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Jleiu Biuiisioick School Scried. 
 
 I'KKSrUllll.K IIV I UK lloAKli Oh IjUCAIlON >>t- Ni:\v Hi;rN>\vuK 
 
 TEACHEir^ Manual 
 
 OF 
 
 Nature lesso:^ 
 
 FOR 
 
 THE COMMON SCHOOLS. 
 
 BY 
 
 JOHN BRITTAIN, 
 
 Insdnclor in Saticral Science in the Provincial Xormal School, 
 Fredericton, N. B. 
 
 -♦-^ 
 
 SAINT JOHN, N. B. 
 J. & A. McMillan, 98 Piunoe William Stkkkt. 
 
 1890. 
 
Entered according to Act of Parliament of Canada, in the year 1896 
 
 Bv J. A A. McMillan, 
 
 In the Office of the Minister of Agriculture at Ottawa. 
 
To My Fellow Teaciieks : 
 
 This little manual is not intended to be of any special interest 
 in itself. It only aims to be a useful index to some of the 
 elementary chapters of the Book of Nature, and to indicate 
 briefly the means by which children may be led to read them 
 with pleasure and profit. 
 
 In order that our teachers, at least the younger ones, may be 
 able to do their part well, it will be necessary for them to deepen 
 their own interest, as well as increase their knowledge by further 
 study of that great Book. 
 
 The teacher will also need to provide himself with a few 
 works which will aid him in taking advantage of the labours of 
 others to hasten his own progress. Elsewhere will be found a 
 list of helpful books, some of which, or similar ones, the teacher 
 of limited means will, by a little self-denial, be able to procure. 
 
 I have tried, herein, to outline a consolidated and correlated 
 course of Nature Lessons which would include, essentially, every- 
 thing embraced under the head of Natural History and Science 
 in the Course of Study for the Common Schools — Lessons on 
 Minerals, Plants, and Animals; Agricultural Topics; Physics — 
 excepting Physiology and Hygiene, which are provided for in the 
 prescribed text-books on these subjects. 
 
 So far as I know this is the first attempt at such a correlated 
 course for our schools. It will doubtless be found to have many 
 defects. I shall always be glad to receive hints from other 
 teachers which may lead to amendments in i second edition. A 
 complete series of suitable illustrations would, doubtless, have 
 made this manual more serviceable, but would have added con- 
 siderably to its cost. 
 
 (iii) 
 
iv Preface. 
 
 I have made arrangements by which I can obtain for teachers, 
 at cost, the minerals, apparatus, and chemicals necessary for the 
 experiments in this course. For about $6 a supply, put up in a 
 neat box, sufficient with the addition of such common things as 
 are obtainable in any country district to last an ordinary school 
 for several years, can be obtained. 
 
 The coui-se of lessons outlined herein should not occupy on 
 an average more than one hour per week of school time in each 
 grade. There should never be two series of Nature Lessons 
 going on together in the same department. For instance, if there 
 is some work on minerals, and some on plants, laid down for 
 the same year, the work on plants should be taken up and 
 completed during the time of year most suitable for their study, 
 and the work on minerals during the other part of the year. 
 Some of the work can be done as well in winter as in summer, 
 but in most of the grades it will be better to discontinue the 
 Nature Lessons during the whole or a part of the winter, and 
 make up for it by having them more frequently in the warmer 
 seasons. 
 
 A great deal can be accomplished by school excursions on 
 Saturdays or other holidays, or after school hours in the long 
 days. I am acquainted with a number of teachers who have 
 tried such excursions, and have found them not only enjoyable, 
 but profitable to themselves and their pupils. It is quite as easy 
 to maintain order out of doors as in the school room. Besides, 
 if any pupil shows himself unworthy of the privilege, he may 
 be excluded. The teacher must exercise judgment in selecting a 
 suitable route and good weather, and be careful not to unduly 
 fatigue the pupils or otherwise endanger their health. The parents 
 should always be consulted, their advice asked, and consent gained. 
 It is true that, although the Course of Instruction recommends 
 
Preface. V 
 
 such excui-sions in connection with the Nature Lessons, they are 
 not obligatory. But there is no teacher who can do his best for 
 his school without devotinj^ some time to it outside of the regular 
 routine. And the teacher who is not willing to do this is not, 
 in my opinion, worthy of his profession. It is only by the 
 practice of self-denial that teachers will ever attain to that 
 influence and efficiency which will enable them to do the work 
 which lies before them. 
 
 In conducting these Lessons the teacher must ever keep in 
 mind that it is not their object to make scientists of the children. 
 It is not the aim of the common school to specialize in any 
 direction. A specialist in science who is ignorant in the other 
 grdt divisions of human knowledge, and has no appreciation of 
 poetry or art, is as unsymmetrical a being as an equally narrow- 
 minded specialist in any other department. If such men arc 
 needed it is not the business of the common school to produce 
 them. Let us strive to teach so that as our pupils' acquaintance 
 with natural forms and processes widens, so will their appreciation 
 of the beautiful in nature and reverence for its Author deepen. 
 
 "Let knowledge grow from more to more, 
 But more of reverence in us dwell ; 
 That mind and soul, according well, 
 May make one music as before. 
 But vaster." 
 
 Hoping that this little book may be able to establish by its 
 doing its right to being, 
 
 I am, 
 
 Yours sincerely, 
 
 John Bkittain. 
 
COURSE OF NATURE LESSONS. 
 
 GENERAL OUTLINE. 
 
 Paok 
 
 Paut r. Naturk Lkssons in TnR Primaky (Jkadks 1 
 
 Paut II. Naturk Lkssons in xriK Intermediatk and Advanckd 
 
 Gradks (5 
 
 Chapt?;u I. TnK Inokqanic World 
 
 Section A : Common Minerals Distinguished by their Properties... 10 
 
 Section B: The Elementary Composition of Minerals 20 
 
 Section C: The Principal Constituents of the Solid Earth 4;{ 
 
 Section D: The Properties and Composition of the Air oo 
 
 Section E: The Constituents of the Waters of the Earth (!1 
 
 Chapter 11. The Organic World. 
 Division I. Plants. 
 
 Section A: The Development of a Plant — Root, Stem, and I.,eaves 03 
 
 Section H: The Development of a Plant (Continued) — Flower, 
 
 Fruit, and Seed 04 
 
 Section C: .\nnuals, Biennials, and Perennials — iierbs, Shrubs, 
 
 and Trees 67 
 
 Section D : Forms and Properties of Roots, Stems, Buds, and Branches 
 — Propagation by Cuttings, Layering, Grafting, Budding; 
 Transplanting (38 
 
 Section Vj : Structural Relations and Classification of Plants - The 
 
 Buttercup, Rose, Pulse, and Lily Families 74 
 
 Section F: Structural Relations and Cliissification of Plants (Con- 
 tinued) 78 
 
 Section G: The Composition of Plants 82 
 
 Section H: The Food of Plants and its Assimilation 87 
 
 (vi) 
 
Qmrse of Nature Lessons. vii 
 
 Chai'teu III. Thk Ojuianic World. 
 
 I>ivlniiin If, Animaln. 
 
 Vaue 
 Section A: The Devolopintnt .-iiid Life History of an Animal - 
 
 Insects „_ 
 
 oo 
 
 Section H: The Adaptation of Form to Fnnction in Animals- 
 
 The DomPHtic Animals j^., 
 
 Section C: The I)i8tinj,niishing Characteristics and Hahits of the 
 
 Common Wild Hirds .q,. 
 
 Section D: Kindness to Animals jjo 
 
 APPORTIONMENT OF WOKK AMONli THE DIFFKIIENT JRADES. 
 
