will still
think it necessary to assume another position. He
will define conscience, ' an emotion or feeling conse-
quent upon certain conceptions of the reason, and
similar in its nature and origin to all other feelings
of the mind,' and, in vindication of this belief, he
will propose the following reasons :
In the first place, the position that conscience is
an innate principle involves by direct inference the
doctrine of innate conceptions or ideas ; the improba-
bility of which, and its relation to this subject, have
before been commented upon.
Secondly. I may remark and the argument is
an important one that if the feelings of conscience
were innate, we might expect an almost entire
similarity of these feelings in all individuals of the
species and in every age of the world. Regarding
conscience as an inherent sense of right and wrong
as the mens divina of humanity, as a principle, to
use the words of Cicero, segregate*, ab omni concre-
tione mortali, we ought to discover in it none of
those diversities which all the other qualities of
humanity display. Yet how completely is this op-
posed to observation and fact ! Looking at the
individuals around us, what varieties do we not
observe in the feelings of conscience as present in
their several minds ! Consulting our own conscious-
ness, how great is the diversity in the impression of
these feelings at different periods a diversity not
of degree alone, but of their nature, quality, and
48 DISSERTATIONS [THE PASSIONS
objects also. The contrast is still more distinct
when we observe the affection of conscience, as
manifested in different communities of mankind.
In some countries infanticide is practised without
scruple or remorse ; among other nations, the prac-
tice of destroying a parent, when burdened with
years, is deemed meritorious and useful ; in others,
again, human sacrifices are considered exalted dis-
plays of piety and virtue. Examples of this kind
might be indefinitely extended, but I apprehend
they must be familiar to every one who has studied
the history of mankind, and their existence suffi-
ciently proves that conscience is no uniform, unalter-
able principle, but varies with the circumstances of
individuals and nations.
The fact seems to be, that the moral sense of
every community is adapted to a certain standard
natural or revealed. With us this standard is the
system of moral doctrine contained in the Scriptures,
and to it each individual action being referred by
the reason, the affections of mind, which we term
feelings of conscience, are the result. Where cir-
cumstances have made the standard different, the
feelings will vary also.
It may be objected to this opinion, respecting
the nature of conscience, that it involves conse-
quences injurious to the moral interests of man.
To discuss the question, how far abstract opinions,
in metaphysics or morals, affect the practical course
of morality, would lead us too far from our subject ;
and I shall therefore shelter myself under the
maxim of the philosopher, 'AX-^Oeiav &JTO), v(fyfj<s
Are we, then, to consider the nature of the
HOLLAND] EOYAL MEDICAL SOCIETY 49
feelings as in nowise connected with or depending
upon the original constitution of the mind ? This
position cannot, I think, be maintained. Though
we have reason to believe that no individual feel-
ing, nor even the tendency to such, can be con-
sidered instinctive or innate, yet are we by no
means authorised to conclude that the general
capacity for feeling is the same in all. Such an
idea is strikingly contradicted by an observation
of facts. We notice in children, at very early
periods of life, an extreme variety in their suscep-
tibility to those impressions which produce or con-
stitute the feelings, and this both in the impressions
which arise directly from objects of sense, and in
those which originate from the complex operations
of thought. In fact, it would seem that a close
analogy here subsists between the feelings and
the intellectual faculties, strictly so called. The
mind, as far as we can contemplate its original
form, enters into existence devoid of all ideas or
conceptions, possessing simply capacities for the
reception of external impressions, for the recollec-
tion of these impressions, and for their comparison
or combination by the processes of reasoning,
imagination, etc. These original capacities appear
to be different in different minds, which diversity,
though greatly modified by circumstances, has still
a general impression upon the after-life of the man.
A similar view may be taken of the metaphysical
nature of the passions or feelings. These have
individually no original existence in the soul ; but
there seems to be in the constitution of the mind
a capacity of feeling varying impressions. This
innate capacity, like those of the intellect, has
D
50 DISSERTATIONS [THE PASSIONS
no uniform standard of vigour or acuteness, and
possibly is in no two cases precisely the same. Its
original tone, however, influences, more or less, all
the affections to which it gives rise.
Thus far, then, have the feelings a relation to
the primary constitution of the mind. From this
proposition may be drawn a corollary of some im-
portance, viz. that in cases where any of the
feelings are acute and strongly marked, it may
be presumed with much likelihood that all the
feelings have the same character. This deduction
is further warranted by experience. We may
observe in every individual a certain character
and tone of feeling, by which, as a standard, are
regulated all the affections of his mind. If a man
is warm and irritable in his resentments, we
usually find that he is capable of strong emotions
of friendship and love ; his moments of joy will
be rapturous and exalted ; his sorrows melancholy
and profound.
Akin to this fact is the remark which has been
made, that the most splendid virtues and infamous
vices are sometimes conjoined in the same person.
All the actions to which the character of virtuous
or vicious can be applied have their origin in the
passions ; and the same warmth of feeling which,
in certain situations, gives rise to actions strikingly
vicious, will produce at other times the most
eminent acts of heroism and virtue.
Before quitting this subject, I must remark that
the original capacity for feeling is capable of infinite
modification from the events of life. Situation,
connection, and education affect it in a thousand
ways, not merely in giving a direction to different
HOLLAND] ROYAL MEDICAL SOCIETY 51
objects, but also in augmenting or diminishing its
general acuteness. Here, too, the analogy with
the intellectual faculties is strikingly marked.
ON THE CONNECTION OF THE FEELINGS WITH
THE INTELLECT.
I now proceed to the third division of the
inquiry, the examination of the Feelings in their
relation to the intellectual powers. Though we
have considered the capacity for feeling, in general,
as an independent principle of mind, yet conscious-
ness must suggest a connection between each single
act of feeling, and certain conceptions of the under-
standing or reason. The inquiry now before us
regards the nature of this connection.
It will at once be allowed that conceptions of
the mind invariably attend the presence of passion
or feeling, whether arising from the perceptions of
the senses, or from associations of ideas. This
uniform contiguity, suggesting the relation of cause
and effect, we consider the conception, as in every
case the immediate cause, of the feeling. Still
it must be confessed that there is a difficulty in
defining the precise distinction between these two
acts or conditions of the mind. The thought has
so far a unity and co-existence with the feeling, that
they may be considered to constitute together one
single state of the mind. Yet are they not identical
in their nature ? Thought may, and often does,
exist without feeling; and when it has the effect
of producing the latter, we are distinctly sensible
of a change of mental condition, of something
added, which was not before present to the mind.
Upon this basis have been founded the in-
52 DISSERTATIONS [THE PASSIONS
quiries of philosophers into the origin of the
passions. Looking to the operations of thought
as the source, they have laboured thence to deduce
all the complicated varieties of feeling which occur
on the great theatre of life, to trace out the com-
binations which they assume, and to display their
various and interesting relations to the character
of man.
A prosecution of this particular inquiry, even if
necessary, would be foreign to the subject imme-
diately before us. A question, however, occurs on
the connection between intellect and feeling, more
novel in feature, and at the same time highly in-
teresting in its nature. What cause is there why
certain conceptions or thoughts should produce feel-
ing, while other conceptions have in no degree the
same effect ? This question has never, I think, been
stated under a perfectly definite form, though many
philosophers have casually and indirectly afforded
their opinions in reply to it. Of this Mr. Hume is
an instance. In his essay on the Origin of Ideas
we find an obvious allusion to the inquiry, though
he does not follow it into detail.
The fact presumed in this question cannot be
doubted. Every one must be conscious that certain
impressions from external objects, or certain thoughts
passing through the mind, produce emotions of
feeling, while other impressions and thoughts have
no similar effect. The inquiry, then, conducts us
to some diversity in the ideas themselves, as the
immediate cause of this fact. And here our choice
is limited to a few suppositions. The distinction
may consist in the vivacity of the conceptions, in
the abruptness of their occurrence, or in the
HOLLAND] ROYAL MEDICAL SOCIETY 53
arrangement or rapidity with which successive
conceptions are presented to the mind. These
suppositions may further be reduced by considering,
as a relation between the first and second, that
ideas abruptly occurring are always lively and
forcible in their character. Admitting this, it is
left to us to consider whether vivacity of ideas or
the order or rapidity of transmission through the
mind is the circumstance most essential to the pro-
duction of feeling.
From the passage in Mr. Hume's writings to
which I have alluded, it seems that he regarded the
former of these causes as principally efficacious. And
this idea is certainly not without its probability.
An appeal to consciousness will show that every act
of feeling is preceded by conceptions more lively and
acute than those of common occurrence, and that
there is a uniform ratio between the vigour of
the conceptions and the vivacity of the feelings
with which they are conjoined. The conceptions of
danger, pain, and death, which occur to the man at
whose breast the dagger of the assassin is pointed,
are highly forcible, and produce a sudden and
violent emotion of fear. If I attempt to imagine
myself in a similar situation I cannot raise concep-
tions as acute as those which the reality presents,
and therefore the feeling, if produced at all, is feeble
and transient in its character. Some individuals
possess more than others this power of drawing
forth feelings by the efforts of the imagination
alone. Imagination is the faculty of reviving and
variously combining former perceptions ; and ac-
cording to the vigour of this faculty is the vivacity
of the feelings produced from this source.
54 DISSERTATIONS [THE PASSIONS
Many illustrations might be adduced in further
proof that the vivacity of impressions or ideas is the
circumstance which renders them productive of
feeling. The limits of my paper do not allow me
to follow these into detail ; they will, however, recur
to every one who affords his attention to the subject,
and accurately refers to the consciousness of his
own feelings.
The other supposition we have made is, that a
certain arrangement or a rapid succession in the ideas
may be possible causes of the production of feeling.
Here, however, we proceed with more dubious lights.
Some notion may perhaps be formed of a harmonious
relation between contiguous ideas, which, when it
exists, produces feelings of a pleasurable nature, and
of a discordant connection, from which the painful
emotions result ; but these impressions are too
indistinct to furnish a basis for deduction or argu-
ment. The same remark may be made as to the
effect produced by rapidity in the succession of
ideas. In many cases of passion or feeling we find
that the conceptions succeed to each other with a
rapidity greater than is usual ; and, coming nearer
to the point, it may be said that there are instances
where a mental emotion seems directly to arise from
this quickness in the succession of the thoughts.
Making, however, such an admission, we still cannot
proceed far along this track. Rapid trains of ideas
do certainly often occur without producing any-
thing that resembles feeling, and the negative fact
is sufficient to destroy any supposition founded on
this basis.
Upon the whole, then, it is probable that a
certain vivacity of impressions and ideas is necessary
HOLLAND] ROYAL MEDICAL SOCIETY 55
to the production of feeling, and that other circum-
stances have little effect, except indirectly, in
modifying this required vivacity of the mental
perceptions.
We have before found reason to believe that
the emotions of conscience are essentially similar to
all the other feelings, and distinguished simply by
their relation to some standard of morals, natural
or revealed. This is further true in regard to their
connection with the reasoning powers. The con-
ceptions of the mind produce and modify these
emotions as they do the other passions and feelings.
It is worthy of remark that whenever such emotions
are produced, the idea of future reward or punish-
ment is always more or less directly present to the
mind. This is so general a fact that its omission
would scarcely be justifiable in a definition regarding
the nature and origin of conscience.
ON THE CONNECTION OF THE FEELINGS WITH
THE BODILY ECONOMY.
We now come to the last, but not the least
interesting, part of our inquiry, the relation of the
feelings to the bodily economy of man. Whenever
passion or feeling exists in the mind a simultaneous
affection occurs of some one of the bodily organs,
the degree of this affection being determined by
that of the feeling itself. A thousand familiar
instances may bring home this fact to the most
casual observer. The blush of shame mantling up
the cheek, the tear of sorrow or of sensibility falling
from the eye, the pallid countenance of fear, are
visible demonstrations of its occurrence. History
furnishes more striking examples than individual
56 DISSERTATIONS [THE PASSIONS
experience can afford. Instances are given where
the operation of fear had been such as in a few
hours to change the colour of the hair ; and others
are stated where life has been at once destroyed by
the violent agitation of passion. These, however,
appear rather like phenomena than examples.
They are, in fact, the extremes of a general rule.
When first I gave my attention to this subject
it seemed to me probable that the sole distinction
between feeling and the simple operations of
thought was the connection of the former with this
affection of the bodily organs ; or, in other words,
that a feeling was simply some train of thought
accompanied by certain corporeal sensations. A
more mature consideration has led me to alter this
opinion, and, admitting a distinction between
thought and feeling in their connection with the
mind, to suppose that this distinction determines
their relation to the bodily economy, giving to the
feelings an influence over the material organs, while
the operations of reason, strictly so called, have no
effect of this nature.
Helvetius, however, in his work Sur VEsprit,
seems to countenance the former opinion, and to
regard the degrees of the passions as produced by a
varying sensibility to corporeal pleasure and pain.
The ingenious Bichat has carried the idea still
further ; and, in considering what he terms organic
life as the exclusive seat of the passions, has given
these affections only an indirect relation to the
intellectual powers. I confess that there are several
circumstances which give plausibility to an opinion
of this nature ; and though, upon the whole, I am
now disposed to regard the feelings as primarily
HOLLAND] ROYAL MEDICAL SOCIETY 57
distinct states of mind, yet I cannot consider this
latter position as a truth finally, and with certainty,
established. It is possible that the fact may be
otherwise.
Upon the connection of the feelings with these
bodily sensations I may remark, in the first place,
that it is invariable and constant. Every affection
of mind which we can, with a sense of the propriety
of the term, denominate feeling, is thus attended ;
and though the corporeal changes are various in
nature and degree, yet may they, in every instance,
be more or less distinctly recognised by the mind.
Secondly, The corporeal sensations thus conse-
quent upon feeling are involuntary in their nature.
No act of the will is interposed between the feeling
and sensation, nor is volition capable of modifying
in any great degree this action upon the material
organs.
Thirdly, It may be remarked that there is so far
an indistinctness in these bodily sensations, as re-
gards the circumstance of pleasure and pain, that in
many cases of passion or feeling it would be difficult
to determine to which class the sensations belong.
It would seem, too, that the nature of particular
feelings and of their attendant bodily affections may
be very different in relation to the sense of pleasure
and pain. It is well known that strong emotions
of joy often produce sensations of a painful kind ;
while similar emotions, less lively in character, create
those which are grateful and pleasing. Here in
relation to the mind the nature of the feeling is the
same in both cases ; while, in respect to the body, a
difference in the degree of the sensation affects
essentially its nature also. The fact evidently
58 DISSERTATIONS [THE PASSIONS
affords a reason for supposing that the feelings exist
in the mind distinctly from the bodily affections,
and that the latter are to be regarded simply as
consequences or effects.
These general considerations conduct us to a
further inquiry : What is the precise nature of the
corporeal changes which the passions thus produce ?
The question is evidently one of much importance
and extent ; and as its complete discussion would
require great amplitude of detail, I must content
myself with throwing out a few general hints as a
basis for more extended investigation.
The remark first occurs that these bodily affec-
tions appear especially in the involuntary organs
an evident inference indeed from the fact before
stated, that the will has little influence in producing
such affections, or in modifying their extent. The
most casual consciousness of our own sensations will
confirm the truth of this remark. The muscles
which, stimulated by the will, perform the various
locomotive functions, are subject to no direct per-
ceptible influence of the feelings. The presence of
feeling in the mind (or rather, perhaps, the presence
of those ideas which produce feeling) may indeed
give rise to particular volitions, and consequent
action of the voluntary muscles ; but this is only a
secondary and occasional effect. On the other hand,
in every case of passion or feeling we are conscious
of an immediate impression upon some one of those
interior organs which, independently of the will,
perform functions essential to the life of man.
The fact here obtained is interesting and impor-
tant in its nature, and merits a more minute atten-
tion than has yet been given to the inquiry. Some
HOLLAND] ROYAL MEDICAL SOCIETY 59
ingenious speculation upon the subject will be found
in the writings of Bichat, who applies here also the
division of life into animal and organic, which he
elsewhere so ably illustrates. Animal life includes
the operations of the intellect and will ; organic life
and its various functions of circulation, digestion,
secretion, etc., are exclusively subject to the in-
fluence of the feelings, or, as Bichat expresses it, are
' the sole seat of the passions.' Prosecuting also
his idea that there is a separate nervous system
connected with each of these great divisions of life,
he considers the various phenomena of the passions
as related to the gangliac system of nerves, or that
which supports exclusively the functions of organic
life, and supposes them to affect the animal or intel-
lectual life only through the medium of the changes
in their organic functions. Though, as I have before
remarked, I differ from Bichat's opinion that the
feelings have no primary relation to the mind, yet
I cannot but think his remarks on their connection
with the bodily economy highly ingenious and im-
portant.
To the general fact, however, that the involuntary
organs are those exclusively affected by the passions,
some apparent exceptions occur. One instance of
such exception is the affection of the voluntary
muscles of the countenance during the presence of
certain feelings in the mind. Another similar in-
stance occurs in the muscles of respiration, where
passion and volition mutually hold their sway. At
moments when feeling is wholly absent from the
mind we can counterfeit upon the features the
strongest expressions of anger or joy ; we can utter
forth sighs profound as those which misery itself
60 DISSERTATIONS [THE PASSIONS
excites. These exceptions, however, do not proceed
far, since in every case where such bodily changes
are an effect of the presence of feeling, they are in
no degree derived from the voluntary powers. It
would seem indeed that in the organs subject to
this double influence the will has a power of modify-
ing, or sometimes of entirely repressing, the in-
voluntary affections consequent upon feeling, as
when by a strong effort of volition we counteract
those expressions of the features which the influence
of passion may create. Few questions connected
with the subject are more interesting than that
which regards this mutual relation of feelings and
the will.
But it will be asked, In which of the involuntary
organs, and in what particular mode, do these bodily
affections occur? Various and singular have been
the opinions given on this point. The ancients, as
is well known, imagined a connection between
certain passions and some of the visceral organs, as
the heart, liver, spleen, etc. Van Helmont sup-
posed the upper orifice of the stomach, Buffon and
others the diaphragm, to be the organ or part chiefly
affected by these emotions of mind, but without
offering for their opinion any very satisfactory
grounds of belief. The prevailing sentiment, how-
ever, of mankind has in all ages regarded the heart
as the centre or principal seat of these affections ;
and this opinion, as it is connected with many cir-
cumstances of probability, it will be proper more
especially to consider.
That the heart and sanguiferous system are the
parts of the material frame chiefly affected by the
passions is a fact derived both from our own con-
HOLLAND] ROYAL MEDICAL SOCIETY 61
sciousness and from the results of a more general
and extended observation. In every case where
passion or feeling occur to the mind we have a dis-
tinct sensation of something unusual about the
prgecordia or region of the heart ; some alteration
takes place in the action of this organ, producing a
change or irregularity in its contractions. This
affection is varied in degree, according to the viva-
city of the mental emotion : where the latter is
acute a feeling of painful oppression is often the
consequence, sometimes proceeding so far as to pro-
duce milch and continued derangement. Succeed-
ing to this affection of the heart and great vessels,
and doubtless, therefore, a consequence of it, we
perceive a more diffused affection of the sanguiferous
system. In some cases, owing to an increased
frequency and tone in the contraction of the heart,
the impetus of circulation is greatly increased, the
capillary vessels become distended by the augmented
vis' a tergo, redness and a sensation of heat occur
over the whole surface of the body. Striking
examples of this effect are afforded by the more
lively emotions of anger and joy. It is manifested
also, though perhaps more feebly, in the emotions of
conscience, of hope, and of love. In other cases the
due vigour of circulation is for a time suspended,
the blood recurs with considerable force to the heart,
while the external parts of the body become con-
tracted and pale. Illustrative examples of this may
be derived from the effects of fear, aversion, and
despair.
A doubt may, however, exist whether the heart
is the organ primarily acted upon by the feelings,
or whether the functions of respiration are not in
62 DISSERTATIONS [THE PASSIONS
the first instance affected. I confess my inability to
form a decisive conclusion on this point ; but, upon
the whole, I consider it more probable that the
affection of the heart is that immediately consequent
upon the mental feeling.
The effects produced upon the different visceral
or glandular organs by the emotions of the mind
form a difficult but interesting object of research.
It is probable that these effects take place chiefly
through the medium of the circulation. In some
cases, however, it would seem that they directly
result from a diffusion of the nervous irritation by
which the heart itself is affected. An instance of
this occurs in the stomach which is often suddenly
and violently affected by agitations of the mind, so
as to produce instant nausea and vomiting. Re-
garding, indeed, the connections of the great sym-
pathetic nerve, it will appear probable that no
involuntary organ is wholly exempt from the direct
influence of feeling a circumstance rendering it
difficult to assign the proportion which the altered
state of circulation has in producing these effects.
That much, however, is to be attributed to the
influence of this latter cause cannot be doubted.
To it we may refer the general paleness or flushing
of the surface of the body, the increase or diminution
of certain secretions, and the remarkable effects often
produced upon the sensorium by the presence of
feeling. When the impetus of the circulation is thus
increased by the influence of passion, we frequently
observe a determination of the blood to particular
organs, depending upon some causes which are
either wholly, or in great measure, unknown. The
affection of the lachrymal gland, producing an in-
HOLLAN-D] ROYAL MEDICAL SOCIETY 63
crease of its secretion, is one of the most striking of
these phenomena, though, from the familiarity, the
fact is little dwelt upon by the casual observer.
That this little organ should be thus affected by so
many and such various feelings is in truth a cir-
cumstance of singular and surprising nature. Not
only is the tear drawn forth by feelings of pity and
grief, but the joyful and exalted emotions of mind
are likewise marked by its presence. It would seem,
indeed, purposely designed in our creation, as an
index to certain affections of the soul: as an evid-
ence, open to general observation, of the presence of
those feelings, which are so important and interest-
ing in the social life of man.
I have now completed the plan which I proposed
to myself in commencing this inquiry. I must
again express my regret that the limits of the paper
have prevented me from pursuing many subordinate
topics as the nature and origin of the sexual feel-
ing, the influence of sympathies, etc. ; and still
more, that I have been obliged to suppress many of
those illustrations which the subject not only admits,
but even requires, for its completion. A regard to
the time and patience of the Society must form
my apology for these deficiencies, which otherwise
I should have been anxious to supply.
VI
RICHARD BRIGHT
1789-1858
ON GANGKENE
Read 1813
MR. PRESIDENT,
As different ideas have been attached
by writers to the term Gangrene, it will be necessary,
in the first place, to state the extensive signification
in which I would apply it.
I consider it that state of animal matter, once
living and organised, when, without being separated
from the body to which it belongs, it loses its
vitality.
' La Gangrene/ says M. Quesnay, ' est la morte
d'une partie ; c'est a dire, 1'extinction ou 1'abolition
parfaite du sentiment et de toute action organique
dans cette partie.'
And I consider the division into gangrene and
sphacelus, adopted by some authors, and into
gangrene, sphacelus, and esthiomenus, adopted by
others, as merely marking different stages of the
same disease.
Those who, with the Arabian physicians, make
use of three appellations, consider gangrene the most
superficial and incipient state, esthiomenus the most
BRIGHT] DISSERTATIONS 65
deep-seated and complete, and sphacelus inter-
mediate between the two.
Those who have employed but two terms ex-
pressive of the different stages have of course
omitted that which applies to the intermediate state.
And though in some points of view it may be ad-
vantageous to preserve the three, they will seldom
be employed in the following observations, where
I shall generally apply the term gangrene in its
extensive signification.
The predisposing causes of this disease are :
1. That capability which exists in every part of
the body, at all times, of having its structure and
functions destroyed.
2. That state of body which favours the de-
struction of powers, and the inordinate action of the
vessels. In other words, the debility of the body,
or part of it, and the tendency to inflammation, the
two states occurring either separately or in conjunc-
tion.
Respecting proximate causes it always becomes
us to speak with great deference. And in the
present case, I only venture to suppose that the
cause of gangrene may be found in the rupture or
obliteration of small vessels, these being the most
probable results of a loss of power and action. Thus
it will appear that I am more inclined to see in this
disease a morbid state of the solids of the body
than of its circulating fluids. The connection, in-
deed, between the two, is at all times, both in
health and disease, so intimate that it is perhaps
impossible for one to be deranged without the other
participating. But I see no reason for considering
the fluids peculiarly or primarily affected in gan-
E
66 DISSERTATIONS [ON GANGRENE
grene. Still more do I doubt the existence of any-
thing analogous to putrescency in the circulating
mass : for if anything very similar to putrefaction
ever goes on in gangrene, it is not till the life of the
part has been destroyed for some time, and the cir-
culation through it has been completely prevented.
And, in some of those diseases where the diminished
crasis of the blood and its putrid tendency are
considered as most plainly indicated, the disposition
to gangrene has been by no means great.
The terminations of gangrene are distinctly of
two kinds, leading to the division adopted by some
authors into the moist and the dry gangrene. But
the two different states are often blended together,
or pass imperceptibly from one to the other, and it
is not easy to ascribe a cause for these very different
conditions, as the results of the same disease. That,
of two limbs suffering under very similar circum-
stances, the one shall dissolve away into ichorous
discharge and soft sloughy matter, while the other
shall dry, as if it had undergone a process of embalm-
ing, seems at first inexplicable. May not this be
owing to the mortification in one case being so
complete as to have occupied all the deep as well as
superficial parts, by which the obstruction likewise
becomes complete, and no effusion can take place ?
Whereas if the more superficial parts only be ob-
structed, the deep-seated parts still having a circu-
lation carried on in them, but being weakened, and
more particularly where in contact with the mortified
parts, effusion may well be expected to take place,
and a consequent dissolution of the dead structure.
Thus, though we frequently read of whole limbs
becoming subject to the dry gangrene, yet the
BRIGHT] ROYAL MEDICAL SOCIETY 67
smaller parts are by far more subject to it ; and not
unfrequently we find a toe or a finger separating
itself completely dry, while the limb is consumed
by moist gangrene. Dry gangrene, again, admits
of some varieties ; sometimes assuming a black
shrivelled appearance, while at other times, as in
a case related by Hildanus, it remains free from
colour, and the skin drying away, the tendons
become distinctly visible through it.
As to the exciting causes, I shall not enumerate
them now ; they will be successively brought into
view as I proceed to speak in order of the differ-
ent cases of gangrene which occur in doing
which I have adopted an arrangement perhaps too
arbitrary, but I hope sufficiently fitted for bringing
under discussion the various phenomena of this
disease.
Since it has been supposed, perhaps in all cases,
certainly in all cases where inflammation has preceded
gangrene, that erysipelatous inflammation has been
present, I know of no point in this extensive subject
which I may better fix upon for my commencing
than those cases in which erysipelatous inflamma-
tion is obvious and undoubted. At the same time,
I consider the truth of the opinion just mentioned
by no means established. If erysipelas be considered
a disease peculiar to the integuments and cellular
membrane, we cannot for a moment support the
hypothesis that it universally precedes gangrene,
seeing that gangrene attacks muscles, tendons, and
bones, and attacks them sometimes in preference to
those integuments which lie in immediate proximity.
The truth may be that the same debilitating causes
acting on the system will induce inflammation to
68 DISSERTATIONS [ON GANGRENE
assume the erysipelatous character on the skin, and
will cause inflammation in other parts to run rapidly
into gangrene. If, however, the term erysipelatous
inflammation be only intended to denote a species
of inflammation whose characteristic is high action
tending rapidly to corresponding debility, there is
little doubt that this is the nature of the inflam-
mation which precedes gangrene. That erysipelas
strongly tends to a termination in gangrene is
matter of daily observation.
It might be well here to mention that gangrene
which is produced by heat, and by substances
capable of acting chemically upon the parts to which
they are applied. All such agents seem to produce
their effects by a double process :
1. Immediately destroying some parts by dis-
organising them, and producing a change in their
chemical composition.
2. By producing excessive inflammation, which
terminates in gangrene.
As to the first of these modes of action, it
admits of no other check than the removal of
the cause by such means as the place of its ap-
plication will admit. And the second would seem
to require the strictly antiphlogistic treatment,
more particularly in its local remedies ; and that
this is frequently efficacious I have no doubt. The
observations, however, of Dr. Kentish lead to a plan
of treatment somewhat different in the case of ex-
tensive burns. Instead of that assiduous application
of cold, which I should conceive capable of prevent-
ing, and even anticipating, destructive inflammation,
he recommends the gradual reduction of stimulus :
beginning with powerful applications, and going on
BRIGHT] ROYAL MEDICAL SOCIETY 69
to the more mild. From the ample experience of
this author we have no room to doubt the utility
of his practice, yet certain it is that it has failed in
ma-ny cases ; and its ill success led to its relinquish-
ment in one of the hospitals of London. The
inflammation which it excited was severe and
dangerous. The action of arsenic and other mineral
poisons upon the stomach is to promote inflammation
and gangrene ; and the most effectual mode of
relieving this is to evacuate the contents of the
stomach, and then to pursue bleeding and such
other remedies as you would employ in common
cases of gastritis and enteritis.
The action of caustics must be referred to the
same division of the subject, but on their mode of
action sufficient has just been said.
It is by no means an unusual circumstance to
find the surfaces and edges of wounds assuming
an erysipelatous appearance, quickly followed by
gangrene, and this sometimes with a degree of
rapidity which is altogether astonishing.
On what this sudden change depends it is not
always possible to discover. In some cases it may
be ascribed to the particular circumstances of the
individual as respects age, previous habits, increased
natural or morbid discharges, diseased blood-vessels,
the influence of depressing passions, or the like ;
while in other cases it appears to be the effect of
some peculiar state of atmosphere operating on
many persons at the same time, so that the sores
and granulating surfaces throughout a whole ward
shall in one day change their appearance, lose their
florid hue, assume a dull red colour, and a glazed
appearance, then become brown, black, or olive
70 DISSERTATIONS [ON GANGRENE
green, and pursue the regular progress of extending
gangrene. This is what the French call La pourre
lieu, and was once so prevalent in the H6tel Dieu
that it was almost expected to take place in every
abscess which was opened. There can be no doubt
that this may be in a great degree prevented by
proper attention to ventilation and cleanliness. The
beneficial powers of fresh air are not perhaps even
yet sufficiently appreciated. Physicians are becom-
ing every day more and more enlightened upon this
point ; in certain instances they may even carry
their practice beyond the bounds of prudence. But
the surgeon should likewise be instructed how
little his art can do while he permits nature to be
thwarted in her kindest attempts, and deprived of
that assistance to which so much is intrusted, whilst
the body is unconfined by disease. The rapid
change of sores to an unhealthy state may likewise
arise from the circulation being retarded by bandages
too tightly applied, from the use of sponges, or
fomentation cloths, which are not properly washed,
or the too severe treatment with regard to inspec-
tion, etc. all which causes may be most easily
avoided. There are, however, independently of
these causes, some circumstances which we cannot
prevent. A man whose body has been constantly
under the stimulus of strong drink, or whose ad-
vanced period of life has reduced his constitutional
energy, may fairly be suspected to repair the injury
he has sustained with less facility than one whose
powers are unbroken.
The part on which an injury has been inflicted,
whether a fracture, a laceration, or a contusion, will
likewise have considerable influence. We know,
BRIGHT] ROYAL MEDICAL SOCIETY 71
for instance, that parts which have but little vitality,
as tendinous structures, are unable to withstand
severe injuries, and in them inflammation quickly
terminates in gangrene. Thus, injuries inflicted
on the fingers and hands are often troublesome
and dangerous, so likewise compound fractures near
the joints are known to go on very frequently to
gangrene.
There are certain states of body induced by
previous disease which render it subject to inflam-
mation, running into gangrene with rapidity, from
causes of irritation, or contusions so slight that they
would not produce the most temporary inconveni-
ence during a state of health. This is particularly
seen in advanced states of fever, where the simple
pressure of the body in a recumbent posture, or the
irritation of urine trickling over a part, or a pressure
of one foot against the other, is sufficient to produce
gangrene.
Treatment. The few instances which I have
cited sufficiently show the urgency of the mischief
we are called upon to obviate, and the consequent
importance of satisfying our minds as to the means
of cure most likely to prove efficacious, that we may
lose as little time as possible in useless attempts.
In the first place, we must endeavour to prevent
the occurrence of the disease by avoiding all excit-
ing causes, and moderating those symptoms which
lead to it. We must in particular moderate in-
flammation, and that with the greater vigour in
proportion to the tendency of the part to run into
gangrene. But, having failed in these attempts,
the next question certainly is how far it is possible
to restore parts already apparently in a state of
72 DISSERTATIONS [ON GANGRENE
gangrene ? It does not appear improbable that
there may be a moment, a certain short period,
when the powers of life have so far deserted some
part of the human body that every vital action is
at an end, that sensation and circulation and
voluntary motion have ceased, and the part may
be justly called gangrenous. And yet the appli-
cation of remedies may restore it to its functions.
Vessalius seems to have been of this opinion when
he said, ' That gangrene is the worst which corrupts
the part it affects, especially when the corruption
has wholly taken place, because it admits of no cure
except cutting off' : evidently leading his reader to
infer that some other state of gangrene does admit
of cure with the preservation of the part.
For a long period it was supposed that the most
effectual remedy was to scarify the part, and to
surround it by incisions in such a manner as to
separate it from the neighbouring sound parts.
This was certainly proceeding on the idea of its
being an affection of a completely local character.
It was a practice inculcated in the French schools
as late as the days of Petit, and persevered in by
his disciples. They, however, gradually relinquished
it, finding not only its inutility, but its injurious
tendency. If you scarify the dead part only, you
do little good. If you scarify the living part, you
stimulate it to an action which it cannot support.
As our science has advanced, medical men have
learned to apply their remedies, not to the name
but to the disease. Hence it might occur that
bleeding should be necessary in one instance, while
bark and stimulants are indispensable in another ;
and it is the power of distinguishing these that
BRIGHT] ROYAL MEDICAL SOCIETY 73
stamps the merit of the practitioner. It is not
probable that bleeding will very frequently be re-
quisite after gangrene really exists. It is, however,
mentioned by O'Halloran and others though the
same authors afford us some striking instances of
depletion being carried too far. As a preventative
while the disease is threatening it may doubtless
be useful ; but the more useful remedies have been
stimulants and tonics. With respect to stimulants,
I should think them very capable of being carried
to excess. In most cases it appears the indication
to strengthen rather than to excite the action of
weakened vessels. The urgency of the danger,
however, and the rapid secession of life, will not
perhaps give sufficient time to our tonics to pro-
duce their effect on the constitution. And in this
emergency we sometimes find that stimulants will
call forth power to oppose the progress of death.
And it is one of the most important and most
difficult questions which presents itself in the treat-
ment of this disease, Whether we shall have re-
course to amputation ? and if so, at what period it
may be best employed ? In very severe injuries, as
compound fractures and gun-shot wounds, the pro-
priety of amputation becomes a question before any
symptom of gangrene makes its appearance. And
though this should never be done in haste, it will
often be found the most certain mode of relief; for
where the injury is very great, with certain circum-
stances of aggravation, it is almost certain that an
exhausting, if not fatal, mortification will ensue.
But this is not the question most generally to be
decided, but rather how far we are to assist nature
after gangrene actually has taken place.
74 DISSERTATIONS [ON GANGRENE
It is a well-known fact that after a time, the
process of mortification being stopped, a healthy
inflammation takes place in the surrounding parts,
suppuration goes on, and the sloughs are separated.
This process of nature is not confined to inconsider-
able parts affected with gangrene, but whole limbs
are not unfrequently separated in the same manner.
Thus La Motte mentions a girl, seventeen years of
age, who had gangrene over her whole leg, but re-
fused amputation. The leg separated at the knee,
and she did well.
The question is simply this, Are we to inter-
fere ? or, giving support to the body, to suffer
nature to take her course ?
O'Halloran, after the relation of several cases in
which nature had performed the whole, without the
assistance of the knife, states two cases where death
followed such interference, even after the process of
separation had far advanced, and is of course in-
clined to judge rather harshly of the practice. His
cases, however, do not strictly apply to the present
question, as they were cases either of spontaneous
gangrene or of gangrene after fever. Dease, in
remarking on a case which healed with great diffi-
culty after the natural separation of the arm, is
inclined to reprobate delay after separation has
fully commenced.
Upon the whole, O'Halloran's rules seem very
judicious, though they involve some theory which
we are not obliged to admit. ' Nevertheless,' he
says, ' as we know there are certain cases in which
life cannot be preserved without taking off the limb,
we may here observe, that when the malignity is
entirely deposited on a part the leg, for instance,
BRIGHT] EOYAL MEDICAL SOCIETY 75
that the mortified part seems cold, livid, and sense-
less ; that the dead parts begin not only to separate
from the sound, but that a laudable suppuration
becomes established from these last. Till it shall
appear in the clearest manner absolutely impossible
to restore or preserve the limb should amputation
be deferred. Not only this, but till it shall at all
appear that the pulse is well established, the ap-
petite restored, and health pretty well confirmed
should not the limb be taken off.'
After the amputation, we are to attempt the
healing of the stump by the adhesive inflammation ;
which, however, will often fail. And we must then
proceed according to the usual rules of surgery.
Prognosis. I shall neither add to nor take from
Dease's observations on this subject : ' Gangrenes
that seize fractured limbs, particularly if the fracture
is a compound one, and near the articulation, and
have come on suddenly, attended with a violent
delirium, seldom admit of any relief.' ' Those that
succeed gun-shot, punctured, or lacerated wounds of
tense, membranous, or tendinous parts, unexpectedly
coming on, are of the most alarming nature.' ' Those
from long lying critical metastasis, malignant car-
buncles, etc., often yield to a proper method of
treatment.'
There are several other cases of gangrene, from
obvious local affections and inflammations, which will
merit separate attention. And though the limits of
a dissertation will not permit of the mention of all, T
shall offer a few short remarks on two or three of them.
The most important viscera of the body are sub-
ject to this, as a termination to the inflammation
with which they are attacked. Thus large portions
76 DISSERTATIONS [ON GANGRENE
of the brain have sloughed away after accidents or
the venereal disease, and that without those severe
mental affections which might reasonably have been
expected. The lungs likewise are said to be subject
to gangrene ; but this is very rare. Huxham men-
tions pneumonic affections, in which such appear-
ances seem to have presented themselves. The
urinary bladder is mentioned by Le Dran ; and the
neck of the uterus, in the memoirs of the Medical
Society, as having been found gangrenous.
The stomach and intestines are the most frequent
seat of this disease, where it forms a fatal termina-
tion of gastritis, enteritis, hernia, and the like. The
symptoms by which its approach is known in the
two last-mentioned organs are thus 'stated by
Cullen : ' The tendency to gangrene may be sus-
pected from the violence of the symptoms not yield-
ing to the remedies employed during the first stage
of the disease. And that a gangrene has already
begun may be known by the sudden remission of
pain, while the frequency of the pulse continues,
and at the same time becomes weaker, accompanied
with marks of an increased debility in the whole
system.' Large and frequent bleeding, blisters,
fomentations, and injections are recommended as
the most probable means of preventing gangrene,
but when it has once formed medicines can be of
little avail.'
I will now proceed briefly to state some of those
cases of gangrene which originate in constitutional
affections, and do not depend on external causes
acting locally. These are of three kinds, offering
themselves either as symptoms of some other disease,
BRIGHT] ROYAL MEDICAL SOCIETY 77
as the sequels of it, or as the principal feature in
the disease. Amongst the first of these I might
have mentioned erysipelatous affections, such as
that of new-born infants, or the malignant erysipelas
(but I have here anticipated myself). The gan-
grenous affections of the fauces, however, in cynanche
maligna, and of different parts of the body, in
purpura hsemorrhagica, will afford examples, and at
the same time seem to point out two very different
states of disease liable to this termination. It
always denotes most alarming derangement in the
balance of power and action, and will call for much
judgment in the practitioner. In scarlatina, where
the sloughs are sometimes very extensive, involving
the fauces, cheeks, and tongue, and inducing caries
of the bones, nitrous fumigations and stimulating
gargles, even made with cayenne pepper, are recom-
mended by Willan.
Perhaps I may include under this division of the
subject those sloughing sores which supervene upon
syphilis, either from the original virulence of the
matter introduced, or more generally from the de-
bility of constitution induced by scrofulous habit, or
from the employment of mercury. These are fre-
quently cases of the utmost difficulty. The syphi-
litic taint seems to demand the use of mercury, but
it cannot be employed.
These will sufficiently serve as examples of this
state of gangrene. And I shall merely add that other
complaints, particularly those which are accompanied
with great debility, as typhus, scurvy, some species
of small-pox, etc., sometimes pass into gangrene.
Independently of any febrile attack, a gangrene
will sometimes take possession of the limb, forming
78 DISSERTATIONS [ON GANGRENE
the true spontaneous gangrene, of which I shall
next proceed to speak.
This species of gangrene chiefly attacks old
people, but it is not confined to them ; it also attacks
persons of both sexes. Generally, however, it may
be said to attack males advanced in age ; and Pott
thinks that amongst these the rich and voluptuous,
who eat to excess, are the most frequent subjects of
the disease. The poor, however, are not exempted
from it ; and it is not improbable that the habit of
dram- drinking may go far to induce that debilitated
state of circulation which either favours or causes
the disease. Probably, whatever diminishes the
strength of circulation, and deprives a part of the
power of maintaining the regular supply of animal
heat and nervous energy, are predisposing, or even
exciting, causes of what we have termed spontaneous
gangrene. Such irregularities of power are induced
by those ' flying and uncertain pains in the feet,'
mentioned by Mr. Pott, and esteemed by him
forerunners of gangrene. The influence of weakened
circulation is also shown in the case related by
Home. It was a man subject to low feverish com-
plaints, in whom gangrene was, after some previous
threatening, immediately induced by the overaction
of a purgative upon his bowels. These patients are
frequently found to have been subject to coldness of
the extremities, and are deficient in bodily exertion.
It is no improbable supposition, though Pott con-
sidered it a mere conjecture, without foundation,
that the ossified state of the arteries is frequently
both the companion and the cause of this disease.
Much as the pain would seem to indicate inflamma-
tion, there is little evidence of its presence.
BRIGHT] ROYAL MEDICAL SOCIETY 79
Treatment. Stimulating cataplasms, as local ap-
plications, have been supposed peculiarly indicated
by the diminished power which in this case prevails.
Bark has likewise been administered, under the
idea that gangrene must yield under what is deemed
the specific against gangrene. Pott, however, on
whose observations we ever feel inclined to rely,
was struck with the total inefficacy of both these
remedies ; particularly of bark, whether taken gene-
rally or applied locally, whatever the mode of its
exhibition, or the form in which it was combined
with other remedies. Chance led him to the em-
ployment of opium, and the good effects were so
decided that he does not hesitate to recommend it
as the most certain means of relief with which we
are yet acquainted. How the opium acts in this
disease I cannot pretend to explain. The effect is
to relieve the pain, and Mr. Pott finds that, what-
ever it does, it prevents the extension of the dis-
ease. From this he is led to reprobate the use
of heating and stimulating applications, employed
locally, as well as the practice of scarification and
the removal of parts before nature has separated
them. The practice he recommends is this, A grain
of opium every third or fourth hour ; keeping the
bowels regular by clysters, with external applica-
tions calculated to soothe and diminish pain, such as
warm milk or very soft and smooth poultices. Mr.
Dease seems to doubt the efficacy of this treatment.
But the only case in which he had tried it certainly
formed no argument against it. Pott did not adopt
this practice from the result of a single case, but
from frequent experience, for he was well aware
that in a disease which often extended to a certain
80 DISSERTATIONS [ON GANGRENE
distance, and then stopped of its own accord, there
was great room for deception in judging of the
effects produced by any remedy. Others, as well as
Pott, had learnt the inefficacy of the means usually
employed. Le Dran tells us that he insisted on its
use only because, doubtful as the remedy was, he
was, as yet, acquainted with no better. And Ques-
nay came to the same conclusion ; and, though he
does not propose opium, insists much on an invigor-
ating diet. Perhaps both bark and opium will
often be found beneficial, and frequently their con-
joined operation will totally fail. I do not know of
any instance in which amputation has been per-
formed in this species of gangrene. And, in general,
the age and condition of the patient strongly forbid
the attempt; yet doubtless cases may occur in which
it would be advisable. Le Dran enjoins particular
caution in amputating under this state of disease,
and seems to have seen it attempted without
success.