 Schools of Two ok More Dei-artments. 
 Grades I and JI, Part I 
 
 Grade III. Part II, Chap. II, Section A (.3 
 
 Chap. Ill, Section B, begnn 102 
 
 Grade IV. Part II, Chap. II, Section B (.4 
 
 Chap. Ill, Section A ; Section B, continued jis ont- 
 
 ^"^'^ ^^'"'••^ 95, 102 
 
 Grade V. Part II, Chap. II, Section C gy 
 
 Chap. Ill, Section B, completed IO2 
 
 Grade VI. Part II, Chap. I, Section A 10 
 
 Chap. II, Section D gg 
 
 Chap. Iir, Section C, begnn 103 
 
 Grade VII. Part 11, Chap. I, Section B 20 
 
 Chap. 11, Section E ^^ 
 
 Chap. Ill, Section C I03 
 
 Grade VIII. Part M, Chap. I, Sections C, D and E 43, 55, 01 
 
 Chap. U, Sections F, (i and II 77^ 82, S7 
 
 Chap. Ill, Section C reviewed, as out-door work 103 
 
viii Course of Nature Lessons. 
 
 Miscellaneous Schools in Country Districts. 
 
 Grades I atid II. Part I 
 
 Grade 111. Same hh for Grades III and IV above 
 
 Grade IV. Same as for Grades V and VI above 
 
 Grade V. Same as for Grade VII above 
 
 Pupils who have completed Grade V. Same as for Grade VllI above. 
 
 Requirements of Candidates for Normal School Entrance Exami- 
 nations, AND Preliminary Examinations for Advance 
 OF Class, in New Brunswick. 
 
 Candidates for Class I should have completed the work laid down for 
 the first eight grades; for Class 11, that prescribed for tiie first seven grades; 
 for Class 111., the work of the first six grades. 
 
 Note. — The Pulse Family is to be included in the work outlined in Chapter II, 
 8ectiou E, along with the Buttercup, Rose, and Lily Families. 
 
PART I. 
 
 rUIMAWY XATl'KK LKSSOXs. 
 
 Xaturo l,a« a „u.ssm,-c for even- little cliil.l. God ,,H.akx 
 to las heart tl,n,„.l, the tlow.ns, l.ir.Is, un.l InUtorflioH. as 
 well as ,„ the ,.,!„, the th,„„h,r, a,n.l the roar of tho oeoa,,. 
 When he enters „,,o„ his s.l.ool life he «houM not he 
 though often he virtually is, shut out fron, this lu.althJ 
 H.tlueuee. The wise an,I earnest teacher will take a.lvan- 
 ';.ge of it as one of the most etfeetive aids in the sy,nn,et- 
 rical (levelopnient o*' tlio child. 
 
 To do this with success, the teacher must not only he 
 a eo,,e and syn.pathetic stndeut of external nature, but 
 of the ,uner workings, as well, of tho chil.Ps heart and 
 "UM, . Teacher and puj.il must take each other by the 
 -Hi here, the instincts of the child will determine 
 .0 path to be taken -there, the superior knowledge of 
 the teacher will point the way. 
 
 The changing seasons in their round present a constant 
 succession of topics. 
 
 - l|^IIIIM> 
 
 SPRIXG. 
 
 The Melting of the Snow and Ice. 
 The Muddy Streams. 
 The Swelling of the Buds. 
 ^^^The^Awakening and Growth of the Infant Plant in 
 
Teacher\s Manual of Nature Lessons. 
 
 Tlio Hii)|)lini!: of the Brook. 
 
 Tlie tSprcadiiia: of the (irassy Carpet over the Fields. 
 
 The Bleatiiiji: of tlie Lanil)s. 
 
 The Arrival of the Birds. 
 
 The New Leaves upon the Trees. 
 
 The Sono:s of the Birds. 
 
 The Buttercup aud tlie Violet. 
 
 The Nestiriii: of the Birds. 
 
 The Awakuuiug of the Sleeping Insect in the Cocoon. 
 
 The Shearing of the Sheep. 
 
 The Ilatcliino; of tlie Eii-ij^s. 
 
 The Croakinii; of the Froirs. 
 
 The Colors of the Flowers. 
 
 The Lengthening of the Days. 
 
 — —Ml Ml I II 1^1 1 HUM l.^— 
 
 SUMMER. 
 
 The Falling of the Bain. 
 
 The Thunder and Lightning. 
 
 The Dew on the Grass and Leaves. 
 
 The Milking of the Cows. 
 
 The Chewing of the Cud. 
 
 The Food of the Birds. 
 
 The Bees and the Butterflies. 
 
 The Ehl) and Flow of the Tide. 
 
 The Rising and Setting of the Mooa. 
 
 The Light of the Stars. 
 
 The Cutting of the Grass. 
 
 The Digging of the Well. 
 
 The Food of the Domestic Animals. 
 
Teacher's 3Iamial of Nature Lessons. 
 
 AUTUMX. 
 
 The Cutting of tlie Grain. 
 
 The Golden-Rod and tlie Aster. 
 
 The Ripening- of tiie Fruit. 
 
 Tlie Food of the Caterpillar. 
 The Whistling of the Wind. 
 The Waves of the Sea. 
 The Building of the Cocoon. 
 The Departure of the Birds. 
 The Falling of the Leaves. 
 The Frost on tlie Grass. 
 The Shortening of the Davs 
 The Rising and Setting of the Sun. 
 
 WIXTEI{. 
 
 The Falling of the Snow. 
 
 The Drifting of the Snow. 
 
 The Icicles on the Eaves. 
 
 The Frost on the I'ane. 
 
 Where is the Grass? • 
 
 Where are the Birds? 
 
 Where are the Bees and the Butterflies ? 
 
 Where are the Leaves? 
 
 The Buds on the Trees. 
 
 n^ 
 
4 Teach€r\s 3Ianual of Nature Lessons. 
 
 It is not expected that the teacher will take up all or 
 only these subjects. Select a topic some time before the 
 year presents it, and by communion witli nature and the 
 chihlren prepare to deal with it in such a manner as will 
 awaken the interest, and arouse and partly satisiy the 
 curiosity of the young pupils. But do not begin by 
 telling them a story or giving them a description of 
 something they have never or scarcely seen. Take them 
 first to Nature, that they may see for themselves. Then 
 let them relate the story, or describe what they saw. 
 Each Nature lesson thus becomes the basis of a language 
 lesson. 
 
 The story or description may be followed by a discussion 
 of the causes of the phenomena, if any of these should 
 come within the range of the reasoning powers of young 
 children. 
 
 Simple songs and poetical extracts, consonant in nuitter 
 and sentiment with the lessons, should be interspersed. 
 Let the children conmiit the choicest pieces to memory. 
 
 In the second year, the pupils may begin to write little 
 compositions on the lessons, and to make tracings and 
 drawings of plants and flowers wdiich they have pressed 
 and dried. 
 
 As an instance of how one of these lessons may be 
 applied, let us take the " Swelling of the Buds " in the 
 Spring. Twigs of the maple, beech, willow, horse- 
 chestnut, or other tree, may be taken into the school, 
 and one placed in the hands of each pupil. Notice 
 the brown coverings of the buds, lead the pupils to see 
 
 i 
 
Teacher's Manual of Nature Lessons. 5 
 
 wliat it is they protect, and how well they are fitted to 
 keep out the cold and moisture. Xext notice the soft, 
 downy blankets inside and take them ofi' one by one' 
 What is it they are keei.in- warm? It is the miniature 
 ilovver, or branch, or stem, which has been formed the 
 previous summer before the leaf fell, and which has beeu 
 securely protected from the frosts and storms of winter. 
 ^' In its case, russet and rude " the tender ^i^erm of flower 
 or stem has been folded up "uninjured with inimitable 
 art." Place the twigs in water, and put them where 
 the warmth of the sun may reach them. In a f "w days 
 the buds will begin to swell ; first they will d> S the*^ir 
 brown waterproofs; next the blankets will be cast off, 
 and the flower or stem within, with its leaves, will begin' 
 to unfold itself and grow stronger and larger each day. 
 
6 Teacher f< Mamidl of Nature Lessons. 
 
 PAR^r II. 
 
 N'ATURK LES80XS FOR IXTKRMKDIATK AXI) 
 ADVAXC^KD (IRADKS. 
 
 INTRODUCTORY. 
 
 Tlie teacher and }>ui)ils arc al)()ut to uiulertake a series 
 of incursions into their natural environment. They should 
 enter it at the points of easiest access, and occupy and 
 fortity those spots whi(di will aflfbrd the best v^antage 
 ground from which to extend tlieir conquests. In the 
 following pages an attcni[)t is made to present the work 
 to be done in a natural and logical order. 
 
 It is necessary that the readier should make himself 
 
 L 
 
 familiar with the ground to be covered, the routes to 
 he taken, and tiie capabilities of his pupils. He must 
 acquaint himself with the natural features and products 
 of his district, and note those spots which offer the best 
 and most convenient opitortunities for observation and 
 study, and for procuring material for work m the school- 
 room. He should try the experiments beforehand, so as 
 to be able to direct the pupils in performing them quickly 
 and successfully. 
 
 Ill school, as far as possible, every pupil should })erform, 
 or, at least, assist in performing the experiments. It does 
 not at all answer the purpose for them merely to look on 
 while the teacher does the work. Thev will not take as 
 much interest, and the educational effect will be greatly 
 
Teacher^ Manual of Nature Lessons. 7 
 
 (liininislied. This niotliod would rodiu'c tlic |>upils to 
 mere learners at most, instead ot' traiiiiiiii' them to be 
 what thev ouii:ht to be — <l(ier.<^ as well as Inirncrs. 
 
 Of course, in some of the experiments, as in those with 
 liydroii'en, and, generally, in such as require ajtparatus 
 whieh caimot be provided for the whole class, it will be 
 necessary for the pupils to content themselves as assistants. 
 
 liefore the lessons begin, the teacher should form an 
 unalterable resolution that he will not tell the [)U[»ils auy- 
 thing which they can find out of themselves with a 
 reasonable expenditure of time and effort. There is but 
 little of fact or of reason necessary to the logical develop- 
 ment of the following series of lessons which is bevond 
 the grasp of the average pupil. 
 
 Adhere as closely as possible to the " method of dis- 
 covery.*' Because their predecessors have forestalled 
 them, is no reason why the children should be i)re vented 
 from making discoveries for themselves. It is true that 
 under the guidance of the teacher thev will be able to 
 make them at an earlier age and with less effort. But 
 that is no argument against it. The cater[)illar passes 
 through all the transformations which its progenitors did, 
 and probably with greater ease and in less time on that 
 ai'couat, vet it does not omit them. 
 
 Not only are the pupils to be allowed and required to 
 do their own observing; it is of etpnil importance that 
 they should be permitted to do their own reasoning. If 
 their arguments be inadequate or their conclusions incor- 
 rect, the teacher should point out the defects and encourage 
 
8 Teacher^s Manual of Nature Lessons. 
 
 them to fresh efforts. Thev will learn maiiv valuable 
 lessons from their mistakes. 
 
 But the teacher will probably titid it easier to restrain 
 liis own propensity for tellhu/ than that of his pupils. It 
 is of primary importance that the work be conducted in 
 «uch a manner that the quicker pupils will not tell the 
 slower ones before the latter have had time to reach the 
 results sought. Lessons are often so managed that none 
 but the brighter pupils do any original work. They thus 
 deprive their duller or slower classmates of all the pleasure 
 and all the profit to be gained by independent observation 
 and research. 
 
 In many of the experiments which follow, spirit lamps 
 are employed. With ordinary care, no danger is to be 
 apprehended from their use. Nevertheless, the teacher 
 should have a pail of water within easy reach for use in 
 case of an accident through carelessness. Every teacher, 
 of course, understands how to employ a woollen garment 
 as a fire-extingnisher. 
 
 If necessary, a thin board or a wooden tray may be used 
 to protect the desk when experimenting with minerals. 
 
 Teachers are at libertv to substitute for anv of the 
 experiments described herein others of their own devising 
 which will more effectively or more conveniently accom- 
 plish the end in view in each case. 
 
 In many cases, the results of experiments and obser- 
 vations, and of processes of reasoning, sometimes the 
 processes themselves, are not given herein. These omis- 
 sions are intended for the benefit of both teachers and 
 
Teacher's Manual of Nature Lessons. 9 
 
 pupils — to contril)iit(' to the devolopniont of the virtue of 
 self-reliance. Anotiier ohject, however, is to enable inspec- 
 tors and examiners to discover more easily whether tin; 
 work has been done in accordance with sound educational 
 principles. 
 
10 Teacher s Manual of Nature Lessons. 
 
 CHAPTKK 1. 
 
 rm: tnor(4axtc would. 
 
 Section A: Common Minkrals Distincuiished by their 
 
 Properties. 
 
 Duriiii;' the suiiimor jiiid iiutiuiin the teaclier should 
 collect ;i good stock of the eommoner mineruls — quartz, 
 feldspar, luiea, hornhleude, limestone, n'vpsuni, liiuonite, 
 hematite, ma<j;netite, pyrite, siderite (chiy iron-stone), man- 
 ganese ore, and graphite. Several varieties of eaeli species 
 should he secured if })Ossil)le, and enougli in every case 
 to su])ply a whole class. Wliite and colored varieties 
 of (luartz can he found anvwhere. Bits of rock crystal 
 are not uncommon. Mica and the natural chalk can he 
 ijot at a hardware store. Common limestone is <::enerallv 
 within reach. Chi[)pings of marhle may he picked up at 
 marl)le works. Limestone rocks usually contain trans- 
 parent crystalline varieties. Clear crystalli/e(l gypsum 
 (selenite) is of frequent occurrence in the plaster rock. 
 The ii'lacial houlders scattered over the countrv will often 
 furnisli specimens of minerals from distant localities. 
 These houlders yield the best spejimens of granite, as 
 they show the dift'erence between the weathered and the 
 unweathered surfaces. Teachers can readilv exchano^e 
 minerals from their several localities. The Inspectors will 
 often be able to assist in these transfers. 
 
 But it will probal)ly be found necessary to make some 
 purchases. Although the iron ores are almost universally 
 
Teachers Manual of Nature Lcasoiin. 11 
 
 (listril>utcMl ill small |tin'ticK's in \hv soil and rooks, <roo(l 
 sju'ciiin'iis for class work arc iiof to \)v tound in many 
 loealiti«'s. Feldspar, althouirh picci's of siiitahlc size may 
 somotimos be u'ot out of' u^raiiite rocks, will usually liax'e 
 to Ix' l)i'ou<i'lit from a distance. 
 
 Tlie earnest teacher will find little ditHculty in socur- 
 iuLi' an adequate stock oi' all the minerals het'ore men- 
 tioneth 
 
 If the school possesses no suitahle cahinet the teacher 
 and pupils should make, or cause to he tnade, a tew 
 wooden travs to hold the minerals. These trays mav he 
 jiacked in a laru'e trunk. The cost of the re(iuired 
 chemicals and apparatus will he tritlinu'. Commercial 
 hydrochloric (muriatic) acid may he ol)tained from a 
 druii\ii;ist at ten cents or less per pound. A little aqua 
 ammoniic will also he useful. These should he kept ii! 
 ♦i'lass stoppered l)ottles. Sup[)ly each desk witli a small 
 hottle for lioldini>' the acid, which, if stron*^, may be diluted 
 with water. An ordinary cork will sufttce for these small 
 
 « 
 
 bottles. Pieces of irlass tubiuir - or ;> inches lonii; and 
 about I inch in diameter may be used for extracting the 
 acid when needed to apply to a mineral. Show the pupils 
 the etfeet of the acid on tiie skin and on cloth that they 
 may exercise due care in its use. l*lace on each desk a 
 spirit lamp, a piece of litmus paper, two slips of window 
 irlass, two test tubes, a cup of water, two pieces of small 
 tiexible brass wire each al)OUt 14 inches long. 
 
 The pupils should also haye kniyes or tiles for trying the 
 hardness and streak of minerals. 
 
12 Teacher' 8 Manual of Nature Lessom. 
 
 A pint of alcohol will last the lamps for a good while. 
 
 Some litmus powder for eoloriiiii" white jtaiier will be 
 fomid C'oiivoiiieiit. 
 