Diagnosis. During the incipient stages of this
disease it is possible to confound it with three
different morbid affections of the toes : the venereal
ulceration, the unhealthy sore which occupies the
interstices of the toes from a neglect of cleanliness ;
and the inflammation attacking the gland of the
nail, which often puts on an erysipelatous and
sloughing character. In all of these cases the pro-
gress of the disease and the preceding symptoms
will quickly enable us to distinguish with certainty.
And in the meantime considerable assistance may
be derived from an accurate inspection of the
appearance of the sore, and something may also be
conjectured from the situation which it occupies.
BRIGHT] KOYAL MEDICAL SOCIETY 81
Thus the two former are situated deep in the inter-
stices of the toes, and the latter generally attacks
the great toe, both of which situations differ from
that pointed out by Pott as the point where spon-
taneous gangrene commences.
Prognosis. The prognosis is always unfavour-
able in this disease, as it bespeaks alarming weak-
ness in the powers of life. Yet, as it may arise
from some local vascular obstruction, or some cause
really acting locally, though we know not how, or
from some cause whose existence is but temporary,
and which remedies may remove, we have always a
right to cherish hope. The prospect of preserving
the limb is indeed small, but the life must not be
despaired of. Much in our prognosis will depend
upon the age and constitution of the patient, and a
knowledge of the particular circumstances of his
situation. If, for instance, he should have been
exposed to depressing mental causes, we may hope
that the removal of them will restore something
like the accustomed vigour to his habit, or if we
find that he has been exposed to insufficient bodily
support, we may still hope to see him re-established.
I shall venture to class under the present divi-
sion of the subject, though with some hesitation,
the very singular case related in the Philosophical
Transactions.
In the year 1762 a mother and six children
living near Bury were seized, on January 10th, llth,
and 12th, with pain in one or both of their legs or
feet, which in five or six days were mortified, and
went on regularly in the progress of separation,
requiring very little assistance from the surgeon.
The father was also slightly attacked in two fingers.
<2 DISSERTATIONS [ox QAXGREXS
Only one, which was a child of four months old,
died of the complaint, the rest continuing to enjoy
good health, both at the time of the attack and
during the progress of the disease. No probable
cause could be assigned for this peculiar affection.
The family was healthy, and exposed to no parti-
cular cold or moisture. Some little stress seems to
be laid on the circumstance of the bread which they
had eaten being made of injured wheat. But this
was chiefly on account of the similarity which was
traced between this affection and one ascribed to
the eating of rye-bread made of grain affected with
a peculiar disease called Ergot by the French.
Caries. Before I draw my paper to a close. I
wish slightly to mention that bone, as well as the
soft parts, is subject to gangrene, and that uncon-
nected with any surrounding gangrene. When by
accident or disease the periosteum becomes inflamed,
the vessels of the bone partake of the inflammation ;
it quickly runs into mortification, and gradually
separates in lamellae by a process called exfoliation.
Thus it would appear that gangrene may exist
in the integuments, in the cellular substance, in the
muscular fibre, and the tendons : in the lungs, in
the coats of the stomach and intestines, in the
cornea, and in bone, in short, may probably exist
in every texture of the animal body ; and wherever
it occurs the same general mode of treatment, some-
what regulated by circumstances, is to be adopted.
All along, as inflammation indicates the tendency
to gangrene, we may do our best to moderate the
inflammation. When the gangrene is actually
established we must support the system, and allay
BRIGHT] ROYAL MEDICAL SOCIETY 83
every source of irritation. And when at last the
gangrene has stopped, we must promote the separa-
tion of the dead part by the mildest means, carefully
avoiding to inflict an injury on those parts to which
the disease has not extended, and, on the contrary,
endeavouring to give them healthy and vigorous
action. And, when the separation is effected,
we must promote the healing of the parts which
remain.
VII
MARSHALL HALL
1790-1854
ON THE DISPERSIVE AND REFRACTIVE POWERS
OF THE HUMAN EYE AND ON SOME
MOTIONS OF THE IRIS
Eead 1813
MR. PRESIDENT,
It is still a matter of dispute with
philosophers and physiologists whether the human
eye be perfectly achromatic. If any dispersion of
the rays of light in their progress to the retina does
really take place, it is in so limited a degree as in
ordinary vision to pass unobserved. Those, there-
fore, who consult the sense alone are convinced that
the achromacy of the eye is perfect. They have
pretended to comprehend the wisdom of Providence
in the construction of so admirable an organ as the
eye, to explain the principle on which its achromacy
depends, and to have copied nature in the invention
of the achromatic eye-glass. According to these
philosophers the different humours of the eye are so
accurately adapted to each other that the dispersion
of the rays of light produced by the agency of the
one is counteracted and remedied by the effect of
HALL] DISSERTATIONS 85
the other. Little knowledge and consideration,
however, are required to point out the fallacy of
this opinion. In the achromatic eye-glass the dis-
persion occasioned by the convex lens is remedied
by a contrary dispersion produced by that lens
which is concave. In the human eye, however,
there is no such concave lens. The aqueous humour
induces a convergency of the incident rays and a
certain degree of aberration. The crystalline lens
increases the refraction, and, whatever be its dis-
persive power, the aberration too, and this not only
at its anterior, but at its posterior surface. For
although the dispersive power of all the humours
may be equal, it is certain that the refractive power
of the crystalline greatly exceeds that of the other
two ; and, of course, whenever an increase of refrac-
tion is produced, the dispersion must be propor-
tionally augmented also.
Those philosophers who have relied more upon
experiments made to determine the respective re-
fractive and dispersive powers of the humours of
the eye, and on calculations and deductions founded
on these, contend that this organ must necessarily
occasion an aberration of light, which, however, is
so small as to occasion no inconvenience in vision.
Dr. Brewster is of this opinion. According to the
experiments of this eminent man, the dispersive
powers of all the humours of the eye are equal.
Consequently there must be a dispersion of light as
the effect of their combined agency.
It is with great diffidence that I presume to
maintain an opposite opinion. But it is difficult to
deny the testimony of sense. In ordinary distinct
and perfect vision there is no appearance of colour.
86 DISSERTATIONS [THE EYE
It is mere conjecture to say that colour is produced
but not discerned, especially as, in some experiments
which I am about to detail, when colour is actually
produced it is actually perceived also.
It appears to me that there is a part of the eye,
the action of which has not been fully ascertained.
The iris is supposed to regulate the quantity of
light admitted to the retina, and in vision at near
distances to exclude those rays which would fall
too obliquely on the crystalline lens for perfect
vision. These effects of the iris are undeniable.
But there is another, as far as I know, not hitherto
adverted to. It is the inflection and the dispersion
which the rays of light which pass near its edge
must necessarily suffer.
Now, is it not possible that this action of the
iris may serve the purpose of the concave lens in the
achromatic eye-glass ? A little consideration will
ascertain that the effects it must produce are pre-
cisely those induced by a concave lens. Let a
house or other object be viewed through a small
perforation in a card ; it will be very perceptibly
diminished. Let the rays of the sun be admitted
through a similar perforation, a dispersion of the
light will be the consequence. It is principally on
the rays which pass near the edges of the perfora-
tions that these effects are produced the very rays,
of which the dispersion in vision requires to be
removed. These are precisely the effects which a
concave lens introduced into the eye would occasion.
Those coloured rays which are the most refrangible
are also the most inflectible ; and thus the disper-
sion produced by the one may be remedied by that
effected by the other.
HALL] KOYAL MEDICAL SOCIETY 87
I am not able at present to appreciate the effect
which the pupil may have in correcting by inflection
the dispersion of the rays of light caused by the
humours of the eye. But it is remarkable that its
influence in this way is greatest when most required ;
namely, when intense light or very diverging rays
strike the cornea. As a diaphragm preventing the
rays passing too near the edge of the crystalline
lens, and as a means of correcting the dispersion of
the rays of light, its contraction on the approach of
objects is in every way calculated to increase the
effects intended to be produced.
Admitting this influence of the iris on the rays
penetrating the pupil, I am inclined to think that
the eye is, in distinct vision, perfectly achromatic.
In this idea we have no difficulty in explaining why
we do not see the colours supposed to be produced
we trust the information of the sense ; and we
remove the difficulty which a calculation of the
effects of the humours of the eye in dispersing the
rays of light occasioned to those who regarded the
achromacy of the eye as perfect, although inex-
plicable.
This discussion, however, relates entirely to the
condition of the eye in distinct vision. In certain
cases of indistinct vision, the human eye is certainly
not achromatic. I shall proceed to the detail of
some of many experiments which I have made to
establish this point experiments which from their
novelty and importance cannot fail to excite much
interest.
I may commence this division of our subject
with the three following general propositions :
1st. Whenever a pencil of rays of light whose
88 DISSERTATIONS [THE EYE
axis is inclined to the axes of the eyes enters the
pupil, the light suffers a dispersion into the prismatic
colours.
2nd. Whenever the rays of light which penetrate
the pupil possess an inclination to the axis of the
pencil which is different from that possessed by*
rays proceeding from an object to the distinct vision
of which the eye is adapted, a similar dispersion of
the rays is induced.
3rd. Whenever the pupil of the eye is larger than
is natural for the vision of the object to which it is
directed, an aberration of the rays of light proceed-
ing from it is occasioned.
1. Let the eyes be adapted to distinct vision at
the distance of 10 inches, and, retaining their con-
formation, let attention be paid to the appearance
of an object at the distance of 6 inches. The
outlines of this latter object will be tinged with the
prismatic colours. If a page of a clearly printed
book be viewed, the lines of the straight letters (the
I's for instance) will appear double, two purple
lines including a space of yellow being formed. A
dot (.) becomes a purple circle with yellow in the
centre. If two O's (oo) be viewed, the purple of the
parts nearest each other is brought to coalesce in
the manner of two penumbree, and a spot of dark
violet is produced. Other objects are also tinged
with some diversity of colours unnecessary to specify.
2. Let the eyes be fixed on an object at the
distance of 6 inches, and, when ^adapted to distinct
vision, be glanced towards another object, at the
distance of 10 inches : phenomena somewhat similar
to those mentioned in the first experiment will be
displayed.
HALL] ROYAL MEDICAL SOCIETY 89
3. It is possible after repeated trials to adapt
one eye to distinct vision at any given distance,
and the other eye to indistinct vision at that dis-
tance, the axes of the two eyes not meeting in the
object viewed. To the first eye the object is seen
without colours, by the second the decomposition of
the rays of light is occasioned.
4. If when the eyes are adapted to the distinct
vision of a near object one eye be pushed aside,
the object seen by it will be observed to be tinged
with the prismatic colours; the other remains
achromatic.
These experiments, which might be much diver-
sified, prove the first proposition. The following
. experiments will exemplify the second :
1. The eyes being adapted to distinct vision,
let a concave lens be interposed between one of
them and the object viewed. The rays of light
will be decomposed.
2. Let the same experiment be made with a
convex lens ; similar phenomena will be observed.
Concave and convex specula and a perforated card
answer the same purpose.
3. Let the eye be adapted to distinct vision
through either of the lenses, and let the other eye
view the object without any interposed lens, the
prismatic colours will be observed.
To illustrate the last proposition, some experi-
ments were made with the pupil enlarged by the
application of belladonna, by myself and several
other members of this Society.
The principal appearances with regard to colour
were the following. At a great distance objects
appeared fringed with purple. At a much less
90 DISSERTATIONS [THE EYE
distance similar or nearly similar colours to those
mentioned in the first experiment (page 88) were
observed. It was remarkable that when the latter
colours were very evident to both eyes, they disap-
peared in great measure when one eye was closed.
But the object being brought nearer to this eye, the
colours again appeared. They were however again
made to disappear by interposing a card perforated
by a small hole, until the object being brought still
nearer the eye, the dispersion of the light a third
time took place.
It is remarkable that of six who have performed
this experiment two have observed indistinct vision
only without colours. The eyes of one of these
gentlemen are more convex, those of the other,
thought to be less convex, than natural. To the
other four the colours were very manifest.
I am doubtful under what proposition the follow-
ing experiment ought to be inserted. If the finger
or other object be interposed between the eye and
the bars of a window, those bars are fringed to a
great degree with the prismatic colours, the edge
nearest the finger with the blue and green, that
more remote from the finger with the red, orange,
and yellow.
The refractive power of the human eye is, as
Dr. Wells has remarked, diminished by the applica-
tion of the belladonna. Persons possessed of natural
sight cannot see at the ordinary distance. A pen,
for instance, cannot be mended at all, if brought
so near as, in ordinary circumstances, to distinguish
the point, indistinct vision being immediately pro-
duced. Persons in this situation are assisted by
convex lenses, and, indeed, this experiment com-
HALL] ROYAL MEDICAL SOCIETY 91
municates a most perfect notion of the assistance
derived by long-sighted persons by the use of
convex glasses.
A short-sighted gentleman, to whose eyes the
belladonna was applied, could no longer see dis-
tinctly with his concave glasses, but vision was
as perfect without them as it usually is when
performed by their means.
It is probable that this effect does not depend
on the enlargement of the pupil, as it remained, in
an experiment related by Dr. Wells, long after the
pupil had regained its natural size.
I have already remarked that distinct vision is
performed at a shorter distance by one eye than
by both. I must add another remark, which has,
as well as this, escaped Dr. Wells that objects seen
by one of the eyes to which the belladonna had been
applied were apparently much diminished in size.
This fact is of too singular and curious a nature
to be passed over without observation. I do not
know whether a similar phenomenon be observed by
long-sighted persons, or persons possessed of the
common, or diminished refracting power. It still
continues in myself some time after the contraction
of the pupil has begun.
It would appear from this fact, relative to dis-
tinctness of vision, that there is some modification
induced by one eye on the other in vision under
the influence of belladonna. I have observed a
similar appearance, with regard to distinctness of
vision, on looking, first, with both eyes, and,
secondly, with one only, through concave lenses ;
and perhaps convex lenses may produce the same
effect, objects being perfectly distinct to one eye
92 DISSERTATIONS [THE EYE
which were confused when viewed by both ; but
this may be explained.
How it is that objects appear less to one eye
than to both is at present equally a mystery to me.
Perhaps the particular degree of inclination of the
optic axes to each other may convey to the mind
some view of the distance, and consequently of the
size of the object.
It has been observed that objects are seen dis-
tinctly nearer by one eye than by both, and nearer
by one eye with an interposed perforated card than
when the card was removed. This circumstance
suggests the idea that the iris naturally contributes
much to distinct vision through a greater range of
distances than would otherwise occur. It is indeed
difficult to separate the effect of the enlargement
of the pupil in these experiments from the other
change in the refractive power of the eye also
observed. It is highly probable, however, that
the perforated card performs the office of a con-
tracted pupil in including those rays which pro-
ceeding from near objects would pass so near the
edge of the crystalline lens as to become extraneous,
and induce indistinct vision.
Some interesting experiments might be devised
for the purpose of ascertaining the relation of the
size of the pupil in different persons, and the
natural limits of distinct vision.
I now come to the last part of my subject, the
Motions of the Iris.
This muscle has been classed amongst those
which are termed involuntary, possibly rather
erroneously. It must always be remembered that,
HALL] ROYAL MEDICAL SOCIETY 93
in a certain sense, all muscles are involuntary.
When I move my hand and fingers in writing
this essay, I do not will to move a particular
muscle ; it is the end, the aggregate motion, not
the means, the individual motions that are under
volition. When I wish to change the place of
vision from one more remote to a nearer, I no
more will to move the two adductores muscles of
the eyes than of the iris, whose motions are con-
comitant with those of the former muscles. But
the adductores are termed voluntary, the iris an
involuntary muscle. It may be said that the eye
may be moved when the lids are closed, and there-
fore without willing to change the place of vision.
Now even this circumstance has a parallel in the
motion of the iris, for it is possible to obtain the
power of moving this circular muscle at will, with-
out fixing the eye on any subject.
1. In the first experiment (p. 88) the pupil is
larger than in distinct vision at the distance of
6 inches.
2. In the second it is smaller than in distinct
vision at the distance of 10 inches.
3. In the experiment under the second general
proposition, similar motions of the pupils are ob-
served.
4. In the third experiment (p. 89) under the
first proposition, the pupils are of an unequal size.
5. Lastly, it is possible by much perseverance
to obtain such command over the iris as to move
it at will when the eyes are bent on vacancy.
The last experiment especially is conclusive with
regard to the motions of the iris being capable of
being urged at will. Nor are the former ones of
94 DISSERTATIONS [THE EYE
an ambiguous nature, for it is not necessary, as
stated in the experiments, to have a real object
situated at the distances mentioned ; the object to
be viewed is sufficient, the adaptation of the eye
and the motion of the iris being performed at will,
with perfect ease, after repeated trials.
A person altogether ignorant of anatomy is no
more conscious of the motion of the straight than
of this circular muscle of the eye in adapting it to
vision at different distances. Therefore to each
muscle may be, with equal propriety at least,
applied the term voluntary, if this term be appli-
cable to muscles at all. It might be less erroneous
to denominate certain motions, rather than the
particular muscles by which they are produced,
voluntary or involuntary. However, I do not wish
to contend further about the use of a word.
I shall only add, in the last place, that the
experiment No. 3 (p. 89) is an instance of real
strabismus. The state where the optic axes do
not meet in the point oscided is not a squint.
Strabismus takes place only where the optic axes
meet out of the mesial plane produced.
I cannot conclude without expressing my obli-
gations to Messrs. Bigsby, Fyfe, Wright, Sandberg,
and Davy, who have all had the kindness to make
some of these experiments for me, and to give me
a written account of the phenomena they observed.
With regard to the whole of this paper, I must
say one word in extenuation of the too manifest
hurry in which it has been prepared. It was all
written and composed in its present form in the
space of three hours after midnight. The necessity
for this was occasioned by circumstances already
stated to the Society.
VIII
ROBERT LISTON
1794-1847
ON FRACTURE OF THE NECK OF THE FEMUR
Read 1820
MR. PRESIDENT,
Before proceeding to give an account of
the circumstances attendant on fracture in this
situation, its diagnosis and treatment, it may per-
haps be proper to say something of the nature of
the apparatus in the healthy state.
Anatomy. # * * #
Fracture of the neck of the femur, as well as the
separation of the epiphysis, may be produced by
blows or falls on the hip, or by force applied to the
distal extremity of the femur, either directly or in-
directly, as in case of falls from a great height in
which the person alights on his knee or foot.
Diagnosis. The diagnosis of injuries of any part,
and above all those of the hip joint, are very difficult.
This difficulty arises from the swelling consequent
to any injury, the great pain attendant on any
examination of it, and also from a peculiar state of
the ligaments and other apparatus by which a kind
of crepitation is produced. In the thigh joint the
feeling is moreover very deceitful, owing to the great
96 DISSERTATIONS [FRACTURE OF FEMUR
thickness of the immediate covering, and the
superincumbent parts. Fracture of the neck of
the femur can with difficulty be distinguished from
fracture through, or immediately below, the trochan-
ters, but fortunately the treatment ought in all
respects to be the same. Before swelling comes on,
and within a short time of the accident, distinct
crepitation of the broken ends may be perceived by
rolling the thigh with one hand, whilst the other
is placed over the trochanter major, and the limb is
slightly extended.
By bending the knee and using the leg as a
lever, we shall find that in fracture the thigh is more
easily rotated. The limb is seldom much shortened,
not more than an inch or two (and in fact without
laceration of the capsule this cannot occur to any
extent) ; the toes are uniformly turned outwards, and
this is easily understood by referring to the powerful
rotators, to the weight of the foot and natural
inclination of the limb. Thus it may be easily dis-
tinguished from dislocation in the thyroid hole, in
which the limb is lengthened, and the toes turned
out ; neither can it be mistaken for dislocation back-
wards and upwards, in which the head rests on the
back of the ilium, the limb is shortened, and the toes
turned inwards.
The position of the toes will enable us to dis-
tinguish this accident from luxation of the head
into the sciatic notch. In this species there is little
shortening of the limb, and the toes are turned
slightly inwards. It may also easily be known from
dislocation of the head forwards from examination
of the part in the groin. But from inflammation of
the ligaments after an accident, and luxation, in
LISTON] ROYAL MEDICAL SOCIETY 97
which the head points towards the cotyloid cavity,
and the trochanter major lies on the back of the
ilium with little change on the length of the limb,
and with the toes turned out, it requires an ex-
perienced eye and hand to form a proper and correct
diagnosis.
The history of the previous occurrences will
easily enable us to discriminate between morbus
coxarius, or separation of the head and shaft by this
disease from fracture of the neck.
Treatment. With regard to the possibility of a
bony union taking place in this situation much
difference has existed amongst surgeons. Some
have even gone so far as to deny that ossific matter
can be deposited into fractures extending into joints.
Against this assertion many proofs may be brought
forward, such as the union of the patella and ole-
cranon, and of fractures extending into the joints of
all sizes and kinds in the extremities. We find
frequently also depositions of bone within the cavi-
ties, as in the humerus and ulna ; and in the knee
ossified tumours connected or not with the sy no vial
membrane are found. Thus it is seen that the
lubrication of a part with synovia is no bar to the
formation of bone. In the fracture of the shaft of a
bone, the extravasation of fluids, and hardening of
the soft parts from this cause and inflammation to-
gether, bind the extremities closely together, and
thus favour the union ; still, however, the connecting
medium (in the first place soft and vascular,
gradually assuming the nature of cartilage, and in
which ossification takes place) is poured out from
the vessels of the broken ends. It has been supposed
that the head of the thigh-bone had not vitality
G
98 DISSERTATIONS [FRACTURE OF FEMUR
enough to go through this process, but we know
now that vessels comparatively large are destined
to supply it. We find, on examining fractures in
which the process of union has been interrupted by
any cause, as at sea in case of rough weather, or in
experiments made on animals in which bones are
broken and moved repeatedly during the cure, that
when nature, as it were, is balked in her first
attempt to produce bony union, she covers the ends
with a smooth substance, and an artificial joint is
the consequence. These I have very frequently
seen on animals and on the human body almost in
every bone. In old subjects, where the powers of
life are low, this is a very common occurrence. The
same causes operate powerfully in fracture of the
neck of the femur to prevent a proper union. The
difficulty of producing a reunion does not depend by
any means so much on the adaptation of the parts
to one another as on the inefficacv of the means
I
usually employed to retain them. So much is this
the case, that some of these means have been com-
pared to the plans adopted by anatomists in their
experiments on dogs for the formation of artificial
joints ; and from such treatment being general, many
are the beautiful preparations of artificial joints
betwixt the head and neck of the femur in the
museums of this country. The cases are but few in
which union by ossific matter has taken place, and
has been satisfactorily proved.
But it is unnecessary for me to dwell on such a
well-known circumstance in a paper intended for so
enlightened a body as the Royal Medical Society of
Edinburgh.
Mr. Pott's method of treating fractured femora
LISTOH] ROYAL MEDICAL SOCIETY 99
by bending the thigh on the pelvis, and the knee on
the thigh, is quite inapplicable here, as is also any
plan in which flexion or motion of the joint is
allowed. If a union is to be expected, it is only by
keeping the broken parts firmly and accurately
adapted to each other for a sufficient length of time.
We have the means of ascertaining their complete
adaptation, by comparing the thighs and legs with
one another, and attending, at the same time, to the
direction of the toes. If we are obliged from retrac-
tion, owing to the insufficiency of the apparatus
employed, to replace the fracture every day or two,
we shall but repeat, and that to their utmost extent,
the experiments I have formerly alluded to, and the
result will be the same.
Surgeons at least many of them are so fully
impressed with the idea that union by ossific matter
is out of the question, that they are not at the
trouble even to make the show of trying a cure. If
they do try it, the means employed are so unequal
to the object that, in either case, the termination is
the same. The patient is disabled by a useless
limb which he is obliged to drag about for the
remainder of his life. The great superabundant
secretion of synovia after an injury of the hip joint
has been supposed by Mr. (now Sir) A. Cooper a
principal cause of the infrequency of union in cases
of fracture within the capsular ligament. Laying
it down as a rule that it is better for the patient to
be contented with a disabled limb than to submit
to the confinement necessary on the attempt to pro-
duce a bony reunion, this excellent surgeon recom-
mends the patient to be moved out of bed after the
subsidence of inflammation, and set on crutches as
100 DISSERTATIONS [FRACTURE OF FEMUR
speedily as possible. In this way, by the strengthen-
ing of the capsular ligament, and smoothing off of the
fractured ends, the patient can, by-and-by, leave off
any support, but remains with a very insecure joint,
and but an unserviceable limb. I question much if
the capsular ligament can be extended so much with
fluid, and that suddenly, so as to force the fractured
ends of the neck far from one another. We see
large collections of fluid in membranes somewhat of
the same nature, as in the tunica vaginalis or in
the peritoneum, and even in those of the same
kind, though more rarely, as in the hy drops articuli
taking place in the knee, ankle, or any other
joint, but these distensions are not produced in
a day, nor yet in two or three ; it is the business
of many weeks, months, or years.
That collection takes place in the capsular
ligament there can be little doubt, and if any fear
is entertained that in this way the bone may be
separated, the sooner means are adopted for its
prevention or removal the better. I suspect Mr.
Cooper will find in the inefncacy of the means
employed to retain the bones in accurate apposition
a better reason for the great infrequency of bony
union of the neck of the femur. The means he
recommends for fractures in this situation (the short
splint and belts to wit) are liable to the same
objections as those I have mentioned above. I hope
no one would be simple enough to leave the limb
without any attempt to replace it, as is recommended
and practised by many surgeons in fractures,
whether simple or compound, of the limbs. They
are regulated by the notion of, in the first place,
subduing the inflammation before reducing and
LISTON] ROYAL MEDICAL SOCIETY 101
securing the fractured bones, a very pretty fancy
indeed ; and this they propose to do by laying the
limb on a pillow, smooth and neat, applying evapo-
rating lotions, and, if need be, leeches. All this is
done from a superficial view of the injury. They
combat an evil which it is in their power to pre-
vent almost entirely. Whilst they are watching the
symptoms, and palliating them by cool cloths, etc.,
they are but watching till the soft parts, irritated
and torn against the fractured and unequal ends
of the bone, become violently inflamed ; until the
patient, with all the symptoms of inflammatory
fever, becomes delirious, leaps out of bed, and stalks
through the ward, to all likelihood forcing the bone
through the integuments. Then the poor victim
must be bled and leeched, his head shaved, and,
perhaps, after profuse suppuration or gangrene of
the limb, recovers of a fracture in the first place
simple (if you can call it a recovery), with the loss
of a limb, and what is worse, deformed by a useless
and unseemly mass in lieu of it.
In my humble opinion, there is no reason why a
fracture of the neck of the femur should not unite
as well as any other, when put in circumstances
favourable to such an occurrence.
The limb must be kept steady with regard to the
trunk, and made, as it were, part of it, so that not
the slightest motion can take place in any part of
it. The fractured extremities should, at the same
time, be firmly compressed against one another, that
separation by any cause may be effectually prevented.
The limb, at the same time, must be permanently
extended, and in such a manner that no change of
position be required. These indications, necessary
102 DISSERTATIONS [FRACTURE OF FEMUR
in every case of fracture, require to be observed with
the greatest strictness in this case.
No means with which I am acquainted are
sufficient to effect all these purposes, excepting the
employment of the apparatus recommended by
Desault, or what is far preferable, that used at St.
George's Hospital in London.
The patient is laid on his back, the two limbs
brought to the same length by the extension of the
injured one, of which the toes are also directed
upwards. The affected limb is then rolled equally
from the toes to the groin with a moderately broad
bandage. The long splint with a foot-piece, and
which should extend from the heel to the short
ribs, is laid along the outside of the limb. This is
retained by a roller to the foot, and by slips of
bandage made to apply to the limb. After it is
firmly attached, a band is passed under the perineum
through a slit in the top of the splint, and by the
tightening of this the limb is to a certainty kept in
its proper place. If swelling comes on, the band-
ages must, of course, be slackened a little. This
apparatus must, of course, be retained six or seven
weeks ; afterwards, slight motion employed fre-
quently to prevent stiffness from adhesion of the
ligamentous apparatus or disuse of the muscles.
When the limb is thus secured, and every joint
rendered immovable, the patient can be gently
raised for any evacuation or other purpose, without
risk of displacement or motion of the fracture. At
some future period I may present to the Museum
of the Royal Medical Society a specimen of the
apparatus, and, if I should be so fortunate as to
obtain it, a preparation of the reunion of such a
fracture.
LISTON] ROYAL MEDICAL SOCIETY 103
I may here notice that another cause of the
great scarcity of preparations of reunion arises
from accidents of the kind occurring in old sub-
jects generally, in which fracture in any situation
almost would with difficulty unite.
IX
JAMES SYME
1799-1870
ON CAEIES OF THE BONES
Read 1821
MR. PRESIDENT,
The truly deplorable ignorance of
many surgical practitioners regarding the diseases
of bones is most astonishing, especially when we
consider the frequency and importance of these
affections. I am convinced that the trepans -and
rugines of our fathers in surgery, though often
misapplied, did, upon the whole, much less mischief
and infinitely more good than the poultices of our
brethren of the present day. Indeed, it appears
that the bones occupied a much larger portion of
surgical attention formerly than they do at present.
It is in this way only that we can account for the
present prevalent ignorance and injudicious treat-
ment, which is the less excusable, considering the
more accurate notions we now possess of the animal
economy.
In the following observations I mean to direct
my attention chiefly to that affection of the bones
generally known by the name of caries. I should
rather say, which is properly understood by this
SYME] DISSERTATIONS 105
term, for caries, to many surgeons, is synonymous
with disease, and conveys no precise meaning of the
particular morbid action to which it is applied in
correct language. It is to this very extended use of
the expression that much of the confusion and
uncertainty of surgical practice in the affections of
bones is to be ascribed, for it is by confounding the
serious and obstinate disease of caries with really
healthy actions which do not require the assistance
of art, that surgeons are led to a feeble and inert
practice.
It therefore appears to me that I shall do well if
I succeed in characterising distinctly the carious
affection ; but before making any attempt towards
this desirable object, it will be necessary to take a
rapid and general view of the different actions,
healthy and unhealthy, to which bones are liable.
Although the diseases of bones may appear to a
careless observer almost endless and complicated
beyond the powers of description, they are found
upon investigation to be few and extremely simple.
They are all preceded by inflammation, and are
the terminations of this action ; of course they vary
with the degree of it, and with the constitution of
the part or patient in which it occurs.
The most gentle action carried on in bones is
the adhesive inflammation, or that which provides
for the union of simple fractures. We know that
there is one set of vessels constantly pouring out
new bone, while there is another as constantly re-
moving it. All that seems necessary in this stage
of inflammation, then, is that the activity of the
former should exceed that of the latter-mentioned
vessels. The only irritation necessary for commenc-
106 DISSERTATIONS [ON CARIES
ing this action seems to be the stimulus of imper-
fection, as it has been called in other words, the
want of due strength felt by the system.
I see no reason why the broken ends of a bone,
when accurately placed, should not unite by the
first intention, just as the soft parts unite directly
when divided. I do not mean to say that the
earthy parts will unite, but that the soft or carti-
laginous basis of one end will unite with that of the
other. This idea appears the more reasonable from
two cases which happened to come under my im-
mediate care.
The first of these was a transverse fracture of
the humerus near the middle. Six days after the
accident, the patient, who was a stout, middle-aged
man, raised his arm and declared that he felt it
strong. The second case was a fracture of the ulna
near the elbow ; the patient, without my knowledge,
removed the splint on the twelfth day and found
the arm quite strong, so much so, indeed, that I
caught him using it for buttoning his clothes and
sweeping the floor.
When the fractured extremities are not accur-
ately adjusted, then a large effusion of bony matter
takes place from both, so as to patch up the fracture.
The ancients, and, I am sorry to say, some of the
moderns too, wishing to give nature the credit of
their own clumsiness, have considered this effusion
as a mistake of hers, and, calling it a redundance of
the callus, have attempted to restrain it by tight
bandaging instead of accurate adaptation.
The same action, viz. a simple effusion of bony
matter, is excited by different stimuli, either con-
stitutional or local. In nodes we have an example
SYME] ROYAL MEDICAL SOCIETY 107
of bony effusion caused by constitutional irritation.
The new matter here is not thrown out upon the
surface of the old, but is placed between its layers.
To satisfy ourselves of this fact, all that is necessary
is to saw up a bone on which there is a node
longitudinally ; the laminae of the sound part may
then be traced through the enlargement. Effusion
of new bone as the effect of local irritation is a very
common occurrence. Any gentle stimulus, either
idiopathic or symptomatic of abscesses, or death of
the internal parts, is sufficient to occasion it.
The next degree of inflammation produces an
effect precisely the reverse of this last this is
ulceration. The irritation acting here is generally
some sort of pressure, as that of an aneurismal
tumour, confined matter, or the like. This action
cannot be considered morbid ; it is merely an effort
of nature to relieve herself, and consists simply in
the activity of the absorbents exceeding that of the
exhalents, the consequence of which is that the ex-
ternal lamina is removed, so that the cancellated
structure of the bone is exposed ; but the surface is
healthy, and pours out new bone to repair the
breach as soon as the offending cause is removed.
The next degree of action is that which has been
called the suppurative inflammation, because the
formation of pus is uniformly an effect of it. Any
part of a bone may enter into this action : sometimes
the medullary canal is the seat of it, and thus we
have the disease called spina ventosa ; at other
times the substance of the bone is affected, and then
abscesses form ; lastly, the surface itself may be
concerned, as often happens in the joints. After
the matter has formed and is evacuated, then granu-
108 DISSERTATIONS [ON CARIES
lations, provided the bone is not too much ex-
hausted, spring up and repair the loss of substance
which may have been caused by the disease. If
two surfaces in this state are opposed to each other,
as is the case in joints, they unite, hence the
frequency of anchylosis.
It appears, then, that bone is formed in two
ways, viz. either by the vessels themselves, their
actions being excited simply, not changed ; or
through the medium of granulation. The first
method of regeneration takes place to a greater
extent in bones than any of the other tissues ; the
second they possess in common with all the others
of the body.
The process by granulation goes on much more
slowly than the other, hence the importance of heal-
ing the external wound in compound fractures
directly, as by this means we lessen the risk of the
bones taking on the suppurative inflammation,
which they almost certainly do when the soft parts
do not adhere by the first intention. But when
any man writing a system of surgeiy declares that
bones will not unite as long as they are exposed, we
must suppose him to be either blind or obstinately
stupid.
The next stage of inflammatory action so im-
pairs the living powers of the bone as to incapaci-
tate it for any healthy process without absolutely
destroying it. It is this condition of a bone which
the word caries properly expresses. The disease
appears under many and various modifications, but
is always essentially the same, follows the same
course, and demands the same treatment.
Lastly, the inflammation may be so intense as
STME] ROYAL MEDICAL SOCIETY 109
to kill the bone outright, and then we have the
disease called necrosis.
From what has been said it will, I think, be
evident that there are many processes carried on in
bones which are really healthy, and must not be
disturbed by the interference of surgical art. The
carious affection is not of this description. On the
contrary, it is a disease of the utmost obstinacy and
malignancy, uniformly requiring the assistance of
art. I wish, therefore, to characterise it so clearly
that the merest surgical tradesman may never mis-
take it for a healthy action. While making distinc-
tions it will not be amiss to observe that surgeons
may be divided into those who practise their trade
merely, and those who also study their profession.
To the former already established in practice I
certainly have not the presumption to expect I
shall be of any use, for men who do not think, and
will not be convinced by what they see, are truly in
a hopeless state. But to those gentlemen who con-
stitute the latter division, and to the rising genera-
tion of the former, the following observations may
not be altogether useless.
Caries for the most part appears in young sub-
jects, and in those particularly of a scrofulous con-
stitution. The inflammation which precedes is
generally caused by strains or other injuries of the
soft parts, but occasionally appears without any
assignable cause. When this is the case an abscess
in the bone generally forms first, the walls of which,
from the intensity of the inflammation, are left by
no means disposed for a healthy action.
During the formation of the abscess the patient
is racked with intolerable deep-seated pain. The
110 DISSERTATIONS [ON CARIES
integuments suffer little change ; generally they are
a little puffy. At last the matter of the abscess by
its pressure causes absorption of the bone, and thus
establishes an outlet for itself. The soft parts are
then elevated into a tumour, an opening into which
is effected either by nature or the surgeon's knife.
The integuments now subside, the edges of the
opening become callous, and a constant, thin, foetid
discharge issues from the morbid bone.
In the other case, that is when the disease is
propagated from without, things go on much more
rapidly. The abscess in the integuments forms
quickly, and the destruction of bone generally occu-
pies a larger surface, though it does not penetrate
to such a depth.
Caries has been divided into different kinds, as
the cancerous, worm-eaten, phagedenous, etc., but
these distinctions do not appear to me at all neces-
sary, as I believe the proper treatment of caries to
be uniformly the same.
It is difficult to describe the appearance of the
carious bone, as it varies with the parts in which it
occurs, the cause which gives birth to it, and pro-
bably many other accidental circumstances so trivial
as to escape observation.
Whenever we find a bone, which for some time
previous to our. examination has not been subjected
to pressure, deprived of its external shell so that it
feels rough, and allows the probe to be pushed into
its substance, we may safely conclude that it is in a
carious state, especially if it can be ascertained that
an inflammatory action has been carried on within
it. The grand distinction between an unhealthy
and a dead bone at least as far as regards their
SYME] KOYAL MEDICAL SOCIETY 111
diagnosis is the want of the external lamella in
the former, and the presence of it in the latter.
For, as the cancellated part of a bone is much more
vascular than the laminated, it is evident that the
latter portion will fall a victim to such a degree of
violence as would only debilitate the powers of the
former, hence the frequency of necrosis in the shafts
of bones and caries in their heads ; but spongy
bones, and the heads of long ones, have a dense
external shell, which cannot resist any more than
the shaft ; they therefore lose this covering of theirs
at the first attack of inflammation.
A carious bone, when macerated very closely,
resembles a piece of sugar which has been immersed
for an instant in boiling water, and then held up
so as to allow the dissolved parts to drain from it.
While still adhering to the body it rarely possesses
this appearance ; indeed, we can seldom see its
structure at all, as spongy, ill-conditioned granula-
tions fill its interstices and thus conceal it, so that
all our information as to the state of the bone must
be obtained from the probe.
Caries, when once fairly established, shows little
tendency to put a stop to itself. It is not un-
common to find a carious bone remain in almost
identically the same state for a series of years.
The disease is not only indolent in itself, but resists
all the efforts of the system to shake it off. The
bony matter destined to supply the wants of the
extremity is almost all carried to the breach, leav-
ing the bones soft and spongy, and is there thrown
out in the form of foul discharge. The system
takes alarm, more and more nutritious materials are
sent to the part, until nothing is retained but what
112 DISSERTATIONS [ON CARIES
is barely sufficient for carrying on the processes of
life. But all is to no purpose, for as soon as the
healthy fluids enter the diseased vessels they are
instantly converted into stinking sanies. Nature,
finding herself foiled in her attempts to repair the
breach, throws up a wall of new bone around it.
Though in this way the disease is prevented from
spreading, it is by no means extinguished. When
of any considerable extent, the patient's health
suffers cruelly from the constant and copious dis-
charge, and, if as yet he has not attained his full
size, his growth is often arrested ; thus it is not
uncommon to see a young man of eighteen or
twenty look like a boy of ten or twelve.
Provided, however, the disease be not very ex-
tensive and the discharge consequently moderate,
the system gets habituated to it, and often, as has
been already stated, supports it for many years.
It does occasionally happen, though certainly
very rarely, that the part of a bone which has been
long the seat of caries, at last from an attack of
inflammation or any other cause, dies and is cast
out, immediately upon which healthy granulations
spring up all over the surface of the bone, and thus
a cure is accomplished speedily and effectually. This
I believe to be the only way in which a natural
cure of caries ever takes place, an event, indeed,
which I am convinced is one of the rarest in
surgery. I know very well that men possessing a
considerable portion of popular confidence assert
that they have seen many cases of caries get well
under the action of poultices, but I think there is
reason for believing that these good people have
mistaken very different actions for the one under
SYME] ROYAL MEDICAL SOCIETY 113
consideration. At least I have seen men who
erroneously supposed themselves acquainted with
their profession, and had even the art of juggling
their patients (patients indeed !) into the same way
of thinking, arguing from cases entirely uncon-
nected with caries, and resembling it only in their
confused and perplexed imaginations.
It is difficult at first sight to discover the cause
of the extreme obstinacy of caries. The phenomena
presented by ulceration of the soft parts explain
the difficulty in a very satisfactory manner.
When a breach of continuity occurs in the soft
parts of an individual possessing a weak or un-
healthy constitution, the attempts at reparation
are always feeble, slow in their effects, and often
altogether abortive.
The same tardy progress towards a cure is
noticed when the cause productive of the injury is
of such a nature as to weaken the vital powers of
the surrounding parts. The ulceration produced by
fire is of this kind. Every one who has seen the
moxa applied must have noticed the extreme slow-
ness with which the resulting sore healed, a cir-
cumstance to be explained, I should think, by
supposing that the parts surrounding the ulcer
have been stimulated beyond their powers.
We are further assisted in our inquiries into the
nature of caries by attending to the very different
effects produced on long and short bones by a
similar moderate and continued irritation. When
an ulcer is kept up for a length of time over the
shaft of the bone, as the shin, and is irritated by
frequent injuries, it sometimes happens that the
bone exfoliates, at others gets into a carious state.
H
114 DISSERTATIONS [ON CARIES
When, again, an ulcer happens over a vascular bone,
I have observed (and to the best of my knowledge
the observation is new) that the bone, instead of
exfoliating or getting carious, may simply have its
vessels stimulated to an increased action, so that
instead of displaying a loss of substance it is much
increased in surface, and seems everywhere as if
shooting into stalactites.
But although by transferring our reasoning on
the processes of the soft parts to those of bones, we
may to a certain extent account for the obstinacy of
caries, the extreme pertinacity of the disease is still
somewhat perplexing; hence some have supposed
that a peculiar morbid action is induced, and this
idea derives some support from the observation of
Boyer, that any stimulus applied to a carious bone,
not powerful enough to destroy it altogether, only
adds strength to the disease.
To whatever cause the obstinacy of caries may
be owing, there can be no doubt that it is a
disease of the utmost perversity ; so much indeed
as to resist but too successfully the well-meant
exertions of nature. Finding such to be the case,
then, it becomes us to lose all reserve and act boldly
and decisively, knowing that the only chance the
patient has of a cure is in our hands.
The practice to be followed is exceedingly simple
and obvious, indeed, nature points it out clearly to
us. Whenever she succeeds in obtaining a cure it-
is by putting to death the ill-disposed bone. We
have therefore only to attempt the same, and if
success attends our efforts, a radical cure will be
the reward of our labours in every case. If the
patient has been too long trifled with before we are
SYME] EOYAL MEDICAL SOCIETY 115
called in to his assistance, so that his health is
ruined and his strength exhausted, amputation
becomes the only, though cruel, means of relief.
But here it is particularly necessary to guard
against rashness ; for although the strength of the
patient may appear worn out, the simple removal
of the diseased action is often sufficient to restore
him to health and strength.