 Tlie teacher shoidd have a good magnet with which to 
 magnetize the blades of the pupils' knives. 
 
 Two small boxjs will be needed for each desk, one to 
 hold the minerals, the other the apparatus for two pupils. 
 
 It will be best to begin with two common minerals 
 Avhich differ widelv. The contrasts broui::ht out in the 
 comparison will help to tix the properties of both in the 
 mind. I^et us select Avhite (juartz, and gray, reddish, or 
 black limestone. Ask the jtupils first to find whicli of the 
 minerals will scratch the otlier, using a corner of each. 
 When thev have noticed that there is a verv white mark 
 left on each when rubbed by the otlier, but that only one 
 of them makes a scratch in the other, ask them to account 
 for these facts. The one whicli scratches the other is the 
 harder, and the one which is scratchetl the softer. Thev 
 will find that the white streak in both cases is the color 
 of the pow^der of the softer mineral, although the mineral, 
 in the nuiss, may be Idack. Tell them that the color of 
 the powder of a mineral is called its streak. The streak 
 of the harder mineral may be obtained by scratching one 
 piece of it with another piece, or by breaking a piece of 
 it into powder with a hammer. Let them now try to 
 scratch a piece of glass with each mineral. They will 
 succeed with the harder one only, and will infer that this 
 one is harder than the glass, the other softer. Similarly, 
 they will find that one of them is harder than ordinary 
 
TencUers Manual of Nature Lesnons. 13 
 
 stei'l, while tlie other is iiiiich softer. The teaclier may 
 now iiitonn them tiiat the hiinhu'ss of minerals is expressed 
 in (leifrees from one to ten, and that the hardness of tlio 
 liarder mineral is seven deii-fcos ; also, that aiiy snl)stan('e 
 as liard or hai'der than that is reii^arded as rm/ han/. Tlio 
 hardness of the softer miner.al will not he more than tliree 
 or four (leirrees. 
 
 Direet each i>n|iil in making a coil at the end of a ])ieeo 
 of rather tine l)rass wire, hv windini;' one entl of it around 
 a lead ])en('il. Sliow them how to close tlie ends of the 
 coil hv hendinu" the wire over them. Ahout five inches 
 of the wire should remain for use as a haiidle. This coil 
 will he found in<lispensahle in lieating nunerals. Before 
 the lesson heirius, thin slivers, for this purpose, shoidd he 
 pre});. red hy carefully hreaking up a piece of the mineral 
 with a hammer. The smaller and thinner the slivers are 
 the hetter. Kacli pupil will open a coil of wire slightly, 
 at one side, insert a sliver of the soft mineral, s<iueeze the 
 turns of wire together again, and steadily heat the mineral 
 for ahout five minutes in the hottest part of the tiame of 
 the spirit lamp. Xote the visible effect of the heat upon 
 the specimen. 
 
 When placed on red litmus paper and dampened it 
 will turn the paper blue. 
 
 Treat the hard mineral in the same manner and notice 
 whether the heat produces the same physical effect upon 
 it. It will not when dampened turn red litmus blue. It 
 will also he found that if either mineral be dampened 
 without being heated, it will not affect the color of the 
 reddened paper. 
 
14 Itacher^s Manual of Nature Lessons. 
 
 The juipils will now apjily u drop of liydroehloric acid 
 to osu'li niiiicral. IJuhhlos will fonn on tin- s^it'tor one, 
 l)iit not on llic otluT. 'IV'Hcli tlieni to iisf the term «//W- 
 n'ficeiwe tor this efVoct. i'ut tlu^ inincnds into the cuii 
 of water to wash otK the acid, and leave tlu'in there for 
 a while. It will he seen that tiiev are not solnhle in 
 water, at least not pereeiytihly so. 
 
 Let the pnjtils hold their inati:nets, or magnetized knife 
 hlades, near small pieces of the minerals, if thev are 
 attracted hy the nnii^net, they are said to he nuKjiictlc : 
 otherwise they are HHmaf/nrfir. 
 
 Xote the color, Instre, trans[)arency or opacity, etc., of 
 hoth minerals. 
 
 Tlie teaclier shonld now% hut not ])efore, give the names 
 of the minerals. 
 
 Fiequire the pupils to write careful notes on their lessons. 
 At least, they should exhihit in tahular form the results of 
 their examination of each mineral. These tahles mav he 
 used afterward as standards for identifying specimens 
 found by the pupils in their excursions. The following is 
 a convenient order for tahulatino; results : 
 
 1. Hardness. 
 
 2. Streak. 
 
 3. Ktf'ect of heat. 
 
 4. Ktfect of jicid. 
 
 5. Etlect of wat'r. ^, . 
 
 6. Effect of magnet. 
 
 7. Crystallization. 
 
 8. Color, lustre, etc. 
 
Tcac/ierfi ManiuU of Nature Lcshquh, 1") 
 
 III rcconlinu- luirdiu'ss, jiiiy iiiiiuTiil wliicli can l)i' 
 scratcluMl with tlic tiiiiii'i' nail iiiav Im- sot down as rir>i 
 .^<if'/. ( )ii«' wliicli caniM^t he scratclicd with tlir nail, Itiit 
 is easilv scratcluMl with tho kiiitr, is sof't. One vvliit-h can 
 h(» Hcratclicd itv tiic knife, Imt witli ditHciiltv, is /mril. 
 It' it cannot be scratched distinct) v with the Unite, hut 
 yields to (inartz, it is ra-i/ hard. 
 
 Marhhs chalk, and otluT varieties of limestone (carhon- 
 ate of lime, caU-ite ) should next he examined in the 
 manner descrihed. and compared closolv with one another 
 and witii quartz. Marble shows little irlisteiiinu; surfaces 
 when broken. Chalk is much softer tlian the others — 
 hardness about 1 dei::ree. P>nt thev ai'e all soft; tliev all 
 have a white streak ; they all effervesce when treated with 
 the acid : thev all become white and (ruiiibly when 
 heated; tlie heatiMl jn-odiict, when dam|iene(l, always turns 
 red litmus blue. 
 
 The pu}>ils are now prepared to Lelieve that these are 
 all varieties of tlie same mineral, limestone or calcite. 
 They may be told that the lustreless white substance 
 obtained by heating them is lime, whence comes the name 
 limestone. They will be able to tell, or to find out by 
 inquiry, how lime is made on the large scale, and will be 
 led to see that the method is really the same as that which 
 they employed. 
 
 The examination of the principal varieties of quartz is 
 next in order. They will all be found to be very hard, 
 unattected by the heat or acid, and insoluble in water. 
 They differ much in color, as do the varieties of lime- 
 
1 6 Teacher's Manual of Nature Lessons. 
 
 stone. The pupils will already begin to see that minerals 
 cannot be distinguished by their colors. 
 
 Before leaving these two minerals their crystals should 
 be compared. It will be found that calcite crystals will 
 split along smooth surfaces running in deiinite directions. 
 These crystals are, therefore, said to possess cleavage, and 
 the surfaces along wliich they split are called planes of 
 cleavage. Their edges are indicated bv lines runnini; 
 across the faces of the crystals. No such planes can be 
 found in the crystals of quartz, although lines of fracture, 
 where the crvstals have bej^un to crack, mav sometimes 
 be mistaken for the edges of cleavage planes. Quartz 
 crvstals are devoid of true cleavage. Thev are terminated 
 by six-sided pyramids, that is, they have six triangular 
 faces on the end. (^-alcite crvstals varv irreatlv in form, 
 and some of them look remarkably like crvstals of quartz. 
 But their softness, as well as cleavage, and their effer- 
 vescence when treated with acid, at once distinguish them 
 from quartz. 
 
 It will be interesting and instructive for the pupils to 
 prepare crystals of some substances which are soluble in 
 water. For instance, lei. them, at home, make strong 
 solutions of common salt and alum, hang a thread or two 
 in each, and set them awav where they will be undis- 
 turbed. In a day or two, if the crystals which form are 
 very small, the threads may be hung in another solution 
 that the crystals may grow. Note carefully the difference 
 in form between the crystals of common salt and alum. 
 
 The pupils may be led to see that if they could dissolve 
 
Teachi 's Manual of Nature Lessons. 17 
 
 the massive (uncrystallized) pieces of quartz and limestone 
 they might o])tain quartz and calcite crystals. They will 
 also infer tliat the crystallized forms of these minerals 
 must have heen li(iuelied, or at least softened, in some 
 way, before they crystallized. 
 
 The class should now be able to proceed with the 
 examination of the other minerals with but little direction 
 from the teacher. 
 
 For class use, the larger specimens may be broken up 
 into pieces about as large as plums. In studying ditferent 
 varieties of the same mineral, note carefully those proper- 
 ties which are common to them all, as these are the only 
 ones essential to their determination. A few notes on the 
 remaining minerals in our list are given here for the 
 benefit of the teacher. 
 
 One of the most abundant of minerals is common feld- 
 spar (orthoclase). Although hard ((j degrees), it can be 
 scratched by quartz. It has cleavage planes running in 
 two directions. With care, specimens can be found which 
 will show the intersection of two of these glistening planes. 
 They make a right angle with one another. Xote the 
 various colors of the specimens. Enumerate the observ- 
 able differences between feldspar and quartz — between 
 feldspar and calcite. 
 
 Mica and transparent crystalline gypsum (selenite) nuiy 
 well be studied together. They are soft minerals. Sele- 
 nite can easily be scratched with the linger nail. Its 
 hardness is 2 degrees. Mica, black or white, is little, 
 sometimes not any, harder. In heating the mica a few 
 
 B 
 
]8 Tcacher\ Manual of Nature Lesso)is. 
 
 little bits should be placed in a small test tube ke}»t closed 
 by the tiiiger. The tube may be held by a wooden holder, 
 similar in form and size to a clothes-pin, cut out a 
 little neiir the end to receive the tube. After hcatinu' the 
 mica, Vieat a piece of selenite in the same manner. In one 
 case the mineral will withstand the heat without apparent 
 change; but in the other, it will be converted into a soft, 
 white, lustreless powder, while drops of water fron) it will 
 settle on the sides of the tube. Et will also Ijc found that 
 although both minerals cleave into thin sheets, that those 
 of one of them are brittle and of the other elastic. Give 
 the names of the minerals after the }>upils have discovered 
 that they differ from one another and from any mineral 
 previously examined. Then tell them that the white 
 powdery substance in the bottom of the tube is calcined 
 plaster of Paris. 
 
 Hornblende so frequentlj' replaces mica in rocks that 
 they should be studied in connection with each other. 
 The greater hardness and heaviness of hornblende, and 
 its lack of elasticity, will distinguish it from mica. 
 Asbestos is a variety of hornblende. 
 
 Study limonite, hematite, and magnetite together. They 
 are hard minerals — in their compact form — although 
 limonite is not as hard as the others usually are. It 
 must be ol)ser\'ed, however, that these as well as other 
 hard minerals seem very soft when reduced to a iine 
 powder, or Avhen they occur naturally in a tine state of 
 division, ilie streak of limonite is yellow, of hematite 
 red, of magnetite black. It will be found that although 
 
Teacher^s Manuo.l of Nature Les.sonn. 19 
 
 the inaii'iiet will not attract the first, and the second only 
 rarely, it has a strong attraction for magnetite. Heat a 
 bit of hematite and another of magnetite in the same 
 closed tube. Then replace them by a small bit of 
 limonite. One of them yields water. When small pieces 
 of limonite and hematite are stroncrly heated in the wire 
 coil, they will become magnetic, and their streak will be 
 changed. 
 
 Pyrite resembles gold in color, bnt its hardness, 
 nearly e([ual to that of (juart/, and its brittleness, distin- 
 guish it from thiit mineral. Notice the beautiful effect 
 produced when a lump of jnrite is biiskly struck with a 
 iile. Tiy to get the same effect in the case of feldspar, 
 quartz, and calcite. When a little powdered ]>yrite is 
 heated in the closed tube, a yellow dejtosit apj)ears on 
 the sides of the tube above tlie mineral. The color, and 
 the sul[)hurous smell which may l)e perceiv'ed on holding 
 the tul)e near the nose, indicate that this deposit is 
 sulphur. 
 
 Submit these aiul the remaining minerals — siderite, 
 common numganese ore (pyrolusite), gra})hite, and rock 
 salt — to all the tests which were ai>plied to calcite and 
 quartz, carefully recording results. 
 
 If specimens of numganese ore cannot l)e obtained, the 
 powdered hlack oxide of manganese may be examined 
 instead. Note the proi)erties which distinguish it from 
 magnetite. Upon testing the black lead of their pencils, 
 the pupils will conclude that it is the same as graphite. 
 Thev should find out whv, althouLch it contains no lead, 
 it is called black lead. 
 
20 Imcher's Manual of Nature Lessons. 
 
 Rock salt will be found to diti'er from any mineral 
 studied before in beiiiiir soluble in water. Find, bv sub- 
 mitting common Halt to tbe sjime tests, wbether it is the 
 same as rock salt. Also observe tbe eftect which this 
 mineral, while beinc: boated in tbe wire coil, lias upon 
 the color of tha flame of the 8[)irit lamp. 
 
 Let the pupils review all the minerals which have been 
 examined, repeating any of the tests whose results have 
 been forgotten. Then the teacher should hold an examin- 
 ation. Supply each pupil with a box or envelope con- 
 taining specimens of the various minerals, including 
 varieties which differ somewhat from those which were 
 used in the lessons. The pupil will identity tbe speci- 
 mens, wrap each in a piece of palter, write the name of 
 the mineral on the paper, and state clearly in writing the 
 considerations which enabled him to reach a decision in 
 each case. He should of course be allowed the use of 
 suflicient apparatus. 
 
 Lastly, require every member of the class to make a 
 collection, correctly labelled, of all the known minerals to 
 be found in the neighbourhood. 
 
 Section B : Tue Elementary Composition of Common 
 Minerals, and some Properties of their Elements. 
 
 Fit a cork, through which the stem of a funnel passes, 
 into a bottle of air. Pour water into the funnel. If the 
 apparatus has been fitted tightly, tbe water will not run 
 through the tube into the bottle until the cork has been 
 
Teacher's Manual of Nature Lessons. 21 
 
 loosened. The air 18 said to occupy tlie space in the 
 bottle because it excludes the water until it escapes itself. 
 It will at once be seen that the water, the glass, and the 
 cork possess the same property displayed by the air. 
 Agree to call anything which thus occupies space l)y the 
 luime of inatter. Give other examples of matter. 
 
 A separate portion of matter is called a bod'/. The 
 amount of space included within the limits of a body is 
 called its volume. The amount of matter in a body is 
 called its mass. 
 
 Fill a test tulte with colored water — red ink will 
 answer for coloring — and close it with a cork which has 
 a glass tube, of small bore, several inches long, tightly 
 litted through it. The water will rise for some distance 
 up the tube in forcing in the cork. Hold the tube 
 slantingly, and warm it along the side with a spirit lam}>, 
 but do not boil the water. The water will gradually 
 expand till it fills the small tube. Without increasing the 
 amount of water — its }nass — we have increased its volume. 
 On cooling the water, it will contract to its original 
 volume. Explain these results. 
 
 rrobably the most satisfactory explanation to be found 
 will be that the water is made up of extremely minute 
 particles of water which were driven farther apart by 
 the heat, thus causing the water to ris^ in the tube to 
 find more space. As the water lost the heat which had 
 expanded it, the particles came as closely together again 
 as they had been at first. The invisible particles which 
 were driven apart by the heat are called molecules. 
 
22 Teacliers Manual of Nature LesHons. 
 
 The t'orcc wliieli eiial)los iiioleciiles to clinu: to osieli 
 other UTitil a jj^reater force separates tliem is culled 
 rohesio/i. If the molecules which attract each other heloiiic 
 to (lift'erent hodies, as when water sticks to ii:lass, this 
 force is usually called <i(lhe^iov. 
 