Caustics of every description have been, and
still are, employed for completing the destruction
of the sickly bone. Of these the lunar caustic,
potash with lime and eau mercurielle, or nitric acid
saturated with mercury, are the best. But it
would be wasting time to dwell upon them as long
as we possess that most valuable agent, the actual
cautery, which is much more effectual, more easily
applied, and less painful to the patient ; but which
at the same time, I am sorry to say, has in the
hands of injudicious practitioners done infinitely
more harm than good. For, when used to repress
a diseased action, it uniformly strengthens it, and
is never of any advantage except when pushed to
such an extent as to insure the certain and complete
destruction of the diseased portion.
But although the red-hot iron may often be
sufficient of itself to accomplish all we wish,
especially if the disease be of no great extent, it is
necessary to conjoin with it other means. When
we encounter the disease of greater strength, rasps,
rugines, scraping, trepans, pieces of glass, and many
other contrivances of the same sort have been re-
commended for removing the bulk of the diseased
bone, so as to allow of the more effectual application
of the cautery. Chisels, flat and grooved, will, I
116 DISSERTATIONS [ON CARIES
should think, from the use I have seen made of them
by my friend Mr. Listen, be found fully sufficient
for digging out the rotten bone. When the
metacarpal or metatarsal bones are affected, it is a
great saving of trouble to remove a portion of the
entire cylinder. Various instruments have been
contrived for this purpose ; of these may be men-
tioned the metacarpal saw, the half-headed trephine,
chain saw, and Machel's saw. The inconveniences
of these instruments are so obvious that it is hardly
necessary to particularise them. The metacarpal
saw can, it is very evident, be applied only to a bone
which is freely exposed on all sides. Now the
exposing of a metacarpal or metatarsal bone is by
no means an easy matter, and necessarily implicates
a very extensive separation of the soft parts. We
may judge of the difficulty, I should rather say
impossibility, likely to be encountered in cutting
through a small irregular bone with a half-headed
trephine, from the trouble which attends the use
of the common full-headed trephine even on a flat
bone.
The chain saw I am inclined to think, both
from the testimony of others and my own experi-
ence, never succeeded in cutting through a bone
ever since it made its entrance into this inventive
world. And as to the saw of Machel, I am ready
to allow that it is a very pretty mechanical con-
trivance, but how it should enter the head of any
man that such an apparatus could be of any use
in surgery excites my astonishment in no small
degree.
The surgeon I have already mentioned, Mr.
Listen, finding the inconveniences just enumerated,
SYME] ROYAL MEDICAL SOCIETY 117
bethought himself of using cutting pliers for this
purpose. He accordingly had some made of
different shapes and sizes, since which time he has
never experienced any difficulty in removing meta-
carpal or metatarsal bones, either in whole or in
part.
I have now finished the account of what appears
to me the truth regarding caries, and shall next
proceed to give some cases in illustration of what
has been advanced.
X
ROBERT CHRISTISON
1797-1882
ON THE CONTAGIOUS NATUEE OF THE BEITISH
CONTINUED FEVER
Read 1822
MR. PRESIDENT,
It was not till near the close of last
century that physicians began to form precise
notions of the nature and properties of contagion.
About that time their attention was directed
towards assembling and arranging together a series
of facts relative to the diffusion of continued fever
and other infectious disorders. Through a careful
generalisation of these facts, and by drawing from
them cautious and legitimate inferences, they were
led to the discovery of certain doctrines which have
since been promulgated under the title of the Laws
of Contagion. More lately they have received
several additions and corrections. But much yet
remains to be done before they can merit the high
title with which they have been dignified.
These laws of contagion, so far as they regard
continued fever, I propose in the following essay to
try by our most recent experience. I shall endeavour
to show how far our knowledge of them may be
CHRISTISON] DISSERTATIONS 119
extended by the observations made upon the
epidemic fever that not long ago laid waste the
British Islands. The opportunity which has been
thus afforded to judge of the tenets of our prede-
cessors is peculiarly fitted for the purpose. For we
have been furnished with careful records of its course
from almost every part of Britain which it visited ;
and there has scarcely ever been an epidemic whose
history was described so purely from observation,
whose progress was observed with so little bias
from theory.
At the outset of this inquiry I shall examine the
preliminary questions, whether the continued fever
of the British Isles be generated by contagion, and
whether contagion be its sole cause ; I shall next
consider some questions that spring from these ;
and lastly, I shall compare the generally received
laws of contagion with what has been observed
during the late epidemic.
That we may prove the contagious nature of
continued fever it is not enough to quote, as many
do, even innumerable instances of entire families
seized with it about the same time. Such incidents
indeed serve to show that the sufferers have been
simultaneously exposed to some common cause of
pretty general diffusion. But instead of that being
an emanation from the bodies of those affected by
the fever, it may be (as the opposers of the doctrine
of contagion assert) a peculiar state of the atmo-
sphere, terrestrial exhalations, or a peculiar mode
of living, conjoined perhaps with exposure to cold,
wet, fatigue, and the like.
It has been frequently found, however, that
fever is rapidly propagated in families if those
120 DISSERTATIONS [CONTINUED FEVER
collateral circumstances are allowed to continue by
which contagion is known to be fostered, but by
which a peculiar constitution of the atmosphere, or
any other great common cause, cannot be affected
in the least. On the other hand, it is equally well
established that the progress of the disorder will be
checked by resorting to such means as dilate, destroy,
or counteract contagious effluvia, but have no power
whatever in controlling any of the other possible
causes. These principles are admirably illustrated
by the tables of Dr. Haygarth in his work on the
prevention of infectious disorders. I may add that
our experience in the late epidemic of this city
amply corroborate them. A very large proportion
of our cases of fever proceeded from certain lodging-
houses in the Grassmarket and Cowgate, occupied
for a night only, by persons arriving in search of
employment. From these places a regular supply
was kept up, till the districts where they lay were
brought under strict superintendence, and not un-
frequently the whole inhabitants of some of them
were ill at one time. But afterwards, when they
were carefully watched, and disinfected so soon as
a single fever patient was discovered in them, the
numbers decreased greatly, and the disease in some
of them was even completely extinguished.
Another circumstance in the spreading of these
epidemics which establishes their contagious nature
is, that while they rage in certain parts of a great
town, they are often utterly unknown in other
districts not very remote, laid out in a manner pre-
cisely the same, and occupied by inhabitants of the
same rank and of similar habits. And as a further
proof that this cannot depend on any peculiarity of
CHRISTISON] ROYAL MEDICAL SOCIETY 121
situation, it is found that the exempted districts,
when once invaded by the disease, suffer as severely
from its ravages as those previously attacked.
But the most decided argument in favour of the
contagious nature of the British continued fever
is drawn from the circumstances under which it
attacks the upper ranks of society. It is known
to attack chiefly the very poorest orders, and in
many parts of the country it was never seen among
the richer inhabitants at all.
During the recent epidemic several very striking
facts were observed with regard to its appearance
in the middle ranks of this city. I shall notice
minutely one of these, because I conceive it to
be absolutely irreconcilable with any other doctrine
but that of contagion.
While the epidemic was at its height, namely,
betwixt the end of 1817 and beginning of 1820, the
fever prevailed very much among the gentlemen of
the resident medical establishment in our hospitals.
Of six resident clerks in particular not one escaped
who remained long enough, insomuch that among
them and their substitutes sixteen cases of fever
occurred within eighteen months. The form under
which it attacked them possessed precisely the
epidemic constitution that appeared among the
hospital patients, and in the infected districts of
the town. I mention this resemblance because it
follows that both in them, and in the poorer ranks,
the disease was the same, and therefore probably
arose from the same common cause, whatever that
cause may be.
The sum of the argument is this : that a disease
identically the same with that raging among the
122 DISSERTATIONS [CONTINUED FEVER
poor prevailed no less among a certain description
of the better ranks, who were very strongly exposed
to contagion, but in no peculiar manner to any other
supposed cause ; and that all others of the same
rank, of the same habits and constitution, their own
families, their friends, their companions provided
they were not exposed to the infection were abso-
lutely and completely exempted.
The next point we have to examine is, whether
contagion be the sole cause of the British continued
fever. This question is still involved in obscurity.
The opinion of physicians upon it seems both
fluctuating and ill defined. Little importance has
been attached to the ordinary mode of proving that
other causes may exist besides contagion.
For example, it has been said that even during
the prevalence of an epidemic some cases cannot be
traced to contagion. But there are several sources
of fallacy which render that fact inconclusive, at
least in the way in which it is usually applied.
For in the first place, during a period of public
alarm, many illnesses, and even deaths, especially
in the better ranks, are ascribed to fever, with
which, however, they had really no connection ; and
it is no wonder that then the source of infection
cannot be discovered. And secondly, many persons
in the lower ranks absolutely forget that they have
been exposed to the contagion ; while others of all
classes may be exposed without their knowledge, as,
for example, in chairs and hackney coaches that have
conveyed fever-patients, and never been disinfected.
Further, it is alleged in proof that fever must
spring from more than one cause, that it is fre-
quently impossible to tell whence epidemics have
CHRISTISON] ROYAL MEDICAL SOCIETY 123
been derived. But this, though a very frequent, is
also a very unnecessary subject of dispute ; for in
every great city it constantly lurks somewhere in
sufficient force to keep itself alive till a season
comes round favourable to its propagation. In
Edinburgh, which is but little exposed to epidemics,
fever is hardly ever wanting. It may often, indeed,
be so rare that the public are not aware of its
existence, but it is not the less known to those
extensively engaged in practice among the poor.
There is seldom any necessity for placing the
origin of an epidemic anywhere else than in the city
itself where it prevails. The impossibility of find-
ing a foreign source for it is scarcely any argument
in favour of its spontaneous origin.
Lastly, it is said that fever has often been
actually observed to arise from other causes, such
as cold, fatigue, passions of the mind, insolation,
hunger, intemperance. But it is objected that we
can seldom make sure of these persons not having
been also exposed to contagion ; and it is added
that the causes I have mentioned, whenever their
action is obvious and unequivocal, engender diseases
totally different from continued fever.
Yet, after all, some of these arguments possess
considerable weight when viewed in conjunction
with the laws recently discovered by which con-
tagion propagates itself. Thus it will be shown
that, in order to render the contagion of fever
effectual, some strong, well-marked exposure is
requisite ; which, therefore, few can forget or un-
knowingly sustain. Hence if the cases untraceable
to contagion be very numerous, it is almost certain
that in some of them at least this has not been the
124 DISSERTATIONS [CONTINUED FEVER
real cause. A few individuals may have been
actually exposed to the extent I have hinted at, yet
owing to their ignorance or forgetfulness the fact
may escape our search ; but it is impossible that
this can hold with regard to so great a number as
are unable to refer their illness to contagion. This
O
reasoning is still more plausible if the same difficulty
be encountered during an epidemic, since actual ex-
posure is then much more readily detected. Now
even while fever rages epidemically a vast number
of cases are thus obscure in" their origin. On con-
sulting the tables of Dr. Welsh it will be found
that the inquiry was made in 546 cases, and three-
fifths only were traced to contagion.
For the same reason, when several authors tell
us they have seen numerous cases of fever arising
apparently from the effects of cold, fatigue, and the
like, without any ascertainable exposure to contagion,
we may be allowed to infer that some of them have
arisen in the manner alleged, since an effective
exposure cannot often escape notice or be forgotten.
An observation, which seems of some weight in
determining the point, was made during the late
epidemic in Edinburgh, namely, along with the more
common kind of fever, manifestly contagious in its
origin, there prevailed also another variety, differing
in its characteristic symptoms, in its duration and
event, in its phenomena under the action of remedies;
and this variety could be very seldom traced to
contagion.
That variety which originated in contagion was
almost always a very acute synochus. It generally
made its attack with great violence, often termi-
nated soon, and suddenly, by critical sweats, or
CHRISTISON] ROYAL MEDICAL SOCIETY 125
about the end of the second week receded gradually
or assumed a typhoid character, and then sometimes
proved fatal. In a vast proportion it lasted only
eleven or fourteen days, and very often not longer
than five or seven. It was commonly accompanied
by strong signs of local inflammation. At all times
it was very much under the control of art, insomuch
that of the hospital patients in 1811 scarcely three
in a hundred died.
The other form of the disease began slowly, so
that seven or eight days might elapse before the
patient had to confine himself to bed. It was never
acute in its character ; the pulse was full, soft, and
rarely exceeded a hundred ; the signs of local
inflammation were mild ; the appetite after the
second week was good ; and about that time, too,
there appeared a kind of confusion, or heavy stress,
which attended the disease throughout ; a mild but
very untractable diarrhoea often came on about the
same time. Its course was very tedious, seldom
shorter than three weeks, often more than twice as
long, and, in one case I knew, it was prolonged to
fifty-two days. There was never any crisis or critical
evacuation, so common in the other variety, and all
the customary remedies were tried without any
being found which had any power to control it.
Little or no difference could be discovered in
the persons attacked by these two forms of disease.
Those who la'boured under the slow variety were
universally young, robust, and plethoric.
Now, while the ordinary fever was for the most
part easily referred to contagion, this more chronic
kind could seldom be tracedto it satisfactorily, and
often not at all. In the autumn of 1818 many cases
126 DISSERTATIONS [CONTINUED FEVER
occurred among the country people employed at the
harvest in this neighbourhood. Several cases of the
kind also occurred in the uninfected districts of the
town, and could as little be traced to contagion.
The strong circumstance is, that a fever of a peculiar
type, differing from the usual form of the truly con-
tagious kinds, could seldom be satisfactorily shown
to spring from contagion, and very often seemed
wholly unconnected with it. It is almost of neces-
sity therefore it should have sometimes sprung from
another cause.
It must be acknowledged, however, that towards
the close of the epidemic it sometimes originated
manifestly in contagion. I have not myself seen
distinct examples of this, but in the spring of 1820
five persons of one family were admitted into the
clinical wards of the Infirmary, all labouring under
a slow nervous fever. The infection, too, was
apparently derived from a case of the same nature.
But such cases were rare, and they will hardly invali-
date the conclusions I have drawn from what was
observed during the rise and height of the epidemic.
Another circumstance by which this opinion
might derive confirmation, would be the continu-
ance of the slow fever after the contagious varieties
disappear. I have had too little opportunity, how-
ever, of ascertaining whether or not such has been
the fact.
But while the remarks just concluded render it
highly probable that some kinds of fever may arise
from other causes besides contagion, they by no
means serve to point out what those cases are.
The researches of late authors have greatly
diminished the number of the supposed exciting
CHRISTISON] ROYAL MEDICAL SOCIETY 127
causes of fever. They seem to me to have proved
in particular that no other effluvia can generate
the disease, except those from a person labouring
under it.
Again, it has been still more confidently main-
tained that exhalations from the living, healthy body,
when much concentrated and long confined, acquire
the properties of the most virulent, contagious efflu-
via. This belief, too, has been successfully combated
by Dr. Bancroft. Two very remarkable epidemics,
which occurred some time ago in England, have
been usually attributed to this cause. The first was
immediately after the Assizes at Oxford in 1517;
the other, after the Old Bailey Sessions in 1750.
They have been of late ascribed to the natural
effluvia proceeding from the prisoners previously
pent up in close, crowded rooms. Both were
violent to a degree unexampled in England ; few
who attended the Courts having escaped the
disease, and few who took ill having survived the
attack. But there is no decided proof that either
of them arose in the manner alleged.
Very recently the doctrine of the identity of re-
mittent and continued fevers has been taken up by
Dr. Armstrong, and defended, not by an appeal to
direct facts, but by a comparison of the essential char-
acter of the two distempers. He affirms that if their
essential symptoms are identical the diseases must
be the same, and have one common origin. Granting
the validity of this assumption, he has founded the
proof of the identity of their symptoms on fallacious
principles ; for he holds their essence to consist in
the origin of local derangement. ' The combined
affections,' says he, ' of the brain, lungs, liver, lining
128 DISSERTATIONS [CONTINUED FEVER
of the air-passages, and alimentary canal, together
with a peculiar lassitude and languor, are the true
diagnostic signs of the remittent and continued
forms of typhus fever.' It is hardly necessary for
me to remark that in this part of the medical world
these symptoms are held to be merely fortuitous,
to constitute no part of the essence of either disease;
that their frequent occurrence in our late fever is
attributed to a particular epidemic constitution ;
that when the powers producing that constitution
are not in activity the symptoms in question do not
occur. The disease is purely a general affection.
Unconnected with the generation of effluvia,
there is another class of agents, whose power to
produce fever is almost universally believed by the
vulgar. The chief of these are cold combined with
moisture ; heat, especially when so applied as to pro-
duce insolation ; repeated fatigue, whether of body or
mind ; long-continued anxiety, and other mental
emotions; hunger, intemperance, and some others
of less consequence.
The precise operation of these agents has not yet
been investigated. They are believed by many,
however, to be no more than predisposing causes, in
which capacity their action is certainly both energetic
and unequivocal. And, moreover, it is alleged that
when they perform the part of exciting causes they
produce, not continued fever, but some one or other
of the phlegmasise.
We have not data enough to encourage us to
enter minutely into this inquiry. Yet I think it
may be shown that at least some of them, especially
in combination with each other, have produced
diseases which differ in no essential points from
CHRISTISOX] ROYAL MEDICAL SOCIETY 129
continued fevers dependent on contagion. One
cause only may be noticed briefly by way of
example, namely, fatigue, frequently repeated, and
combined either with insolation or with mental
anxiety. The former of these combinations seemed
to be the cause of the slow fever, which, I have
observed, was prevalent in the autumn of 1818
among the shearers around Edinburgh.
The next inquiry that naturally presents itself
is the following : Supposing that continued fever
may originate in the causes I have mentioned, with-
out the aid of contagion, do the cases so originating
ever prove infectious ?
I believe we are not yet prepared with the
means of deciding this question. Dr. Bancroft,
indeed, has thought to decide it upon pure hypo-
thetical reasoning, disguised under an appeal to
common sense. He considers it unphilosophical arid
incongruous to suppose that a disease propagated
by contagion can arise from any other cause. Such
a disease he calls a 'monstrous product of incom-
prehensible generation, which no one can believe
in who is accustomed to reason, and has not dis-
carded common sense/ He does not attempt, how-
ever, to show wherein the incongruity resides, and
for my own part I see none in the supposition that
a febrile disease arising from cold, fatigue, or the
like may engender certain secretions or effluvia by
which a similar disease may be excited in others.
Neither do we want the support of analogy for
such belief. There is every reason to believe that
some varieties of ophthalmia become infectious,
though they spring in the beginning from another
cause. The same remark applies even more strongly
i
130 DISSERTATIONS [CONTINUED FEVER
to erysipelas, to dysentery, and perhaps also to the
hydrophobia of animals.
But it is not by such reasoning that the matter
will ever be satisfactorily determined. The only
legitimate mode of deciding it is by selecting cases
of sporadic fever, and observing what then takes
place among the attendants of the sick, especially
under circumstances that encourage the action of
contagion.
It appears that the fever of the Oxford Assizes
and that of the Old Bailey Sessions did not spread,
even in a single instance, to any one who was not
in the Court on the day when the disease was
caught. On the other hand, however, indepen-
dently of the obscurity now hanging over these
events, the contagion, if any was engendered, had
not full scope, for none suffered but the middle
ranks, among whom we have seen contagious fever
is hardly ever propagated.
As the matter stands at present, it is proper to
adhere to the safest and most prevalent opinion,
that fever, whatsoever its origin, may be com-
municated by infection. Nor should we rashly
infer in any particular instance that it is not in-
fectious because it does not spread ; for not only is
the concurrence of certain circumstances requisite
that exposure to the contagion may be effectual,
but it is likewise probable that certain terrestrial
and atmospherical states are requisite to give
sporadic fevers an infectious character.
I proceed, in the last place, to give a brief
sketch of the laws of contagion regarding fever.
They may be considered under two heads, the
CHRISTISON] ROYAL MEDICAL SOCIETY 131
means by which it is communicated, and the
powers that influence its activity.
The chief and most undoubted means of com-
municating it is through the application to the
healthy body of certain effluvia arising from that
of the sick.
It is not yet distinctly ascertained from what
part of the body these effluvia proceed, or on
what part their action is primarily exerted. The
breath and insensible perspiration are generally
most dreaded ; many are likewise afraid of the
urinary and alvine excretions ; some attribute the
most virulent power to the effluvia exhaled by
newly-drawn blood; and a few believe that the
infection resides only in the sensible perspiration,
which must be touched before the disease can be
communicated. There is, perhaps, but little reason
to dread any of these sources except the breath, the
cuticular exhalations, and possibly the alvine dis-
charges. The cuticular exhalations, when long pent
up, are particularly virulent. To them, at least,
have been usually attributed those singular cases,
where at the moment of infection the person is
struck with a peculiar unconquerable fcetor, attended
with sudden weakness, praecordial anxiety, and a
strange consciousness of danger. This has also at
times appeared to have been derived from the
alvine discharges, but for obvious reasons they
are much less hazardous ; I even question whether
they are very powerful. The water-closets of the
fever wards of our Infirmary, though of a very bad
construction, are daily used by the surgical patients
with perfect impunity.
The lungs, as affording the most active and
132 DISSERTATIONS [CONTINUED FEVER
delicate absorbing surface, are generally thought
to be the part of the system through which the
poison is introduced. There are still some persons,
indeed, who believe it is conveyed with the greatest
certainty by actual contact ; but this opinion, once
generally enough received, is now as generally
abandoned, perhaps, however, without any decided
proof of its incorrectness. Of course, under these
ideas the air is the vehicle by which the effluvia
pass from one person to another. A question here
occurs, whether they are capable of being condensed
upon clothes and other substances, and afterwards
discharged again, still preserving their poisonous
properties ; in short, can the contagion of fever
be transmitted by fomites ?
To determine this matter, it is useful previously
to make a distinction in the kind of exposure to
which the supposed fomites have been subjected.
Some substances are in immediate contact with the
patient's body, and will therefore be deeply tainted
with the cuticular excretions. These are almost
universally thought capable of conveying the in-
fection, but I believe the notion is derived not so
much from fact as from analogy. Other contagious
diseases, namely, of the exanthematic kind, being
conveyed in this way, why should not fever also ?
The analogy, however, is fallacious, for these dis-
orders cause the formation of a peculiar matter,
possessing highly infectious properties, and capable
of transporting them to any distance by adhering
to fomites. Instances have certainly been recorded
where fever has appeared to travel in the same
manner, but they are for the most part unsatis-
factory ; and, on the other hand, there are not
CHRISTISOX] ROYAL MEDICAL SOCIETY 133
wanting facts to show that many people have been
exposed to these alleged fomites without sustain-
ing injury. It is probable that in this way fever
cannot be so easily communicated as is generally
thought, and that to prove efficacious the fomes
must be applied soon after it has been infected.
Other substances never come in contact with the
skin, but are exposed at some distance to its in-
visible effluvia only. In this situation it is highly
probable they cannot be so imbued as to transmit
the disease. We know that crowds of persons are
every day liable to have their clothes so infected,
yet no one can bring forward an unequivocal
example of the disease having been conveyed in
that manner. I may mention as a strong case of
the kind, that no one ever suspected the contagion
to have been carried by the clerks of our hospitals,
even when the epidemic was most prevalent, so that
they had to spend half the day in the fever wards.
The powers that influence the activity of febrile
contagion are referable to three heads, those de-
pendent upon the source of the infection, upon the
condition of the person exposed to it, and upon the
particular mode of exposure.
The modifying circumstances relative to the
source of infection are chiefly, the kind of fever,
the period of the disease, and the period of the
epidemic.
There are few or no observations concerning the
relative activity of the effluvia proceeding from the
different kinds of fever ; as far as we can judge,
however, the typhus gravior, now fortunately rare,
is the most active. It is a curious circumstance
that those epidemics which spread with the greatest
134 DISSERTATIONS [CONTINUED FEVER
rapidity are also the most malignant ; take, for
example, the fever of the Black Assizes, or the
Corunna fever. As to the potency of the contagion
of the different varieties met with during the late
epidemic, nothing certain is known, but it is reason-
able to suppose that the most violent case would
be the most infectious, because probably a larger
quantity of poison would be exhaled.
On the same principle, the period of fever at
which the effluvia are most virulent should be just
after it is fully formed ; and this seems the general
opinion, though it rests upon no decided facts that
I am aware of. If it be correct, we perceive the
uselessness of limiting the period of inspection to a
certain day, as Dr. Haygarth has done, for the fever
of one may be as fully formed in two or three hours
as that of another in seven, eight, or ten days.
Continued fever does not appear to be, like some
other disorders, infectious during convalescence.
The time of day when the infection has the great-
est activity is probably the evening, that is, the
time of exacerbation ; it is in the evening at least
that the cases of sudden infection have generally
occurred.
There would appear, moreover, to be a particular
period in the progress of an epidemic during which
the contagion is most efficacious, and this appears
to be about the time when it is reaching its height.
It was at this time that the gentlemen of our
hospitals suffered so much. About the middle of
the epidemic, when it had continued stationary for
some time, many of them escaped the infection, but
hardly one while it was on the rise. This tendency
to decrease in activity, after continuing its ravages
CHRISTISON] ROYAL MEDICAL SOCIETY 135
for a certain length of time, seems to be one great
cause of the decline of epidemics. It would be a
most interesting object to inquire into the circum-
stances that thus temper its virulence. Some in-
fluence must without doubt be attributed to the
preventive measures put in force, and likewise to
the immunity imparted by previous attacks, but
these counteracting powers will not altogether
account for the rapid decline, and still less for the
occasional extinction, of epidemic fevers. Much will
still remain to be attributed to the mysterious
operation of unknown terrestrial and atmospherical
influences.
The next class of modifying powers relates to the
circumstances of the person exposed to the infec-
tion. These are age, sex, temperament, manner of
living, habit of exposure, and what may be called
seasoning, the effect of a previous attack.
Age, if we may trust our experience in Edin-
burgh, operates in a way somewhat different from
common belief; advanced age offers little or no pro-
tection, infancy is certainly protected against the
contagion.
It is difficult to estimate the relative suscepti-
bility of the sexes. More women were admitted
into our hospitals than men ; but then the former, as
they remain much in the house and tend the sick,
are far more exposed to the contagion.
No temperament, or I should rather say no
habit of body, seems to import exemption. But
some are more liable than others ; and as far as I
have observed, no habit is more susceptible than one
often met with in young adults, especially in the
middle ranks, which is marked by a combination of
136 DISSERTATIONS [CONTINUED FEVER
health and robustness, with delicacy of external
sense, and acuteness of perception. There are also
some individuals who, how much soever they are
exposed, are insusceptible of receiving the infec-
tion.
Manner of living is universally believed to in-
fluence the activity of infection, but it is difficult to
appreciate its power, and, upon the whole, if we
except that part of it which consists in careful venti-
lation, it is less important than many have thought.
This at least is certain from what I have often
seen, when the exposure is strong and decided, no
manner of living will afford much protection.
It is disputed whether habit has any power in
rendering the body proof against contagion. The
fact of medical men being seldom attacked with
fever is a fallacious one, even if it were true, for few
medical men in ordinary practice are subjected to a
strong exposure. It is nothing for a person to visit
a number of patients for a few minutes only, and at
a time too when their apartments are well venti-
lated. Let such a one domesticate himself in a
fever hospital, and all the habit he has acquired
will hardly ever preserve him. One of my com-
panions in the Infirmary here, was taken ill after
being ten months in the heart of the epidemic, and
another was affected when it had begun to recede,
although it had left him unharmed for nearly two
years ; surely if habit was of any effect, these two
persons might have escaped.
The advantage of a previous attack of fever is
less doubtful. It will seldom prove a complete safe-
guard to any one ; for, if he remains long enough
in an hospital, it is difficult to say how often he
CHRISTISOX] EOYAL MEDICAL SOCIETY 137
may suffer. A vast number of our patients in Edin-
burgh, and a still greater proportion of our nurses,
had it twice. Fourteen months after the opening
of Queensberry House as a fever hospital, three of
the nurses there had been ill three times, and I was
myself attacked thrice in sixteen months ; but we
observed almost universally that after each attack
a longer exposure was endured before the contagion
took effect. For example, a violent synochus of
fourteen or nineteen days, with marked typhoid
symptoms in the second week, appeared in general
a sure safeguard, and I never knew an instance of
a person having it again after the slow or nervous
variety so often mentioned.
The third and last class of circumstances that
affect the efficacy of contagion relates to the mode of
exposure. These circumstances are chiefly the dis-
tance of its source, and the length of exposure.
It is unnecessary to observe that those incur the
greatest danger who approach nearest the sick, and
that beyond a certain distance every one is safe.
An important conclusion may be drawn from this
law combined with what I have said on the small
danger of ordinary fomites, namely, that fever
wards may be safely constructed in a general hospi-
tal at no great distance from the wards of the other
patients.
The practice of our clinical physicians will even
show that a few fever patients may be mingled with
others in one ward without danger, but if the cases
of fever be numerous, for example, if they amount
to one-half, the infection will sometimes spread, and
if a single ordinary patient be put into a crowded
fever ward he will almost infallibly suffer.
138 DISSERTATIONS [CONTINUED FEVER
Unless the exposure endure for a considerable
period of time very few indeed are infected. There
is a singular deviation from this law, however, in
the case of sudden infection, many of those who,
struck down as it were with the fcstor of a patient,
have been exposed to it for a few seconds only ;
but these cases are very rare, and in almost all, the
concentration of the effluvia has made up for the
shortness of the exposure.
We cannot tell what length of exposure is
requisite in ordinary cases to prove effectual, but it
is probably considerable. It is thus alone that we
can explain why fever never spreads in the better
ranks. Our hospital clerks, who generally went
home when they were taken ill, gave it to none, an
excellent confirmation of what has been observed
elsewhere, for there could be no doubt that the
cases were of a true infectious character. Now,
even in the middle ranks, the attendants are often
as strongly subjected to the effluvia as they can be
in an hospital ; but it is only at intervals, so that
the whole duration of exposure is limited. The same
remarks apply to the pupils and dressers of hospitals ;
the former, I am satisfied from frequent observa-
tion, may study cases of fever without risk, provided
they shun those situations in which sudden infection
may be caught. The clerks and nurses, on the
other hand, do what they will, can seldom or never
escape, because they frequent the fever wards many
hours a day, and are often obliged to remain close
to their patients. Even they, although they daily
imbibe a large quantity of the poison, have been
rarely seized till three weeks after beginning their
duty. This curious circumstance cannot be wholly
CHRISTISOK] ROYAL MEDICAL SOCIETY 139
accounted for by what is called the latent period,
or interval between infection and seizure, for it is
probable that the latent period is generally much
shorter than authors imagine. When a person
catches fever from a single distinct exposure, it is
observed to begin soon afterwards. In those par-
ticularly in whom the act of infection is accompanied
with a strong foetor, and sense of depression, the
symptoms begin either immediately, or in two or
three days at the utmost, but in the more ordinary
case of a person attending a fever patient, and not
exposed to concentrated effluvia, they accumulate
in the body by degrees, and therefore some days are
required before the dose becomes large enough to
be effective.
We may now see the truth of what I was
obliged to anticipate in proving the diversified
origin of fever, namely, that few can forget or un-
knowingly sustain an effectual exposure to con-
tagion.
Before concluding, I should remark that the fore-
going observations contain less than might be ex-
pected of what others have written both upon the
late and upon former epidemics. This has happened
partly because the late fever of Edinburgh furnishes
a stock of materials which frequent reference to
authors would have swelled to an unfitting bulk,
and partly because the recent writers on Domestic
Fever have bent their attention chiefly to its
history and treatment, and have offered little new
or important with regard to its contagion.
XI
WILLIAM SHARPEY
1802-1880
ON CANCER OF THE STOMACH
Read 1823
MR. PRESIDENT,
Though cancer of the stomach is neither
a common disease, nor capable of being removed by
any known means, yet it is not for these reasons
unworthy of the consideration of the Society ; for
besides what interest it may possess in a pathologi-
cal point of view, it is so liable to be confounded
with other complaints of daily occurrence, that a
thorough knowledge of its history is highly requisite
for the practical physician.
Symptoms. This, like many other chronic dis-
orders, is slow and insidious in its attack ; it most
commonly commences with a feeling of uneasiness
or pain in the epigastrium, which, after some time,
becomes increased in severity, and is particularly
aggravated on taking food. To this pain or uneasy
sensation, other symptoms are soon added which
indicate a disordered state of the functions of the
stomach, such as acid eructations, 'frequent vomit-
ings of a limpid fluid, sickness after taking food,
SHARPEY] DISSERTATIONS 141
and for the most part a great degree of flatulence.
In addition to these there is often a sense of weight
or even a shooting pain in the back and loins. The
patient now begins to vomit after meals, so that a
considerable part of the food is rejected with little
alteration, after it has remained a short time in the
stomach. During this period, sometimes, though
rarely, there is a diarrhoea, but in by far the greater
number of cases the bowels are obstinately con-
stipated.
After the disease has proceeded thus far, we
may generally discover a degree of swelling in the
region of the stomach. This swelling is hard, in
some cases movable, in others fixed, and for the
most part painful on pressure. It sometimes changes
its position, and from its weight, or, other circum-
stances, sinks down in the belly, or, from adhesions
taking place between it and some neighbouring part,
it may even withdraw itself under the hypochon-
drium, and become inaccessible to the touch.
The most distressing symptoms of the disease,
which hitherto may have appeared only at intervals
of days, or even months, now become constant, and
daily increase in severity. -The stomach grows very
capricious with regard to the food, some sorts being
rejected, while others, though perhaps to all ap-
pearance more indigestible, are retained. The con-
stipation continues, and the dejections, even should
they be liquid, are always in small quantity.
The complaint may have reached this length
without affecting the general health to any consider-
able degree, but now, in addition to his former
sufferings, the patient rapidly loses strength, his
colour changes, and becomes of a sallow or earthy
142 DISSERTATIONS [CANCER OF STOMACH
hue, his eye sinks back in the socket, and his whole
features are contracted. His body also, not receiv-
ing its due supply of nourishment, becomes thin and
emaciated, or sometimes from the same cause swelled
and dropsical. The matters vomited, which hitherto
may not have been much altered, are now mixed
with a black or brown liquid, and have a most
offensive smell ; the dejections also are usually of
the same dark colour. About this time both the
vomitings and dejections sometimes contain con-
siderable quantities of blood, and little flocculi like
shreds of a membrane. A short time before death,
the costiveness not unfrequently gives place to a
diarrhoea, which contributes not a little to shorten
the patient's existence. The pain in the stomach
now becomes very severe, and the torture on taking
food is extreme.
During the whole course of the disease, but
especially in the later stages, the pulse is increased
in frequency during the attacks of pain, or even at
last a slow fever comes on which might possibly be
called hectic, but true hectic fever is rarely an
attendant on this disease when it goes on without
complication. At length, the patient, worn out with
so much suffering, and want of sufficient nourish-
ment, dies in a state of extreme emaciation and
weakness, after the disease has existed for a period
which may vary in its duration from a few months
to several years. Death in a few cases is preceded by
convulsions or delirium, but in far the greater num-
ber of instances it takes place without commotion.
Such is the usual train of appearances attending
cancer of the stomach, but it is far from presenting
in every case such well-marked symptoms.
SHARPEY] ROYAL MEDICAL SOCIETY 143
The vomiting, for example, which has commonly
been reckoned one of the most constant and charac-
teristic symptoms, sometimes remains absent for
long periods, and appears only at irregular intervals.
There are other instances in which it does not take
place above two or three times during the whole
course of the disease, and not a few cases have
occurred where it was absent altogether. Nay, we
have the best authority for believing that extensive
scirrhus, and even open cancer of the stomach, may
be found in individuals who even to their death
have never had either vomitings, pains in the
epigastrium, or even any dyspeptic symptom.
It is not easy to account for the vomitings being
so constant and troublesome in some cases, and
entirely absent in others. It has been observed
that they are not so frequent when only a small
part of the body of the stomach is affected, its
cardiac and pyloric orifices being unaltered. This
we might a priori have been led to expect, as here
there is no obstruction to the passage of the alimen-
tary matters ; nor are these so necessarily and
constantly brought into contact with the diseased
surface. M. Bourdon has "given a case where the
whole of the stomach, except the cardia, was scir-
rhous, and where there was great nausea with desire
to vomit, but this could not be accomplished. He
supposes that in this case the absence of vomiting
was owing to the whole muscular coat being con-
verted into scirrhus, and hence concludes that the
stomach is active in vomiting. Several cases, how-
ever, are related in Magendie's Journal to shew that
vomitings do frequently take place though the whole
of the stomach is scirrhous. M. Piedaguel, who
144 DISSERTATIONS [CANCER OF STOMACH
brings forward these cases, attempts to account for
the absence of vomiting in other instances by sup-
posing that the pressure of the abdominal muscles
forces the contents of the stomach through the
pylorus during the efforts to vomit, for in some
cases this orifice is enlarged when scirrhous, though
commonly much contracted ; he also thinks that
when the cardiac orifice is much narrowed, the food
will be forced into the intestines by the same cause.
It would be interesting to ascertain the compara-
tive frequency of vomiting as connected with these
different states of the stomach ; but it is evident
that no accurate conclusion on this point, can be
drawn from a collection of detached cases related by
different individuals, as most of these are attended
with some peculiarity which induces the authors of
them to make them public. It is only from a series
of cases admitted successively into an hospital, or
occurring to the same practitioner, that a fair
average can be taken.
After having thus detailed the symptoms of
cancer of the stomach in general, I shall now pro-
ceed to enumerate their principal differences, accord-
ing to the part of the stomach affected, so far as
these have hitherto been ascertained.
When the disease occupies the cardia there is a
peculiar, uneasy, or painful sensation experienced
on attempting to swallow solid food ; this uneasy
feeling continues till the food is thrown up, which
is done by eructation, or a peculiar effort, approach-
ing nearer to that which occasions hiccup than to
vomiting, and probably depending on a,n inverted
action of the muscular fibres of the gullet. When
the food is thus rejected the patient obtains relief.
SHARPEY] EOYAL MEDICAL SOCIETY 145
There is a similar difficulty in swallowing liquids,
though less in degree, and on taking a quantity of
liquid into the throat, a part often passes into the
stomach with a gurgling noise, while the rest is
returned. Scirrhus of the cardia also is frequently
attended with vomitings of a clear fluid, which is
viscid and ropy like saliva. It is but rarely that
we can feel any swelling. It is remarked, however,
by Dr. Pemberton, that sometimes from the great
emaciation attending this form of the disease, 'a
tumour surrounding the cardia may be discovered
by a minute investigation in the region of the
stomach.' A probang may be passed down to the
stricture, and thus we have an additional means of
distinguishing when the cardia is affected.
When the pylorus is principally the seat of the
disease, the food enters the stomach with facility,
and occasions no uneasiness till after it has entered
it ; it is retained for a longer or a shorter time,
generally from a quarter of an hour to a couple of
hours or more, and when thrown up it is by vomit-
ing, and not by the peculiar effort or eructation,
already described as attending scirrhus of the cardia.
The swelling may also for the most part be felt, and
its position, between the cartilages of the ribs and
umbilicus, may in some measure serve to point out
the seat of the disease, but this is by no means to
be absolutely trusted to, as the pylorus, and even
the whole stomach, are often much removed from
their natural situation. When a portion of the body
of the stomach is affected, the pylorus or cardia re-
maining sound, the symptoms on the whole are not
so severe, nor, as has already been remarked, are
the vomitings in particular so frequent. When
K
146 DISSERTATIONS [CANCER OF STOMACH
they do occur in this form of the complaint, although
they may often continue through the whole course
of it, yet it is observed that^most commonly, they
are confined to the commencement, or take place
near its close, when the stomach has contracted
adhesions with the neighbouring parts.
Morbid Appearances. On opening the abdomen
of those who have died of this disease, we sometimes
find a quantity of serous fluid effused into its cavity ;
but when this is the case, the liver or some other
viscus in the neighbourhood of the stomach is
usually diseased. It is, therefore, in general to be
regarded not so much as the consequence of cancer
of the stomach itself, as the effect of complications.
The stomach is often altered in its capacity in
this disease, usually being larger when the pylorus
is affected, but in other cases generally smaller than
natural ; sometimes even its capacity is so much
diminished that it is hardly capable of containing
an egg. Its position too is sometimes altered, and
it is often connected by adhesions to the surround-
ing parts.
When cut into, it is very often found to contain
a blackish liquid in greater or less quantity, mixed
with any alimentary matters that may be present,
and exactly resembling the black matter rejected
by vomiting during life ; this liquid, as is observed
by Bayle and Cayal, is not necessarily connected
with ulceration, nor produced by it, for it is some-
times present when the disease has not advanced to
ulceration, and is not always found even when the
ulcer is of considerable extent. It is mentioned by
Morgagni that a case of cancer of the stomach
occurred to Valsalva, where there was a large ulcer
SHARPEST] ROYAL MEDICAL SOCIETY 147
with abundance of black fluid, but on squeezing the
ulcerated part, the fluid which was forced out was of
a whitish colour.
A case was lately mentioned to me by a friend,
in which the stomach was scirrhous, and contained
a black liquid, but showed no trace of ulceration.
The part of the stomach affected is usually con-
verted into scirrhus, and it is most commonly
believed that scirrhus is the only morbid texture to
be met with in this disease ; Bayle and Cayal, how-
ever, assert that portions of cerebriform matter are
frequently mixed with the scirrhus, besides several
of what are, by them, termed accessory or accidental
tissues ; and M. Laennec, who, as well as these
pathologists, considers the encephaloid or cerebri-
form matter as a sort of cancer, affirms that cancers
of the stomach are sometimes entirely formed of
that substance. Several considerations might be
brought forward, both for, and against the opinion of
the identity of cancer, and the encephaloid tumour
or medullary sarcoma, as it has been called in this
country. But the subject is more fitted for an essay
on cancer in general than a dissertation of this sort ;
I shall therefore proceed to give an account of the
diseased changes which constitute scirrhus of the
stomach.
Upon making a section of a part of the stomach
affected with scirrhus, we can generally distinguish
its different tunics readily enough from one another,
but these are very much changed from their natural
appearance. The mucous or internal membrane is
much thicker than natural, and' converted into a
homogeneous white substance, varying in its con-
sistence, but most frequently lardaceous, and pre-
148 DISSERTATIONS [CANCER OF STOMACH
senting no appearance of fibres or blood-vessels ;
the muscular coat is also very much thickened, and
appears to consist of a very dense yellowish or
greyish substance, intersected by membranous-
looking septa. With regard to the peritoneal or
external coat, pathologists do not agree in their
descriptions. Dr. Baillie describes it as many times
thicker than it ought to be, and having almost a
gristly hardness ; the French pathologists, on the
other hand, affirm that it is very rarely affected,
except when the stomach is perforated by ulceration.
It is probable that the free exhaling surface of the
peritoneal coat is rarely affected, though the cellu-
lar membrane, on its adhering surface or between
this and the muscular coat, may often become
scirrhous.
When the disease is further advanced, this
thickened portion of the stomach is ulcerated on its
inner surface ; the ulcer has hard, thick, and everted
borders, and its surface is covered with a sanious
fluid ; frequently it throws out irregular fungous
excrescences, which are covered with a foul, greyish
or brownish liquid. The ulceration may have gone
so far as to perforate entirely the coats of the
stomach, and even penetrate some way into a neigh-
bouring part ; thus the bottom of the ulcer is some-
times formed by the liver, spleen, or pancreas, and
the abdominal muscles or diaphragm are sometimes
destroyed to a greater or less extent ; in the same
way a communication is sometimes formed between
the stomach and colon, which allows a considerable
part of the food to pass straightway from the one
viscus into the other. In all these cases, however,
the stomach is in general, previously united to these
SHARPEY] KOYAL MEDICAL SOCIETY 149
parts by adhesions of considerable strength, by
means of which the effusion of alimentary matters
into the belly, and consequent death of the in-
dividual, are prevented. But although, in far the
greater number of cases, Nature thus admirably
guards against such a serious occurrence, her efforts
are not always successful, for instances of such an
effusion taking place, and death immediately follow-
ing it, are recorded by various authors.