 Heat a little ice, until it liciuefies, in a test tube. Fill 
 one end of a douhle e_<2:i!^-cup with a mixture of snow 
 and salt. IJoil the water in the test tube. A visible 
 vapour will ai)pear at the mouth. Hold the egg-cu}i so 
 that its emptv half will receive this va}»our. Water 
 will collect on the inside of the cu}), and fall in drops 
 into a dish set below, (continue till the water in the 
 tube has disappeared. l*our the water out of the dish 
 into another test tube and push it down into a deep dish 
 tilled with a mixture consisting" of salt with about twice 
 its weight of snow or pounded ice. Tn a minute or two^ 
 the water will be converted into ice again. It will be 
 concluded that there must have been water in an invisible 
 state in the bubbles while the water was boiling, and that 
 when they rose and burst this invisible water tilled the 
 upper part of the tube; and further tliat the loss of heat 
 transformed this invisible water into visible drops. Water 
 in the invisible form is called steam. 
 
 The water existed in three different states : First in 
 the solid state (ice), then in the liquid state, next in the 
 gaseous state (steam). Although it is usually called water 
 only in the liquid state we must infer that it is the same 
 substance throughout these changes — that it is composed 
 of molecules of water throughout all its changes. The 
 
Tcavhcr^s Manual of Nature Leiisom. 23 
 
 heat loosens the luoleenles from each otliei- in cliiniifiii!^ 
 ice into water; (h'ives tliem apart in (•lianii:ini!; Tuinid 
 water into steam ; while loss of heat resnlts in the mole- 
 cules returninii' to their orio-iiuil arranii'ement. 
 
 Pieture out for yourself a hrook as it would aj)i)ear if 
 its molecules were niau:nitie(l to the si/e of i)eas. Descrihe 
 your picture. 
 
 The chauii'O of a solid into a li(|ui(l is called //'(/Hrfartion 
 or fusion : of a li(|uid into a gas, craporaflon ; of a gas 
 into a licjuid, roiK/cnmfion : of a liquid into a solid, soikli- 
 jicatioH. Evaporation and condensation constitute dist'iUa- 
 f/oii. The experiments just descrihed illustrate all these 
 l>rocesses. The water which fell into the dish was (/isfiUcd 
 wafer. Distil some water containing salt in solution, and 
 account for the ditference in taste hetween the distilled 
 water and the sohition. 
 
 Fill a hottle havino- a small neck with water. Cork it 
 ti2:htlv and set it out of doors on a cold winter night. 
 Account for the effect upon the hottle. Does the ice differ 
 from the water which froze in weight or in volume, or in 
 hoth ? Account for the floating of ice upon water. 
 
 Examine a thermometer, atid study its action. Learn 
 the freezing and hoiling points. What temperature is 
 meant bv "blood heat?" 
 
 Drop two or three crystals of chlorate of potash into a 
 test tul)e containing a little water. When the crystals 
 liave dissolved compare the taste of the solution with that 
 of chlorate of potash. You will infer that the water 
 simply loosened the molecules of chlorate of potash, and 
 
24 Teachei-'s Manual of Nature Lessons. 
 
 that they are now mixed with those of the water tliroui»:li- 
 oiit. To estahlisli tliis evaporate tlie water. What sul)- 
 stanee remains in tlie bottom of the tube? 
 
 r*ut a small teaspoonful of chlorate of potash into a 
 test tube, followed by one-tifth of its bulk of dry blaek 
 oxide of niaui^anese, and shake them till thorouijhlv 
 mixed. 
 
 Cut oft a piece of i^lass tubing, ] inch bore, with the 
 nid of a file; heat it two inches from the end in the 
 Hanie of the spirit lami), and when soft enough bend it 
 slightly at that point. Ivound the sharp edges of the 
 ends by. holding them in the outside of tlio Hame until 
 thev become red hot. Select a good cork which will tit 
 the test tube tightly when half way in ; with a round 
 file make a hole through it, into which fit the end of the 
 glass tube which is farther from the bend. Fill with 
 water a pickle bottle aiul two smaller bottles with wide 
 mouths, and invert them in a pan of water or a pneumatic 
 trough. Insert the cork tightly into the test tube by 
 twisting it in, and connec^t the bent glass delivery tube 
 with a piece of rubber tubing of fitting size. While one 
 pupil heats the mixture in the tube with the spii'it lamp, 
 let another collect in the bottles over water the gas which 
 escapes. As the smaller bottles fill, remove them, mouth 
 down, in a dish. Leave some water in the dish so that 
 the gas cannot mingle with the air. Take away the tube 
 before the pickle bottle is quite full of the gas. Note the 
 large volume of gas obtained from the small amount of 
 solid matter. 
 
Teacher's 3Ianual of Nature Lesaons. 25 
 
 Twist one etid of a j/it'cc of flL'xil)U' l)russ wire around 
 a small jtiece of soft charcoal. Tush a piece of i^lass 
 under the mouth of one of the small bottles of <!;as, and 
 keeping the glass pressed against its moutli, turn the 
 bottle up. Heat the charcoal until it begins to glow and 
 ]»lunge it into the gas. The ett'ect at iirst will be very 
 brilliant, l)ut soon the charcoal will cease to burn. 
 Remove the wire and close the bottle ([uickly with a 
 damp slip of glass. 
 
 Invert in the same way another l)ottle of the gas; ])our 
 a little lime-water into it, cover its mouth with the hand 
 and shake the lime-water through the gas. (For the 
 method of preparing lime-water see page 89.) Now pour 
 lime-water into the gas in which the charcoal was burned. 
 Note the difference in the visible effects. 
 
 Take a coil of fine iron wire, having a thread which has 
 been dipped in sulphur attached to the lower end, and 
 fastened to a piece of card-board at the ni>per end; ignite 
 the sulphur with a match, and then lower the wire into 
 the gas in the pickle bottle. The wire should burn with 
 brilliant sjtarks. 
 
 The teacher may now tell the |)upils that this gas, in 
 which charcoal and iron burn, is called oxi/gen. They will 
 infer that the gas remaining in the bottle after the 
 charcoal ceased to burn, which would not allow the 
 remainder of the charcoal to burn, and which had such a 
 remarkable effect on the lime-water, must be a different 
 gas from oxygen. 
 
 The (iuestion now is to find what the oxygen came 
 out of. 
 
26 Tc(ichcr\s Manual of Nature Lessons. 
 
 Fill with water tlio tent t>il)0 coiitaiiiiiii:; the rosiduo of 
 the iiiixtuiv tVoiii which oxyLCfii ^vas ohtaiiK-d. In a few 
 hours j)()ur the eontents into a filter ita[»er fitted into a 
 funnel. The fiffrafr, i. e., the liquid which parses through 
 the filter pajHU', will he found to have a saline taste^ 
 showinii; that soniethinu' from the tuhe is dissolved in it. 
 Pour enou<::h of it into a fiat dish to cover the hottoin Uy 
 a depth of { of an inch. Set the solution in a warm 
 place where it will he undisturhed, and with it a solution 
 of chlorate of potash in a similar dish. 
 
 In a day or two, the water in hoth dish>s will have 
 eva})orated. The chlorate of potash and th; snhstance 
 which ii:ave taste to the filtrate will then he found 
 crystallized on the hottom of the dishes. But the crystals 
 will <liifer distinctly in form. 
 
 In the filter when dry will be found an insoluble black 
 powder exactly like the black oxide of manganese which 
 was mixed with the chlorate of potash. (To show that 
 this powder is the same as at first it may be used a 
 second time in the preparation of oxygen.) Di'aw the 
 lourical conclusion as to the source from which the oxvii:en 
 came. 
 