The pylorus and smaller curvature are much
more frequently the seat of scirrhus than the cardia
or any other part of the stomach ; when the pylorus
is affected, the scirrhous degeneration not unfre-
quently extends a considerable way along the
pyloric end of the stomach, but rarely spreads into
the duodenum ; in the same way, a scirrhus of the
cardia rarely extends higher than an inch into the
gullet, but often affects a considerable portion of the
smaller curvature. As already mentioned, there are
instances where almost the whole of the stomach is
converted into scirrhus. The part affected is usually
well defined, though sometimes it has no very well-
marked limit between it and the sound structure.
It is difficult to say in which of the textures the
scirrhus commences ; some have supposed that the
little bodies called glandules Brunneri, situated
between the mucous and muscular coats, are the
original seat of the disease. Bayle and Cayal remark
that when only one of the coats is scirrhous it is
almost always the muscular, the mucous membrane
being very rarely primarily affected. The disease
appears sometimes to have commenced by the
growth of scirrhous tumours in the neighbourhood
of the pancreas, and thence spread to the stomach
150 DISSERTATIONS [CANCEE OF STOMACH
in consequence of adhesions between this organ and
the diseased mass ; it is evident that in such cases,
the cancer of the stomach is to be regarded in a
great measure as a consecutive complaint.
In most cases of cancer of the stomach, the
lymphatic glands in the neighbourhood, particularly
those lying on its lesser curvature, are enlarged,
hardened, or otherwise altered in their structure.
Diagnosis. Although the chief difficulty in de-
tecting this disease is owing to its occasionally
presenting no well-marked symptoms, yet even the
presence of such symptoms is not always a sure
indication of its existence, as many of these are
common to other complaints which may therefore
be very readily mistaken for it.
1. As most of the principal symptoms of this
disease are such as indicate a disordered state of
the digestion, it is very liable in its early stage to
be confounded with ordinary dyspepsia unconnected
with any alteration of structure ; and also with
various sorts of obstinate vomiting, which, though
independent of any organic disease, bear a strong
resemblance to it, and counterfeit some of its most
striking symptoms. These vomitings may be occa-
sioned by a variety of causes, such as irritability of
the stomach, sympathy between that organ and
other parts, and, according to some, on chronic in-
flammation of its mucous membrane.
From such affections it is to be distinguished
chiefly, by the peculiar alteration of the colour of the
skin, so characteristic of cancer ; by the appetite fre-
quently continuing unimpaired for a great length of
time, by the advanced age of the patient, and, most
certainly of all, by the swelling when it is present.
SHAEPBY] ROYAL MEDICAL SOCIETY 151
2. Various tumours in the upper part of the
belly, whether they be scirrhous in their nature or
not, yet if they happen, as is sometimes the case, to
be accompanied by dyspeptic symptoms, may very
readily be mistaken for a scirrhus of the stomach,
and cases of this sort puzzle the most experienced
physician. It is chiefly by a careful investigation
of the history of the disease, and by considering the
whole of the symptoms in their various bearings,
rather than by any particular one, that we are to be
guided in our diagnosis in cases of this sort.
3. The symptoms of scirrhous contraction of the
cardia may be imitated in a great degree by a spasm
of the gullet ; but this affection is neither of long
duration, nor does it necessarily occasion dyspeptic
symptoms.
4. A scirrhous swelling of the pylorus often has
a pulsation communicated to it, and may thus be
mistaken for an aneurism. But it is clear that this
mistake can hardly take place except when the
scirrhous pylorus is unattended by its usual symp-
toms.
Causes. Many circumstances have been sup-
posed to have considerable effect in inducing cancer
of the stomach, and hence have been regarded as
exciting causes of this disease ; of these the follow-
ing have chiefly been enumerated : long-continued
anxiety or grief, suppression of habitual evacuations,
whether natural or artificial, stimulating substances
taken into the stomach, particularly spirituous
liquors, if their use be long persisted in.
These causes may undoubtedly assist in bringing
on cancer, but it often makes its appearance, when
none of them could have operated, and in innumer-
15 DISSERTATIONS [CANCER or STOMACH
able instances they have had their full operation
without occasioning it. Hence it is inferred that
there generally exists a sort of constitutional pre-
disposition to cancer, without which the various
exciting causes already enumerated, though enjoy-
ing their full operation, would in most cases have
no effect. In what this state of the system consists,
or rather how it is to be recognised before the actual
occurrence of cancer, we are not informed : various
considerations, however, besides what has been
already mentioned, render it probable that such a
condition of the system does in many cases actually
exist.
By some this condition is supposed to be heredi-
tary, and this opinion is principally supported by
the fact, that now and then several individuals of
one family are affected with cancerous complaints.
Yet when we consider that such complaints are by
no means uncommon, and that instances of two or
more of the same family being affected with them
are comparatively rare, while many individuals
suffer from cancer, none of whose relations, to their
knowledge, ever laboured under that disease, there
seems considerable reason for ascribing these sup-
posed cases of hereditary cancer to mere accidental
coincidence. This question may, however, be re-
garded as not yet settled, and need not detain us
here, as it hardly comes within the scope of this
dissertation. Most persons affected with cancer of
the stomach have reached their fortieth year, hence
it seems that an advanced period of life is favourable
to its occurrence.
With regard to the intimate nature or proximate
cause of this disease, little or nothing satisfactory is
SHARPEY] ROYAL MEDICAL SOCIETY 153
known. Most of the opinions which have been held
on this subject are so vague and improbable, as
scarcely to be worth our consideration if perhaps
we except the one which regards cancer as a sort of
slow inflammation, or the product of such an in-
flammation. But even this opinion, though some-
what more worthy of attention, is not at all satis-
factory ; for although the diseased textures which
constitute cancer, after existing a certain ^ime,
generally occasion inflammation of the surrounding
parts, or undergo a slow inflammation themselves,
yet this does not take place till after these textures
are actually formed, and there is no proof that the
particular operation by which they are formed must
be an inflammation. The belief that stimulating
substances taken into the stomach sometimes occa-
sion cancer of that organ, may be supposed to
favour the opinion of its being an inflammation, but
it remains yet to be proved that these substances
can operate in no other way but by exciting in-
flammatory action ; and in a number of the cases
where stimuli have been supposed to act in this
way, besides the cancer of the stomach, there have
been found cancerous growths in other parts, where
they could have had no sort of influence.
Prognosis. It is obvious that the prognosis here
must be uniformly most unfavourable, yet death
happens sooner in some forms of the disease than in
others. Thus when it has its seat in the cardia, the
contraction of this orifice may be so great as to
occasion the death of the patient from inanition, be-
fore ulceration takes place. In all forms of the
complaint, if we wish to have a probable idea of the
length of time the patient's life may hold out, we
154 DISSERTATIONS [CANCER OF STOMACH
must pay particular attention to the degree to
which the system in general is affected, as of course
the more it has suffered, the nearer, generally
speaking, has the disease advanced to a fatal
termination.
Treatment. Although medicine can hold out no
prospect of cure in this intractable disease, yet the
aid of the physician is not therefore entirely useless,
for by means of a proper regimen, we may in some
measure retard the progress of the complaint, and
by various medicines, we are enabled to alleviate
some of its most distressing symptoms, so that at
least we may render the patient's life less miserable,
if we cannot prolong it.
The consideration of the various remedies, which
have from time to time been held forth as specifics for
cancer, need not detain us long ; indeed, the simple
inspection of a part affected with cancer, and the
thorough alteration which it has undergone, would
almost of itself be a sufficient proof of the inefficacy
of all such remedies in effecting a cure. Prepara-
tions of iron, of mercury, the muriate of barytes,
and a host of other medicines, have been proposed
with this view, but perhaps none ever attracted
greater notice than the conium maculatum, originally
recommended as an internal remedy in this disease
by Baron Storck of Vienna. Store k flattered him-
self that he had by means of it succeeded in resolving
cancerous swellings, as well as other sorts of chronic
indurations, and in consequence laid the results of
his experience before the public, in two or three
different publications. Unfortunately, however, his
specific had by no means an equal success in other
hands, for from the most extensive trials by De
SHARPEY] EOYAL MEDICAL SOCIETY 155
Haen, Fothergill, and other physicians of repute,
it appeared that though hemlock is often useful in
alleviating some of the symptoms of cancer, and
can be used in cases where opium would be in-
convenient, yet as a means of cure it is wholly
inefficacious. The case is nearly the same with
belladonna, hyoscyamus, and some other narcotic
vegetables which have similar powers. It appears
therefore, as already mentioned, that our treat-
ment must consist chiefly in endeavouring to retard
the progress of the disease, and dimmish the severity
of its symptoms, and this is to be attempted in the
following manner :
1. By a proper diet and regimen. All sorts of
strong drink, particularly spirituous liquors, should
be carefully avoided. The food should combine, if
possible, the qualities of being easily digestible, and
mild and unirritating perhaps milk and the farina-
ceous vegetables or mild animal soups will be found
on the whole most eligible. If the milk cause
acidity on the stomach it may be mixed with a little
magnesia or lime-water.
2. From the known effects of local blood-letting
in retarding the progress of cancer in the breast, we
might be led to think that taking blood from the
epigastrium by leeches or cupping would be useful
in cancer of the stomach ; it is evident, however,
that this could be done with impunity only in the
commencement of the disease, and before the
strength has begun to fail, at which period, unfor-
tunately, its existence can rarely be detected ; hence
it is not astonishing that blood-letting has been
but seldom recommended, and still more seldom
practised, in this complaint. Blisters kept open
156 DISSERTATIONS [CANCER OF STOMACH
with savine cerate, or an embrocation of tartar
emetic rubbed on the epigastrium, may be of some
service, and at least their employment is attended
with less risk than that of blood-letting.
3. The means just mentioned as proper to retard
the progress of the disease, will also contribute to
relieve the pain which is so often an attendant upon
it ; this symptom, however, if it continue as it often
does, in spite of the employment of these measures,
is to be alleviated principally by the use of opium,
or cicuta when the opium is inconvenient ; and by
fomenting the epigastrium with warm water, or
decoctions of anodyne vegetables.
4. For allaying the vomitings, we must trust
chiefly to the effervescing draught or solid opium, or
we may prescribe the tincture of opium with a little
ether for the same purpose.
5. The acidity, heartburn, etc., when present, are
to be removed by alkaline and earthy substances,
such as magnesia, lime, potash, etc., but the best
way is to avoid as much as possible all sorts of
acescent food.
6. Although the bowels are for the most part
exceedingly costive in this disease, we should employ
only the mildest means of opening them ; for this
purpose magnesia, either alone or combined with
rhubarb, is perhaps the best medicine. In many
cases it will be better to use clysters and supposi-
tories than laxative medicines.
7. If in the case of scirrhus of the cardia, there
is reason to fear the patient will die from want of
sufficient nourishment, we must endeavour to sup-
port life by pouring nutritious liquids into the
stomach through a flexible tube, or if this cannot
SHARPEY] ROYAL MEDICAL SOCIETY 157
be done (which I should suppose most probable), the
same sort of liquids must be conveyed into the
intestines in the form of an injection.
Having brought this dissertation to a close, it
now only remains for me to apologise for its many
defects ; of these perhaps not the least is the hasty
and awkward manner in which it is drawn up.
For this, however, I hope that want of sufficient
leisure will be considered as some excuse ; as for its
other numerous imperfections, I must trust solely to
the indulgence of the Society.
XII
ALLEN THOMSON
1809-1884
ON THE FOKMATION OF THE EGG AND THE
EVOLUTION OF THE CHICK
7M1829
MR. PRESIDENT,
The newly-laid egg consists of two
kinds of parts. First, the external coverings, con-
sisting of the shell and its lining membranes, which
undergo scarcely any change during incubation ;
and second, the parts contained within these cover-
ings, consisting of the white or albumen with the
chalazae, and the yolk with the cicatricula or germ-
spot.
The shell or external covering of the egg gives
to it its peculiar form, and is so constituted as to
preserve it from external injury, and at the same
time to allow of those changes taking place within
it that are necessary to the development of the
embryo. The substance of the shell is hard, brittle,
and of a granular structure. On the outer surface
are numerous indentations which might at first
sight be mistaken for the openings of the foramina,
but which do not extend to the inner surface of the
shell, and appear rather to be marks produced by
THOMSON] DISSERTATIONS 159
the villi in that part of the oviduct in which the
shell is secreted. The shell consists chiefly of
carbonate of lime ; it contains also a little phosphate
of lime, phosphate of magnesia, and traces of iron
and sulphur, which ingredients are all held together
by means of a little animal matter, amounting to
two per cent.
On carefully removing the shell alone, we
expose its lining membrane, which consists very
evidently of two layers. The external adheres
firmly to the whole of the inner surface of the shell,
and is dense and tough. The interior layer is of a
softer consistence, and is smoother and thinner than
the exterior, to which when the egg is quite
recently laid, it generally adheres in every part.
These membranous laminaB, when examined in the
microscope, present the appearance of cellular or
filamentous membrane, but they are so dense as to
render their examination very difficult. While the
exterior lamina adheres closely to the shell, the
interior seems to be more properly the membrane of
the white, which it surrounds, for as the egg cools
and the evaporation of some of its more watery
parts takes place, the internal layer separates itself
from the external at the large end of the egg, so
as to leave a circular space between them, which
has received the name of air-follicle or air-space.
This separation is often to be found in eggs at the
time they are laid, and may perhaps even exist in
some before they leave the oviduct ; the air which
it contains seems to be pure atmospheric air, and is
therefore probably introduced from without. As
the length of time that eggs have been laid in-
creases, this air-space expands, and at length some-
160 DISSERTATIONS [FORMATION OF EGG
times separates more than half of one layer of the
membrane from the other. The air-space is easily
seen in transparent eggs, such as those of the duck,
by holding them against the sun's rays or a candle ;
and in most eggs its existence can be ascertained by
the application of the tongue a little to one side
of the obtuse end of the egg, in consequence of the
shell feeling warmer at that part of the egg where
this separation takes place than at any other part of
its circumference.
The membrane of the shell consists in great part
of animal matter, and, according to Dr. Prout, when
burnt gives traces of phosphate of lime.
The albumen or white of the egg consists of three
parts : 1st, the exterior and thinnest layer ; 2nd,
the interior layer, which is of greater consistence ;
and the 3rd, the chalazae or tortuous bodies situated
between the white and the yolk, which are the most
consistent of all. The two first of these parts, the
layers of the white, surround the yolk on every
side. When the egg is placed on its side or upon
either end, the yolk floats higher than the middle,
but it never entirely breaks through its covering of
albumen, there being always a thin layer of albumen
left between the yolk and the membrane of the
shell, a fact which is best illustrated by boiling to
hardness eggs that have been placed in different
positions, and then making sections of them. The
structure of the two layers of the white, as altered
by coagulation, seems to differ ; the exterior is
distinctly lamellar, while the interior, which is more
dense, can be torn with equal facility in all direc-
tions. When the albumen is thrown into water its
surface becomes slightly opaque, a circumstance
THOMSON] ROYAL MEDICAL SOCIETY 161
which probably gave rise to the idea at one time
prevalent that it is inclosed by a membrane. When
the albumen is left for some time in water, the
superficial part becomes still more firmly coagulated,
and can be inflated to three or four times its original
bulk. According to the analysis of Mr. John, the
white of the egg is chiefly composed of water and
albumen ; the saline ingredients are soda, sulphates
of soda and potash, phosphates of lime and magnesia,
their carbonates, and a trace of oxide of iron.
On opening the egg at the side, we perceive
floating at each end portions of albumen of an
irregular shape, and of a somewhat thicker consist-
ence than the layers of which we have just spoken.
These bodies, generally known by the name of
chalazse, hang in a direction outwards and down-
wards from the yolk ; they are traversed by white
threads, which are very tortuous, and have much
the appearance of bundles of vessels. From these
circumstances the chalazae have been described as
vessels by many authors, and they have been
supposed to perform the office of transmitting the
albumen into the yolk ; but it appears from the
observations of Purkmje that they are not tubular,
but merely twisted membranous bodies, which are
prolongations of a layer of hardened albumen that
lies immediately in contact with the membrane of
the yolk. There is no evidence that the membrane
of the yolk is perforated at any part, it seems to be
an entire sac, and the transmission of the white into
the yellow is more probably effected by transudation
through the membranes of the cicatricula. It is
quite well known that that part of the yolk on
which the cicatricula or germ-spot is placed always
162 DISSEKTATIONS [FORMATION OF EGG
floats uppermost, so long as the yolk is invested
with the white and chalazse ; but when these are
separated from it, the cicatricula floats indifferently
in any position, which renders it probable that its
original position is owing to the peculiar mode in
which the chalazse are attached to the yolk. When
the egg is boiled to hardness on its side, the cica-
tricula is generally found on the upper side, and the
chalazae have fallen to the lower part of the egg.
The upper surface of the yolk is flatter and broader
than any other part, and the distance between the
attachments of the chalazse on the upper side is
greater than that on the under. The same thing
occurs when eggs are boiled on either of the ends.
The cicatricula always tends towards the end which
is uppermost, while the chalazae hang down from
the yolk apparently regulating the position of the
cicatricula.
The yolk is composed of two kinds of globules
swimming in a transparent fluid. These globules
are of two sizes ; the largest may be easily seen
with the naked eye or a common lens, they are
chiefly composed of the oily substance of the yolk,
and give to this part its peculiar colour. The smaller
globules, which probably correspond with the
globules of the blood, seem to consist of albumen.
The structure of the yolk, however, is not uniform
throughout, the central part is of a darker colour
than the rest, and when hardened by boiling,
assumes the consistence of coagulated albumen.
From this nucleus there rises to the cicatricula a
cone of the same sort of matter, and both nucleus
and cone are generally surrounded by concentric
layers of a similar substance, which alternate with a
THOMSON] ROYAL MEDICAL SOCIETY 163
matter of a brighter yellow colour that seems to
contain a larger proportion of oil. This latter sub-
stance, which constitutes the great bulk of the yolk
and all its external part, becomes dry and brittle
when boiled to hardness. The yolk is composed in
great part of water, of a sweet oil, of a large pro-
portion of albumen modified in a peculiar manner,
and of some gelatine : it contains sulphur, free and
in combination, a little phosphorus, some free acid,
and a peculiar red matter.
On the upper part of the yolk we perceive the
round spot, to which reference has already been
made, of a lighter colour than the part of the
yellow which surrounds it, to which the names of
macula, germ-spot, cicatrice, cicatricula, etc., have
been given. In this spot there exists the germ,
embryo, or that part of the future chick which is
first formed. We can, with the aid of the micro-
scope, perceive that the cicatricula is composed of
globules of different sizes, united together so as to
form a soft membrane. This membrane, which has
been termed the blastoderm or germinal membrane,
from its containing the rudiments of the foetus,
separates into two layers after it has been macerated
for a short time in water : the upper of these layers,
called the serous, is thin, homogeneous in its struc-
ture, and transparent through its whole extent ; the
lower, called the mucous layer, is thick and velvety,
and transparent only at its centre, so that it is in it
only that the transparent spot or area is conspicuous.
The diameter of the cicatricula is in general about
one -fifth of an inch, though its size varies much in
different eggs : the transparent area of the blasto-
derm is about one-twelfth of an inch in diameter.
164 DISSERTATIONS [FORMATION- OF EGG
In the centre of the cicatricula Rolando, Prevost
and Dumas have lately observed a dark line, which
they believe to be the rudiment of the nervous
system of the chick ; it is situated in the serous
layer of the blastoderm, and passes like a radius
from the centre to the circumference of the trans-
parent area. Malpighi is the first and only other
author who has observed this line before incubation.
The cicatricula is likewise found in the unim-
pregnated egg, and, on a superficial inspection,
seems to resemble that in the egg which is capable
of being hatched. A more minute inspection shows
us that the dark central spot or transparent area is
entirely wanting, its place being occupied by a part
of a lighter colour than the rest of the cicatricula.
The areola which surrounds this generally contains
a number of round spots, which seem to be perfor-
ations of the blastoderm ; from this circumstance
the cicatricula of the unimpregnated egg has been
described by Malpighi and others as composed of
a network, in the centre of which the meshes
are united together so as to form, a white mass.
According to Prevost and Dumas no trace or
rudimentary line can be found in the unimpregnated
egg, and Pander asserts that the two layers of the
blastoderm do not exist in it, an observation which,
from the statements of later authors, appears to be
incorrect.
Such is a general description of the newly-laid
egg, but in prder fully to understand the structure
of its parts it will still be proper to say a few words
respecting the manner in which they are formed.
The perfect egg is composed of the ovulum con-
taining the yolk and germ, and of other parts which
THOMSON] ROYAL MEDICAL SOCIETY 165
are added to the ovulum after its formation has been
completed. The principal organs of the hen con-
cerned in the formation of these parts are 1. The
ovarium, in which the ovula are developed ; and
2. The oviduct, by which the accessory parts are
supplied.
The ovarium of the hen is situated immediately
behind the liver, and below the lungs, and is
recognised by the large number of ovula which it
contains in the season of laying. These are attached
by membranous pedicles to a common branch, called
the racemus viteUorum, which is itself attached to
the bodies of the dorsal vertebrae. When the hen
is not laying the ovarium is much smaller, and there
can only be seen in its place a mass of small white
globules, collected together round the vertebral
column and the surrounding ribs. The small white
globules are the rudimentary ovula or yolks. Their
number does not appear to be limited. As the
season of laying approaches some of them increase
in size, and become filled with a whitish semi-trans-
parent fluid. When the ovulum has acquired the
diameter of a line it is composed, according to
Purkinje, of two small vesicles, the one within the
other. The exterior vesicle is what afterwards forms
the yolk itself inclosed in its membrane, the interior
corresponds to a small vesicle, afterwards to be
noticed as being distinctly perceptible in the centre
of the cicatricula. When the ovulum is the size of
a pea the capsule in which it is formed becomes
vascular. This capsule consists of two layers of
membrane, and surrounds the ovulum on every side,
except at the part where it is itself attached to the
pedicle of the ovarium. The external layer is most
166 DISSERTATIONS [FORMATION OF EGG
vascular, the vessels descend on it from the main
trunk of the ovarium along the pedicle of the ovulum,
and are beautifully ramified over its whole surface,
except at one part which is quite free from vessels.
At the part of the capsule opposite to the pedicle,
there is a transparent band extending over one-third
of the long circumference of the ovulum ; the rami-
fications of vessels, on reaching the margin of this
band, stop short, and are in part reflected on the
internal layer of the capsule of the ovulum. This
band is perceptible in very small ovula as soon as
their capsules become vascular, and it is very obvious
in those which have attained their full size. The
internal layer of the capsule is rougher and thicker
than the external one, to which it adheres firmly by
prolongations of the small vessels. The fluid in the
ovulum becomes of a more and more opaque white,
till this body has acquired the size of a pea, when it
is tinged with yellow by the deposition of globules
of a yellow oil. The transition from a white to a
yellow colour is gradual, but by the time the ovulum
is one-third of an inch in diameter its composition
seems to be nearly perfect. At this time we can
perceive with ease the blastoderm or white disc of
the cicatricula, the centre of which is occupied by a
very small dark spot. It is in this dark spot that
the vesicle, of which we have already spoken, is
placed. At this period the cicatricula is about a
line, and the central spot one-tenth of a line in
diameter. The ovulum now increases rapidly in
size, the number of oily globules becomes greater,
and the vessels on the capsule are more turgid with
blood. The cicatricula is seen lying below the
proper membrane of the yolk ; it is generally situ-
THOMSON] ROYAL MEDICAL SOCIETY 167
ated near the pedicle of the capsule ; sometimes,
also, it has been found near the clear band, but never
in any other situation ; it adheres firmly to the
proper membrane of the yolk, so that when this is
removed the cicatricula comes away along with it.
When examined with care under water, the cica-
tricula presents the appearance of a disc composed
of white globules, thicker at the middle than at the
edges. In the centre of this disc we find the vesicle,
which is seen to bulge out from the disc when we
look at it laterally. Appearances nearly the same
are seen in the unimpregnated ovulum, but in it the
parts appeared to Purkinje to be weaker and thinner
than in the impregnated.
Though there are two oviducts in the hen, only
one of them seems to be developed for the reception
of ovula and the formation of their accessory parts.
This is the oviduct of the left side which, in the
laying season, occupies the greater part of the back
of the abdomen ; it is necessarily very much con-
voluted, as its whole length is generally about two
feet. The tube of the oviduct is enclosed between
two serous membranes, which join one another at
each side of it, and thus constitute a double mesen-
tery, by which it is very tightly bound down. The
upper portion of the tube opens into the cavity of
the ovarium ; the margins of the tube are expanded
so as to form a funnel-shaped opening. A strong
band passes from the upper margin of the funnel to
the angle of the second left rib, while the opposite
margin of the funnel is attached below to the con-
volutions of the oviduct by a contracted portion of
the peritoneal covering, so that by this means the
mouth of the oviduct is held stretched below the
168 DISSERTATIONS [FORMATION OF EGG
o vula. The funnel leads into the Fallopian tube or
entrance of oviduct ; the coats of this tube are
thicker and stronger than the inftihdibulum, and
are lined internally by oblique longitudinal stripes,
which appear to be folds of the inner mucous mem-
brane, and to be of a glandular structure. The
Fallopian tube becomes gradually wider till about
five inches from its commencement, when it attains
its greatest width, which is about two inches and
a half in circumference. The folds on the internal
surface are much more developed at this part ; they
are very distinctly glandular, and cannot be effaced
by pressure, and when the tube is inflamed during
the passage of the ovulum through it, vessels are
seen ramifying very beautifully upon them. ' This
part of the oviduct is about half the length of the
whole ; it terminates in a narrower part about three
or four inches in length, from which it is separated
by a slight stricture. In this part of the oviduct
the spiral glands are smaller and more closely set
than in the rest. In the region of the sacrum the
oviduct expands into a wide cavity of a different
structure and appearance from the rest : this is the
cavity in which the egg receives its shell, and has,
not perhaps with great propriety, been called the
uterus. Before entering the uterus tHe tube makes
a very sharp turn, and is considerably narrowed ;
the cavity of the uterus itself is of the size and form
of the full-sized egg ; the mucous membrane is
studded with villi, which are so large as to have the
appearance of glands ; its colour is brownish red,
and its consistence very soft. From the lower part
of the uterus there extends another narrow tube
called the vagina, which opens into the cloaca at
THOMSON] ROYAL MEDICAL SOCIETY 169
the side of the rectum. The parietes of the vagina
are very thick and fibrous, and the sides are quite
contracted together in the collapsed state of the
tube.
Let us now return to trace the progress of the
completely-formed ovulum suspended in its capsule
from the ovarium. As the ovulurn approaches to
maturity the vessels "of the capsule, instead of
becoming more turgid with blood, diminish in size,
so that the capsule appears of a lighter colour.
When the ovulum is completely ripe, the expanded
part of the infundibulum, in a manner which has
not yet been explained, applies itself closely to it in
every part, so that,, the free, edges of the infundi-
bulum embrace firmly its pedicle. Either by the
direct pressure thus given, or by the stoppage of
the blood that it occasions, the capsule gives way at
the side opposite to the pedicle where the trans-
parent band exists. The ovulum makes its exit
from the capsule, and very soon passes down into
the first part of the oviduct. In the meantime the
infundibulum relaxes, and allows the empty and
broken capsule to escape from its hold. These
empty capsules are frequently observed hanging
loose among the ovula ; they are at first very vas-
cular, but soon diminish in size and are absorbed.
The only change which can as yet be observed in
the ovulum is in the central part of the cicatricula.
The vesicle that existed in the ovulum while con-
tained in its capsule, cannot be seen in that which
has passed into the oviduct.
As soon as the ovulum enters the oviduct the
secretion of the albumen commences, . and when it
has advanced several inches into this canal the
170 DISSERTATIONS [FORMATION OF EGG
albuminous layer is of considerable thickness. The
oviduct is expanded only at the place where the
ovulum lies, and is collapsed on either side. As
yet we see no trace of the chalazse, unless we regard
as such a small quantity of albumen which adheres
to each side of the ovulum. As the ovulum moves
onwards layer after layer of albumen is added, and
in the meantime that part of the albumen which
immediately surrounds the yolk begins to thicken,
and is gradually condensed into a very thin mem-
brane, which applies itself closely to the membrane
of the yolk. From this new membrane arise the
tortuous cords which are afterwards seen in the
chalazse, and which are formed by a condensation
of albuminous matter similar to that by which the
membrane itself is formed. It is to this newly-
formed membrane, according to Dutrochet and
Purkinje, that the chalazse are attached ; and it is
from the difficulty which we experience in separat-
ing this membrane from that of the yolk that the
existence of a communication between the white
and the yolk, by means of the chalazse, has been so
universally believed.
In the egg as contained in the oviduct, the
transition from the thicker internal layer of the
albumen to the thinner external is so gradual that
they cannot be distinguished from one another as
in the recently-laid egg.
Whilst the ovulum receives the white it
gradually moves onwards, the small end proceeding
foremost, until it reaches the narrowed part between
the oviduct and uterus. It is probably in this part
that the membranes covering the albumen are
deposited, but this circumstance has not yet been
THOMSON] ROYAL MEDICAL SOCIETY 171
established by observation. The egg arrives in
the uterine part of the oviduct, covered by the two
layers of membrane, and immediately the deposition
of the shell commences. On examining the egg in
this state, the transparence of its membranes enables
us to perceive the motions of its internal parts
when the position of the egg is changed ; it then
appears obvious that the cicatricula has a tendency
to rise to the highest part, though in one particular
position this tendency seems to be greater than in
any other. The structure of the membrane ex-
amined by the microscope is clearly filamentous.
The outer layer is covered by small crystalline
bodies, joined together in groups of two or three ;
these little bodies appear to be the first deposition
of the calcareous matter of the shell, as they dis-
appear with effervescence when muriatic acid is
poured on them. A very short space of time is
sufficient to complete the deposition of the shell,
and the egg then lies perfect in the uterine portion
of the oviduct, its small end being turned towards
the lower opening. The canal of the vagina takes
on, like the rest of the tube during the formation of
the egg, an inflammatory action when the egg is
about to pass through it. The egg perfected in the
uterus by the addition of the shell, is in no way
changed in its passage through the vagina.
The Evolution of the Chick.
******
Conclusion. It would have been interesting to
have traced the points of analogy and difference be-
tween the development of the foetus of birds and of
other animals, and the gradual complication of the
172 DISSERTATIONS [FORMATION OF EGG
organs of the foetus by which it seems to pass
through the whole animal chain, at one time assum-
ing the form of the hydatid or animalcula, till pass-
ing through its successive stages of development and
complication, it arrives at the perfect state in which
it comes out of the shell.
But time will not permit me to enter on these
subjects, and I have only to hope that the observa-
tions of other members conversant with the subject
will supply this defect as well as the other imper-
fections of this Essay.
XIII
JAMES YOUNG SIMPSON
181 1-1870
ON THE DISEASES OF THE PLACENTA
Read 1835
MR. PRESIDENT,
The diseases of the placenta, to which I
have the honour of directing the notice of the
Society this evening, form a subject of inquiry which
appears to have hitherto attracted, especially from
British pathologists and accoucheurs, a very incom-
petent share of attention. In the works of various
medical authors of the last and preceding century,
as in those of Bonnetus, Morgagni, Ruysch, Lietaud,
and others, notices of some individual cases and
forms of placental morbid lesions are occasionally to
be met with, and more lately several of the diseases
of this organ have been investigated with greater or
less attention by different continental pathologists,
as by MM. Murat, Desmoreaux, Brache, and Cru-
veilhier in France, and by Professors Stein, d'Outre-
pont, and Wilde in Germany. I am not aware,
however, that the medical literature of England
contains any account of the various morbid states to
174 DISSERTATIONS [DISEASES OF PLACENTA
which the placenta is liable, beyond what is to be
found in the casual observations and in the details
of incidental cases recorded in the obstetrical writ-
ings of Smellie, Denman, Burns, Ramsbotham, Lee,
Ingleby, Granville, and others. It is not, therefore,
without hesitation, that I venture to lay before the
Society the following general remarks upon some of
the principal forms of placental disease, as derived
partly from the data furnished by others, and partly
from the observations which I have myself had an
opportunity of making upon a few recent, and a very
considerable number of preserved specimens of mor-
bid placentae, contained in the different pathological
museums of this country. At the same time, I may
be allowed to plead in excuse for the many imper-
fections and omissions in the following Essay, the
paucity of materials still existing upon the subject
of which it treats, the difficulty of collecting these
materials from the numerous different sources over
which they are scattered, and the haste with which
the observations it contains have latterly been
thrown together.
The human placenta, though an organ enduring
for a very limited period of time only, being destined
to serve as a mere temporary medium of communi-
cation between the mother and foetus, and passing
through its different stages of formation, growth,
and ultimate expulsion, in the short space of seven
or eight months, yet appears to be liable during its
comparatively brief existence, to a considerable
number and diversity of morbid conditions, more
frequent, I believe, in their occurrence, and im-
portant in their effects, than seems to be generally
suspected. Nor are the morbid conditions and
SIMPSON] ROYAL MEDICAL SOCIETY 175
lesions of this organ matters of pathological curiosity
and interest only ; a more accurate knowledge of
their various phenomena appears to promise results
of no inconsiderable consequence to practical medi-
cine. The peculiarities of the placental economy of
the human female, and the nature of the relations
which exist between it and the uterus, constitute,
particularly when these relations are deranged by
placental or uterine disease, one of the great sources
of danger and fatality in human parturition.
Numerous facts also seem fully to prove that dif-
ferent morbid actions and lesions of the placenta,
exert a marked and powerful influence upon the
health and well-being of the mother during preg-
nancy ; and, above all, the study of these lesions
promises to throw an entirely new light upon the
abnormalities of development, the diseases and death
of the foetus in utero. Most of the latest inquiries
instituted upon these points by Geoffrey St. Hilaire,
Velpeau, and others, go to prove that several varie-
ties of malformation of the foetus, are, in not a few
cases, attributable to morbid conditions of the
placenta as their immediate existing cause ; that
the not infrequent occurrence of the death of the
foetus, in the earlier as well as in the later stages of
pregnancy, is almost always the result of a diseased
state or states of this organ, and that the act of
abortion, occasionally the indirect cause of that
death, but much more commonly its indirect effect,
is in very many instances capable of being traced to
the same source. It seems not, therefore, irrational
to hope that by a more careful investigation into the
nature of the different diseased states to which the
placenta is subject, and by a more diligent and
176 DISSERTATIONS [DISEASES OF PLACENTA
rigorous observation of the symptoms which precede
and accompany these states, and of the causes by
which they are produced, we may be gradually led
to a greater degree of facility and accuracy in their
detection, and the adoption of better established
principles for their prevention and treatment, and
that in this way may be promoted in no inconsider-
able degree those great and ultimate objects of all
medical study the preservation of human life and
the alleviation of human suffering.
The two principal and (both in a pathological
and practical point of view) most important dis-
eased states to which the placenta is liable appear
to be sanguineous congestion and hasmorrhage, and
inflammation with its different consequences. The
placentary parenchyma and the membranes investing
the organ are liable to other morbid states : to hyper-
trophy and atrophy, to softening and induration, to
cartilaginous and ossific degeneration, and the secre-
tion or formation of other morbid products and tissues,
to an abnormal or cystoid hydatiform structure,
and to various forms of malformation and displace-
ment ; but in a practical point of view, most of these
lesions are comparatively minor in their importance
to congestion and inflammation, and the effects
which these diseased conditions produce. It is to
congestion and inflammation of the placenta, there-
fore, that I would wish first and principally to direct
the attention of the Society.
By the term congestion of the placenta, I mean
to imply the existence of a greater than usual quan-
tity of blood in the vessels of that organ, taking
place rapidly or more slowly, in some cases rapidly
or more slowly terminating in resolution, and in
SIMPSON] ROYAL MEDICAL SOCIETY 177
others leading to the infiltration or effusion of blood,
in greater or less quantity or quantities, into the
substance of the placenta, upon its uterine or foetal
surfaces, or between the membranes of the ovum.
The excess of blood in the vessels of the placenta
constituting congestion of that organ may, there is
every reason to believe, have its seat primitively
and separately either in the placental ramifications
of the foetal umbilical arteries and veins, or perhaps
more frequently in the vascular prolongations
which seem to be extended from the uterine vessels
of the mother into the substance of this viscus ;
but a state of congestion in one of these systems
of vessels, the foetal or the maternal, scarcely perhaps
ever continues for any considerable period of time,
without giving rise to a similar state in the other.
The anatomical characters of simple congestion
of the placenta may, I believe, be sufficiently illus-
trated by a reference to the engorged and dark
coloured condition which this organ presents in
cases in which the head of the child has unfor-
tunately happened to be long and dangerously im-
pacted in the passages of the pelvis. The appear-
ances which the placenta exhibits on its being
expelled after such cases, and more particularly if
the impaction has been so great as to prove fatal to
the child, are well known to every practical accou-
cheur. The external surface of the organ is of a
more or less deep violet, and sometimes almost livid
colour ; its internal structure when torn or divided
by the scalpel presents a deep purple hue, its vessels
are everywhere loaded and distended with dark-
coloured blood, the organ appears enlarged, and its
substance feels heavier and more solid than natural.
M
178 DISSERTATIONS [DISEASES OP PLACENTA
In cases of abortion occurring subsequently to
physical injuries of the uterine region, or to any of
those causes which give rise to it by producing a
strong determination of blood to the vessels of the
uterus, the same congested and engorged state of
the placenta, as that to which I have just alluded,
is generally met with ; and in these instances also
the blood is not unfrequently found effused in more
or fewer points from rupture of the lacerated or
distended placental vessels, constituting the state
of ' occult internal haemorrhage ' of Baudelocque, and
the ' apoplexy of the placenta ' of M. Cruveilhier,
who, along with Laennec, Andral, and other Parisian
pathologists, has employed of late years this term to
designate the existence of an effusion of blood into
the tissue of the lungs and other organs of the body,
while the word literally and originally signifies one
of the more striking external phenomena or symp-
toms only, which such an effusion of blood generally
produces when it happens to occur within the cavity
of the cranium.
The blood effused in placental congestion and
haemorrhage, occurring during pregnancy, may
occupy different anatomical situations. In some
instances it is found on the external surface of the
organ, or between it and the uterus, occasionally in
very large quantity, as in cases described by
Mauriceau and Coloy ; in other not infrequent
instances the blood is situated towards the foetal
surface of the organ, or insinuated between the
membranes, and in others, again, it is seen effused
into the substance or proper structure of the
placenta, as mentioned by Deneux and Baudelocque,
and as I have myself had an opportunity of observ-
SIMPSON] ROYAL MEDICAL SOCIETY 179
ing in a considerable number of specimens. In cases
in which abortion occurs in the earlier periods of
pregnancy, the extravasated blood is frequently
found diffused over the whole, or nearly the whole,
surface of the chorion, and between it and the
amnion, in the form either of a continuous layer or
layers of coagulurn, or of more or less isolated
nodules ; and in two instances I have seen it occupy-
ing these situations at the same time that it was
extrayasated in the form of roundish masses into
the rudimentary structure of the placenta, and
effused into the cavity of the amnion itself.
The quantity of blood effused internally in
placentary haemorrhage occurring during pregnancy
is generally small, but it is occasionally also, par-
ticularly when .the blood is extravasated between
the uterus and placenta, towards the later stages
of utero-gestation, so great as to endanger or destroy
the life of the mother.
When in placentary haemorrhage or apoplexy
the blood is extravasated into the substance of the
placenta itself, it most generally appears, as far as
I have myself observed, under the form of roundish
coagula, often accurately circumscribed ; but in other
cases the form and outline of these coagula are alto-
gether irregular, and the transition between the sound
and diseased portion of placenta not very accurately
marked. In some instances one or two coagula only
are observed, or the extravasation is confined to one
or two lobes or cotyledons only ; but generally a
considerable number of coagula are seen scattered
throughout different parts of the same placenta, the
sanguineous extravasation having occurred at several
points, either simultaneously or successively. In
180 DISSERTATIONS [DISEASES OF PLACEXTA '
one extreme case of this kind which I have met
with, the section of a placenta of about the fourth
month presented throughout its whole structure
only one agglomerated mass of distinct and separate
roundish coagula, and the organ was increased so
greatly in thickness by these interstitial effusions as
to infringe very considerably upon the cavity of the
amnios.
The size or volume of the individual coagula
or effusions is liable to great variation. In some
instances they do not equal a small pea in size, and
again I find in my notes -two cases mentioned, in
one of which a single coagulum as large as a walnut
is described, and in the other case, another coagulum
is alluded to as equal in volume to a pigeon's egg.
Weisberg appears to have met with a placental
sanguineous coagulum still larger than either of
these two.
The substance of the placenta more immediately
surrounding sanguineous extravasations is, particu-
larly when these extravasations are recent, occa-
sionally darker red than natural, from imbibition or
infiltration of the effused blood into the neighbour-
ing portions of tissue, and sometimes the surround-
ing placentary structure is studded with a number
of dark spots or points probably originating in
partial sanguineous extravasations, or in blood
stagnated and coagulated in the cavities of some
obstructed vessels.
The immediate anatomical seat of sanguineous
effusions situated in the substance of the placenta,
as well as the set of vessels from which they pro-
ceed, probably differ considerably in different cases.
In several instances I have observed the extrava-
SIMPSOX] ROYAL MEDICAL SOCIETY 181
sated blood situated towards the foetal surface of
the organ, or between it and the chorion ; in others
it is completely surrounded by the substance of the
placenta on all sides, being probably effused into the
cellular texture connecting its innumerable vessels ;
or into the irregular cells or cavities which the
organ contains, supposing the description of these
cells or cavities given by the Hunters, Meckel,
and Hildebrand to be correct. M. Deneux states
that, in the case which he has given, the effused
blood was situated in the interstices between the
lobules or cotyledons, a circumstance which I have
not had occasion to observe in any of the specimens
of the disease that I have happened to examine.
When hsemorrhagic effusions*take place towards
the fcetal surface of the placenta, or in the earlier
stages of pregnancy, between the decidua and
chorion, the coagula of extravasated blood very fre-
quently protrude these membranes before them
towards the cavity of the amnion, and appear in the
form of projecting eminences or elevations on the
amniotic surface.
These eminences vary greatly in number and
extent in different cases. In some instances almost
every part of the amniotic cavity is crowded with
them, in others they are seen only in that part
which corresponds to the placenta. They vary in
size from a very small pea to a hazel-nut and larger.
Occasionally they form very slight projections, only
above the general level of the surface of the amnion ;
generally they appear as rounded irregularly hemi-
spherical eminences ; and again I have seen them
standing out from the walls of the amniotic cavity, of
an elongated nipple-like shape, and nearly as large as
182 DISSERTATIONS [DISEASES OF PLACENTA
the first joint of the little finger. In some cases
I have seen the umbilical cord at its insertion into
the placenta, at the same time greatly distended
with coagulated blood for a distance of six or eight
lines, an appearance very correctly represented
in a delineation of an aborted ovum figured by
Sandifort.
In latent placentary haemorrhage or apoplexy,
the blood, after its effusion, undergoes a variety of
changes interesting in themselves, and important in
this respect, that a misconception of their nature
has, as it appears to me, led pathologists into error
in regard to the nature of some of the lesions
occasionally observed in this organ. When the
blood is poured out from its containing vessels into
the substance or cells of the placenta, or between
the membranes, it gradually coagulates and assumes
a very dark purple, and sometimes (as I have seen
it in two cases) almost a melanotic black colour.
After a time, however, it begins to lose this tint,
the colouring matter gradually becomes removed,
and the coagulum successively assumes a chocolate
brown a reddish or brownish yellow hue and,
latterly, if time sufficient is allowed, it presents a
pale yellowish white, or straw-coloured substance,
the fibrinous portion of the coagulum being then
alone left. When these fibrinous and generally
firm and indurated masses are divided, they, for the
most part, exhibit internally a dense uniform or
homogeneous tissue, but in some cases, where the
individual mass or coagulum has been formed by
several successive effusions of the blood occurring at
the same point, and probably from the same vessel,
its section shows a more or less perfect concentric
SIMPSON] ROYAL MEDICAL SOCIETY 183
laminated structure. M. Cruveilhier has repre-
sented an apoplectic placenta in which the structure
of the coagulum appears to be concentrically
laminated in this manner, and the more external
layers are seen to be losing their colouring matter,
while the nucleus of the effusion is composed of
darker and more recently effused blood. I have not
had an opportunity of observing these changes in
specimens of laminated placental coagula, but have
had repeated occasion to remark the decoloration
of the more common single or homogeneous coagula
proceeding from their circumference to their centre.
I have been able to trace in the blood effused in
placentary haemorrhage, a change still more advanced
than that of its decoloration and conversion into a
yellowish straw-coloured fibrinous mass. In four
instances I have seen these fibrinous masses in
different parts of the same placenta, contracted to a
size considerably less than the space which they
originally occupied, arid consequently appearing, as it
were, to be contained in cavities which were only but
partially filled by them. This appearance is parti-
cularly well seen when the blood has been extra-
vasated towards the foetal surface of the placenta, or
behind the chorion and amnion, and, when it has pro-
truded forwards these membranes, in the form of the
eminences or nipple-like projections already alluded
to. In such cases, after the colouring matter of the
effused blood has been removed, and time is given
for the fibrinous masses which are left to contract,
the folds of the chorion and amnion which they
carried before them, being inelastic membranes,
remain in the position in which they were placed,
and present themselves when the ovum is afterwards
184 DISSERTATIONS [DISEASES OF PLACENTA'
examined, in the form of half- empty loose bags or
sacks projecting towards the cavity of the amnios.
Intone of the four placentae in which I have ob-
served this contraction or diminution at least of the
fibrinous coagula, the cavities containing these con-
tracted coagula were filled up with a limpid serum,
but in the other three cases I do not find in my
notes any mention of such an effusion.
In no case have I seen the complete removal of
the fibrinous coagula from their containing cavities,
or any appearance whatever betokening the organi-
sation of these coagula ; and I have to regret not
having directed my attention particularly to the
state of the placentary tissne more immediately
surrounding the effusions, or observed the changes
which take place in it upon the occurrence of these
sanguineous extravasations. In some instances, as
in those represented by Cruvejlhier, the surrounding
placentary structure appears to become atrophied
and anaemic after the effusion has occurred, and
perhaps in other cases this state may precede these
effusions, but whether a cyst is ever formed around
the sanguineous coagula, and under what circum-
stances it is formed, I have no data to determine,
either from observations which I have myself made,
or which I can find in the works of others.
A number of the cases of tumours and circum-
scribed indurations of the placenta described by
Morgagni in his 48th letter, of the schirrous tubercles
mentioned by Albrecht, and admitted by Murat,
and of those eminences on the surface of the amnion
figured by Huysch, Sandifort, Breschet, Velpeau and
Dr. Granville, and spoken of by this last author
under the name of tuberculated ova, appear to me
SIMPSON] ROYAL MEDICAL SOCIETY 185
to consist in reality of coagula of blood, which have
undergone more or fewer of the changes which I
have attempted to describe. The white masses in
the placenta, composed of a substance resembling
'both fat and cartilage, recently mentioned by Pro-
fessor Stein, not improbably consisted also of the
fibrinous matter of effused coagula of blood. In the
notes which I took of the first specimen of ttysse
yellowish fibrinous masses which I had occasion to
examine, I find that I have described them as
internally not unlike scrofulous or dense encephaloid
matter ; but since that period I have had ample
opportunities of correcting this conjecture by an
examination of above twenty additional speci-
mens of this particular lesion, and I have now not
only been able to trace in different placentae the
gradual transformations already described as occur-
ring in the effused blood, from its appearance as a
recent dark-coloured coagulum to its condition of a
yellowish white fibrinous mass, but I have seen more
than one instance in which these two states, with
all their intermediate gradations of change and
coloration, could be observed in different coagula
which had been effused at successive periods in the
same individual case.
The occasional exciting or determining causes of
placental congestion may be considered as existing
either on the part of the child or of the mother.
With the causes existing on the part of the child
we are as yet bu^ very imperfectly acquainted, but
it seems probable that whatever states and physical
lesions and malformations of the, foetus and umbilical
cord tend directly, or indirectly, to prevent or im-
pede the free return of blood through the umbilical
186 DISSERTATIONS [DISEASES OF PLACENTA
vein, will have the effect of producing more or less
marked congestion in the minuter placental ramifi-
cations of this vessel, and perhaps in some cases ex-
travasations of blood from these ramifications. We
now know that the foetus in utero is liable to vari-
ous febrile, contagious, malarious, and inflammatory
affections, to plague, small-pox, and perhaps measles
and scarlatina, to ague, and a number of acute
internal inflammations, but whether the presence of
these diseases in the foetal economy is capable of
exciting placental congestion or not, through the
long and tortuous tract of umbilical arteries, and
what effects they produce on the placental circula-
tion in general, are points still open for investigation.
As occasional exciting or determining causes on
the part of the mother of placental congestion and
sanguineous effusion into the substance, and upon
the surfaces of the placenta and ovum, may be men-
tioned physical injuries, such as blows, faUs, etc.,
strong muscular exertions and bodily fatigue, excess
of venery, morbid irritations of the uterus and
neighbouring organs, acute febrile and inflammatory
diseases, and in general terms all those circum-
stances which have a tendency to produce plethora
and increased action of the whole maternal vascular
system, and of the uterine system in particular.
These various causes may produce placental con-
gestion and hemorrhage, in different ways ; certain
of them, as the physical injuries alluded to, may
occasionally lead to this effect by directly or
mechanically rupturing, by the concussion which
they create, some of the placental and utero-placental
vessels and attachments ; others of them, and even
these same causes at other times, may act by in-
SIMPSON] ROYAL MEDICAL SOCIETY 187
ducing a morbid determination of blood to the
uterus and placenta, or by exciting such muscular
contractions of the uterus as will separate to
a greater or less extent the mutual uterine and
placental connections.
In respect to the mode of action of general and
local plethora and increased vascular action, in
producing placental congestion and haemorrhage, I
shall only venture one remark. If we admit, with
some authors, that the newly formed vascular canals
which, in the doctrine of the Hunters and others,
are believed to pass from the uterine vessels into
the placenta, are less firm and resistent in their
coats or texture than the other blood-vessels in the
maternal system, it will follow that when a greater
than usual plethora or vascular action happens to
occur in the sanguiferous system of the mother, or
when, from any causes, the blood is determined in
a particular manner to the divisions of the uterine
arteries and veins, it will be most apt to become
congested in the naturally little elastic vascular
tubes and canals of the placenta, and if, further, the
momentum of the whole mass of blood in the body
of the mother, or of that in the branches of the
uterine vessels alone, be preternaturally increased,
the placental and utero-placental vessels or canals
will be the first to yield or rupture under the
generally increased degree of internal pressure, inas-
much as they are the least capable of affording the
requisite resistance to the distending force of the
contained fluid.
All the above effects will be naturally more or
less promoted by the existence of any such diseased
state or states of the tissue of the placenta, or of
188 DISSERTATIONS [DISEASES OF PLACENTA
the placental and utero-placental vessels themselves,
as diminish the elasticity and power of cohesion of
the component tissues of these vessels.
The symptoms produced by placental congestion
and haemorrhage are, in many instances, obscure
and difficultly appreciable, but in other cases,
especially in those in which sanguineous extravasa-
tion occurs, the preceding and accompanying pheno-
mena are frequently sufficiently characteristic and
well marked.
Simple placentary congestion, whether primitively
seated in the foetal or maternal vessels, seldom,
perhaps, if ever, exists for any considerable period
of time, without' more or less speedily superinduc-
ing a degree of uterine congestion ; and again the
state of congestion or determination of blood to
the vessels of the uterus, when occurring as the
primary pathological affection, is probably as gene-
rally and directly followe'd by a similar condition
of the placental vascular system or systems.
Placentary congestion, therefore, whether proceed-
ing or not to extravasation of blood, usually
appears to be either preceded or accompanied by
those symptoms which denote an increased activity
in the uterine sanguiferous vessels, as by a feeling
of oppression or weight, and tension or bearing
down in the uterine and pelvic viscera.
If there exists a general plethoric state of the
system, various febrile phenomena may also present
themselves. Occasionally the uneasy feelings in
the uterine region proceed to a degree of fixed
or intermittent pain, confined to one part of the
uterus or uterine region only, or diffused generally
over it. This pain seems frequently to extend to
SIMPSON] ROYAL MEDICAL SOCIETY 189
the loins, and the same sensation is said in pro-
tracted cases to be sometimes even felt in the
mammae. At the same time the morning sickness
and vomiting, with the other sympathetic affections
which so frequently attend upon the natural de-
velopment of the uterus during pregnancy, are in
most instances manifested in an increased or unusual
degree.
When placentary congestion occurs after the
period of quickening, and is very acute in its char-
acter or rapid in its appearance, the motions of the
foetus would appear to be sometimes rendered
suddenly irregular, and at times almost convulsive ;
if the congestion is more chronic in its nature, the
motions of the foetus occasionally become extremely
languid, or not at all appreciable, but under a timely
detraction of blood they may be, as Madame
Lachapelle has remarked, again reproduced after
having ceased for several days. How much we may
be assisted in the later months of pregnancy by
auscultation in our detection of the morbid states of
the placental and foetal circulation, it is difficult if
not impossible at this moment to determine, but
more accurate and extensive observations upon this
subject may yetjead to some not unimportant results.
When the placental congestion has proceeded
to the extravasation of blood, besides the symptoms
already mentioned, others of a more unequivocal
character frequently present themselves. The
effused blood may, as we have already seen, be
poured out into situations in which it cannot escape
externally. Perhaps, however, in the earlier months,
at least in the larger proportion of cases, a small
quantity of it does escape per vaginam, and this
190 DISSERTATIONS [DISEASES OF PLACENTA
circumstance, when found in connection with other
symptoms, particularly with lumbar and uterine
pains, and with the knowledge of the previous action
of any of the directly exciting causes of placentary
congestion or haemorrhage, may be considered as
furnishing very unequivocal marks of the existence of
these states. If a pregnant woman, for instance, im-
mediately after receiving a fall or blow, or any sudden
succussion of the body, such as that occasioned by
severe coughing or retching, be seized with disten-
sive uterine pain and more or less effusion of blood
externally, little doubt can in most cases be enter-
tained in regard to the nature of the internal morbid
conditions which these symptoms betoken. One
of these symptoms only, however, the uterine or
lumbar pain, or the external haemorrhage, may alone
be present. The feeling of uterine pain, if occurring
alone, can perhaps be but little trusted to as a
diagnostic mark in the state of pregnancy, unless
when taken into consideration with various collateral
circumstances. In placental haemorrhage it is pro-
bably produced, as M. Baudelocque has supposed,
by the mechanical distension of the uterus with the
blood effused, and this distension can, it is alleged,
be sometimes actually traced externally in the
enlargement of the absolute volume or bulk of the
uterus. In some instances the pains remit or dis-
appear entirely in the course of a few days or weeks,
when the uterine development has again proceeded
considerably in its course ; and in many other in-
stances they pass sooner or later into the intermittent
and regular pains indicative of uterine contraction.
The external haemorrhage is in some instances ob-
served to be in considerable abundance from the
SIMPSON] ROYAL MEDICAL SOCIETY 191
beginning ; but more frequently it presents itself in
the first instance as a few drops of blood, or of
blood and serum only, afterwards becoming increased
or not in quantity. In many cases it is seen to
remit and return repeatedly after the lapse of a few
days, or at the distance of some weeks.
When placental haemorrhage occurs in the later
months of pregnancy, the internal effusion of blood
is sometimes so great, when arising from a separation
of the placenta, to a greater or less extent, from the
internal surface of the uterus, as rapidly to produce
all the most alarming symptoms caused by extreme
loss of blood, and under such circumstances the
extravasation may even proceed to a fatal extent, as
I have already mentioned, without any sanguineous
discharge whatever appearing externally. In other
cases of placental congestion and haemorrhage oc-
curring in advanced pregnancy, there is an external
discharge as well as an internal effusion of blood,
without, as is found on examination, any part of the
placenta being placed over the os uteri a case
which I have not included, and consequently
avoided all allusion to in the preceding observa-
tions.
The occurrence of sanguineous effusion from the
placental, utero-placental, or exposed mouths of the
uterine vessels, though often in the later and almost
always in the early months of utero -gestation un-
attended with any great danger to the mother, and
very frequently making no impression whatever
upon her system, or not even betraying itself by
any external discharge, must always be looked upon
as a circumstance threatening the most direct and
imminent danger to the life of the foetus, for a very
192 DISSERTATIONS [DISEASES OF PLACENTA
small quantity of blood, whether extravasated in the
earlier weeks upon the villous surface of the chorion,
or at a later period, into or around the placenta,
may be amply sufficient to arrest the processes of
foetal nutrition or respiration to such a degree as
effectually to impede the development, or destroy
the life of the embryo, and in this latter way prove
an indirect cause of abortion. For my own part, I
feel assured that the preparations of aborted ova
contained in the pathological museums of this
country fully bear out, as far as I have myself seen
them, the opinion of Professor Duges, that the most
frequent cause of abortion is active placental con-
gestion, under which term he at the same time
includes placental haemorrhage. This remark, I
believe, will be found in particular to apply to
abortion in the earlier months.
In the greater proportion of cases which I have
met with of ova aborted in consequence of internal
placental haemorrhage, I have found the embryo
arrested at about the fifth or seventh week of de-
velopment, or at that stage at which the extremities
of the body begin to appear in the form of rounded
buddings. Expulsive uterine contractions had not
however supervened in many of these cases for
weeks after the effusion had actually taken place,
and, in some of them, the general growth of the
membranes and placenta appeared to have proceeded,
while in one or two cases the embyro itself had also
enlarged to nearly the size of the thumb, although
the individual development of its extremities, and
perhaps of other organs, had been arrested.
The next series of morbid conditions of the
placenta to which I have to direct the attention of
SIMEON] ROYAL MEDICAL SOCIETY 193
the Society, consists of inflammation and its various
consequences.
*
Having exhausted so very large a portion of the
limits of this Essay in inquiring into the anatomical
characters and products, the causes, symptoms, and
effects upon the mother, and upon the child, of the
two most frequent and important morbid conditions
of the placenta, congestion and inflammation, I shall
be obliged to confine myself in the remaining pages
to a mere enumeration rather than description of the
other forms of disease to which this organ is liable.
Hypertrophy of the placenta is sometimes met
with at the full term of utero-gestation. Thus
Biecke speaks of placentae of three pounds and
upwards, and Stein mentions one as heavy as six
pounds in weight ; but it is principally in cases of
death of the foetus in the early and middle periods
of pregnancy that placental hypertrophy, or a morbid
disproportion in size between it and the child, has
hitherto been studied, and it is admitted by Vater,
Morgagni, Ruysch, Frank, and others, that the organ
may not only live, but increase in growth after that
occurrence has happened, and even, in some instances,
after the total expulsion of the immature foetus
from the uterus.
The placenta is occasionally found atrophied.
This atrophy may be partial or general. When
partial, or confined to one or two lobes only, it
seems in general to originate in a separation of the
atrophied portions of the organ from the internal
surface of the uterus. The atrophied lobes are
thinner than the other parts of the viscus, and
present an orange or yellowish white colour ; they
N
194 DISSERTATIONS [DISEASES OP PLACENTA
contain little or no blood, and appear transformed
into a kind of semi-desiccated cellular or filamentous
tissue. Atrophy of a whole, or of the half of a double
or twin placenta is sometimes met with in those
cases of plural conceptions, where one of the foetuses
perishes during the earlier periods of utero -gestation
but is not expelled till the full, or near the full,
term of pregnancy, along with the other perfect and
generally living child. The whole placenta, or
portion of placenta, belonging to the blighted foetus,
is under such circumstances almost always found
greatly atrophied, and presenting the anatomical
characters just now mentioned.
Cartilaginous and osseous degeneration of the
placenta is not unfrequently met with.
Tubercular deposits in the placenta are men-
tioned by D'Outrepont as having been met with by
him in one case where the mother was labouring
under pulmonary phthisis.
Various instances in which sarcomatous tumours
of different varieties are said to have been met with
in the placenta are referred to by Voigtel and Otto
in their works on pathological anatomy.
Of all the different morbid states to which the
placenta is liable, none perhaps has hitherto attracted
so much attention from pathologists as that to
which the various names of hydatid mole, hydatid
placenta, vesicular mole, acephalocystis racemosa,
etc., have been given. In this form of abnormal
structure the substance of the placenta is occupied,
or its situation more or less completely replaced, by
serous, hydatoid, cystiform bodies or vesicles of
different shapes and sizes, generally co-existing in
great numbers, and arranged in regular racemose or
SIMPSON] ROYAL MEDICAL SOCIETY 195
grape-like clusters upon branching footstalks or
pedicles arising from the uterine surface of the
chorion. On the origin, nature, and general patho-
logical history of this form of abnormal placental
lesion I had collected a very considerable variety of
facts with a view to lay them before the Society, but
the unusual and unexpected length to which this
paper has already extended prevents me from doing
so on the present occasion. I may mention, how-
ever, as the result to which I have myself arrived
in this investigation, that numerous circumstances
appear to me to show that the hydatoid placenta
essentially consists of the enlarged gangliform bodies
and villi of the chorion, and ought not to be looked
upon as a morbid degeneration, morbid transforma-
tion, or species of acquired disease, but should rather
be considered as a species of primitive malformation,
consisting, as many other malformations do, in
an arrestment, in the first instance, of the natural
changes of development, in so far that a type of
structure which was intended to be temporary only,
becomes permanent for the whole remaining period
of intra-uterine life.
The limits of this paper necessarily prevent me
also from entering here at any length into the other
varieties of malformation of the placenta. The mal-
formations by displacement of the placenta form
also an interesting subject of inquiry to which I
can only here allude.
I cannot allow myself, Mr. President, to bring
this Essay to a conclusion without apologising to the
Society, at once for its great length and great
imperfections. Of its errors in both of these
respects, no person, let me assure you, can be more
196 DISSERTATIONS [DISEASES OP PLACENTA
sensible than I myself am. But amid other more
immediate and pressing avocations, and on a sub-
ject so comparatively novel, I have not been able
to find leisure sufficient to condense the (for the
most part) raw and scattered materials that I have
had to work upon, into a form such as I could have
wished. In some instances, also, I fear I may have
appeared too hasty and dogmatical in the generalisa-
tions which I have ventured to draw ; but if the
limits of the present paper had allowed me to bring
forward at the same time all the individual facts or
data on which these generalisations were founded, I
trust that any such impression as that I allude to
would have been averted or removed. If the Essay,
however, imperfect as it is, may be fortunate enough
to turn in any degree the attention of the Society
to the neglected but not altogether unimportant
class of diseases of which it treats, I shall consider
any time or labour that I may have spent in
collecting and arranging the observations which it
contains as fully and amply repaid.
XIV
JOHN REID
1809-1849
CAN ACQUIRED HABITS AND PHYSICAL CON-
FIGURATION OF BODY DESCEND TO THE
OFFSPRING?
Read 1836
MR. PRESIDENT,
It becomes an object of considerable
importance, not only in our attempts to modify
the breed of the domesticated animals, but also
for the better elucidation of some very interesting
points in Physiology, to endeavour to ascertain
what are the circumstances which influence the
propagation of these varieties, which may occur in
any species of animals. And as it appears to me
that in many of the discussions upon this subject,
the accidental changes upon the habits and disposi-
tions and upon the structure and appearance of the
body, by which I mean all those which have taken
place since the birth of the individual, have not
been sufficiently distinguished from the congenital
all those with which the individual was either born
or which have appeared shortly after birth, and
apparently from causes which had been put in
198 DISSERTATIONS [HEREDITY
operation during the growth of the foetus ; I hope
that the following remarks may not prove uninter-
esting to the Society.
As preliminary to the observations which are to
follow, I will offer a few remarks upon the terms,
species, genera, and varieties. When we see a
number of animals or plants agreeing in all peculi-
arities of structure, all of which were transmitted to
them by parents similar to themselves, or when
they do differ, if these differences can be accounted
for by the known laws of the vegetable or animal
economy, these are said to belong to the same
species. Several species, though distinguished by
peculiar characters, may yet have a general resem-
blance, by which they are more widely separated
from others, may be ranged into a group, and this
group constitutes a genus. From this it will be
seen that the principles upon which the species
may be determined are fixed and immovable, and
if any doubts ever arise upon the subject, they
must depend on our ignorance of facts, and not
upon any difficulty in the application of them, while
the formation of genera must depend upon the
peculiar views, the whim or caprice, of the classifier.
For one man may see a difference when another can
see none, or one man, by viewing the subject from a
different point, may perceive an analogy which can
be seen from no other. Differences, however, may
be effected upon the original organism of individuals
of a species, by the influence of external circum-
stances, or the offspring of a perfect individual of a
species may even differ in its original organism
from its parents, and these constitute varieties.
The latter at least, viz. where the organism is
REID] ROYAL MEDICAL SOCIETY 199
originally different, are capable of producing indi-
viduals possessing their own peculiarities. From
this a source of fallacy arises, for a variety, the
history of whose origin is unknown, may at last
come to be considered as a distinct species. Still,
this depends entirely upon our ignorance of facts.
We find botanists occasionally puzzled to decide in
such cases whether a plant ought to be considered
merely a variety or a distinct species. And it is
very probable that many plants which are now con-
sidered as distinct species were not so originally ;
indeed, some have gone so far as to assert that most
of the species of the same genus are, or may be,
mere varieties.
Though the offspring in general resembles the
parents, yet not unfrequently varieties occur, and
we have just remarked that the origin of these may
depend upon two causes, first, differences may be
effected upon the original organism of an individual
of a species by the influence of external circum-
stances, and, second, the offspring of a perfect
individual of a species may even differ in its original
organism from that of its parent. We have also
remarked that the latter at least, viz. where the
organism is originally different, are capable of pro-
ducing individuals possessing their own peculiarities.
And this is so well known, and is so often acted
upon, as to require from us no arguments in proof of
it. We will only select a few facts in illustration.
Individuals with five fingers or six toes are
found to have recurred repeatedly in the same
family, and in the same manner a partial ichthyosis
has been present at birth which has remained ever
afterwards. Scrofula, mania, and asthma are found
200 DISSERTATIONS [HEREDITY
to occur much more frequently among particular
families, and on this account these diseases have
been termed hereditary. It is this fact which is
constantly acted upon in the formation of new or
improving of old breeds of the lower animals, when
by the selection of individuals possessing some
peculiarity or another, we can in general, in a short
time, either produce an entirely new breed, or
greatly modify the old.
Another circumstance to be considered here is
that though varieties frequently arise, nevertheless,
if they intermingle freely with the other individuals
of the species, their peculiarities become lost in
their descendants, and the general characters of the
species are thus more widely maintained. This is
well known to jockeys by the phrase ' breeding in
and in.' If the offspring of a draught-horse and a
hunter be selected, possessing the characters of each
in an equal degree, this may be made in a few
generations, by a proper management of the breed-
ing, to assume the characters of the one only, those
of the other being completely lost, viz. by the
proper selection of hunters for the purpose, the
descendants will become indistinguishable from other
hunters ; if draught-horses be selected, they will
completely assume the characters of the draught-
horse. Upon this the resemblance which runs
through the mass composing a nation or tribe de-
pends, notwithstanding that varieties are constantly
springing up, and we can easily understand how
this should be more apparent in a small tract of
country, when the intercourse among the inhabi-
tants is more complete. And by this we can pro-
bably also explain how the cattle and horses which
REID] ROYAL MEDICAL SOCIETY 201
have run wild in Paraguay have almost all assumed
the same appearance, while among the domesticated
animals all the varieties of colour and appearance
are to be found as in Europe.
It appears then to be allowed by every one that
some kinds of varieties, viz. those in which the
organism is originally different, can generate off-
spring like themselves, and we now proceed to
examine if this is equally true of the other kinds of
varieties, or those in which the changes upon the
original organism have been induced by the agency
of external circumstances, subsequently to the birth
of the individual. Upon the truth or fallacy of this
position very important conclusions depend, for it is
evident that if the proofs in favour of it are found
inconclusive, all the attempts made to explain the
varieties of the human race, or of the domesticated
animals, by the influence of climate or any other
external circumstance, must be totally abandoned,
and in the selection of animals for propagating a
breed we must carefully distinguish the varieties
dependent upon original conformation from those
which have been induced after birth. That external
circumstances can produce astonishing effects both
upon the moral and physical constitution of man,
no person can for a moment deny, but it is equally
undeniable that the differences between a Negro
and a European are perfectly well marked in early
infancy. And since their peculiarities cannot be
explained by the operation of external agencies, as
they have not yet been exposed to any, it is clear
that the question resolves itself into the physiological
law which we are about to examine, whether or not
acquired changes upon the constitution of an indi-
202 DISSERTATIONS [HEREDITY
vidual can be transmitted to his offspring. And
the ascertainment of this law may enable us to set
aside a great deal of discussion upon these varieties,
and promises, if fully carried out, to lead to more
accurate results.
For example, much has been said of the striking
differences to be observed among the different castes
into which, from moral and political causes, the
Hindoos are divided, when the same condition of
life and the same occupation are continued for
successive generations. If these are only to be
observed among the adults of the different castes,
it only affords an excellent example of the great
changes to which man is liable from varied external
circumstances, the truth of which no person who
has attended to the subject for a moment ever
doubts. I have been unable to ascertain whether
a similar difference is to be observed among the
children of these castes during their early infancy,
and whether the child of a Pariah (the name given
to one of the lowest castes) might not differ little,
if any, from that of a Brahman if they were brought
up and educated together.
If we are to consider all the Hindoos as consist-
ing of the same stock, about which I suppose there
can be little doubt, it would be very desirable to
ascertain this, and until that is done any arguments
drawn from the differences to be found among that
people ought I conceive to be totally abandoned.
Supposing even that it could be rendered evident
that an original difference between the offspring of
these two castes actually existed at present, yet
before this could be adduced as an argument in
favour of acquired habits affecting the offspring,
REID] ROYAL MEDICAL SOCIETY 203
it would require to be shown that these differences
could not be explained by the constant tendency to
the production of congenital varieties in all species
of animals, but more particularly those which are
placed under artificial circumstances, such as man
and the domesticated animals.
The advocates for the all-powerful effects of
climate in producing the varieties found among
animals, have always assumed the possibility of the
offspring being affected by causes operating upon
the parent as a thing undoubted, without bringing
forward any satisfactory proof in its favour. There
are many and powerful facts which stand directly
in opposition to this opinion. We know that various
nations attempt to mould their bodies into particular
shapes ; some of the American tribes use bags of
sand to flatten their foreheads ; several savage
nations elongate their ears ; the Chinese compress
their feet into one-third of their natural size ; the
Jews remove the prepuce by circumcision ; and yet
though these previous means have been put in
practice for many centuries, it does not appear that
they have had any effect in producing an exemption
to the offspring from these painful and often cruel
methods of distorting and maiming different parts
of the body. We are in the habit of removing the
ears and tails of many of our domesticated animals ;
the human body is frequently mutilated by accident
or disease, yet we never expect that this will affect
the offspring. Considerable importance has been
attached by those who believe that acquired habits
can descend to the offspring, to a remark made in the
report drawn up by MM. St. Hilaire and Lennes, on a
paper by M. Roulin in the sixteenth volume of the
204 DISSERTATIONS [HEREDITY
Annales des Sciences Naturelles, upon the change
which the domesticated animals have undergone by
their introduction into the New World. In that
report it is stated that the observations of M. Roulin
prove the transmission by way of generation of certain
acquired habits ; for M. Roulin has shown that the
wild horses of that country, the offspring of horses
which have been trained to an ambling pace, have
transmitted to their offspring this singular manner of
progression. On consulting the original paper it ap-
pears to me that this is not exactly a fair inference
from the facts recorded by M. Roulin. M. Roulin
states that in that part of America where he resided
(New Grenada), the horses are early trained to an
ambling pace, and that great care is taken that they
practise no other. At certain seasons the finest of the
stallions are let loose amongst the mares running
wild, and that there results from this a breed of
horses in . which the amble is the natural pace.
Now M. Roulin nowhere states whether or not the
wild horses have this ambling pace, nor does he
assert that the stallions thus let loose have no
opportunity of imparting this artificial pace to their
offspring by their example, for we have every reason
to suppose that the principle of imitation exercises
its influence upon the young of the lower animals
as well as in the human species. Before the obser-
vations of M. Roulin can afford sufficient data to
justify the conclusions which G. St. Hilaire and
Lennes have drawn from them, it would be necessary
to show that the offspring would practise this arti-
ficial pace under circumstances where they had no
opportunity of acquiring it from others by imitation.
In a paper upon the domestication of animals by
REID] ROYAL MEDICAL SOCIETY 205
Bureau de la Malle in the twenty-first volume of the
Annales des Sciences Naturelles, he attempts to
illustrate what he considers to be ' universellement
reconnu, chez des animaux sounds a la puissante
influence de Thomine, les modifications de forme, de
couleur, les qualites physiques et meme les qualites
morales et intellectuelles sont transmissibles par la
generation.'
O
In a paper upon a similar subject in the ninth
volume of the same work by Frederic Cuvier, we find
that he is of the same opinion. There are two
reasons, besides others, which may be mentioned,
which lead me to believe that these authors -have by
no means succeeded in proving the truth of this
opinion which appears to be so generally acknow-
ledged. In the first place, F. Cuvier has himself
sufficiently shown that the dispositions of the lower
animals are so greatly modified by the circumstances
under which they are placed, that the same animals
may be rendered fierce or mild, shy or familiar. He
has shown that the hyena, from having been observed
under certain circumstances only, has become pro-
verbial for its sanguinary cruelty, while the same
animal, when treated with mildness, will come to the
feet of his master and solicit him for caresses and
food ; that the dog when brought up in a seques-
tered place with his master .attacks every other
person that comes in his way ; and that it is often
dangerous for any person except the herdsman to
approach cattle accustomed to feed in solitary places.
He adduces many examples to show that the most
erroneous notions have been entertained upon the
dispositions of various animals from their having
been examined under certain circumstances only.
206 DISSERTATIONS [HEREDITT
These facts would induce us to place little confidence
in the instances brought forward by Dureau de la
Malle, and upon which he principally rests the truth
of his position, and by which he attempts to show
that the domesticated animals of the present day
are originally of a milder disposition than hi the
time of the ancients. In the second place, M.
Dureau de la Malle does not draw a line of distinc-
tion between the acquired and congenital dispositions
of the animals, and consequently, granting that
these have undergone the changes for which he
contends, he has not attempted to prove that the
powerful influence which man indubitably possesses
of modifying the breed by limiting and directing
the sexual intercourse of those individuals which
best suit his purpose, may not have been sufficient
to account for this. Those who maintain that
acquired habits, or, as they are sometimes erron-
eously styled, acquired instincts, can descend to the
offspring, have a host of other facts at command, all
confirming, as they believe, this opinion.
It has been stated by Roulin, and triumphantly
appealed to by others in support of this opinion,
that the constant practice of milking cows in Europe
has induced the habit in these animals of continuing
the secretion of milk after the calf has been removed,
while on the contrary the wild cattle of Columbia
only give milk while their calves are with them.
We might have simply contented ourselves with
objecting to the paucity of the details, which prevents
us from judging of the data from which the narrator
drew his opinion ; however, the conclusion itself
which is deduced from it by those entertaining the
notion of the transmissibility of acquired habits,
REID] ROYAL MEDICAL SOCIETY 207
supposing the facts related to be perfectly correct,
is also liable to strong objections.
To procure the continuance of the secretion of
milk in domesticated cows it is necessary the udder
be daily emptied. Every dairy-maid knows the
yielding of the milk by the cow is so far a voluntary
act, that she can suspend it at her pleasure, and
that when a cow has been long milked by one
particular person, she often refuses her milk to a
stranger. Now what is more likely to happen than
that a wild cow should refuse to yield her milk
after her calf is removed, and that the secretion of
milk should in this manner be arrested ? Besides, if
habit had been able to superinduce upon the nature
of the animal the continuance of the secretion of
milk after the removal of the calf, how does it
happen that this should be so suddenly lost in their
descendants which have run wild ?
Some, as Mr. Lyell, entertain a considerably
modified view of the opinion against which we are
contending. He believes ' that acquired habits
derived from tuition are rarely transmitted to the
offspring, and when this happens it is almost uni-
versally the case with those merely which have
some obvious connection with the attributes of the
species when in a state of independence.' I have
seen no satisfactory proof even of this modified
view. It has been a favourite opinion of some that
the cultivation of the moral feelings and intellectual
faculties in the parent must exert a genial influence
upon the congenital aptitude for moral and intel-
lectual excellence in the offspring, and that as
the tide of civilisation rolls on, it must thus be
constantly receiving fresh impulses and additions
208 DISSERTATIONS [HEREDITY
at every stage of its progress. I am afraid that this
is an opinion adopted without much previous
reflection by individuals of a vivid imagination.
For it remains to be shown that when a nation has
been long placed under circumstances highly fav-
ourable to its intellectual and moral improvement,
each successive generation is born with finer moral
feelings, and a higher order of mental qualifications,
than that which preceded it. Are we entitled to
conclude, for example, that the present generation in
this country surpass in original mental endowments
those that produced a Bacon, a Shakespeare, a
Milton, a Sir Isaac Newton, and others of their
contemporaries, men also of commanding and colossal
intellects ? And though I am not inclined to think,
with others who, taking a retrospective glance at
the labours of these giants in science and in litera-
ture, exclaim that the days in which we live ' are
the days of little men and little things/ yet I
believe that though of late astonishing progress has
been made in the arts and sciences from the
accumulated labours of their numerous cultivators,
and though a knowledge of these is more generally
diffused among the community, yet it remains to
be shown that the original mental endowments of
the present generation surpass the generations long
gone by.
If acquired habits and mental qualifications
descended to the offspring, why should the child of
a Hindoo be obliged to undergo the usual drudgery
of learning the trade or profession of his caste ?
Some have gone so far as to maintain that even
temporary states of mind, particularly of the mother,
may descend to the offspring, and they pretend to
REID] ROYAL MEDICAL SOCIETY 209
account for the extraordinary genius and military
talents of Napoleon by the circumstance that his
mother, a woman of great firmness of character,
when pregnant with him partook of the dangers of
her husband during the civil wars of Corsica.
The acquired habits and modes of life* of the
inhabitants of large towns exert a very material
influence upon the physical constitution of their
offspring, as is well exemplified in their comparatively
greater liability to various diseases than the chil-
dren of the inhabitants of the country. In fact, the
rate of mortality, and this particularly in children,
is so great in the very large towns, as to require a
constant influx of people to keep up the number of
inhabitants.
In examining the bearing of this fact upon the
question we are discussing, it is at once evident
that it cannot be considered as an evidence that
acquired habits and modes of life can be transmitted
by generation ; it only shows that the influence
which these exert upon the constitution of the
parent may affect the offspring. And in endeavour-
ing to ascertain whether this can be considered as
a change induced upon the organism after birth
affecting the offspring, it is necessary to understand
fully the nature of this deleterious influence exerted
upon the constitution of the offspring, and the
manner in which it is induced.
It is probable that the greater tendency to
certain diseases in the children in large towns
depends almost entirely on a weaker constitution of
body ; at least we can refer it to no other cause in
the present state of our knowledge on the subject,
and we know that everything which tends to
210 DISSERTATIONS [HEREDITY
increase the general strength serves to diminish
the tendency to disease. The production of this
increased susceptibility to disease (principally
scrofulous diseases) in the children of large towns
may arise from two causes : first, it may arise from
their being born with a weaker structure of body,
and, second, this debility may be either induced or
greatly increased by their breathing a less pure
atmosphere, and being frequently less perfectly
nourished and clothed than children in the country.
What may be the relative influences of these two
causes would require extensive observation to
ascertain. It is however probable that the latter
exercises a greater influence in this respect than
the former.
It is plain, then, that the only part of the facts
now under consideration which appears to favour
the opinion that acquired habits and modes of life
can influence the organisation of the foetus, is the
more frequent occurrence of an originally weaker
organism in the children of large towns than in
those of the country. And before even this can
be adduced as an argument in favour of the opinion,
it would be necessary to show that the occurrence
of a weaker constitution in the children of large
towns is more frequent than what would be ac-
counted for by various causes connected with the
modes of life in large towns, which may affect the
nutrition of the foetus in utero. To inquire how
far different modes of life influence the nutrition of
the foetus in utero would lead us into a lengthened,
and I am afraid unsatisfactory discussion, at least
as far as the present question is concerned. It
appears to me that we have not facts sufficient to
REID] ROYAL MEDICAL SOCIETY 211
enable us to come to any decisive conclusion. I
believe, however, that I am not going too far in
assuming that from the more vitiated state of society
in large towns, from the derangement of the system
produced by keeping late hours, and from the
highly artificial modes of life in which many of the
inhabitants live, it follows as a necessary conse-
quence that the perfect organisation may be inter-
fered with, and that there may be a greater pro-
portion of the children born with weaker organism
than when the parents live more regular lives.
And since this in these cases is the original
structure of the body, we can easily conceive
how it can descend to the offspring. The in-
fluence of modes of life upon the offspring cannot
in the present state of our knowledge afford any
analogical argument in favour of the opinion that
any change induced upon the individual subsequent
to birth can descend to the offspring, though it
may show that any cause acting upon the mother
which may determine the original organisation of
the foatus may descend to the offspring. This dis-
tinction must be kept fully in view, for we shall
find that they are frequently confounded with each
other.
Varieties frequently spring up when animals
are placed under artificial circumstances, yet we
cannot perceive any connection between the kind
of variety and the circumstances to which the
animal was exposed. We may also remark that
these varieties are confined within certain limits,
and never go the length of interfering with the
characters of the genus.
All the attempts made to explain the varieties
212 DISSERTATIONS [HEREDITY
of the human race by the influence of climate or
modes of life have completely failed. We can
scarcely refrain from smiling even at the acute Dr.
Smith, when we find him attempting to account for
the dark colour of the negro by supposing that the
bile becomes inspissated under the skin, as if all
the dark races (as has been well remarked) laboured
under an habitual jaundice ; for the woolly hah: of
the same people by the crisping effect of great
heat upon the animal textures ; for the elevated
shoulders, small eyes, high cheek-bones, and broad
faces of some of the Mongolian tribes which inhabit
the northern parts of Asia and Europe by the dis-
tortion of the features which is naturally assumed
while a shower of snow is driving in the face. It
is almost unnecessary to remark that we frequently
find long and lank hair in tribes which are fully
exposed' to the operation of the causes which are
assigned for the presence of the woolly hah-. In
the Mongolian tribes inhabiting the central parts
of Asia the same configuration of the face is found
as in those inhabiting the northern part, and there
undoubtedly the alleged exciting causes cannot
exist.
It has been argued that climate and modes of
life may, after the lapse of several successive
generations, effect the various changes upon the
human race which we find to exist, though we
cannot explain how they produce these. A sup-
position of the kind without some facts in its favour
appears to be entitled to very little consideration,
and more especially as there are numerous facts
and observations opposed to it.
As far back as any records reach, the variations
REID] ROYAL MEDICAL SOCIETY 213
among the human race appear to have been as well
marked as at the present day.
From an exact copy taken by Belzoni from an
ancient Egyptian tomb, the peculiarities of the
Negro and Arab are quite distinctly marked. Of
course, we cannot prove that sufficient time did
not intervene between the creation of man and the
period when these tombs were formed for allowing
these changes to be effected, but it must be ad-
mitted that this fact at least throws suspicion
upon that explanation. And these suspicions gain
strength when we are informed that frequent
instances can be adduced where individuals of
different races have been exposed to similar cir-
cumstances for many years, and where all the char-
acteristic peculiarities of each were still retained.
We would not wish to affirm that climate and
modes of life have no influence whatever upon the
production of varieties, but we think that we have
brought forward sufficient evidence to show that
varieties thus produced end in the individual, and
do not extend to the offspring. We likewise would
not peremptorily maintain that acquired habits and
physical configuration of body never descend to the
offspring, but we think that we are justified by the
facts adduced in affirming that this must be to an
exceedingly limited extent, and that the opinion
rests upon very insufficient data. And we have
not been led into the adopting of this opinion by
any excessive love of generalisation, for we are fully
convinced that this is a fertile source of much error
and much altercation. The application of these ob-
servations is sufficiently obvious to some hypotheses
of Lamarck upon the change induced in the organism
214 DISSERTATIONS [HEREDITY
of various species of animals by the influence of
habit and modes of life, and even, according to
him, by the wishes of the animal ; and also to a
hypothesis of G. St. Hilaire, by which he attempts
to show that the present animals found on the
earth's surface may be descendants of those animals
whose remains are now only found in a fossil state,
only altered in their structure by the influence of
varied external agencies.
XV
MARTIN BARRY
1802-1855
ON THE UNITY OF STKUCTUEE IN THE
ANIMAL KINGDOM
Read 1836
-4
MR. PRESIDENT,
All finite existences presuppose design.
This is a position which, happily, in the present
day we may assume.
It has been usual to regard organic structure as
manifesting design, because it shows adaptation to
the function to be performed. It has also been
suggested that function may be equally well con-
sidered as the result of structure ; and truly so it
may, yet, perhaps, we are not required to show
the claim of either to priority, but may consider
both structure and function, harmonising, as they
always do, as having been simultaneously contem-
plated in the same design.
The object of the present Essay is to offer a few
considerations on structure only ; but the subject is
so vast, and our limits are so circumscribed, that
these considerations must be of the most general
216 DISSERTATIONS [UNITY or TYPE
character. Yet some details on development will
be found indispensable.
The expression ' organic structure ' includes the
structure of what we call animals and plants. But
while both are comprehended as beings contem-
plated in the same original design, while the meta-
morphoses presented in a realisation of this design,
and the remarks that may be made on development
in general, will apply equally to both, it is intended
to restrict the further prosecution of the subject to
animals alone.
A law, not less vast in its importance than it
seems to be general in its application, may be sup-
posed to direct structure in the animal kingdom.
This law requires that a heterogeneous or special
structure shall arise only out of one more homo-
geneous or general, and this by a gradual change.
The importance of this law appears to have been
insisted on chiefly by Von Baer, who arrived at it
by long and attentive observation of development.
Let us then inquire, in the first place, what
analogy there is in the states of germs in general
at the earliest period of observation, and whether
they have in common a homogeneous or general
structure.
In animals presenting the most simple manifesta-
tions of life, ' in which every point of the creature
is, as it were, an epitome of the whole, without any
relation to or dependence on the rest, and capable
therefore, when separated from the rest, of an inde-
pendent existence,' maturity alone appears suffi-
cient to produce offspring, and simple separation
sufficient to constitute a new being. Such is the
case with many zoophytes.
BARRY] ROYAL MEDICAL SOCIETY 217
Reproduction becomes less simple as vitality
grows complex, because now ' every point of the
creature has a more close relation to, and depen-
dence on, the rest than before.' When something
like ova begin to be discernible, they consist of a
half-fluid, throughout homogeneous, more or less
granulous mass. This is the state of bodies regarded
as ova, in some infusoria, some polypes, and many
other zoophytes. Bodies of this kind have been
called 'germinal granules.' Such imperfect ova
seem to hold a middle place between 'shoots' on
the one hand, and ' germinal vesicles ' on the other.
The ovum of more elaborate structures, perhaps
of all the rest of the animal kingdom, is a sac con-
taining a sort of yolk, the germinal vesicle, and a
layer of granules.