 The pu[)ils will now see that chlorate of })otash must 
 be made up of oxygen and the saline substance from 
 the filtrate which is now crystallized in the disli. Thev 
 must also conclude that a little oxygen is present in 
 every molecule of chlorate of potash, and hence that the 
 heat broke up these molecules, and drove the oxygen out 
 of them. The crystals from the filtrate must be made 
 
Teacher\^ Mamial of Nafnre Lrsftonft. 27 
 
 up of inolcM'iilcs wliicli (lifTrr tVoin tlu^ iiiriltM'ult's of 
 chlorate ot" jtotasli in t'oiitaiiiiiii;' less oxvi^t'ii or iioiu'. 
 
 Since the iiioU'culcs of ('lih)rsite of potasli contain inor6 
 tliun one suhstancc, it is calKMl a cttnipotnxl siihsf/tnrc : l)nt 
 oxvsrcn. since no one lias hi'cn ahU' to break it no into 
 
 I/O 1 
 
 two different sul)stanees, is ealled a simple siihsi<iticc or 
 elieniical elniunf. The niolecnles of tiie salitie snhstance 
 remaininii: after tiie oxviren has l)een driven out ol" tlie 
 chlorate of potash have been found to consist of t\v(^ 
 eloineiits, ])otassiuni and chloiine, which the pupils have 
 not seen. Molecules, then, can he hroken up into snudU'r 
 jmrts. P'ach of the indivisible parts of ji molecule is 
 called an atom. ((Jr. ", not; tinuio, I cut.) Tlie force 
 which brino;s and binds too-ether the atoms of a molecule 
 is called clitmiad (ilUnii;i. 
 
 The chemical mimrs of compound substances depend 
 upon the elements of which tliey are made up. The 
 names of compounds consistinij^ ot" two elements, i. e. 
 l^inary com|)ounds, are distinguished by the affix iilc ; the 
 names of those which contain three elements, called 
 iernari/ comi)Ounds, take the affix afc. Since these ternary 
 compounds usually contain oxy^jen, ate may be taken to 
 indicate the presence of that element. Since ciilorate of" 
 potash consists of potassium, chlorine, and oxyii:en, it may 
 also be callecl potassium chlorate ; while the binary coni- 
 jtound, feft witli the oxide of manganese after the oxygen 
 is expelled, is called potassium chloride. 
 
 Our next undertaking is to find what gas, so diflferent 
 from oxygen in its properties, remained in the bottle after 
 the charcoal ceased to burn. 
 
28 Teacher^ 8 Manual of Nature Lessom, 
 
 I'liro clijircoal \n a simple siihstiince — it is tlio element 
 4-iirbim. Now, siiK^e oxygen is also an element, the new 
 ^as could not have hoen formed hy cither of them 
 breaking up. The conclusion is that this gas must he a 
 <3omp()und suhstance formed hy the )W.ii)H of carhon and 
 oxygeti. Its molecule has heen found to consist of one 
 atom of carhon and two atoms of oxygen. Its exact 
 chemical name is carbon dioxide, hut it is commonly called 
 4U(rbt»uc acid f/as. 
 
 .Just as the charcoal in hurning was u»'iting with the 
 <)xygen around it, so, we must think, the iron in hurning 
 was condjining with oxygen. As fast as this oxide of 
 iron was j)r()duced, it was seen dropping through the 
 water to the hottom of the pickle hottle, where it may 
 yet he found in the form of solid black glohulcs. This 
 is the bljtck oxide of iron. Since it is attractable by the 
 magnet, it is also called iiiuf/iirtic iron oxide. 
 
 Shake up some lime-water in a bottle of air. Then 
 burn the charred end of a stick in the air above the 
 lime-water, fn a minute or two, cover the mouth of 
 the bottle tightly with the hand, and shake agaiti. Tf 
 properly done, the same eft'ect will be produced on the 
 lime-water as when it was shaken in carbon dioxide. 
 
 The pupils will infer that the charcoal must have 
 been uniting with oxygen while burning in the air, and 
 further, that there must therefore be oxygen in the air. 
 
 Hold a piece of sulphur near the nose, no smell is 
 perceptible. Ignite the sulphur in an iron spoon ; a 
 strong smell is observable. Account for this. 
 
Teacher^ }fami(d of Nature Lcmodm. 29 
 
 It will 1)1' ccuK'liKlrd tliat wlicn subHtaiu'cs burn in tlir 
 iiir, tlit'V arc uiiitiiii; witli the oxyy'cii prcsont tlicre, iiud 
 torniiuij: (ixitjcs, i. v. midcri^oinn- (ixidntion, just as tlicy 
 <!() wIk'M Imrniiiic in jtui'i^ oxvi^cn. 
 
 Arraiii^o on tin- desks, in hoxos or dislics, specimens of 
 the coinmoncr solid vlcnicnts, sncli as iron, sulphur, 
 earhon, tin, zinc, co)>pcr, ahmiinuin, and lead. Kxplain 
 tliat none of these iUihstances have ever been deeonipoHcd. 
 (iiiide the pn)'i]s in coinpariiiii; thcni in color, lustre, 
 hardness, nialleahility, fusihility, etc. 
 
 Make a smooth hall from the drv pith of the stalk 
 of the elder or the sunflower. Sus[)eTid it hy a silk 
 tliread from some support. Hold a piece of amher or 
 a rubber comb near it. Xo visible action takes place. 
 
 Rub the comb or amber witli a piece of flannel. J^ring- 
 it near the ball. The ball is at first attracted, and tlicn 
 re])elled. lirini."; the rubbed side of the flannel near tlie 
 ])all which the comb or amber repels. It is now attracted. 
 
 The new power develo[)ed in these bodies by the 
 friction is called electriciti/ — that of tlie amber and comb, 
 and of tlie ball which they touched negative electricity — 
 that of the flannel rubber, positive electricity. 
 
 Rub a glass rod with silk. It will then attract a ball 
 which a rubbed comb will repel, but the rubbed side 
 of the silk will attract a ball which the glass repels. 
 Was the glass positively electrifled, or negatively? — the 
 silk? 
 
 Electrify a pith-ball negatively by touching it with a 
 rubbed comb. The comb then repels it. Touch the ball 
 
30 Teachev^s 3Ianual of Nature Lessons. 
 
 -svitli tlie tiiiii;('r; the l>iill will then attmet it. Electrify 
 ii ball positively and proceed in the «ame manner. 
 Explain the facts. 
 
 The fin<!:er is said to conilnct the electricity from the 
 balls. Try pieces of unrubbed sealing wax and rnbber. 
 They leave the ball in the same electrical state as before 
 they touched it. They are bad eonductors of electricity. 
 
 Try the solid elements under examination, and classity 
 them as good or bad conductors of electricity. Pulverize 
 a little of each of them, and briuii' electrified bodies 
 near the powder. Record the ett'ect. 
 
 Hold the ends of a glass rod, or tube, and of a 
 i'0}>per wire of about the same diameter in the Hame 
 80 that the heat comes ecpially upon them. They should 
 be grasped by the fingers at equal distances from the 
 flame. Drop the one which tirst becomes uncomfortably 
 liot, and continue to hold the other as loug as prudence 
 permits. Account for the ditference. The one is said 
 to be a (food, the other a bad conductor of heat. By 
 the aid of similar experiments, classify the elements on 
 the desk as iijood or bad conductors of heat. 
 
 It will be found that those which are good conductors 
 of electricity are also good conductors of heat, and that, 
 although tliey differ in color, they all have the same 
 kin«l of lustre. These elements are called iiutafs, and 
 their lustre the metaUic lustre. The other elements before 
 us are called wm-mffah. Oxygen, then, is a non-metal. 
 Classify mercury as a metal or a non-metal. 
 
 Bring a magnet, first one end of it niid then the otaer, 
 
leacher's Manual of Nature Letsaoiis. 81 
 
 ♦ 
 
 near the jiowder of each of tlie elements on the desk. 
 The powder inny be conveniently placed on ii slip of glass. 
 Note the effect and explain it as far as vou can. Classify 
 .such as are attractable by tbe magnet, as )Nf/_<puiic sub- 
 .>tances, the others as minuupietlc. 
 
 Hold a [)ieee of each element above the desk and tlien 
 take the hand away. They all move toward the earth, 
 (■all attention to the fact that they would move towai'd 
 the earth if dropped twelve hours later, although the 
 direction would be contrary. Acc(Mint for this as far 
 as you can. 
 