The yolk of ova generally is very much the same
in essential character, but performing a more impor-
tant part in some animals than in others ; it differs
much in quantity.
The germinal vesicle is an exceedingly delicate,
transparent sac, measuring in diameter sometimes
less than ^th of a line, and containing a pellucid
fluid. On the internal surface of the germinal
vesicle there has lately been discovered an opacity
the germinal spot (Macula germinativa) consisting
of extremely minute granules, more or less spherical
in form. With a magnifying power of eight hundred
diameters, that is to say, magnified 640,000 times,
this spot has not yet been found to consist of other
than homogeneous parts. It has been already said
that it is contained within the germinal vesicle, the
latter measuring in diameter sometimes less than
i~th of a line.
218 DISSERTATIONS [UXITT OF TYPE
In some infusoria the contents of the germinal
vesicle are rather a mass of granules than a fluid
and a spot, perhaps corresponding parts in a less
concentrated state. Indeed, may not ' shoots/
' germinal granules/ and the contents of the
germinal vesicle, be, all of them, corresponding parts
in different states of concentration ?
The layer of granules (germinal layer) containing
perhaps in part the rudiments of the future germinal
membrane, lies immediately on the internal surface
of the primary membrane that contains the germ and
yolk. This layer is more or less circumscribed, and
often indistinct, because of its periphery coalescing
with the yolk. The germinal vesicle is found lying
in the centre of this layer of granules, on the surface
of the yolk, though there are reasons for supposing
that originally the germinal vesicle is situated in
the centre of the yolk.
We have then, firstly, ' shoots/ as in many
zoophytes ; secondly, ' germinal granules/ a half-
fluid granulous mass, as in some infusoria, some
polypes, and many other zoophytes ; thirdly, the
ova of some infusoria, in which the germinal vesicle
contains a mass of granules ; fourthly, perfect ova,
of more elaborate animals, consisting of the following
parts, viz. a. germinal spot ; 6. fluid contained
in germinal vesicle ; c. germinal vesicle ; d. layer
of granules, having the germinal vesicle in its centre ;
e. yolk ; f. primary membrane enclosing the germ
and yolk ; fifthly, superadded, in mammals and in
man, there are the Graafian vesicle and its fluid.
There are reasons for supposing that the germinal
vesicle is formed before the yolk, one of which is
afforded by its relatively greater size ; and, if so, the
BARRY] ROYAL MEDICAL SOCIETY 219
germinal vesicle, with its contents, constitutes the
primitive portion of the ovum, which in all animals
where found, appears to be essentially the same.
It has thus been shown that in all classes of
animals, from infusoria to man, germs at their origin
are essentially the same in character, and that they
have in common a homogeneous or general structure.
It appears also that essentially the manner of
the metamorphosis, or metamorphoses, from a more
homogeneous or general structure to one more
heterogeneous or special, i.e. the manner of de-
velopment, is universally the same.
Such a proposition seems deducible from what
we know of development, not only in all the verte-
brata, but also in many invertebrated animals, such
as the insecta, Crustacea, arachnida, and even mol-
lusca, and Von Baer seems to have meant the
observation to apply to animals in general when he
spoke of development proceeding by * a continued
elaboration of the animal body through growing
histological and morphological separation.' Even
zoophytes themselves, so far as their development
extends, may also be included.
The layer of granules, already spoken of as
having in its centre the germinal vesicle, appears, on
the bursting of the latter, to contribute to the forma-
tion of the germinal membrane, though the central
and most important part of the latter is perhaps
constituted by the contents of the germinal vesicle.
The germinal membrane in some of the verte-
brata is at first a more or less circumscribed disc,
covering only a part of the yolk, and afterwards
extending itself to surround and enclose the whole
of it ; in others it incloses the whole of the yolk
220 DISSERTATIONS [UNITY or TYPE
from the first. This membrane in the invertebrata
presents differences in this respect regarding which
physiologists are not quite agreed.
In most vertebrated animals the embryo is at
first nothing more than the exuberant growth of a
part of this germinal membrane near its centre, i. e.
in the situation occupied by the germinal vesicle,
before the bursting of the latter, the exuberant part,
projecting, but not being distinguishable from the
rest by a well-defined border. The projecting por-
tion becomes more and more distinct, until its
growing independence is manifested in a tendency
to withdraw itself from the remainder.
This separation of the central part of the germinal
membrane from its periphery, and from the yolk,
gives rise eventually to the appended umbilical
vesicle in man and other mammals. In birds the
corresponding part is taken into the abdomen. In
frogs the embryo occupies from the first so large a
portion of the germinal membrane, and the latter
so nearly surrounds the yolk, that the yolk becomes
contained in the embryo before the independence of
the latter has time to manifest itself by a tendency
to withdrawal.
The manner of development seems to be as
follows : The germinal membrane separates into
two disjoined layers, viz. into a mucous or vegetative
and a serous or animal layer, the . latter being in
contact with the primary membrane enclosing the
germ and yolk, the former lying immediately upon
the yolk itself. The vegetative layer is afterwards
seen to be composed of two intimately united
laminae, viz. the proper mucous and the vascular.
The animal layer also, in the embryo at least,
BARRY] ROYAL MEDICAL SOCIETY 221
divides itself into two larninse, viz. into the skin on
the one hand, and into a mass containing the fleshy
layer, as well as in vertebrated animals the osseous
and the nervous layers, on the other. This division
into layers is the primary separation. During the
course of this separation the layers become tubes,
or fundamental organs.
There occurs at the same time a separation of
tissues in the substance of the layers or tubes,
cartilaginous, nervous, and muscular substance,
separating from each other, while a part of the mass
becomes fluid. Some of the elementary parts or
tissues also assume the form of laminae, which are
subordinate to the original layers ; the latter there-
fore (now tubes) become the central portions of
systems. This separation into tissues is the liistolo-
logical separation.
Besides the above there arise differences in
outward shape, single sections of the tubes being
developed into distinct forms or organs destined to
perform particular functions, which functions are
subordinate members of the function of the whole
tube, but differ from the functions of other sections
of the latter. For example, the mucous tube
divides itself into the mouth, oesophagus, stomach,
intestine, respiratory apparatus, liver, urinary blad-
der, etc., the peculiarity in the development being
connected with either an increased or diminished
growth. This is the morphological separation.
Thus, by a threefold division, the mass becomes
heterogeneous ; and the further back we go the
more do we find, not single organs only, but
histological elements united.
' Fresh parts are acquired, not by new forma-
222 DISSERTATIONS [CUITY OF TYPE
tion, but by transformation. When, for example,
the foundation of a cartilage forms, there was not
previously a vacancy in the place it occupies, but a
homogeneous mass, the change in which consists in
the appearance of an assemblage of opaque granules,
and a surrounding pellucid fluid. This is the
manner of histological separation, calling forth, as
it were, antitheses.'
' No part is formed that was not previously in
connection with some part earlier formed ; no part
has an isolated origin, then adding itself to the
rest. Nothing swims freely around, annexing itself
here or there, as formerly was said of the whole
embryo, and even lately has been conceived and
taught of the spinal cord. Each organ is a modified
part of a more general organ.' This is the manner
of morphological separation.
It was to uniformity in the manner of the
primary, of the histological, and of the morpholo-
gical separations just described, that we referred
in the proposition that essentially the manner of
the metamorphosis, or metamorphoses, i.e. the
manner of development from a more homogeneous
or general to a more heterogeneous or special
structure, is universally the same, and we have
already mentioned researches which seem to warrant
this conclusion.
The direction taken by development is, however,
not the same precisely in any two animals, and in
different classes the direction differs very widely.
But of direction we shall treat more particularly
hereafter.
It has then been shown that there is a great
analogy in the states of germs from infusoria to
BARRY] ROYAL MEDICAL SOCIETY 223
man, and we know that there are some structural
characters common to all animals in a perfect state ;
especially to those of the same class, as, for example,
the vertebrata ; there are besides resemblances
between some of the more elaborate structures in
certain of their embryonal phases, and many less
wrought out structures in their permanent condi-
tions, which resemblances are observable, not only
between animals included in the same great class,
but also, though more remotely, between animals
belonging to different classes.
To sum up these important facts : If the struc-
ture of germs has been found in animals at ' both
ends ' of the animal kingdom, as well as in the
intermediate classes, to be essentially the same ; if
between the homogeneous masses, forming germinal
membranes, there is found no essential difference ;
if the primary separation of this membrane into
layers (the vegetative layer being always directed
towards the yolk), and the subdivisions of these
layers, incipient in the membranal, and completed
in the embryonal states, are the same in character ;
if the formation, not of tissues only, but of organs
also, proceed in the manner just described ; and,
above all, if permanent structures, among many of
the less elaborate animals, resemble most obviously
different degrees of histological and morphological
separation, as presented in the embryonal phases of
an individual destined to be more wrought out ; are
we not entitled to conclude, not only that a more
heterogeneous or special structure arises only out of
one more homogeneous or general ; but also that,
essentially, the manner of the metamorphosis, or
metamorphoses the manner of development from
224 DISSERTATIONS [UNITY OF TYPE
the latter to the former state is universally the
same ?
And are we not then led fairly to the conclu-
sion that all the varieties of structure in the animal
kingdom are but modifications of, essentially, one
and the same fundamental form ?
Now, seeing that not only the vertebrata, but
all classes of animals, in their development must
pass thus gradually from a merely animal form to
the most special forms they respectively attain ;
further, that the manner of development may be
considered as essentially the same in all, is it sur-
prising that there are resemblances between some
of the embryonal phases of very different animals ;
and that some of the stages in embryonal life of the
more elaborate structures resemble perfect states of
those that are less wrought out ? Could it, indeed,
have been otherwise ?
Let us inquire a little more particularly into
the development, firstly, of the vertebrata ; and,
secondly, of some invertebrated animals.
Vertebrata. The layers into which the germinal
membrane separates become, as already said, tubes.
These tubes are more or less bent towards the yolk,
at each extremity ; but extend the whole length of
the animal, including its head and tail. Therefore,
out of the upper tube, constituted by a union of
the laminae dorsales, are formed the arches of the
caudal, lumbar, dorsal, and cervical vertebrae, the
arched cranial bones, and the soft parts covering all
of these, together with the central portion of the
nervous system. While out of the under tube,
constituted by a union of the laminse ventrales, are
formed the ribs, the soft parts of the thorax and
BARRY] ROYAL MEDICAL SOCIETY 225
abdomen, the hyoid bone, and all that portion of
the neck, anterior (or inferior) to the vertebrae, the
lower jaw, and some other parts, both osseous and
fleshy, of the face. The bodies of the vertebrae,
and the base of the cranium, are formed out of a
portion of the animal layer of the germinal mem-
brane, common to the upper and the under tube.
The central portion of the nervous system in
different animals may, in its ultimate elaboration, pro-
duce very different structures, all grades between
the splendid cerebral hemispheres in man, and the
mere rudiments of hemispheres in fishes. The
nervous portions of the organs of sense are, in all
the vertebrata, processes of the central portion of
the nervous system, through the laminae dorsales ;
so that, though so varied in different animals, not
only all parts of the central portion of the nervous
system, but all processes from the latter, with a
common origin, and the same manner of develop-
ment, may well bear a general resemblance to each
other in the perfect states of the less, and the
embryonal states of the more, elaborate animals.
The muscles of the trunks of different animals of
the class vertebrata are but modifications of the
fleshy portions of the laminae dorsales and ventrales,
and the muscles of their extremities are only similar
metamorphoses of those portions of the latter that
are carried out with the osseous (or at first cartila-
ginous) foundation of the extremities themselves.
All the resemblances in the vascular system of
different animals are, in like manner, referable to a
common origin, and the same manner of develop-
ment, and its varieties to various modifications in
direction and degree.
P
226 DISSERTATIONS [UNITY OF TYPE
The m.ucous tube originates as processes the
mouth, oesophagus, stomach, respiratory apparatus,
liver, urinary bladder, and other organs ; in part
also, and in conjunction with the vascular tube, the
genital organs; which parts, in all their varieties,
bear a general resemblance to corresponding parts
in different animals.
In the substance of the fleshy portion of the
lamina dorsalis and ventralis of each side, there is
formed an osseous arc constituting the radical
portion of the extremities of the superior maxillae,
etc. ; and, from a point near the middle of this arc,
there issues a process corresponding to the middle
and terminal members of the latter. Now, it is
obvious that with this common origin, and the same
manner of development, corresponding parts in
different animals of the class vertebrata, whether
arms, legs, wings, fins, maxillae, etc., are likely to
retain a general resemblance, though the absence of
the middle members, or modification of the whole
extremity, etc., may render them very dissimilar in
their details.
Corresponding parts of structure may, however,
in different animals, perform very different func-
tions. Thus, besides the extremities just men-
tioned, many other examples might be given, such
as a fact pointed out by Geoffroy St. Hilaire, that
certain parts of the hyoid bone in the cat correspond
to the styloid processes of the temporal bone in
man ; and the different functions of the generative
organs in the two sexes afford a still more remark-
able example.
In development, germs, and even embryos, be-
longing to different groups of the same great class,
BARRY] ROYAL MEDICAL SOCIETY 227
may long be indistinguishable, and still longer those
that are more nearly allied. But those belonging
to different great classes begin to diverge sooner, or
rather, the angle of divergence being greater, a
difference is appreciable at an earlier period, and in
proportion to the angle of divergence in a germinal,
are the structures unlike in a perfect state. Just as
in a tree, those branches that have been given off
nearest to its root become most widely separated in
their terminating twigs.
In different classes, development, though it pro-
ceeds in the same manner, yet, taking thus different
directions, attains, with materials perhaps essentially
the same in primordial structure, very different
ends.
Thus it proceeds in the vertebrata or osteozoa
with especial reference to the central portion
of the nervous system ; in the arthrozoa (which
include, besides the articulata, some zoophytes),
havin gfor its chief object the organs of locomotion.
In both of these classes, therefore, it is the serous
or animal layer of the germinal membrane that is seen
first advancing, and out of this, in these two classes,
there is thus produced a veiy different system of
organs.
In the gastrozoa (i.e. the mollusca and most
zoophytes), on the other hand, the organs of nutri-
tion are especially the object, and in them, there-
fore, development proceeds chiefly in the mucous or
vegetative layer.
To these priorities in development, and to the
important influence they have on the direction
which development takes in other parts of the
system, are referable the leading characters of
228
DISSERTATIONS
[UNITY OF TYPE
classes. Yet it is in direction only that develop-
ment can be said to differ in different animals ; in
manner it remains the same.
Invertebrata. The following diagrams will illus-
trate different directions of development, though the
manner be the same :
IDEAL TRANSVERSE SECTIONS SHOWING THE STRUCTURES
FORMED OUT OF THE ANIMAL LAYERS.
OSTEOZOA (Vertebrata).
FIG I
FIG. 1. OSTEOZOA.
Upper tube
a, Central portion of the nervous system, situated in the upper part
of the animal layer.
Arches of the vertebrae, some of the cranial bones, etc. (part of
the internal skeleton).
c, Fleshy layer.
d, Skin.
Under tube
e, Ribs, lower jaw, etc. (part of internal skeleton) ; the other parts
of this tube as c and d of upper tube.
(/), Mucous tube
FIG. 2. ARTHROZOA.
Upper tube, incomplete, viz.
a, Situation of what there is, corresponding to the central portion of
the nervous system situated in the lower part of the animal
layer.
BARRY] ROYAL MEDICAL SOCIETY 229
b, External skeleton secreted from the skin"; , . .
forming an extremity,
c, Fleshy layer, such as it is . . . v j-ui
. . J J a mandible, etc.
d, Skin J
Under tube
e, External skeleton secreted from skin ; the other parts of this tube
as c and d of upper tube.
(/), Mucous tube.
It is obvious from the above,
First. That in the osteozoa, the central portion
of the nervous system ; in the arthrozoa, the organs
of locomotion, mandibles, etc., are the especial
objects in the early stages of development.
Second. That the central part of the animal
layer is appropriated accordingly. Thus it may
perhaps be said that parts corresponding to the
laminae dorsales of the osteozoa go to form the
extremities in the arthrozoa.
Third. That the upper tube in the arthrozoa
is imperfect, though there is evidently a tendency
to its formation.
Fourth. That, from the direction taken by
their extremities, the arthrozoa must move about
with the thorax and abdomen uppermost, the
relative position of the fundamental organs being
reversed. The internal parts, too, or organs formed
out of the mucous and vascular layers, are found to
be inverted, if compared with corresponding parts
in the osteozoa ; but there occurs such an adjust-
ment in the situation of the external parts, as, for
example, in that of the mouth and organs of sense ;
and, as what in the osteozoa is the extensor becomes
in the arthrozoa the flexor side of the body, that, so
far as these are concerned, it cannot be said that the
arthrozoa move about on their backs. Rather may
it be affirmed, with Valentin, that ' they have no
230 DISSERTATIONS [UNITY OP TYPE
true back, but only the tendency to form one.'
But their thorax and abdomen are certainly inverted.
Fifth. That the situation of what these animals
have of the central portion of the nervous system, is
a part of the Body corresponding very,nearly to that
occupied by the central portion of the nervous
system in the osteozoa, viz. it is in the former
(arthrozoa) situated in the under, in the latter
(osteozoa), in the upper part of the animal layer,
supposing each of these classes of animals to be
situated above the yolk.
Sixth. That the term ' dorsal ' vessel is calcu-
lated to mislead, the part so called obviously corre-
sponding to the aorta in other animals, and,
according to the above diagram, having a truly
thoracic and abdominal locality.
Of the development of molluscous animals we
know very little ; enough, however, to render it
quite safe for us to extend to them the laws, already
laid down, of the heterogeneous arising only out of
the homogeneous, and of identity in the manner of
histological and morphological separation, the man-
ner of development, whatever may be the direction
which the latter takes, and however limited the
degree.
Even to zoophytes the same laws may be applied,
the germinal granule of the polype, a homogeneous
shapeless mass, separating into a softer portion on the
one hand, and a more rigid, horny, or calcareous sub-
stance on the other, and assuming its proper, more
or less special form. Shoots, even those, for example,
of the hydra, at first simple swellings, then cone-
like, afterwards more or less cylindrical, and
gradually funnel-shaped, like the parent ; processes
BARRY] ROYAL MEDICAL SOCIETY 231
then appearing wart-like at the circumference of the
common cavity, and these by degrees elongating
into arms.
The whole animal kingdom, then, perhaps all
organised beings, may be considered as directed,
in development, by the above laws ; and all animals
present besides, the antithesis of an internal or
vegetative, and an external or animal portion of
the body.
It seems as if, with the original design to create
organised beings, there had arisen a scheme of more
or less complete division and subdivision, continued
down to species, and including in the latter all
individual forms.
One of the supposed grand divisions may have
included animals ; one of the first subdivisions, the
type of the vertebrata ; subordinate to which, and
co-ordinate to each other, we have the types of
fishes, reptiles, birds, and mammals. Each of these
groups presents its families, each family genera,
each genus species, and every species has its indi-
vidual forms. So would the other classes admit of
being referred to subdivisions of the supposed
scheme.
In thus speaking of classes and other divisions of
the animal kingdom, however, we by no means
acknowledge the present arrangement to be perfect.
The only sure basis for classification is not struc-
ture, as met with in the perfect state, when function
tends to embarrass, but the history of develop-
ment, at that period when structure presents itself
alone ; and, as Von Baer has justly said, this will
perhaps ' one day become the ground for nomen-
clature,' as it can be the only one on which to form
232 DISSERTATIONS [UNITY OF TYPE
a correct estimate of parts in different animal
forms.
Certain elements proceeding from the elements
of an individual, or from the elements of two indi-
viduals of the same species, constitute, by a separate
or distinct -existence, another individual a germ,
destined, like its parent or parents, to undergo,
by a succession of elements, continued changes in its
component parts, and, by degrees, to attain a state
of being represented by a form belonging to the
parent-type.
These elements, while they constituted part of
the parent or parents, shared the state of being
peculiar to the latter. It is, then, easily conceiv-
able that, having themselves acquired a separate or
distinct existence, the new being they constitute
should contain within itself properties analogous to
those of its parent or parents ; and that, therefore,
in its progress towards its destined state of being,
it should undergo similar changes ; that it should
attain the parent-type, and also more or less of
individual resemblance to its parent or parents.
The elements of every germ must have innate
susceptibilities of a certain definite arrangement,
so that on the application of stimuli there results a
certain structure. These we shall in future call
innate susceptibilities of structure, or innate plastic
properties. All innate plastic properties are, ^of
course, derived from the parent or parents. If the
germ be animal, its leading properties are those
characterising animals in general. But it has others
common respectively to the class, order, family,
genus, species, variety, and sex to which the germ
belongs. Lastly, it has properties that were pre-
BARRY] ROYAL MEDICAL SOCIETY . 233
viously characteristic of its parent or parents, in
which, indeed, all the others are included. But no
innate properties, except those merely animal, are
at first, to our senses at least, apparent in the
structure of the germ.
The sum of these innate plastic properties
determines the direction taken in development,
determines, therefore, the structure of the new
being.
The general direction taken in the development
of all the individuals of a species is the same ; but
there is a particular direction proper to the develop-
ment of each individual, and, therefore, a particular
structure not identical with any other ; for in no
two individuals is the sum of the innate plastic
properties in all respects the same.
As the elements of an individual cease in turn
to be constituent parts of the same, the identity
of that individual must be continually changing, can
exist, indeed, at no two periods of time, inasmuch
as new elements are continually entering into its
constitution, while old ones are departing.
Hence individual peculiarities in structure must,
in their turn, become hereditary, to succeeding sets
of elements, continually renewed, as we have just
asserted these elements to be. Nay, more, there
must continually present themselves fresh pecu-
liarities, and, in their turn, these also must be
inherited by sets of elements succeeding.
For the same reasons th$ first set of elements
constituting a germ, proceeding, as already said,
from the elements of a parent or parents, must
possess properties that were characteristic of the
latter at the moment when their separation took
234 DISSERTATIONS [UNITY OF TYPE
place ; and can, indeed, possess no others, since the
elements of the parents are continually changing.
Hence it is that the sum of the innate properties
can be in no two individuals the same ; hence the
particular direction of development proper to each
individual ; and hence individual peculiarities of
structure.
The innate plastic properties include, as already
said, some that are characteristic of animals
generally, and others common to all the animals
contained in that division of the animal kingdom
to which the species is subordinate. Now the pro-
perties characteristic of the parent or parents at the
time of the separation of the germ must include all
of those transmitted to the latter.
This assists us to understand why properties of
the same kind should all, in a modified form, reappear
in the development of the offspring ; and, indeed,
since it is plain that ' every step in development is
possible only through the condition preceding/ that
'becoming depends upon having become,' we see
why those properties can reappear in a certain order
only viz. in the order of their generality in the
animal kingdom.
Thus, in development, the structure character-
istic of the vertebrata only, cannot manifest itself
until there has been assumed, essentially, a struc-
ture common to animals, of which the vertebrata are
but a part, and to whose type the type of the verte-
brata is subordinate. In like manner, structures
subordinate to the type of the vertebrata cannot
manifest themselves until after a modified appear-
ance of the general type, of which they are but
partial metamorphoses. More and more special
BARRY] ROYAL MEDICAL SOCIETY 235
forms are thus in succession reached, until the one
most special is at length attained.
To the law requiring that a more fundamental
type shall uniformly manifest itself before the
appearance of one more subordinate, is perhaps re-
ferable the formation of parts that seem to answer
no other purpose than the fulfilment of this law
viz. parts that either continue rudimentary through
life, or, not being used, disappear.
An example of the first occurs in the appendix
vermiformis of the caput caecum coli in the human
subject ; of the second, in the embryonal gills of
land- and air-vertebrata, which latter, having at no
period an aquatic respiration, can never use gills.
Development proceeds to a certain point though
this point may differ in different animals in obedi-
ence to the law requiring that a more fundamental
type shall uniformly manifest itself before the
appearance of one more subordinate ; so that the
special purpose to create birds, quadrupeds, and even
man himself, is, as it were, subordinate to the more
general purpose, to create a vertebrated animal.
This explanation will perhaps apply to all parts
present in a rudimentary state alone.
It has thus been shown that a heterogeneous or
special structure arises only out of one more homo-
geneous or general, and this by a gradual change ;
that the manner of the change is probably the same
throughout the animal kingdom, however much the
direction and degree of development may differ, and
thus produce variety in structure, which, however,
there is good reason to believe, is in essential character
fundamentally the same ; that no two individuals
can have precisely the same innate susceptibilities
236 DISSERTATIONS [UNITY OF TYPE
of structure or plastic properties, and therefore, that
though all the individuals of a species may take in
their development the same general direction, there
is a particular direction in development proper to
each individual ; that structures common to a
whole class must, in a modified form, reappear in
individual development ; and lastly, that they can
reappear in a certain order only viz. in the order
of their generality in the animal kingdom.
It has been our endeavour throughout this paper
to limit the idea of fundamental unity of structure
to essential character alone, specific, and even in-
dividual, peculiarities, however inappreciable, forbid-
ding more. Each germ, even when presenting the
merely animal type, must do so in a modified and
peculiar form, on which the nature of its future
metamorphoses depends ; and if in the course of
embryonal life there occur resemblances in certain
parts of structure to corresponding parts in other
animals, they are no more than resemblances, since
individualities cannot be laid aside.
There is a danger in the present day of general-
ising too freely, of carrying transcendental specula-
tion much too far, of being so captivated by ' the
idea of a subjective unity that real variety may be
lost sight of : as bright sunbeams veil myriads of
worlds that might show to mortal man what they
are compared with his world, and how little he is in
the latter.'
XVI
WILLIAM BENJAMIN CARPENTER
1813-1885
ON THE PHYSIOLOGICAL INFEKENCES TO BE
DEDUCED FKOM THE STEUCTUKE OF THE
NEKVOUS SYSTEM IN INVEKTEBRATA.
Read 1839
ME. PRESIDENT,
I much regret that the shortness of the
time allowed me for the preparation of this Essay
should have prevented me from doing that justice
either to my subject, to the Society, or to myself,
which each might have fairly required at my hands.
I must apologise in the language of Pascal : ' I had
not leisure to be briefer.'
The department of Physiology which embraces
the phenomena of the nervous system, is one which
is universally confessed to be so difficult that it needs
all the light which can be brought to bear upon it
from any quarter for its perfect elucidation. Amongst
the sources of information which lie open to the
student, comparative anatomy is certainly among
the chief, and it is perhaps to be wondered at that
more use has not been made of the facts which it
supplies. It has been with the view of bringing
238 DISSERTATIONS [INVERTEBRATA
together the results of the investigations of various
recent labourers in this extensive field, in such a form
as to admit of comparison and generalisation, that
the present Essay has been undertaken ; and what-
ever merit this Essay may possess must be looked for
in the comprehensiveness of the survey which has
been taken, and in the probability of the inferences
drawn from the facts brought under consideration.
There can be no doubt that where a nervous
system exists, the vital actions of the being are
influenced by it ; but it would require evidence
of a different character from any that has been
yet adduced, to prove that they are dependent
upon it.
It is obvious that just ideas on this subject
should be at the very foundation of our system of
nervous physiology ; and they will even influence our
views of its anatomical character. For in the ex-
tensive group of acrita, in which are associated the
lowest of all the types of structure presented in the
higher forms of the animal kingdom, the existence
of a ' diffused nervous system ' is commonly regarded
by naturalists as the necessary alternative result-
ing from the want of any definite indications of its
presence.
If, then, we allow any sensibility, conscious-
ness, and voluntary power to the beings of this
group to deny which would be in effect to exclude
them from the animal kingdom we must regard
these faculties as associated with nervous filaments
so delicate as to elude our means of research ; and,
when the general softness of their textures, and the
laxity of structure which characterises the nervous
filaments in the lowest animals in which they can be
CARPENTER] KOYAL MEDICAL SOCIETY 239
traced are kept in view, little difficulty need be felt
in accounting for their apparent absence.
The lowest animals in which nervous filaments
can be distinctly traced are the echinodermata
among the radiated classes ; the entozoa among the
articulated series ; and the tunicata among the mol-
luscous tribes. In each of these we shall find the
type of their arrangement to be different, though
there are links of transition which unite the most
characteristic forms of each group with one another.
The Echinodermata have not been usually re-
garded as possessing any other sense than that of
touch, which seems to reside in their extensile feet,
and especially in those modifications of them which
are placed round the mouth, and serve especially as
tentacula. Ehrenberg, however, is disposed to re-
gard certain red spots at the extremity of the rays
as rudimentary organs of vision ; J and states that
the nervous trunk is continued towards each, and
swells into a sort of ganglion where it is connected
with it. This is at present very uncertain ; and the
only observed fact which would seem to confirm the
supposition is the readiness with which they seem
to perceive objects of food at a little distance from
them. But this may be ' due to some modification
of the general sensibility of the body, allowing of
the perception of impressions in some degree allied
to the sense of smell in higher animals, and re-
lated in character to the kind of sensation by
which the actiniae and other polypes are able to
appreciate the presence of light, though absolutely
deprived of visual organs.'
A nervous system has been detected in some
of the class acephalse. In the Beroe, for example,
240 DISSERTATIONS [INVERTEBRATA
a circle with diverging filaments has been traced
by Dr. Grant surrounding the oesophagus as in the
Echinodermata ; and in some of the larger Medusae
nervous filaments have been traced, and eyes are
supposed by Ehrenberg to exist at the margin of
the mantle. These forms, however, approximate
so closely to those already described, that little
more can be said respecting them.
Feeble as are the animal powers in a great pro-
portion of the molluscous tribes, they would seem
to be almost extinct among the members of the
class Tunicata or Acephala nuda.
So far as the regular vital operations are con-
cerned, we see no indication of any voluntary actions
in these animals, or even of that kind of respond-
ence to external impressions which would lead us
to suspect the existence of a connected nervous
system. But in the simultaneous contraction of the
whole muscular sac which is occasionally witnessed,
we can scarcely fail to acknowledge the operation of
nervous agency. If one of these animals be touched
when its cavity is full of water, a jet of fluid is
thrown out to some distance.
We shall find, accordingly, on examining into
the character of the nervous system, that it is most
simple in its structure and distribution, and that it
only appears to be connected with the contractile
sac. It usually consists of a single ganglion lying
between the two orifices, and sending filaments
towards each, as well as others which ramify upon
the muscular sac. Such a conformation is exhibited
in the nervous system of the Ascidia mammilla ta.
We next pass on to the Conchifera or Acephala
testacea, a class which, though somewhat higher in
CARPENTER] ROYAL MEDICAL SOCIETY 241
the scale than that just described, has a very close
affinity with it. There is a good deal of variety in
this class as to the degree of sensorial and loco-
motive power possessed by its different species ;
and we shall find the structure of the nervous
system to vary in exact proportion, from a type
little higher than that of the single ganglionic
centre of the Tunicata, to the far more complex
apparatus of the Gasteropoda.
As an illustration of the lowest form of the
nervous system among the Conchifera, that of the
oyster may be selected. In the nervous system of
the oyster we observe a slight advance upon that
of the Tunicata. The principal ganglion is situated
at the posterior muscle between the branchiae, and
hence may be called the posterior ganglion. It
obviously corresponds, both in situation and in its
relation to the respiratory organs, with the single
ganglion of the Ascidia. It sends branches to the
mantle, others to the branchia, small twigs to the
posterior muscle, and two trunks which connect it
with the labial or anterior ganglia.
In the Pecten the relative situations of the
anterior and posterior ganglia are not very dissimilar
from those which they hold in the oyster, except-
ing that the latter have partially separated so as to
form a bilobed mass, which in other instances
(Modiola) becomes completely double.
In the next class of Mollusca, the Gasteropoda,
we recognise a type of the nervous system essentially
the same as that which has just been described,
but modified to correspond with the conditions in
which the animals are formed to exist, and especially
with changes in the situation and development of
Q
242 DISSERTATIONS [INVERTEBRATA
their locomotive and sensory organs. Although
none of this class possess very active powers of
locomotion, none are entirely fixed ; all are more or
less dependent upon the exercise of these powers
for their supply of food ; and the higher tribes
employ them also for the perpetuation of the race,
since the connection of two individuals is in them
an essential part of this function.
In every division of the animal kingdom we find
the development of special sensory organs to bear
a close relation with that of the locomotive apparatus.
This is well seen in the common snail, which, ' al-
though at rest within the shelly covering that forms
its habitation, will with great quickness perceive
the proximity of scented plants which are agreeable
articles of food, and promply issue from its conceal-
ment to devour them.' It is not a little curious,
however, that although the general surface appears
exquisitely sensitive to impressions which excite
responsive movements adapted to fulfil some im-
portant office in the economy, it does not seem to
be susceptible of painful impressions in anything
like the same degree. This, which cannot but be
regarded as a beneficent provision for the happiness
of animals so helpless and so exposed to injury,
would appear from the observations of various ex-
perimenters, and especially from the testimony of
M. Ferussec, who says, ' I have seen the terrestrial
gasteropods allow their skin to be eaten by others,
and, in spite of large wounds thus produced, show
no sign of pain.'
A still greater subdivision of the nervous centres
is described by M. Van Beneden in the Linneus
glutinosus.
CARPENTER] ROYAL MEDICAL SOCIETY 243
From these complex forms, which show us the
distinctness of parts which appear simple, we may
advantageously pass on to one which exhibits the
nervous system in the most concentrated aspect
that it presents in this class, that, namely, of the
Tritonia. In this class, the sensory apparatus, the
foot, the mantle, and the branchiae are the organs
which seem to require nervous centres for the
reception of impressions and the excitation of
respondent motions. These centres are modified,
both as to situation and development, in accordance
with the situation and development of the organs
which they supply ; and it is from their connections
only that we can judge of their character.
The class of Cephalopoda is a most interesting
one in many respects, exhibiting to us the modifica-
tion of the molluscous type (which is perhaps most
characteristically presented in the Gasteropoda)
produced by their proximity to the vertebrated
division of the animal kingdom. In no organs is
this modification more evident than in the nervous
system ; for, whilst in the lowest members of the
group we find it approximating closely to the form
it presents in the higher Gasteropods, its whole
character and relations in the most elevated species
are so like those which exist in the lowest fishes,
that the analogies between their several parts may
be traced with little hesitation.
In the Nautilus we observe a transverse ganglionic
cord lying upon the oesophagus, swelling at its
extremities into the optic ganglia, and communicat-
ing with two collars which complete the ring below.
This transverse cord evidently corresponds with the
cephalic ganglia of the Gasteropods, giving off not
244 DISSERTATIONS [INVERTEBRATA
only the optic nerves, but also filaments to the
mouth and tongue (which are apparently of a sensory
character) as well as branches that connect it with
separate labial ganglia presently to be noticed,
which, as in the Patella, lie at a considerable
distance anteriorly. The anterior of the sub-oeso-
phageal collars evidently corresponds in part with
the pharyngeal ganglia of the Gasteropods, here in-
creased in size and importance on account of the
increased development of the buccal apparatus with
its powerful mandibles, firm fleshy tongue, salivary
glands, and contractile pharynx, and brought into
close approximation with the cephalic ganglion.
The greater part of the tentacula receive filaments
proceeding directly from the anterior part of this
collar ; but the internal labial processes are supplied
in a different manner. A flattened ganglionic mass
lies at their base, which is principally connected
with the pharyngeal collar, but also with the
cephalic ganglion, as already mentioned. This
labial ganglion sends twigs to the internal labial
processes, and also to the parts which are regarded
as olfactory laminae. From the posterior collar,
which evidently corresponds with the sub-ossopha-
geal ganglion of the Tritonia and other Gasteropods
in which it forms but a single mass, filaments are
distributed to the shell muscles, and four others
arise from it which extend backwards along the
vena cava. Of these, the two internal form a plexus
upon the vein, whilst the two external swell into
ganglia, from which ramifications are distributed to
the branchiae as well as to the digestive and repro-
ductive organs. This distribution resembles that
found in many of the higher Gasteropods inhabit-
CARPENTER] ROYAL MEDICAL SOCIETY 245
ing spiral shells ; and the system of nerves inay be
termed branchio-visceral. Although the anterior
sub-oesophageal ganglion has been spoken of as
corresponding to the pharyngeal of Gasteropods, it
must be regarded as uniting this with their palleal
ganglion, since the external respiratory nerves,
those, namely, which supply the muscular edges of
the mantle and the muscles of the funnel, by whose
movements the respiratory currents are produced,
proceed from it. There is nothing surprising in
this change of situation, since we have already had
to notice how constantly the position of the nervous
centres is governed by that of the organs they
supply. The central masses of the nervous system
in the Nautilus rest upon a firm cartilage, which,
however, does not inclose them, but gives attach-
ment to the powerful muscles of their neighbour-
hood. In the higher order this internal skeleton
makes great advances towards the form which is
characteristic of the Vertebrata.
We shall now take a general review of the
structure and offices of the nervous system in the
Mollusca, in order to deduce from the details which
have been brought together such general conclusions
as they may seem to warrant. It will be only by
determining the characters of the different parts of
the system in the highest of its forms, and tracing
it downwards through its progressive stages of
degradation, to the simplest indication of the mol-
luscous type (such as is presented in the Tunicata)
that we shall be able to recognise the true nature
of the latter.
The supra-oesophageal mass in the Sepia evidently
corresponds principally with the optic lobes in the
246 DISSERTATIONS [IXVERTEBRATA
brain of fishes the tubercula quadrigemina of
higher Vertebrata. The anterior portion of it, how-
ever, may perhaps be regarded as the rudiment of
the cerebral hemispheres, more especially as from
this arise in part the peduncles which connect with
the central mass the labial ganglion, whose function
seems in part to minister to the sense of smell,
especially in the Nautilus. If this should be re-
garded, therefore, as combining the characters of an
olfactive ganglion with some other (to be presently
inquired into) ; its situation will evidently resemble
that of the olfactory lobes in the brains of many
fishes, which are isolated by peduncles from the
general mass. The infra-cesophageal mass pretty
evidently represents the medulla oblongata, giving
origin, as it does, to the auditory and respiratory
nerves, as well as to those of general sense and
motion. It is only the situation of the locomotive
organs around the head that occasions the giving
off of these nerves from one spot, and that the
anterior portion of the cesophageal collar. -We
have seen in other classes how moveable the pedal
ganglion is ; and we can easily conceive that, if the
feet had been at the opposite extremity of the body,
this portion would have been removed to a distance
from the remainder of the mass, and would have
become the analogue of the spinal cord of Vertebrata,
which (so far as relates to the extremities) is a kind
of prolonged locomotive ganglion. So far, then, we
have little difficulty in recognising the characters
of these portions of the nervous system. But what
is the nature of the branchio- visceral nerves sent
off from the posterior part of the collar, and of the
venous plexus ? There can hardly be a doubt that
CARPENTER] ROYAL MEDICAL SOCIETY 247
these unite the offices of the sympathetic with those
of the respiratory portion of the par vagum; and
that they convey to the ganglionic centre those
impressions from the branchiae, the stimulus of which
is necessaiy to keep up the respiratory movements,
effected by the dilatation arid contraction of the
mantle excited by the motor nerves proceeding from
the neighbourhood. Such a union of the sympa-
thetic and par vagum appears to exist through an
interlacement of their filaments, to a greater extent
than has been hitherto supposed, even in man and
mammalia ; but it is far greater in fishes.
We may next inquire into the character of the
stomato-gastric system, consisting of the labial and
pharyngeal ganglia, with the cesophageal plexus
and cceliac ganglion. Here would seem to be con-
joined in one system, and that but little dependent
upon the cephalic mass, the nerves concerned in the
prehension, deglutition, and digestion of food. What
have we analogous to this in Vertebrata ? If we
contrast it with the highest forms of the latter, we
should be at a loss for an analogue ; but upon look-
ing at the nervous system of fishes, we perceive the
connection between the fifth pair, the glosso-pharyn-
geal, the par vagum, and the sympathetic, to be so
well marked that a natural group is at once estab-
lished, which is evidently analogous to the one
under consideration. In the higher Vertebrata these
connections still exist, being established by the
interchange of fibres, although there is less evident
inosculation. We may, then, with much probability,
regard the labial ganglia as partly analogous to the
Gasserian, and the pharyngeal to that upon the
glosso-pharyngeal nerve of Vertebrata. It will
248 DISSERTATIONS [INVERTEBRATA
scarcely be an objection to this view that to the
labial ganglion has already been assigned a partici-
pation in the function of smell ; since it is well
known that the branches of the fifth pair are
distributed to the olfactive organs, even where
their separate nerve is fully developed ; and the
advantage of associating this sense with the others
immediately concerned in the supply of the digestive
system, those, namely, of touch and taste, is obvious.
By this association the impressions made upon these
sensory organs may give rise to the respondent
motions which they are adapted to excite for the
supply of the digestive organs, without the inter-
vention of the cephalic ganglion, with which their
communication is small ; just as impressions made
upon the fifth pair and glosso-pharyngeal in Verte-
brata will excite respondent motions when the brain
has been removed.
There would seem much reason to believe that
ganglia are situated wherever sensory impressions
are thus destined to excite motions ; and this may
probably be the rationale of the curious structure
which has been described in the arms of the Sepia.
The suckers seem capable of contracting and fixing
themselves, either in obedience to the will of the
animal, communicated to them along the non-gangli-
onic cords from the central mass, or in respondence
to a stimulus excited by contact, and acting through
the afferent and efferent nerves of the ganglion. In
like manner we may explain the structure of the
pedal ganglia of Gasteropods, as demonstrated by
Leuret.
The small size of the superior cephalic mass in
these animals, relatively to that of the inferior
CARPENTER] KOYAL MEDICAL SOCIETY 249
portion, entirely coincides with what is known of
their actions, which seem to be of that purely in-
stinctive character to which a highly developed
brain is not essential, however complex and beauti-
fully adapted to their requirements they may be.
Their movements appear immediately destined to
the acquirement of food and the propagation of the
race. One action of the naked species has been
regarded as evincing intelligence which scarcely
deserves such a character. This is the ejection of
the contents of the ink-bag, which takes place when
the animal is alarmed. By this means the water
around it is coloured so deeply as to enable it to
escape from its pursuers. Is it to be supposed,
however, that the animal goes through a chain of
reasoning so complex as that required if it executes
this action with the intention assigned to it ? Is it
not rather an involuntary or instinctive action,
analogous to the expulsion of the contents of the
rectum and bladder under the influence of fear,
which takes place in higher animals, and which
many of the human species know by experience to
result from an impulse of an uncontrollable char-
acter ? This view is strengthened by the fact that
the secretion of ink is reaUy analogous to that of
urine.
As we descend towards the Tunicata, in which
no separate cephalic ganglion exists, we observe it
gradually becoming less and less predominant, at
the same time that it loses its connection with
special organs of sense. It is obvious that where
visual organs are developed, the impressions made
upon these will determine the movements of the
animal more than those of any other kind ; and it
250 DISSERTATIONS [IXVERTEBRATA
would seein to be chiefly owing to the information
which they communicate that the cephalic ganglion
has such an evident presiding influence, even where
smaller than others in the same system. This is,
however, more the case in animals whose movements
are rapid, and in which, therefore, the perception
of distant objects is peculiarly important, as in the
articulated classes. Even where eyes are absent,
and the animal still possesses locomotive powers, the
cephalic ganglia will be their principal directors,
since the most delicate organs of touch are situated
in connection with them, on the foremost part of
the body, and therefore in the direction towards
which the animal usually moves. Although, there-
fore, we find no separate cephalic ganglion in the
Tunicata, we must regard it as consolidated with
the other centres into the single ganglion which
exists between the orifices of the mantle ; since
through it are produced the movements which result
from irritation of the tentacula.
The most constant, perhaps, of all the ganglia
in the Mollusca is that which is connected with the
respiratory organs or the branchial ganglion. The
evident respiratory motions are stimulated through
a distant set of nerves ; but there is reason to believe
that some influence is also propagated along the
efferent or centrifugal portion of the par vagum,
though its nature has not been satisfactorily deter-
mined. In the Cephalopoda we find the respiratory
movements evidently excited in a similar manner,
the impressions being propagated to the sub-cesopha-
geal mass from the branchial trunks, which produce
reflex actions in the motor nerves of the mantle
and siphon.
CARPENTER] ROYAL MEDICAL SOCIETY 251
We must now direct our attention to the other
great division of the Invertebrata, the Articulated
series ; and we shall inquire how far the inferences
we have drawn from the study of the nervous
system in the Mollusca are applicable to the ex-
planation of the phenomena presented by these.
******
The nervous system of the larvae of Insects
resembles almost perfectly that of the Annelida, con-
sisting in both cases of a chain of ganglia disposed
along the ventral surface, similar to one another in
every respect, and of a cephalic ganglion more or
less developed, according to the perfection of the
sensory organs connected with it. Besides the
symmetrical nerves which come off from the cord
at its ganglionic enlargements, and which consist
(as in the former instances) of two portions derived
from its ganglionic and aganglionic columns, we find,
as in the lower classes, a series of nerves given off
at intermediate points, without any apparent swell-
ing at their points of divergence. It is not easy
to ascertain the true connections of these except in
the thoracic region, where the ganglionic columns
usually diverge laterally, especially when the meta-
morphosis is taking place into the pupa state. It is
then seen that a third column exists on the superior
or visceral side of the ganglionic tract, and that
these nerves are given off from minute ganglionic
enlargements upon it. Although they communicate
with the nerves of the symmetrical system, they
have a separate distribution, being transmitted to
the muscles of respiration, especially those which
govern the opening and closing of the stigmata.
They would thus seem analogous to the nerves of
252 DISSERTATIONS [INVERTEBRATA
the gills and mantle in the Mollusca, and may be
regarded as corresponding with the pneumonic por-
tion of the par vagum in Vertebrata, with its asso-
ciated motor nerves. It is to be recollected that the
respiratory apparatus of insects is diffused through-
out the whole system, and that its presiding system
of nerves must be proportionally extended. It is
an interesting fact that the ganglionic enlargements
on its central chain are scarcely perceptible until
after the animal has undergone its metamorphoses,
when the function of respiration is remarkably in-
creased both in amount and importance.
The number in variety of the reflex actions
which take place in insects, etc., after decapitation
is very remarkable, and they seem to have a con-
sentaneousness proportioned to the degree of con-
centration of the nervous centres in the particular
species. Where the ganglia appropriated to each
segment remain distinct, an impression made equally
upon the afferent nerves of all will produce a con-
sentaneous action.
If we regard the ganglionic portion of the cord
as sensory, and the non-ganglionic as motor, how
are we to account for this reflection of impressions,
since the two columns are distinct along the greater
part of their course ? And are we to suppose that
the parts of the body of the perfect insect in which
no ganglia are found are destitute of sensation while
they retain their motor faculties I This would seem
highly improbable, since these are the very parts
in which the least active movements take place,
whilst the ganglionic matter is carried to those
segments which give attachment to the members
whose reflex actions are so remarkable.
CARPENTER] ROYAL MEDICAL SOCIETY 253
The stomato- gastric system of insects is in
general highly developed, and its analogies to the
sympathetic and par vagum of Vertebrata become
more evident. That which may be selected as
a characteristic form is the one presented in the
Gryllotalpa vulgaris. Two distinct portions of this
system are here apparent, one on the median
line, and the other disposed laterally. The median
system appears to originate in a small ganglion
anterior to the cephalic mass, with each side of
which it communicates. The ganglia of the lateral
system are two on each side. The anterior pair
are the largest, and meet on the median line, just
behind the cephalic ganglia ; behind and externally
to these He the second pair at a distance from one
another. Two cords pass backwards on each side
one derived from the anterior, the other from the
posterior ganglion. They run along the sides of
the oesophagus and dorsal vessel, inosculating with
the respiratory system of nerves, and being finally
distributed to the digestive viscera, where they
assist in forming the ganglia already mentioned.
The connections of these two systems would seem
to indicate that the first may be regarded as
analogous to the gastric portion of the par vagum,
and the second to the sympathetic of Vertebrata.
The anterior ganglion, however, also sends filaments
to the mouth, which may be considered analogous
to the glosso-pharyngeal.
It is scarcely necessary to extend this Essay to
the consideration of the nervous system of the
Crustacea and the Arachnida, since these will not
supply us with any data which we have not already
obtained from other sources,
XVII
JOHN BROWN
1810-1882
ON THE ADAPTATION OF THE EYE
TO DISTANCES
Read 1839
ME. PRESIDENT,
The eye has the power of distinct
vision at different distances. It is said to be
adapted to this end by some change in its general
figure, or in the relative position of its parts. I
shall shortly enumerate and explain the very
various opinions as to the mechanism of this
singularly beautiful adjustment.
The opinion of Kepler was, that the contraction
of the processus ciliaris changes the form of the
eye, and by the elongation of it places the crystal-
line lens at a greater distance from the retina.
Descartes imagined that the crystalline humour
itself became altered in its curvature by the con-
traction of these ligaments, or rather by its own
muscular action, these ligaments constituting its
tendons. Delahire maintained that there was no
change in the figure of the eye, and that in order
to view objects at different distances, all that is
BROWN] DISSERTATIONS 255
necessary is an alteration in the size of the pupil.
This opinion was held by Haller, and long after
was defended by M. Le Hoi. He brought forward
in corroboration the fact that the nearest objects
may be viewed with ease and distinctness through
a small hole in a card. Moreover, employing an
artificial eye, he found that when with a large
aperture the images of near objects were confused
and ill- defined in its retina, they became very dis-
tinct by contracting the aperture. Huygens con-
ceived that the crystalline approached the cornea
by the pressure of the external muscles, or that
the lens might be made more convex by the same
action. Dr. Monro made a set of experiments to
prove the effect of the orbicularis palpebrarum. He
first opened his eyelid wide, and endeavoured to
read a book, the letters of which were so near the
eye as to be indistinct. He found he could not do
it. He then, keeping the head in the same relation
to the book, brought the edges of the eyelids within
a quarter of an inch of each other, and made an
exertion to read. He then found he could see the
letters distinctly. He concludes that in this action
of the eye the iris, the recti muscles, the two
oblique muscles, and the orbicularis palpebrarum
have all their share. Dr. Porterfield, after a very
full account of all previous opinions, asserts 'that
the change in our eyes consists in the motion of the
crystalline,' that ' the ligamentum ciliare performs
this change/ and likewise increases the convexity
of the cornea. His experiments are very numerous,
and described with great minuteness. They prove
most satisfactorily the incorrectness of Delahire's
theory, while they establish the important fact
256 DISSERTATIONS [ACCOMMODATION
that the change in the conformation of the eye
always follows a similar motion in the axes of
vision, with which it has been connected by use
and custom.
Dr. Juvin's supposition is that the uvea at its
attachment to the cornea is muscular, and that the
contraction of this ring makes the cornea more
convex. He says that the fibres of this muscle may
as well escape our observation as those of the muscle
of the interior ring. Musschenbrock conjectures
that the relaxation of the ciliary zone, which appears
to be nothing but the capsule of the vitreous
humour, where it receives the impressions of the
ciliary processes, permits the coats of the eye to
push forward the crystalline and cornea. We now
come to the inquiries of Dr. Thomas Young upon
this curious and vexed question. In them he has
exhibited his characteristic mastery of details,
simplicity of experiment, and comprehensiveness of
conclusions. I shall shortly analyse his two papers in
the Philosophical Transactions the one in 1793, the
other in 1 &0 1 . In the fi rst, after a rapid sketch of the
theories already mentioned, with his objections to
each as unsatisfactory, he takes up Descartes' notion
of the muscularity of the crystalline lens. He states
, that before examining the structure of the lens he
had been led by reasoning, and by the observation
of Dr. Porterfield that those who have lost the lens
by couching for cataract have no longer the power
of accommodating the eye to different distances,
' to conclude that the rays of light emitted by
objects at a small distance could only be brought
to foci on the retina by a nearer approach of the
crystalline to a spherical form.' Such a power, he
BROWN] ROYAL MEDICAL SOCIETY 257
imagined, could only reside in the muscularity of
part or the whole of its capsule. Accordingly, he
says, then, ' In closely examining with the naked
eye, in a strong light, the crystalline of an ox,
turned out of its capsule, I discovered a structure
which appears to remove all the difficulties with
which this branch of optics has long been obscured.
On viewing it with a magnifier this structure be-
came more evident. The crystalline lens of an ox
is an orbicular, convex, transparent body, composed
of a considerable number of similar coats closely
adherent. Each of these coats consists of six muscles
intermixed with a gelatinous substance, and attached
to six membranous tendons. Three of the tendons
are anterior, three posterior. Their length is about
two-thirds of the semi-diameter of the coat. Their
arrangement is that of three equal and equidistant
rays meeting in the axis of the crystalline, one of
the anterior is directed towards the outer angle of
the eye, and one of the posterior towards the inner
angle, so that the posterior are placed opposite to
the middle of the interstices of the anterior, and
planes passing through each of the six, and through
the axis would mark in either surface six regular
equidistant rays.' After a great deal more minute
description of the microscopic appearances, he says :
' Such an arrangement of fibres can be accounted
for on no other supposition than that of muscularity.'
When a person wishes to view an object at a small
distance, he conceives that the influence of the mind
is conveyed through the lenticular ganglion to the
orbiculus ciliaris, which may be considered as an
1 annular plexus of nerves and vessels, and thence
by the ciliary processes to the muscle of the crystal-
it
258 DISSERTATIONS [ACCOMMODATION
line, which by the contraction of its fibres becomes
more convex, and collects the diverging rays to a
focus in the retina. The disposition of fibres in each
coat is admirably adapted to produce this change,
for, since the least surface that can contain a given
bulk is that of sphere, the contraction of any surface
must bring its contents nearer to a spherical form.
He then goes on to inquire whether these fibres can
produce an alteration in the form of the lens suffi-
ciently great to account for the known effects, and
after an elaborate calculation, he declares they can.
He alludes to Descartes's supposition, but shows that
he did not apply it so much to change in the lens
itself as to the elongation of the eye's axis by the
action of the muscular lens in the sides of the eye.
Leeuwenhoek also had described the course of the
fibres of the crystalline in a variety of animals, and
has even called it crystallinum musculum alias hu-
morem crystallinum dictum, but he has not applied
this structure to the explanation of the problem
of the eye's adaptation to distances. Such is the
substance of his first paper. In the other, which
formed the Bakerian lecture for 1800, he maintains
the same doctrine, to which John Hunter had been
led by some physiological observations. His second
dissertation is much more elaborate in its experi-
ments, and more general in its subjects than the
first. After a general consideration of the sense of
vision, he enumerates a number of dioptrical pro-
positions, and gives a description of an instrument
for ascertaining the focal distance of the eye, which
he calls the optometer. He then investigates the
dimensions and refractive powers of the human eye
in its state of rest, and the form and magnitude of
BROWN] ROYAL MEDICAL SOCIETY 259
the picture which is delineated in the retina, and
concludes by inquiring what and how great are the
changes which the eye admits, and relating a
variety of experiments confirmatory of the different
suppositions. We shall confine ourselves to what
is strictly connected with the present subject. His
experiments for ascertaining if there be any change
in the length of the axis of the eyeball are very
ingenious and simple. He considers it necessary, in
order to account for the power of the eye in adapting
itself to the distance of objects, that the diameter
should be enlarged one-seventh, its transverse diame-
ter diminished one -fourteenth, and the semi-diameter
one-thirtieth of an inch. To determine this he fixed
the eye, and at the same time forced in upon its
ball the ring of a key so as to cause a phantom
accurately defined to extend within the field of
perfect vision : then looking to objects at different
distances, he expected if the figure of the eye were
altered, that the spot caused by the pressure would
be altered in shape and dimensions ; he expected
that instead of an increase of the length of the eye's
axis, the oval spot caused by the pressure of the
key resisting this elongation should have spread
over a space at least ten times as large as the most
sensible part of the retina : but no such effect took
place, the power of accommodation was as great as
ever, and the oval phantom remained unchanged in
size and shape. Again, he placed two candles so as
exactly to answer to the extent of the termination
of the optic nerve ; he marked accurately the point
to which the eye was directed ; he then made the
utmost change in its focal length, expecting that if
there were any elongation of the axis the external
260 DISSERTATIONS [ACCOMMODATION
candle would appear to recede outward upon the
visible space ; but this did not happen, the apparent
place of the obscure part remaining unchanged.
From these two experiments he inferred that in the
act of adjustment there is no change in the shape of
the body of the eye. He next investigates the
condition of the cornea. One of his experiments for
this purpose is so beautiful, that we give it in his
own words : ' I take out of a small botanical
microscope a double convex lens of eight-tenths
radius and focal distance, fixed in a socket one-fifth
of an inch in depth, securing its edges with wax. I
drop into it a little water nearly cold till it is three-
fourths full, and then apply it to my eye so that the
cornea enters half-way into the socket, and is
everywhere in contact with the water. My eye
immediately becomes presbyopic, and the refractive
power of the lens, which is reduced by the water to
a focal length of about 1 6 tenths, is not sufficient to
supply the place of the cornea rendered inefficacious
by the intervention of the water ; but the addition
of another lens restores my eye to its natural state,
and somewhat more. I then apply the optome-
ter, and I find the same inequality in the horizontal
and vertical refractions as without the water ; and I
have in both directions a power of accommodation
equivalent to a focal length of four inches as before.
At first sight, indeed, the accommodation appears to
be somewhat less, and only able to bring the eye from
the state fitted for parallel rays to a focus at five
inches distance, and this made me once imagine that
the cornea might have some slight effect in the
natural state, but considering that the artificial
cornea was about a tenth of an inch before the
BROWN] ROYAL MEDICAL SOCIETY 261
place of the natural cornea, I calculated the effect
of this difference sufficient to account for the
diminution of the range of vision.' This may be
considered a crucial experiment. Nothing can be
more simple and unavoidably conclusive. He then
' inquires into the pretensions of the crystalline
lens/ and in doing so, he first disposes of the grand
objection to the efficacy of a change in its figure,
derived from the experiments in which those who
have been couched for cataract have yet appeared
to retain the faculty of accommodation. It is need-
less to enumerate every particular experiment made
by him for settling this point, but the universal
result was contrary to his expectation that in an eye
deprived of the crystalline lens, the actual focal
distance is wholly unchangeable. Having therefore
cleared his subject, he goes fully into the develop-
ment of his opinions regarding the lens. He begins
by stating two experiments which he thinks come
very near to a mathematical demonstration of the
existence of an internal change in its figure, and
moreover explains its origin and its mode of opera-
tion. If a point be beyond the furthest focal
distance of the eye, it appears like a star, that is,
its centre is -considerably the brightest part. But
when the focal distance is shortened, matters are
reversed. The imperfect image is enlarged, its
centre is faint, and its margin brilliant ; if the
slider of the optometer is applied, the shadows of
the slits, while the eye is relaxed, are perfectly
straight, but when the accommodation takes place
they instantly become curved. The same phenomena
occur when the effect of the cornea is neutralised by
immersion in water. The only account he can give
262 DISSERTATIONS [ACCOMMODATION
of these appearances is that the central parts of the
lens acquire a greater degree of curvature than the
marginal. From his investigations he abandons the
opinion he formerly held, that the external coats of
the lens have anything to do in this change, and
enters with great keenness into the proof that
nothing but the muscularity of the substance of the
lens can suffice for this end. He then passes to the
physiological argument. The first reference to the
muscular nature of the lens, he says, was made by
Dr. Pemberton, but he seems to have obscured the
subject by intricate calculations. He argued for a
partial change of the figure 'of the lens. Albinus
favours this theory, Camper likewise, and Reil. Dr.
Young then details a series of experiments which
he made, at the suggestion of John Hunter, to
ascertain if the crystalline could be stimulated to
contraction by any artificial means. After great
care and repeated attempts, they entirely failed to
produce any sensible change by galvanism, or any
other stimulus. He confesses also his inability to
demonstrate the existence of nerves in the lens ;
and, as in the first paper, he gives a most minute
account of the arrangement of the radiating fibres.
This most elaborate memoir concludes with a re-
capitulation of the results of his investigations,
1st. He determined the refractive power of a variable
medium, and applied this to the constitution of the
crystalline ; 2nd. The optometer ; 3rd. By immerging
the eye in water he demonstrated that its adapta-
tion does not depend on any change in the cornea ;
4th. By confining the eye at the extremities of
its axis he found that no material elongation of it
took place ; 5th. He found the inability of persons
BROWN] ROYAL MEDICAL SOCIETY 263
couched to adjust their eye ; and lastly, He deduced
from the aberration of the lateral rays an argument
in favour of an internal substantial change in the
figure of the lens.
I have been so particular in my analysis of this
memoir, both on account of its containing much
that explains and refutes former theories, and like-
wise on account of its own singular worth as a philo-
sophical exercise. There is now only another theory
to be noticed, that of Sir David Brewster, as pro-
pounded by him in his Treatise on Optics, and more
fully exemplified in a paper read before the Edin-
burgh Royal Society in 1823. As it is the latest,
and, in my opinion, the best account of this interest-
ing and puzzling question, I shall briefly analyse it.
He declares that, though the most profound mathe-
maticians and the most acute anatomists have done
their best, this subject is as little understood as it
was in the time of Kepler. This we think some-
what too strong after such a memoir as Dr. Young's.
He then runs rapidly over the different theories.
Of Dr. Young he says, ' He revived the doctrine of
Descartes, and sustained it with all the ingenuity
which might have been expected from his profound
knowledge of optics and physiology,' but he thinks
that his attempt at proving the muscularity of the
lens has failed, and that, even granting that it were
muscular, he says that, from the fibres running in
lines of contrary flexure, no sagacity could predict
the actual effect of their contraction, and that those
of the outer laminae would in the act of contraction
press upon the uvea, and destroy that compound
gradation of density by which the aberration of
sphericity is so exquisitely corrected. Having ex-
264 DISSERTATIONS [ACCOMMODATION
pressed his dissatisfaction with all former theories,
he prepares a new one. He begins by stating that,
' when the eye adjusts itself to different distances,
it has long been observed that the pupil contracts
on viewing near objects, and dilates in observing
distant ones.' He then notices the false view Dela-
hire took of this fact, in combination with a fallaci-
ous experiment, and remarks that other philosophers,
seeing the general fallacy of his principle, regarded
this very singular fact of contraction and dilatation
of the pupil as merely a concomitant effect, depending
entirely upon the varying intensity of the light.
He gives as an instance of this neglect, Dr. Wells's
observation that in the pupil being dilated by bella-
donna, the eye lost its power of accommodation, and
the referring this very instructive fact away from
its natural cause to some paralysis of the deeper
parts of the eye. He then details his own experi-
ments. He first found, by making use of two
objects at different distances, but with the same
degree of illumination, that this contraction and
dilatation are produced by something else than the
varying stimulus of light. ' In order to ascertain
what took place at the two limits of the range of
distinct vision,' he says, ' I took a paper and wrote
upon it the three words, ON THE EYE. Having
placed a fold of paper behind the word THE, and two
behind the word EYE, I fixed the piece of paper at
one end of a square draw-tube, and placed my eye
at the other end, so that I could read all the words
by the transmitted light of a candle behind the
paper. The word ON was most luminous, THE less
so, EYE still less. I now brought the paper as near
my eye as possible, so that I could see the word ON
BROWN] ROYAL MEDICAL SOCIETY 265
with perfect distinctness. When this was done, no
exertion whatever could enable me to read the word
THE, and still less EYE. I then looked at them
through a small aperture, which, upon Delahire's
principle, ought to have given me distinct vision,
but it increased the indistinctness of the two last
words. By making the words THE and EYE as
luminous as ON, or by bringing another candle near
the eye, so as to increase the contraction of the
pupil, they could be read easily.' From this experi-
ment he draws the three following conclusions :
1st. That the contraction of the pupil which accom-
panies the adjustment of the eye to near objects
does not produce distinct vision by the diminution
of the aperture, but by some other action that
accompanies it. 2nd. That the eye adjusts itself to
near objects by two actions, the one voluntary, the
other involuntary, from the stimulus of light. 3rd.
That when the voluntary power fails, the adjust-
ment may still be effected by the other.
He then proceeds to inquire what takes place at
the other extremity of the range of distinct vision,
namely, in viewing distant objects, remarking that
if contraction be necessary to adjusting the eye
to near objects, dilatation ought to have the same
relation in the case of distant objects. After
giving up the experiment with belladonna, as
it may be said against it that the whole eye is
paralysed, he says, ' It occurred to me that if
the dilated condition of the pupil was essential to
remote vision, all short-sighted persons ought to
have their sphere of vision extended in the even-
ing. I accordingly found upon inquiry that this
was the case to a great degree, and that several
266 DISSERTATIONS [ACCOMMODATION
short-sighted persons could count the six stars of
the Pleiades, though unable to see objects distinctly
at a moderate distance during day. This remark-
able effect of the dilatation of the pupil may be
deduced from the converse process of observation.
If we look at distant objects while the light of the
sun is reflected on the eye, the voluntary power of
adjustment is still capable of dilating the pupil, so
as to produce distinct vision ; but the tendency of
the iris to contract under the involuntary stimulus
of light produces such a painful feeling in the eye
as to leave no doubt, even if the dilatations were
not visible, that the iris was under the influence of
two different and opposite actions.' He concludes
by affirming that the mechanism by which the eye
is adapted to distances depends on the action of the
parts which are in immediate contact with the ball
of the iris. This mechanism, he conceived, may
produce the adjustment in four ways : 1st. By
elongating the eye during the contraction of the
pupil ; 2nd. By increasing the convexity of the
cornea ; 3rd. By altering the convexity of the cap-
sule of the lens ; and 4th. By increasing the distance
of the lens from the retina. The first and second
are excluded by the observations of Dr. Young.
Sir E. Home and Mr. Ramsden say that the third
mode cannot produce the effect, because the liquor
morgagni in which the lens floats has nearly the
same refractive power as the aqueous humour ; con-
sequently he thinks it almost certain that the lens
is removed from the retina by the contraction of the
pupil.
Such are the various theories on this very curi-
ous subject. The experiments of Dr. Young dis-
BROWN] ROYAL MEDICAL SOCIETY 267
proved all previous explanations, and reduced the
agent in this mechanism to something connected
with the crystalline lens ; and Sir David Brewster
seems to have further simplified the matter by his
experiments and conclusions therefrom. One great
difficulty remains unexplained, how an eye, appar-
ently quite perfect in its structure, should be short-
sighted, and have no power of adjusting itself to
distant objects, and yet on placing before it a con-
cave glass, it not only sees distant objects at a
certain point, but at various points, and has in fact
now all the power of accommodation that the more
perfect eye has. There seems to have been too little
regard paid to the power of attention, by which the
mind wills that certain objects are to be exclusively
attended to. There is a great difference between
seeing and looking, the one being a state, the other
an act.
XVIII
JOHN GOODSIR
1814-1867
ON CONTINUED FEVER
Read 1842
MR. PRESIDENT,
An attempt to treat of continued
fever within the limits of a single paper can only
be successful when the whole of so extensive a
subject is submitted to a careful analysis. The
result ought not therefore to be fragmentary, but
ought to afford general yet precise views of the
whole question. That I have been successful in my
attempt, I cannot pretend to say. One thing at
least I may assert, that this dissertation will contain
statements and questions which will afford members
of the Society an opportunity of considering and
discussing subjects of paramount importance to the
practical physician.
Definitions are dangerous, and specific characters
have not yet been detected in disease. I shall there-
fore merely indicate the leading features of continued
fever.
Section I. An individual feels languid ; he is ill,
GOODSIR] DISSERTATIONS 269
without being able to say how he is affected, and is
slightly chilly, as if he were scantily clothed. He
sits down before a fire, with his head supported
on his hands, indifferent about everything that is
going on around him. He is not very thirsty,
although his mouth is lined with scanty viscid
saliva ; and, besides, he feels as if cold water would
increase the chill. He thinks that a little food will
relieve his uncomfortable sensations, but after a few
mouthfuls the increased tension across his forehead,
the load which rolls from side to side within his
head, and the tendency he feels to vomit, soon
convince him that he must desist.
He throws himself on the top of his bed, and
closes his eyes, but the increasing sensation of chilli-
ness at the small of his back, and the clammy
coldness of his feet, prevent him from enjoying any
relief. He now undresses, gets into bed, orders his
friends to push the clothes down into his back, and
requests that warmth may be applied to his feet.
He begins to shiver outright, and feels as if it
were brought on by contact with the cold sheets.
Time and warm applications begin to produce a
change in his feelings. He feels somewhat warmer,
but with a dread of the return of the shivering.
After a time he believes he must have been asleep,
for he has had an uncomfortable dream, and has
suddenly started into consciousness of his situation.
He is now rather hot, and the flying pains in his
limbs, which had for a day or two rendered him
uneasy, settle down in his legs and back. These
pains are so annoying that he does not know in
what position to place his limbs, and his back, he
thinks, would be relieved if the bed-clothes were
270 DISSERTATIONS [CONTINUED FEVER
pushed harder into it. At every beat of his heart he
hears, as well as feels, the rush of the blood through
his neck and head ; and the pillow under the latter is
so hot that he changes it backwards and forwards,
turns himself round upon his other side, and, at last,
orders another pillow to relieve the burning sensa-
tion of the under side of his face and head.
He is greedily engaged with a glass of cold water
when the doctor arrives ; and now, in the course of
the short examination into the nature of his case, he
is reminded that for some days previously his bowels
had been sluggish, his stool scanty and unsatisfactory.
An emetic is exhibited, and during the period
of relaxation which follows its action he is much
relieved. Instead of being dry and rough, his skin
becomes moister and more pliable. After the action
of a purgative he feels still better, and begins to
consider himself in the way of recovery.
In a short time, however, especially if it be
drawing towards evening, he relapses into his
former state ; his skin becomes dry and hot, his
temples throb, his thirst increases, and the restless-
ness is incessant. In the course of the night his
attendants observe that, although sensible when
spoken to, yet he talks incoherently when left to
himself. In the morning he is again cooler.
He thinks he has had a little restless sleep, but
is not aware that he has been talking incoherently.
He attributes the relief he experienced at break of
day to the influence of the evening medicine, and,
therefore, very willingly takes his morning dose.
The same state of matters continues for some
days. He is worse towards evening, and at night
gets no sleep, dozes, and is better towards morning.
GOODSIR] ROYAL MEDICAL SOCIETY 271
All the symptoms continue to increase steadily
in intensity.
About this period of the disease a change comes
over him. Instead of lying on each side alternately,
he rolls over on his back. The incoherency con-
tinues more or less throughout the night and day.
His countenance expresses great anxiety, and his
skin becomes very dry and harsh. Slight stupor
appears. He answers questions snappishly. His
eyes appear stiff and glazed ; his nostrils stuffed ;
his lips chapped ; his tongue dry and brown, and is
protruded slowly, stiffly, and tremulously. He
applies his finger to his nostrils to remove acrid
mucus. Bleeding from the nose may ensue in
small quantity, or so profusely as to run back into
his throat.
If the ear be applied to his breast, rattles and
chirping may be heard all over the cavity. It also
appears that he has been coughing more or less for
a day or two.
If the palm of the hand be applied to the surface
of the abdomen, it may be felt to be excessively hot,
and probably slightly tympanitic. The pulse, which
for a day or two had been rather weak at the wrist,
may be felt to be very strong and full in the abdo-
ominal aorta and femoral arteries. If the forefinger
be gently butjsteadily pressed into the abdomen, be-
tween the crest of the ilium and the navel, over the
caecum and small intestines, and if his countenance
be at the same time watched, a slight expression of
uneasiness may be observed. It may now be ascer-
tained that, instead of being confined, his bowels
had, for the last day or two, been slightly loose, and
that, too, without the use of medicine. A little
272 DISSERTATIONS [CONTINUED FEVER,
blood may pass by stool, and, by-and-by, a very
great quantity in clots, uncoagulated, or like coffee-
grounds.
A papular eruption may now appear on the chest
and arms, or red spots, like flea-bites, on various
parts of the body, or large and livid blotches here
and there on the back and limbs.
The patient may continue* in this condition for
eight or ten days longer, in a state of low delirium,
or approaching stupor. When there is purging
and tympanites the delirium assumes another type,
namely, constant irritable muttering, without
stupor ; a restless, terrified, and depressed expres-
sion of countenance. He keeps his heavy, glazed
eyes constantly bent on those around him, and
moves his tremulous hands, as if to prevent too near
an approach to him.
About this time also the lips may become livid,
and the chest dull on percussion in the posterior
region. The abdomen becomes more swollen and
tympanitic, and the diarrhoea may increase; but
more generally those symptoms are by no means
well marked. He now begins to pick his lips and
teeth, and to twitch up the bed-clothes. His wrists
and arms exhibit muscular starting, and spasms of
a tetanic nature may supervene.
From the commencement of the disease the
pulse has continued to increase in rapidity, and to
diminish in fulness and steadiness.
Death may now ensue in one of four ways : (1)
Often with the involuntary discharge of urine and
faeces, the formation of bed-sores, shrinking and col-
lapse of the whole body, hiccough, cold extremities,
increased stupor, thready iregular pulse, contracted
GOODSIR] ROYAL MEDICAL SOCIETY 273
countenance, and tracheal rattle. (2) With the addi-
tion to the last symptoms of lividity of countenance,
with laborious and oppressed respiration. (3) With
increasing weakness unaccompanied by increase of
stupor, and ultimately with fades Hippocratica
and insensibility. (4) Often heat of belly and tym-
panites, sudden distension of the abdomen, intense
pain on pressure, and coldness of inferior extremities
up to the hips. The patient does not survive this
sudden attack above two or three hours.
Section 2. What structural lesions 'are observed
in the bodies of those who have been carried off
during continued fever ?
(l) Death may take place, and no decided
morbid appearance be met with. (2) The cavity of
the head may exhibit marks of inflammation and its
consequences, as well as congestion and effusion of
serum. (3) The cavity of the chest may present in-
flammatory action in the bronchial mucous mem-
brane, and congestion of the lungs. (4) The cavity
of the abdomen and its contents may be affected ;
sometimes as simple gastro-enteritis, but generally
as a congested and inflammatory condition of the
vesicular glands of the ileum, with a deposition into
these glands of a peculiar matter, which is generally
thrown off by a process which resembles sloughing.
This change in the vesicular glands is apt to ter-
minate in ulceration, perforation, and peritonitis.
It may, I think, with safety be assumed that
.when the function of an organised -body is deranged
its structure or molecular arrangement is so also, even
when the eye can detect no change in the physical
character of the part affected. Such minute changes
s
274 DISSERTATIONS [CONTINUED FEVER
are daily becoming better known to morbid ana-
tomists, in consequence of the improved modes of
research now in use ; and ultimately, without doubt,
every deranged function will be referred to its cor-
responding alteration of structure. We may there-
fore at present, when considering the pathology of
continued fever, group lesions of structure in two
divisions: (1) Lesions appreciable to the senses,
and capable of being connected with known symp-
toms ; and (2) lesions not yet recognised by the
senses, unaided, or with instrumental assistance,
but producing nevertheless numerous and varied
symptoms.
We have seen that death may ensue in a case of
continued fever, and that no decided morbid appear-
ances may present themselves. General febrile
symptoms, and even symptoms referable to the head,
chest, and belly, may be met with, and yet no
appreciable lesion of structure can be detected.
It has been stated that the blood is altered, and
I have no doubt that it is ; but so little is known
on this subject, and that little is doubtful, that I
shall not consider it as of any value at present.
Continued fever, then, may run its fetal course,
while the structural lesions which undoubtedly
occur altogether escape our notice. It is a disease
which, for the present, we may consider merely
functional that is, depending upon molecular struc-
tural lesions. The hypothesis of Rokitansky is
as yet unsupported by facts, and depends for its
very existence on the ingenuity with which it is
framed, and the explanation it affords of some of
the phenomena of the disease.
Must we then consider the congestions and in-
GOODSIR] ROYAL MEDICAL SOCIETY 275
flammations of the head, chest, and belly which so
commonly occur during continued fevers as mere
secondary affections, as not necessary to the consti-
tion of the fever 1 We are not in possession of data
sufficient to answer this question. It is sufficient
for our purpose at present to know that continued
fever may run its course without local structural
lesion, but that such lesions do occur in a great
majority of cases.
Section 3. From these views of the structural
lesions in continued fever, it is evident that the
symptoms group themselves into two great divi-
sions : those of the fever itself, and those of the local
affections which may occur during its course.
Again, the symptoms arising from the local affec-
tion group themselves into two divisions : those
strictly local, and those arising from sympathetic
action of other organs. Hence the great difficulty
of analysing and grouping the symptoms in many
cases of fever, and the great importance of being
able to do so. In proceeding therefore to analyse
and to group the signs and symptoms in any given
case of continued fever, we must ever bear in mind
the following pathological laws : (l) Local affec-
tions may be characterised by symptoms strictly
local, but may also present symptoms apparently re-
ferable to other organs, and therefore denominated
sympathetic symptoms. (2) The more urgent the
sympathetic symptoms are, the more subdued are
the local symptoms, and the more latent the affec-
tion itself. (3) If a local affection co-exist with a
general affection of the whole system, the local affec-
tion has a tendency to become latent.
276 DISSERTATIONS [CONTINUED FEVER
Thus inflammation of the intestinal mucous
membrane not only presents symptoms strictly
local, such as tympanites, pain on pressure, local
arterial action, etc., but also sympathetic symptoms,
such as intense headache, delirium, etc., from sym-
pathy in the brain ; cough and hurried respiration
from sympathy in the lungs. Again, the more
violent the headache and chest symptoms, the less is
the pain on pressure of the abdomen. The insidious
nature of the local suppurations in phlebitis is a
good illustration of the third law.
All these reactions, and others of minor import-
ance, concur to render the grouping of the symp-
toms in continued fever very difficult, but at the
same time absolutely necessary for successful treat-
ment. Thus headache in a case of fever may arise
from three causes : (1) The general febrile state ;
(2) an inflammatory condition of the cranial con-
tents ; or (3) from sympathy with an abdominal
lesion.
We must ascertain from which one, or from what
combination of these, the headache arises, before we
can proceed to prescribe for it with becoming deci-
sion and certainty. The same kind of analysis must
be undertaken for most of the important fever
symptoms before they can be satisfactorily treated,
and will tend to dispel much of the mystery in which
the pathology of continued fever is involved.
Section 4. If we were certain that any parti-
cular case of fever was not complicated by local
lesions, the treatment would be sufficiently simple.
It would resolve itself into the use of general
bleeding, emetics, and purgatives during the first or
GOODSIR] ROYAL MEDICAL SOCIETY 277
active stage of the complaint, and the use of stimu-
lants and other measures for supporting the powers
of life during the latter stages. This is the treat-
ment suggested by common sense (a faculty of more
use to the practical physician than all the science
of Newton), and approved of by the experience of
every age. In treating cases of simple uncompli-
cated fever, it must ever be recollected that it has
a tendency to terminate by what has been denomi-
nated crisis at certain periods, generally at the
commencement of the hot stage, or on the seventh,
fourteenth, or twenty-first days.
Bearing this in mind, we may make the attempt
to cut the fever short at the commencement of the
hot stage by an emetic, a purge, or abstraction of
blood, keeping however two things in view, first,
whether the patient's constitution is such as to
bear this treatment, and, secondly, whether the fever
is of a kind which will reduce him so much at last
as to render it necessary to husband his strength
for the trial. A proper decision on these points
requires on the part of the physician, that experience,
tact, and long-headedness, without which no power
of diagnosis will avail.
If not cut short at first, the case must go on
till another period of crisis arrives, the practitioner
using every endeavour to keep it uncomplicated so
as to admit of its progress to spontaneous cure.
He must not suppose, however, because there
may be violent headache, that there must therefore
be inflammatory action in the head. It may be
merely the head symptoms of the febrile condition,
and is to be relieved, and that only to a certain
extent, by leeching, cold applications, and general
278 DISSERTATIONS [CONTINUED FEVER
treatment. The red suffused eye and throbbing
temple must not lead him astray. They are symp-
toms which may merely depend on want of sleep,
and a full dose of opium will afford perfect relief.
Again, the hurried breathing may not arise from
chest affection. His ear will satisfy him of this.
It may be a general fever symptom, and is to be
relieved by general management of the case.
Lastly, the tongue may be in every known con-
dition, and yet there may be no abdominal affection.
Tenderness, flatulence, and distension are not surer
tests. They may all be general febrile symptoms,
and may be relieved by the cautious use of a mild
purgative.
When at last the patient begins to sink from
continuance of the disease, the practitioner must
not be afraid to give opium, wine, or ardent spirits
to any extent the case may require. The same
tempered boldness which led him in the midst of
doubt to bleed and purge freely at first, now induces
him to prescribe stimulants to an extent no one
around him would be inclined to do. He never
forgets that most important therapeutical law, that
the same case may require directly opposite modes
of treatment.
When it appears certain that a case of continued
fever is complicated by local lesion, the following
facts must be borne in mind in proceeding to treat
it : (1) Although the local lesion be removed, the
fever does not necessarily cease. (2) The persistence
of the local lesion may be the cause of the protracted
continuance of the fever. (3) Local lesions may be
marked by two circumstances : first, the general
febrile symptoms, and, secondly, by the sympathetic
GOODSIR] ROYAL MEDICAL SOCIETY 279
symptoms of the local lesion itself. (4) Local lesions
may be treated antiphlogistically, while powerful
stimulant treatment is being applied for the general
fever. (5) The local lesion, although inflammatory,
may require local stimulant treatment, in accordance
with the general therapeutical law already stated.
Such are a few of the numerous considerations
which must be borne in mind in treating a case
of complicated continued fever. The management
of such a case requires on the part of the physician
a rare combination of talent : great boldness, great
caution, perfect facility in taking two views of every
circumstance, and last, although not least, great
common sense.
The important subject of Prognosis in fever I
can only hint at. Time will not admit that I should
do more than merely allude to the unfavourable
nature of hysterical and tetanic symptoms, and to
the tedious nature of those cases in which sweating
occurs.
Neither can I enter upon that most difficult
question the origin and mode of propagation of
fever. I may state, however, my conviction that in
time this country will be mapped out, so that the
type of fever, be it cephalic or abdominal, prevail-
ing in, or rather peculiar to, each district and
town, will be ascertained by inspection of the map.
Lastly, I believe that the type of fever prevailing
in any district or number of districts varies ac-
cording to circumstances, social, meteorological,
and geological, with the laws of which we are
not yet acquainted.
XIX
CHARLES MURCHISON
1830-1879
ON THE EED CORPUSCLES OF THE BLOOD
Read 1849
MR. PRESIDENT,
The importance in the animal economy of
the blood must be self-evident to all. The celebrated
John Hunter has justly remarked, ' Every part of
the body is formed from the blood we grow out of it.'
And we have higher testimony than even Hunter's
to bear upon this, for in the Holy Scriptures we
find it written, ' The Blood is the Life of the Flesh/
And not only does the blood prepare and supply
the various and numerous materials necessary for
the nutriment and growth of the bodily frame, but
it also receives and carries off these same materials,
after they have performed their peculiar functions
in the building up and subsequent disintegration
of the animal tissues, by which processes the life of
the whole body is preserved. It is therefore a
mixed fluid, or in other words is composed of two
fluids, one proceeding to the nourishment of the
tissues, the other coming from that work, and about
to be cast off from the body, or undergo certain
MURCHISON] DISSERTATIONS 281
changes whereby it is again fitted for nourishing
the tissues. These various processes would seem to
be all affected by the agency of cell growth, and
hence we naturally conclude that the red corpuscles
(as well as the white) which are suspended in the
liquor sanguinis constitute a very important, if not
the most important, portion of the blood. What their
more peculiar functions probably are we shall after-
wards consider, but in the first place, as in every
other physiological investigation, before consider-
ing function itself, we must have a correct know-
ledge of structure, of structure not only in a state
of health, but also of structure as modified by
disease. For this reason I think I may with pro-
priety divide the present subject into the three
following heads, viz. : The histology, pathology,
and physiology of the red corpuscles of the blood.
And first their
I. HISTOLOGY.
Here we shall consider :
1. The general appearance, etc., of the red cor-
puscles as seen in man.
I need hardly mention that the red corpuscles
of the human blood are invisible to the naked eye,
and require the assistance of a powerful microscope
to determine their structure in a satisfactory manner.
When examined under the microscope the human
blood corpuscle is found to be a circular disc, the
diameter of which varies from ^ to -j^ of an English
inch. Their thickness is about or J of their trans-
verse diameter. The corpuscles have not always
the same size even in the same individual. This
has been observed to be the case even in man, and
282 DISSERTATIONS [BLOOD
still more so in some of the lower animals. The
corpuscles have the same form and volume in
arterial as in venous blood. Though each blood
disc is compressed from side to side, its surfaces are
not flat, but considerably depressed towards the
centre, as will be understood by looking at an
imaginary section through the centre of one of the
discs. Each disc is therefore much thinner at the
centre than towards the circumference, and it is this
central thinness which gives rise to the appearance
of a spot, dark or light according to circumstances,
in the centre of the red particle. When the cor-
puscles are examined under a brilliant light this
central spot has often the appearance of being pro-
duced by a nucleus. A nucleus, however, is never
present, and I shall afterwards endeavour to show
that the corpuscles are themselves the nuclei of
cells which have disappeared, differing considerably
from the blood discs of reptiles, etc. As Dr.
Carpenter remarks, the dark spot which is seen in
the centre of the blood discs of mammalia is ' merely
an effect of refraction in consequence of the double
concave form of the disc.' The colour of the blood
discs is generally said to be red. Other observers,
however, as Professor Bennett, maintain that they
are yellow, and that the red colour of the blood is
produced by the immense number of these minute
yellow bodies existing together, in the same way as
a bottle of saffron powder appears red, though the
individual grains are yellow. Certain it is, that the
blood corpuscles, viewed under a microscope by trans-
mitted light do appear to present a yellow colour,
but such observers as maintain that they are yellow
and not red would seem to jump too readily at con-
clusions, not reflecting that the phenomenon admits
MTJRCHISONJ ROYAL MEDICAL SOCIETY 283
of a far more easy and plausible explanation. Many
substances, we know, vary in their colour according
as they are viewed as opaque objects, or by trans-
mitted light. Take, for instance, the chromate of
silver. The crystals of this salt are dark green ;
but when viewed by transmitted light they
appear red, and such would also seem to be the
case with the blood discs. No one would dream
of saying that the crystals of chromate of silver
are red and not green ; and with as little reason
do we think, are the blood corpuscles said to
be yellow and not red. Chemical analysis shows
that the red colour of the blood corpuscles is partly
owing to the presence of iron, though its exact state
of combination has not yet been determined. Some
maintain that the colour of the blood remains even
after the removal of its iron. Berzelius believes
that iron in the colouring matter is in the metallic
state ' organically combined ' with nitrogen, carbon,
hydrogen, and oxygen, together with a small
quantity of phosphorus, calcium, and magnesium ;
Liebig again says that the iron exists in the state
of carbonate of protoxide in venous, and as hydrated
peroxide in arterial, blood. The corpuscles of the
blood are somewhat elastic ; thus they will often
regain their natural form after this has been altered
by pressure.
I now proceed to the consideration of :
2. The differences exhibited by the blood cor-
puscles of the lower animals.
The red corpuscles of all mammalia agree with
those of man in having no nucleus. They are also
all of a circular form, except those of the camelidse,
which are oval, but these also have no nucleus. In
mammals there is no connection between the size of
284 DISSERTATIONS [BLOOD
the corpuscles and that of the animals themselves in
the different orders, but in the same order there is
a correspondence. Thus the corpuscles of the larger
ruminantia and rodentia are larger than those of the
smaller species. The corpuscles of the elephant are
the largest among mammalia. Those of the napu
musk deer are the smallest.
Descending to birds, we find that in them, and
indeed in all the lower vertebrata, the blood discs
differ remarkably from those of mammalia, and that
in two respects : (1) In their form, which is seldom
spherical, but generally oval ; (2) In their being
all possessed of a central nucleus which produces a
central elevation in place of depression in each of
them. In birds the long diameter of the corpuscle
is rather more than double the short diameter. In
a few cases the long diameter is three or four times
that of the short. Those of the cassowary are the
largest, and those of the humming-bird the smallest.
The nucleus of the corpuscle is generally of a longer
oval than the corpuscle itself. In reptiles the blood
corpuscles are also of an oval form. The nucleus
too is often very large and prominent. In the
naked amphibia the corpuscles are generally larger
than in any other animals, especially in those with
permanent gills, as the siren. In osseous fishes the
corpuscles have a rounded oval form, and the nuclei
are nearly round. In the pike, however, the
corpuscles are pointed at the ends. In the cyclos-
tomatous fishes the corpuscles are of the same shape
as in. man, but slightly larger. In the amphioxus,
which forms a transition to the invertebrate animals,
the blood is colourless, and the corpuscles like those
of lymph.
Bodies analogous to red corpuscles are also
MTJRCHISON] ROYAL MEDICAL SOCIETY 285
found in the blood of invertebrate animals. In the
mollusca they are generally of a pale colour, and their
form is by no means regular. Among the articulata
they vary remarkably in colour as well as in size.
In terrestrial species they are generally of a greenish
colour, as in caterpillars, whereas in the lobster and
shrimp, which live in water, they are white. Cor-
puscles also exist in the blood of the radiata. The
blood of the starfish Professor Goodsir has observed
to contain organised particles of a reddish colour, as
also that of the echinodermata. They may also be
seen in the medusae.
In many zoophytes, as in the genera tubularia
and sertularia, the fluid, which is seen to circulate
through their stem, is loaded with minute granules
of nearly equal volume and shape, and endowed with
a proper mobility. ' These particles/ writes Mr.
Lister, ' present an analogy to those of the blood in
the higher animals on the one side, and of the sap
of vegetables on the other. Some of them appear
to be derived from the digested food, and others
from the melting down of parts absorbed.' The way
in which they are produced, however, has not yet
been ascertained.
Particles exactly similar may be seen in infusoria.
Thus the proteus, the simplest of all infusoria, if
submitted to a very high magnifying power, is
found to contain an immense number of such
particles, many of which, no doubt, are analogous to
and perform the functions of the blood corpuscles in
the higher animals.
We have thus seen that there exist in the blood
of animals three different sorts of corpuscles, viz. :
(1) The non-nucleated corpuscle of man and mam-
malia ; (2) The nucleated corpuscle of birds, reptiles,
286 DISSERTATIONS [BLOOD
and fishes ; (3) The irregular granules of inverte-
brata, which also, along with the other forms, exist
in the blood of vertebrata.
In the blood of man and mammalia we have the
fully formed red corpuscle, which is always devoid
of a nucleus, and which is very different from the
corpuscle met with in birds, and other vertebrata.
These latter all possess a nucleus, and would seem
never to have reached such a high degree of de-
velopment as those of man and mammalia, but to
be referable to some earlier stage. The corpuscle
of a mammal may be thus theoretically regarded as
analogous to the liberated nucleus of the corpuscle
of a frog. And here I may mention a very interest-
ing fact in connection with, and in support of this
theory, which is, that in the very young embryo,
even of mammalia (before the development of the
liver) all the blood corpuscles possess a distinct
nucleus, and are larger than those of the adult.
They thus resemble the corpuscles of the lower
vertebrata. ' These, however,' to use the words of a
modern writer, ' disappear in the later stages of
intra-uterine life.' The mode of their disappearance
is not mentioned, neither, indeed, has it been
observed. But if we might be allowed to hazard an
explanation, it would be this, that it is not the
nucleus which disappears, but the external cell
wall which bursts and dissolves away, while the
permanent nucleus constitutes the perfect blood
corpuscle of the adult mammal. This also would
explain why the corpuscles are larger in the foetal
than the adult state. The granules found in the
blood of in vertebrata probably belong to a grade of
development lower than either of the former. What
MURCHISON] ROYAL MEDICAL SOCIETY 287
still further strengthens the view we have taken of
the different degrees of development of these bodies
is the fact that we find in the blood of mammalia
representatives of all the three stages, viz. :
(1) Irregular granules ; (2) Nucleated cells, or the
white corpuscles, and (3) The ordinary red corpuscles,
or the liberated nuclei, so to speak. From this it
will at once be evident to you all that we regard
the nucleated white corpuscle of the human blood
as analogous to the red corpuscle of birds, reptiles,
and fishes, a statement which, though at first sight
it may appear somewhat startling, will, I have no
doubt, after deliberate reflection, be unanimously
responded to. And now comes a question which, I
dare say, has already suggested itself to the minds
of most of you : What relation does the white
corpuscle bear to the red in the blood of man and
mammalia ? Is the former the parent from which
the latter is developed, or is it not ? But the
answer to this question naturally leads us to the
consideration of the third subject to be treated of
under the present section of this Essay, viz. :
3 . The development of the blood corpuscles :
Under this head we shall notice (a) Their
development in the embryo, or the process by which
they first of all make their appearance, and (6) their
development in the adult, or the process by which
new corpuscles are formed to make up for the loss
which the blood is constantly sustaining of these
bodies by their dissolution and excretion.
(a) Their development in the embryo. The red
corpuscles may be said to be developed in the
embryo in two distinct localities, though both of
these originally spring from the same foetal struc-
288 DISSERTATIONS [BLOOD
ture, viz., the vascular or middle layer of the
germinal membrane. In the larger vessels the
blood corpuscles are formed from the inner layers of
a mass of cells of the vascular membrane, the outer
layers of which go to form the walls of the vessels
themselves. In the case of the capillaries, again, the
blood corpuscles are formed from other cells of the
same vascular membrane. These cells send out
radiating processes, the processes of contiguous cells
unite and form continuous tubes, and the original
contents of the cells become transformed into blood
corpuscles. The embryo corpuscles are at first
large, powerless, and spherical, and full of laminar
particles, which are of a fatty nature. After a time
their contained laminar particles become broken up
and liquefy, and the whole body assumes a red
colour. A nucleus, too, now becomes apparent
which had before been obscured. These changes
have been traced by Vogt, Kolliker, Cramner, and
Paget. The nucleated corpuscle thus formed exists
in the embryonic blood of mammalia, as well as of
other vertebrata. In birds, reptiles, and fishes this
also constitutes the permanent form in the adult,
whereas in mammalia it is probable, as has been
already stated, that the external cell wall dissolves,
and the liberated nucleus constitutes the mature
blood corpuscles. In addition to their original de-
velopment Kolliker, Falconer, and Kirkes maintain
that they have observed the corpuscles of mam-
- malian embryos multiply by a process of bipartition
of the nucleus, each half of which either by appro-
priating half the cell, or by developing u new cell
around itself, becomes a corpuscle exactly similar to
the parent.
MUBOHISOX] ROYAL MEDICAL SOCIETY 289
(b) As regards the formation of new red corpus-
cles in the adult, few observations have as yet been
made. The celebrated Leeuwenhoeck remarked that
certain of the red corpuscles might occasionally be
seen dividing themselves into six, which, at first very
small, gradually increase to the size of their parents.
Dr. Martin Barry holds a somewhat similar view.
He regards the multiplication of the red corpuscles
as due to the development of six young cells, which
sprout from the circumference of the nucleus, being
at first confined within the cell wall of their parent,
but afterwards rupturing this, and becoming free.
Again, Dr. G. O. Rees remarks that he has observed
a constriction gradually forming at the centre of
certain of the corpuscles ; and that by the gradual
increase of this the single corpuscle became ulti-
mately divided into two. If this observation of the
fissiparous multiplication of the red corpuscle in
mammalia be correct, it affords another proof that
the corpuscles are nuclei and not cells ; for fissipar-
ous division has never elsewhere been observed in
animal cells. Viewing them, as nuclei, this would
be just an example of exogenous cell development.
Dr. Copland considers the red corpuscles of the
blood as formed from the white. The latter, he
says, become in the process of sanguification sur-
rounded by a coloured envelope, and .thus constitute
the red corpuscles. This was the view held by
Hewson nearly a century ago, who also thought that
the spleen was the particular locality of the circula-
tion where this coloured envelope was manufac-
tured. This, however, is a mere theory, one not
based upon observation, and easily refuted. The
white corpuscles, we should recollect, are globular,
T
290 DISSERTATIONS [BLOOD
the red are flat. Now if the white corpuscles became
flattened out, and in addition to this surrounded by
a coloured envelope, they would be immensely larger
than we find the red corpuscles to be, seeing that
they surpass them in magnitude even in their
natural globular state. Kirkes and Miiller likewise
maintain that the red corpuscles are all formed from
the lymph and chyle corpuscles by a process of meta-
morphosis. Professor Weber even maintains that
in the frog he had observed many of the red globules
lose their red colour and become in fact reconverted
into white globules while passing through the
capillaries. His observations, however, have not been
confirmed, and are by no means probable. If they
were correct, then venous blood would contain far
more white corpuscles than arterial, and would con-
sequently be of a lighter colour, neither of which
conditions, we learn from ocular inspection, hold
good. Though the view of Miiller and Kirkes may
explain the development of the red corpuscles in the
case of birds, reptiles, and fishes, it is not equally
applicable in the case of mammalia. The red
globules of these last, as has been already stated,
are devoid of nuclei, and correspond to the nuclei
of the red corpuscles of the frog, etc. But in the blood
of mammalia we find white nucleated corpuscles, as
well as in the blood of the frog ; and arguing
analogically from the facts that the red corpuscle
of the frog is a mere modification of the white, as
shown by. Miiller, and that the red corpuscle of
the mammal corresponds to the nucleus of the red
corpuscle in the frog, we are naturally led to infer
that the white corpuscle in the mammal is the parent
of the red in other words, the latter is the liberated
MDRCHISON] ROYAL MEDICAL SOCIETY 291
nucleus of the former. The actual liberation of the
nucleus, it is true, has not yet been observed, but
we have often been able to trace the nucleus of
the white corpuscle in man, presenting all forms of
gradation from one or two almost invisible molecules
adhering together, to that of a fully formed red
corpuscle. Enough, however, has for the present
been said with regard to the development of the
red corpuscle, as I have some intention of making it
the subject of a communication to the Society at
some future period. We now proceed to consider
4. The termination of the existence of the red
corpuscles. The exact period of the duration of
the life of a red corpuscle is not known ; but this
we know, that after it has performed the functions
assigned to it in the animal economy, it dis-
appears, and its place is supplied by others. ' When
a corpuscle/ says Kirkes, ' is past its perfection it
degenerates, and probably liquefies. It never forms
the germs of new corpuscles.' He describes the de-
generated corpuscles of fishes and reptiles as white,
pellucid, and often cracked, quite distinct from the
white corpuscles. From this we infer that the
haematine or colouring matter is dissolved out before
the corpuscle actually liquefies. If we examine
blood in the act of decomposing, we find that the
walls of the globules, losing their texture, permit
the outward escape of their contents, and both the
haematine and globuline are dissolved in the serum,
which thus becomes of a reddish colour. Vogel re-
marks that it is highly probable that the solution of
the red corpuscles after death is due to the genera-
tion of carbonate of ammonia in the blood. Such,
it is true, may be the case after death, but during*
292 DISSERTATIONS [BLOOD
life there is no necessity for having recourse to
such an explanation of the liquefaction of the red
corpuscles which, obeying the laws which regulate
cell growth in general, break up and dissolve into
the surrounding fluid when they have reached the
termination of their existence. Ecker maintains
that the spleen is the organ in which the blood
globules undergo their final metamorphosis. In this
organ, he says, they are broken up into granular
masses, which are carried by the vena cava to the
liver, and thence expelled from the system. Kol-
liker holds a somewhat similar view. The true
function of the spleen has not yet been made out ;
but that it is the organ in which exclusively the
red corpuscles undergo their last metamorphosis is
extremely doubtful. It is far more probable that
the corpuscles become dissolved generally throughout
the vascular system.
II. PATHOLOGY.
Observations are still wanting before we can
have a correct idea of the relation which subsists
between the red corpuscles and the various diseased
states of the body. At present we have but a few
scattered observations with regard to the changes
exhibited by the corpuscles in a few diseases, and
with the brief enumeration of these we fear we must
for the present content ourselves ; and, first, as to
1. The morbid changes in their number. The
red corpuscles may be increased or diminished in
.number in proportion to the other constituents of
the blood. It should be remembered, however, that
even in health they vary in number according to
age, sex, temperament, etc. Thus they are more
MURCHISON] ROYAL MEDICAL SOCIETY 293
abundant in the foetus than in the adult, in man
than in woman, in sanguineous than in lymphatic
temperaments. The red corpuscles are increased in
number in plethora, and also in most febrile condi-
tions of the body. In diabetes, dropsy, chlorosis,
and the true inflammations, on the other hand,
they are diminished. Venesection is said to diminish
the number of the red corpuscles, while it increases
that of the white. Now you will observe that
this is quite in keeping with the theory we have
already laid down, that the red corpuscles are
developed from the white. If the blood be deprived
of a number of red corpuscles their place must be
first supplied by white corpuscles, seeing that the
latter are antecedent to the red in development :
and it will take some time before the nuclei of
the white corpuscles are sufficiently matured to be
liberated and constitute the perfect red corpuscles.
2. The form of the blood-corpuscles may be
altered. In purpura the corpuscles lose their normal
shape and size, and become mixed up with
granular matter. In a case of typhus fever Dr.
Bennett found corpuscles presenting an irregular
outline and a granular aspect. In haematocele
corpuscles are often seen containing four or more
granules, and ultimately breaking down. The
blood-corpuscles which are developed in pathological
epigeneses, such as tumours, have been observed to
present certain peculiarities which are worthy of
notice. They are of various sizes, have a rounded
form, and have not the central depression observable
in ordinary corpuscles. They have usually a clearly
defined outline, and their diameter is generally some-
what less than in the normal state. Newly formed
294 DISSERTATIONS [BLOOD
corpuscles in a pathological structure are never, like
those of the embryo, larger than the normal ones.
They dissolve in water and acetic acid, without
yielding any indication of nuclei.
3. As regards the colour of the blood-corpuscles,
Haller and Dame' say that it is paler in chlorosis,
darker in jaundice. These are statements, however,
which I have never been able to confirm ; and I
think it more probable that the pale colour of the
blood in chlorosis is due to a diminution of the num-
ber of the corpuscles ; while its dark colour in
jaundice is to be attributed to the solution of bile
pigment in the liquor sanguinis.
4. An' increased attraction for one another is
exhibited by the corpuscles in inflammation, and
certain other conditions of the body, such as preg-
nancy. The corpuscles adhere to one another by
their flat surfaces, forming strings which reticulate.
It is this which causes the buffy coat of inflammatory
blood, or, at all events, assists in its formation. The
only conclusions to be drawn from these observations
must be of a very general nature, viz., that in those
conditions of the body in which the functions of
nutrition are increased, we generally find a great
number of blood-globules, while the opposite is the
case when the functions of nutrition are carried on
but languidly. Moreover, when nutrition is per-
verted, we find alterations in the number, form, and
attraction (and, as some say, also in the colour
and volume) of the red corpuscles.
III. PHYSIOLOGY.
That the red corpuscles do perform a very im-
portant function in the economy of the animal
MURCHISON] ROYAL MEDICAL SOCIETY 295
organism is a fact incontestably proved, and which
there is no denying. Indeed, as we have already
hinted in our introduction, they would seem to be
the most important constituent of that all-important
fluid in which they exist the blood the liquid
flesh, the source of life to all the body. As a proof
of the importance of the corpuscles in the blood, we
may state that it has been demonstrated by Milne
Edwards that the beneficial effects, which in many
cases follow upon the transfusion of blood from one
individual to another, are mainly to be attributed to
the increase of the blood-globules.
The actual importance of the blood-globules in
the animal system being thus proven, the question
now comes to be, What is the nature of that func-
tion which they perform ? And here we are obliged
to confess that to state their actual function is as
difficult as the importance of that function is certain.
Various opinions on this point are entertained by
different physiologists. We shall now endeavour to
lay these before you, afterwards mentioning what
view we consider most tenable in consistence with
known facts.
Some physiologists consider the blood-corpuscles
as carriers of oxygen and carbonic acid. Thus
Simon observes that the greater part of the carbonic
acid exhaled by the lungs arises from the red cor-
puscles, and that such substances as urea, uric acid,
and bilin may be products of active changes in the
blood corpuscles in connection with these changes.
Liebig supposes that the colouring matter of the
corpuscles of venous blood contains the carbonate of
the protoxide of iron, and that this in the lungs is,
by the action of the oxygen in the atmosphere, con-
296 DISSERTATIONS [BLOOD
verted into the hydrated peroxide of iron, carbonic
acid being given off. This hydrated peroxide is
again converted into the carbonate of the protoxide
when the blood is passing through the systemic
capillaries, and in this way, he says, the tissues are
furnished with the amount of oxygen necessary for
their growth and nutrition.
Other physiologists consider the blood-corpuscles
as concerned in elaborating the crude protein prin-
ciples of the chyle, and rendering these more fit for
the complex process of nutrition. This is the view
entertained by Kirkes. A similar opinion, viz., that
the red corpuscles are floating glandular cells, is also
held by Henle, Wagner, Wharton Jones, Newport,
Bischoff, and others, and even by physiologists as
far back as Turpin, A.D. 1700.
I believe, however, that here, as often elsewhere,
the truth lies with no one of them, but rather some-
where between them all. In what remains of this
Essay I shall endeavour to lay before you what, to
my mind, is a plausible and also probable ex-
planation of the functions of the corpuscles, taking
into consideration their different stages of develop-
ment as I have already detailed them, as also the
known changes which the blood undergoes in its
circulation through the system. I shall commence
then with the white corpuscles, as I have already
endeavoured to show that they are the parents of
the red. The white corpuscles of the lymph and
chyle are, as you are aware, identical with those
found in the blood. Then the question comes to be,
From what do the chyle corpuscles take their
origin ? What is the process of their development ?
Miiller, Rudolphi, and others seem to think that the
MURCHISON] ROYAL MEDICAL SOCIETY 297
chyle globules may be ' absorbed into the lacteals '
from the chyme in the intestinal canal. The late
admirable researches of Professor Goodsir, however,
with reference to the structure of the intestinal villi,
prove that this is a physical impossibility. The
investigations of the same distinguished observer
also show that the epithelium lining the lacteals
undergoes a remarkable modification on entering the
mesenteric glands. Its particles, from being flat-
tened scales, are transformed into spherical nucleated
cells. Now I think it exceedingly probable that
these spherical nucleated cells lining the lacteals,
in their passage through the glands, afterwards
constitute the white corpuscles found in the chyle
and blood, and on the following grounds : (1) The
epithelium of the lacteals undergoes the above-
mentioned transformation evidently to serve some
particular purpose. (2) As in all epithelia, so here,
the individual particles must, after a certain time,
be thrown off to make room for new generations
of them. (3) When so thrown off, there is no alter-
native for them but to pass into the fluid of the
lacteal vessels. (4) These nucleated particles re-
semble, in size and general appearance, the chyle
corpuscles.
If this view be correct, it follows that the chyle
cells are not formed, as some say, in an isolated
fluid independently of pre-existing cells, but that
their development is quite in accordance with the
laws which regulate that of epithelia in general (or
of gland cells). The chyle corpuscles thus formed
pass along to the blood, and in process of time
their nuclei enlarge, assume various shapes, and
ultimately form the red corpuscles. But in order to
298 DISSERTATIONS [BLOOD
effect this change the cell wall by its inherent
endosmotic power draws in nourishment from with-
out, and this nourishment must be derived from the
circumambient fluid portion of the chyle which has
been absorbed by the lacteals. The principal
protein ingredient of the chyle is shown by analysis
to be albumen, but we know that in order to fit it
for the nutrition of most of the animal tissues, it
must be converted into fibrin. Now it is not im-
possible that this important change is effected at
the very moment of the passage of the liquor of the
chyle through the external walls of the white
corpuscles, in the same way as the matters secreted
by glands, as the liver, are said to be transformed
at the very moment of secretion. This view would
explain why in scrofula there should be an increase
of albumen and diminution of corpuscles in the
blood, as also other morbid changes. In process of
time, in man the external cell wall bursts and
liberates its nucleus, which already is, or at all events
is afterwards to become, a red corpuscle. These dis-
solved cell walls, along with the fluid which existed
between them and the nuclei, no doubt form certain
of the protein principles (fibrin) of the blood, and
are consumed in nutrition. The liberated nucleus,
the red corpuscle, however, is destined to effect
future changes in the blood. The precise nature of
this change is by no means certain, but would seem
to be intimately connected with the function of
respiration : and here we see no reason for not
adopting the theory of Liebig already mentioned,
by which he endeavours to show that the blood
corpuscles carry oxygen from the lungs to the
tissues, and carbonic acid from the tissues to the
MURCHISOX] ROYAL MEDICAL SOCIETY 299
lungs. These changes, which are of a chemical
nature, no doubt form one of the great sources of
animal heat. The red corpuscles, after having per-
formed this, or whatever other function may be
V
allotted to them, decompose or die. The products
of their decomposition pass into the liquor sanguinis,
and they in all probability go to form the urea, uric
acid, bilin, and other oxygenated principles which
are excreted by the kidneys and liver. We have
thus followed the blood-corpuscles from their origin
to their final disappearance, from their cradle to
their grave, and have endeavoured to assign to each
stage of their existence its peculiar duty in effecting
the various known changes undergone by the blood.
Much, we are aware, in what has been stated will
be said to be purely theoretical, and that such is
the case we do not pretend to deny. But, theories
though they be, we trust that they are theories
which are not inconsistent with, but rather tend to
explain, the known phenomena, while at the same
time they are conformable with the general laws
(' ultimate facts ') which have been arrived at in
physiological science.
I now, gentlemen, have finished the task allotted
to me, a task which, irksome though it may to
some appear to be, is certainly conducive to much
useful information. I trust you will pardon the
very imperfect way in which it has been performed,
from the t circumstances which compelled me to do
it in so short a time.
Gentlemen, if the reading of this paper, or the
discussion which I trust will ensue, affords to any
of you the slightest degree of the benefit which the
writing of it has conferred upon myself, I am more
than satisfied.
XX
JAMES MATTHEWS DUNCAN
1826-1890
REFLECTIONS ON THE DURATION OF PREGNANCY,
WITH REMARKS ON THE CALCULATION OF THE
DATE OF CONFINEMENT
Bead 1854
MB. PRESIDENT,
In the numerous elaborate Essays which
have been written on the subject of the duration of
pregnancy in woman and in animals, it has always
appeared to me that a,n important source of error
has lain concealed. The exposition of this will, I
trust, throw some light on this interesting question,
and I am sure that when it comes to be completely
investigated our notions as to the duration of preg-
nancy will be much more definite and satisfactory
than they now are. My object in the present
communication is to make a few remarks on this
particular point, and then briefly to discuss the
general subject.
In the beginning it will be useful to define the
meaning to be attached to some important terms
frequently recurring in this discussion, viz. in-
semination, conception, and impregnation. By the
DUNCAN] DISSERTATIONS 301
word insemination is to be understood, simply, the
injection of semen into the genital passages, the
conjunction of the two sexes. By conception is to
be understood the more hidden and mysterious
union of the semen and ovum ; while the word
impregnation implies both of these processes.
The confusion of the two former of these different
processes is so general among obstetric writers that
it is needless to quote authorities for the assertion.
That they should always be held distinct in study-
ing this subject will, I hope, be made apparent.
For in fixing the commencement of pregnancy it is
necessary to date only from the period of concep-
tion. Authors in discussing this subject have
delighted to quote as crucial examples those cases
where the date of a single connection, or of connec-
tions within a short and limited time, could be
satisfactorily decided. But it is evident that such
a date only fixes the time of insemination, and not
the time of the commencement of pregnancy. For
a woman cannot be said to be pregnant whose body
merely contains seminal matter. Pregnancy is a
state of fertility, of breeding, which, as Leeuwenhoeck
long ago pointed out, cannot be said to commence
till such time as may have elapsed after insemina-
tion before the union of the ovum or ova and semen
has taken place. This period of time, whatever may
be its possible length, must be subtracted from all
these supposed crucial cases of the duration of
pregnancy. The interval which they describe as
pregnancy, that is, between successful insemination
and parturition, must be considered as in strict
language a false period ; and it is so, because it
contains the period between insemination and con-
302 DISSERTATIONS [PREGNANCY
ception, during which a woman is not pregnant. By
this interval, then, all such cases must be curtailed.
Very little has as yet been ascertained as to the
possible length of this interval. It was my inten-
tion to have attempted to make it out in regard to
some of the lower animals ; but my inexperience in
such investigations, and the pressure of other avoca-
tions, have hitherto deterred me from the pursuit of
this subject. There is then at present no resource
in this question but to facts already known. Now
it has been ascertained by physiologists that semen
newly expelled by the male is not essential to im-
pregnation. Animals have been frequently impreg-
nated by Spallanzani and others with semen which
has not only been kept for some time, but has even
been variously altered, in mechanical properties at
least, in experiments. And there seems to be no
limit to the time during which the semen may be
kept without losing its virtues, except the term of
the life of the spermatozoa.
That this period is not insignificant, and cannot
be passed over without risk of important error in
fact, that it may extend to many days or weeks,
will appear from the following observations. We
omit the facts in regard to animals so low in the
scale as insects, in the females of which the semen
is laid up in cavities where it retains its power for
months. In regard to the dog, Leeuwenhoeck
pointed out that these animalcules might live for
more than seven days preserved in a glass tube, and
if such be the case in a rude experiment, it may be
expected that they should retain vitality consider-
ably longer in the passages of the bitch, where
they have heat and moisture supplied under peculiar
DUNCAN] ROYAL MEDICAL SOCIETY 303
circumstances. That they do live for some days in
the genital passages has been proved by abundant
observations, although the possible length of this
period is not certain. The decision, indeed, of this
point by microscopic observations would be a very
difficult matter, as it would involve the almost
impossible search for spermatozoa over every part
of a long tract of mucous membrane. And this
search would be necessary, for we know by the
experiments of Spallanzani that semen highly
diluted, or, in other words, the smallest quantity of
semen, is sufficient for successful impregnation.
Again, the elaborate experiments of Haighton,
long ago performed, show that in the rabbit con-
ception generally does not take place till about
fifty hours, or more than two days after insemination.
He found that division of the Fallopian tube earlier
than this time prevented conception, and that, by
waiting longer, or till the ova had descended from
the ovaries, the conception was not prevented by
the mutilation. It thus appeared that the conjunc-
tion of the ova and semen in the rabbit generally
did not take place till more than two days after
insemination. In the rabbit, then, there was found
in Haighton's experiments this long interval between
insemination and conception, and in some cases it
is possibly much longer. In the rabbit the interval
between insemination and parturition is ordinarily
thirty days. The observations of Tessier upon 161
rabbits give five days as the extreme limit of the
protraction of this term, a period of time which may
be accounted for without any great stretch of the
space during which the semen may retain its
fructifying power. And in this way it may have
304 DISSERTATIONS [PREGNANCY
happened that the real period of gestation, that is,
from conception to parturition, may not have been
at all protracted in those cases. The cases also in
which the period was less than thirty days may be
explained by supposing the ova to have been further
matured, or even advanced into the uterine horns
before impregnation took place, so that conception
may have happened very soon after insemination.
And in Tessier's observations it is remarkable that
in none of the rabbits did labour anticipate the
usual time more than two days, the period which
Haighton's experiments seem to show to be the
usual interval between insemination and conception
in this animal. In the present state of our know-
ledge, however, these explanations cannot be
established.
For reasons which do not require to be stated,
there is great deficiency of evidence in regard to the
analogous subject in the human female. But there
is every reason to believe that the circumstances of
conception in her closely resemble those in the
higher animals. It has of late years been shown
that, in woman, at every menstrual period an ovum
is matured and expelled from its Graafian vesicle,
and that she is liable to conceive during its progress
along the Fallopian tube. How long after its matu-
ration the ovum can retain its vitality and suscepti-
bility to the seminal influence is not known, but
probably the time is short. But cases might be easily
adduced from the works of eminent obstetricians
to prove that a single insemination at any period of
the interval between two menstrual periods may
result in the fertilisation of the female. Of such
cases those only are important, in our present point
DUNCAN] ROYAL MEDICAL SOCIETY 305
of view, where conception has resulted from insemi-
nation shortly before the return of a period. They
admit of explanation in three different ways. Either
the ovum has remained up to this time entire, and
susceptible of being influenced by the semen a
supposition which is very improbable as regards the
ovum, and is at variance with what we know of the
history of the decidua or nidus prepared for the
egg's further development ; or the excitement of
connection may have hastened the maturation and
rupture of a Graafian vesicle, a view which is in
itself improbable, and inconsistent with what we
know results from similar circumstances in the lower
animals. But it may also happen that the seminal
animalcules may remain in the passages till the
ovum is prepared and discharged from its vesicle.
An objection at once appears to this explanation,
namely, that these spermatozoa would be removed
by the menstruation contemporaneous with the
discharge of the ovum. When menstruation does
supervene to a single recent coitus, this will pro-
bably happen, unless the semen have permeated the
Fallopian tubes, and thus advanced beyond the scope
of the menstrual flux. But the study of such cases,
as recorded by authors, reveals this interesting fact,
that under such circumstances menstruation often
does not take place at all, or only very scantily, the
uterine system, as it were, anticipating the concep-
tion, and preventing the failure which might result
from a free discharge of blood. It is evident that
such cases occurring in married life would be very
liable to be considered cases of gestation protracted
a month.
The interval between insemination and parturi-
U
306 DISSERTATIONS [PREGNANCY
tion is a period of the greatest importance in a
medico-legal point of view. It is discussed by
obstetric authors as the period of gestation, or as
the term of the duration of pregnancy. We have
already shown that the present state of our know-
ledge requires us to make a distinction between the
date of insemination and that of conception ; and it
strongly appears to us that the full comprehension
of the bearings of this distinction will go far to
equalise the discordant views as to the term of
pregnancy in the human female, and to account for
many of the so-called cases of prolonged gestation.
But with our present ignorance of the possible
interval between insemination and conception, the
attainment of the result is impracticable.
No reliance can be placed but upon accurately
ascertained dates of parturition and of fruitful
connection. In regard to the latter of these dates,
no confidence can be placed in the statements of
women living habitually with males, however truth-
ful they may be, or whatever additional evidences
they exhibit. We are therefore reduced to a
limited class of observations, namely, those where
the pregnancy resulted from a single coitus, includ-
ing those where this never took place but on a single
day, and those where it was removed on both sides
from other similar occasions by months, or such
other periods as would render it absurd to refer the
parturition of a fully developed foetus to them.
With those dating from a single day we have in-
cluded some dating from one or two days ; but in
such cases our calculations are dated from the coitus
of the first day only. This statistic contains forty -
six cases, which yield the period of 275 days as the
ROYAL MEDICAL SOCIETY 307
average interval between insemination and parturi-
tion. While 275 days was the average interval, it
may be remarked that the largest number of cases,
at any particular day, was seven, at the 274th day.
The interval between the last menstruation and
parturition is a period which, for obvious reasons,
can be much more easily and frequently ascertained
than that last under discussion. It is one, the
knowledge of which is of the greatest practical
importance in the everyday life of the married
female, and of the obstetric practitioner, seeing that
by aid of it he attempts to predict the date of the
expected confinement. In the vast majority of
cases it is the only fixed point from which the
calculation can be made, and hence the necessity of
accurately ascertaining it, if possible.
Authors have too frequently neglected the dis-
cussion of this important period, the only one
available in most cases of pregnancy. They gene-
rally decide the term of pregnancy theoretically, and
upon insufficient grounds, and direct that, in calcu-
lating for the day of confinement, this term should
be told off from some day after the last menses,
which day they conceive to be that on which con-
ception most frequently or most probably takes
place. For instance, Montgomery states, upon the
evidence of a very few cases only, that the natural
period of human gestation is 280 days, and, in
calculating the date of parturition, recommends this
to be added to any day within a week after the
last menstruation. He thus includes, between the
last menses and the date of parturition, a period
varying from 281 to 287 days, a period which we
shall show considerably overreaches the mark.
308 DISSERTATIONS [PREGNANCY
Other authors and teachers, considering that a
woman is equally liable to conceive on any day be-
tween two menstrual periods, direct that the middle
day of that interval be taken, and the supposed
period of gestation, 280 days, added thereto ; thus
including the exaggerated space of 290 to 295 days
between the last menstruation and parturition.
The exact decision of this interval, as of that
last under discussion, can be obtained only by a
reference to actual observations. Modern researches
have shown that it is at the menstrual period that
the ovum quits its Graafian vesicle and traverses
the Fallopian tube on its way to the uterus. It
is in the course of this passage that it encounters
the semen, and conception results. This passage
occupies about three days in the rabbit, and, in M.
Bischoff's opinion, it occupies eight or ten days in
woman. During all this time, then, the woman will
be liable to conceive. It will therefore be expected
that the interval of which we are at present speak-
ing will be some days, at least, longer than the last.
The statistical calculations on this subject give,
on an average, 278 days as the interval between
the last menstruation and parturition ; a period less
even than the 280 days which we have generally
been taught in this country to be the interval
between impregnation and parturition, or the
duration of pregnancy.
The largest number of cases on particular days
conglomerate about the 280th. Among Dr. Reid's
500 instances, 283 were within the 280 days, and
217 beyond it. So far is it then from 280 days
being the ordinary duration of pregnancy, that a
woman generally does not go more than 278 days
DTWCAN] KOYAL MEDICAL SOCIETY 309
after the last menstruation is over. This period
exceeds the average interval between insemination
and parturition by three days ; and we may argue
from this, with some little probability, that concep-
tion takes place generally a few days after menstrua-
tion is finished ; a view which is confirmed by
numerous other physiological observations.
The prediction of the day of confinement is one
of the functions ascribed to the accoucheur ; and
apart from the comfort and convenience to the
mother attending the foreknowledge of it, she often
makes its failure or success a test of the more subtle
acquirements of the physician. The foregoing
statistics, however, will always justify the latter in
never giving a decided prognosis of the day of con-
finement ; and if he has been guarded and careful
will afford him asylum, showing as they do that
with certain knowledge of the termination of the
last menstruation, or even of the date of a single
coitus, no safe prediction can be made unless within
limits so extended as to deprive it of much of its
value. At the same time, there is no doubt it will
always be a desideratum to know the most probable
day of confinement, and this can generally be settled
with some exactness.
If the date of a single connection is ascertained,
which is of course very rarely the case, then the
process of deciding the probable day of confinement
simply consists in telling off 275 days (the average
interval between insemination and parturition)
from that date. Now any nine consecutive calen-
dar months include 275 days, if February is not
in the number. If February is in the number, the
nine calendar months include only 273 days, and
u 2
310 DISSERTATIONS [PREGNANCY
the correction necessary is apparent. The whole
process of calculation then consists in attaching
the number of the day of connection to the name
of the month ninth succeeding, and adding two
additional days if February is included in the
interval.
In the vast majority of cases the day of con-
finement is predicted from the date of the ter-
mination of the last menstrual period. In many
cases the calculation can be aided and corrected
by comparison with former pregnancies in the
same female. But when this source of information
is wanting, the nearest approach to truth will be
made by adding to the day of the disappearance of
the menses, 278 days, the average interval between
the end of menstruation and parturition. The
prediction will, of course, prove erroneous in a great
number nay, in the majority of cases, but it forms
the nearest approximation which the mother can
obtain to guide her. If a woman, then, knows the
last day of her last period, she has only to tell the
same day for the ninth month following (most
mothers do so on their fingers, which thus form an
admirable periodoscope) and add three days, or, if
February is in the interval, five days. She thus
has the most likely day of her confinement, or, per-
haps better, she has the middle day of the week
on which she will probably be laid up.
I have already casually shown how much this
varies from the calculations ordinarily recom-
mended by most British authors and teachers.
It would be tedious to enter further on this sub-
ject. I may merely remark that a more correct
plan prevails on the Continent. And from some
DUKCAN] ROYAL MEDICAL SOCIETY 311
inquiries and observations I have made in Scot-
land and England, I find that popularly a more
correct calculation is in use than that recommended
in the schools. For instance, in Edinburgh, and
some parts of Scotland, it is common to find
women calculate in this way. They find the last
day of menstruation, and they hold that the same
day nine months after will be the day of confine-
ment. The celebrated Harvey's opinion on this
subject was also very correct, and his remarks tally
with Dr. Tyler Smith's ingenious views on this
subject.
Protraction of the period of pregnancy beyond
the common or natural term is a phenomenon which
most obstetricians are now willing to admit. But,
although believing in its possibility, I am at the
same time convinced that it is not so frequent in
occurrence as late writers on this subject seem
to think, and that most of the cases of this kind
which are recorded have not sufficient evidence to
support them. They are mostly based upon the
signs of the disappearance of the menses, of the
sympathetic phenomena of pregnancy, and of a
physical examination of the uterus ; all of which, it
is needless to say, are abundantly liable to create
misapprehensions and fallacious reasonings, and,
singly or combined, can justify no absolute conclusion
from them. One great reason for discrediting the
evidence of most of the cases recorded by authors is
that we hear nothing of great development of the
uterus, or of large size of the child, or of the placenta
in such cases, results which, to say the least, might
be expected. On the contrary, we find such authors
stating that in these so-called cases of protracted
312 DISSERTATIONS [PREGNANCY
pregnancy the child is no bigger than usual, or is
even smaller than ordinary. ' Although in some of
the cases of protracted gestation,' says Dr. Mont-
gomery, * the child was of enormous size, it by no
means follows that it should be so in all such
instances ; and, in point of fact, we find it expressly
mentioned in some of them that the child was
smaller than usual, as happened in one of Dr.
Hamilton's cases ; and Fodere says that in three
instances in which gestation was evidently pro-
longed, the children were undersized and ill-thriven ;
while, on the other hand, the largest children are
often produced where no extension of the term could
have taken place.' Dr. Burns also says that ' some
causes which we cannot explain nor discover have
the power of retarding the process (of gestation), the
woman carrying the child longer than nine months ;
and the child, when born, being not larger than the
average size.' In further corroboration of these
views the valuable observations on cows and mares
by Tessier and Spencer have been cited as showing
that there was no marked coincidence of increase
of size and weight of the foetus with protraction of
gestation. But this reasoning from analogy between
the cow and the woman appears to be very much
overstretched ; and there are evident reasons for
expecting, a priori, that the period of gestation in
women should be limited on the side of protrac-
tion more than in the lower animals. Of these the
strongest is based on a consideration of the adapta-
tion of the well-developed nine-month foetal head
to the maternal passages, and the evils that are so
well known to result from even slight disproportion
between them. And unless it be supposed that
DUNCAN] ROYAL MEDICAL SOCIETY 313
pregnancy is protracted for the special behoof of
small and ill-developed children, it must be admitted
that an extraordinary development of the ovum is
to be looked for in such 'cases. The acknowledged
absence, then, of this extraordinary intra-uterine
development is a strong evidence against the reality
of the great mass of so-called cases of prolonga-
tion. On the other hand, the presence of this sign,
in addition to others, is, in my opinion, powerfully
corroborative of the supposed protraction in any
instance. In illustration of this, I may state that
the best example I have met with of probable pro-
traction occurred in a female who had borne several
children, and who had previously been correct in
the calculation of the period of confinement from
the cessation of menstruation. On the occasion in
question she passed her calculated time four weeks,
and before confinement expressed her conviction, all
the more strongly in consequence of my incredu-
lity, that she had passed her time a month. The
labour was more tedious than usual, in consequence
of the great size of the foetal head. The child
proved of very large size and advanced development.
It weighed 10 Ibs. 4 oz. The placenta was 2 Ibs.
in weight. Other cases similar to the above have
been communicated to me by professional friends,
and some are to be found recorded.
In these cases the ordinary sources of evidence
were confirmed by the evidently exaggerated de-
velopment of the ova, the result of these protracted
pregnancies. I have lately had under my care two
cases in which gestation was supposed to be pro-
longed, but which I reject from this category
because, although the ladies were in good health at
314 DISSERTATIONS [PREGXASCY
the time of falling in the family way, yet the infants
born were not at all larger than their former children.
The ladies were sisters, and in each of them their
calculation and mine was passed by nearly a month.
The data founded upon were the cessation of men-
struation, and the occurrence of morning sickness.
In both cases the respective nurses were residing
with them for about a month before the superven-
tion of labour.
Such cases as those of the two sisters just men-
tioned, and numerous other so-called cases of pro-
traction, are easily explained by supposing simply
that that menstrual flux was suppressed which
should have occurred about the probable time of
the eventful intercourse, or, in other words, the
decidua prepared for the ovum destined to be
impregnated did not as usual throw off the bloody
fluid. In these cases we must suppose either that
the suppression for this one period arose from some
ordinary constitutional cause, or, what is more
likely, that the fruitful intercourse occurring shortly
before the ordinary menstrual period anticipated
and prevented it. This phenomenon we believe
not to be very rare, and to be sufficient to explain
away many cases of protracted gestation. In further
illustration of this circumstance, we must be satisfied
with referring to those cases of pregnancy after a
single coitus taking place shortly before menstrua-
tion, the coitus producing, firstly, the partial or
complete suppression of the menses at the approach-
ing period, and, secondly, the fertilisation of the
ovum discharged in coincidence with the suppressed
period. Some careful observations of this sort are
recorded by Raciborski and Montgomery.
DUNCAN] ROYAL MEDICAL SOCIETY 315
The evidence of highest value in regard to this
subject which we possess is founded upon cases
where pregnancy resulted from a single connection.
The results of these cases go far to establish the
well- founded opinion of Dr. Montgomery, that the
cases most deserving of confidence are those in
which the usual term is exceeded by more than three
or four weeks. But the cases referred to give us
the interval between insemination and parturition,
a period which, I have elsewhere remarked, requires
a connection which physiology has not yet enabled
us to decide for the possible interval between in-
semination and conception. In a practical and
medico-legal point of view, however, the interval
obtained is of great importance. In the collection,
of cases of this kind the longest duration found is in
one case, where the period was 293 days.
The theory of the duration of pregnancy is still
unknown. Some authors, believing that labour
comes on at the tenth menstrual period, explain the
protraction by the female's having a longer mens-
trual interval than usual, ten of which will make
up a period exceeding the usual term of pregnancy.
Others have supposed that from some cause a
female might miss the usual period and go on to
what would have been the next menstrual period
had she not been impregnated. Others have con-
nected it with tardy development of the fcetus, with
the influence of depressing emotions, etc., but all
these are mere hypotheses.
In conclusion, we beg to state the following
propositions :
1. That the interval between conception and
316 DISSERTATIONS
parturition (the real duration of pregnancy) has not
been exactly ascertained in any case.
2. That the average interval between insemina-
tion and parturition (commonly called the duration
of pregnancy) is 275 days.
3. That the average interval between the end
of menstruation and parturition is 278 days.
4. That the intervals between insemination and
parturition, and between menstruation and parturi-
tion, have no standard length, but vary within
certain limits.
5. That while absolute proof of the prolongation
of real pregnancy beyond its usual limits is still
deficient, yet that there is sufficient evidence to
establish the probability that it may be protracted
beyond such limits to the extent of four weeks.
Printed by T. and A. CONSTABLE, Printers to Her Majesty,
at the Edinburgh University Press.
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