 The power by wliich the earth attracts bodies is called 
 the force of (/radtj/. The amoioit of force with wdiich the 
 earth attracts a body is called its ireight. 
 
 Find the weight of a bottle of water. Fill the same 
 bottle witl) kerosene oil and find its weight. Also find tlie 
 weight of the same bottle full of sand. Deduct the 
 weight of the ])ottle in each case. We now have the 
 \veights of equal volumes of the three substances. Divide 
 the weight of the oil and the sand re8[»e{!tively by the 
 weight of the water. The one (piotient is called the 
 •specijir (/rarif// of the oil, the other of the sand. Tlie 
 ^yater used as the standard should be artiticially distilled, 
 ])ut rain-water will answer the pur])ose. 
 
 Collect two bottles of oxygen by tlie method before 
 described. Prepare carbon dioxide in one of them l)y 
 burning a piece of charcoal in the oxygen. Shake a 
 little water through the gas, keeping the hand closely 
 pressed upon the mouth of the bottle. 
 
32 Teacher's Manual of Nature Lessons. 
 
 Twist one end of a wire around a piece of crayon, and 
 i,i»;nite a piece of sulphur placed in a cavity at the end 
 of the crayon. Lower the ])urning sulphur into the 
 renuiininic l)ottle of oxyo-en. As soon as active com- 
 hustion ceases, remove the crayon, and pour a small 
 ([uantity of water in with the strong-smelliuiJ^ gaseous 
 oxide of sulphur (snl[)hur dioxide), and shake thoroughly 
 as described before. The liquid now in the bottle in 
 whicli the sulphur was burned will have a distinctly sour 
 taste, that in which the carbon was burned should be 
 very slightly sour. 
 
 Dip blue litmus paper, or pour a solution of blue 
 litmus powder, into each bottle. The color will be 
 changed to red in both cases. 
 
 These substances with the sour taste which turned 
 blue litmus red are called acids. Each of them is com- 
 posed of an oxide united with water. The one which is 
 made up of carbon dioxide and water is named earhonic 
 acid, and the other for a similar reason is named 
 ftidpfmrous arid. There is another acid consisting of the 
 elements of sulphur trioxide and of water, which is called 
 snlphuric acid. The affix ic liere denotes a greater amount 
 of oxygen than ous does. 
 
 Examine a piece of magnesium wire or ribbon. Note 
 its lustre and find whether it is a good conductor of heat 
 and electricity. You will conclude that it is a metal. 
 Ignite it with a match or in tlie flame of the lamp. The 
 white product, which might be mistaken for ash, is 
 macjnesium oxide. Dampen this oxide with a little water 
 
Teacher^s Manual of Nature Lessons. 8S 
 
 on a piece of red litmus paper. Xote the ettect on the 
 Utnins. 
 
 This Biihstiince eliaiiu'es the color of litmus, which 
 has been reddened l)y an acid, l)ack to blue, and is 
 called a base. It is coniitosed of the elements of 
 magnesium oxide and of water. Why did we not get 
 an acid as we did wlien the oxides of carbon and sulphur 
 were mixed with water ? The difference must be due 
 to the fact that the element we began with in the last 
 case is a metal, whereas carbon and sulphur are non- 
 metals. Xotice that the acids contain a non-metal other 
 than oxviicen, while the base contains a metal. 
 
 Make a weak solution of hydrochloric acid in water. 
 Note its taste and its effect on litmus. Put graimlated 
 zinc, or little pieces of sheet zinc bent so that they do not 
 lie too closely together, into an ignition tube or large test 
 tube until the metal occupies nearly one-third of the tube. 
 Fill the spaces between the pieces with water. Make 
 arrauirements for collectiuii' two bottles of ii:as, as in the 
 preparation of oxygen. Pour hydrochloric acid into the 
 tube until the liquid reaches half an inch above the metal. 
 An active effervescence should set in at once. Insert a 
 cork, with delivery tube, and collect two snndl icide-mouthcd 
 bottles full of the gas. 
 
 Should the gas cease to flow before the bottles are filled, 
 or at any time before the completion of the experiments 
 upon it, the cork may be taken out of the tube, part of the 
 liquid poured off the zinc, and more acid added. 
 
 Take the rubber delivery tube out of the water, and hold 
 c 
 
34 Teacher^s Manual of Nature Leasons. 
 
 it upward in the inoutli of a small, irklc-iuoathed bottle or 
 thick tiiml)ler held mouth downward in the air. In about 
 a minute remove the bottle from the tube, and while its 
 moutli is Ktill turned downward, plunge a lighted match 
 up into it. The gas will burn, probably with a slight 
 explosion. If the bottle be turned up as soon as the match 
 enters the gas, the flame may be seen. Hold the tube for 
 a longer time in the mouth of the bottle ; the gas, when 
 ignited, will burn quietly, showing that the explosion was 
 due to the combustible gas being mixed with air. This 
 combustible gas is called hydrogen. 
 
 What was reallj' happening when the hydrogen was 
 burning? The presumption is that it was uniting with the 
 oxygen of the air. Let us try to find what its oxide is like. 
 
 Insert a piece of glass tubing, drawn out at one end till 
 the bore is (juite small, into the free end of the rubber tube. 
 Ignite the gas as it issues from the smaller end of the tube. 
 Hold the flame in the moutli of a clean dry bottle held 
 mouth downward. A colorless liquid will colleat like dew 
 on the inside of the bottle. This liquid condenses just as 
 water does, and upon examination it will be found to be 
 really water. Water, then, is a compound substance con- 
 sisting of hydrogen and oxygen. It is an oxide of hydro- 
 gen, and may be called hi/dric oxide. 
 
 Turn the mouth of one of the bottles of hydrogen flrst 
 collected, up under the mouth of a smaller wide-mouthed 
 bottle full of air. It will be found on applying a match to 
 the mouth of the smaller bottle that the hydrogen has risen 
 through the air and displaced it. Account for the fact. 
 
Tcacher^s Manual of Nature Lesscrus. 35 
 
 Raise the otlior bottle of hydrogen, pass a lighted taper 
 or candle uj* into it for a short distance, and stc^adily lower 
 it again until well out of the l)Ottle. The candle tianie will 
 he extinguished as soon as it enters tlie hydrogen, but will 
 take fire again in coming out. This may be repeated sev- 
 eral times with the same bottle of hydrogen. Explain the 
 ohserv^ed facts. 
 
 We must now find whence the hydrogen came. Being 
 a sim[»le substance, it could not have been formed by the 
 union of other substances. No gas was evolved when 
 we mixed hydrochloric acid with water, nor when we put 
 water on zinc. The hydrogen, then, resulted from the 
 zinc coming in contact with the acid. Hence, since zinc 
 is a simple substance, the hydrogen must have come out 
 of the acid. 
 
 But the zinc, although insoluble in water, has been dis- 
 appearing. What is becoming of it? The only explanation 
 we can find is that it takes the place in the acid which had 
 been occupied by the hydrogen, uniting with that part of 
 the acid with which the hydrogen had been united, and 
 thus settiuii" the hvdrocren free. 
 
 Hydrochloric acid, or hydric chloride, as it may be called, 
 is known to be a compound of hydrogen and chlorine. If 
 our exjdanation is correct, there should be a compound of 
 zinc and chlorine in the tube. We cantiot see any new 
 substance there, but we may taste it by touching the water 
 in which it is dissolved to the tongue. When the water is 
 evaporated we obtain it in the solid state. This newly- 
 formed compound — zinc chloride — is called a salt. 
 
36 Teacher^ Manual of Nature Lessons. 
 
 Zinc irt uot the only iiietul wliieli has the power of taking' 
 the place of the hydrogen of an acid. Try iron filings 
 instead of zinc with hydrochloric acid. What salt can he 
 tasted in the water? 
 
 Since these tw^o salts are ohtained hv the aid of hydro- 
 chloric acid, ditt'ering from it in composition only in con- 
 tainino; a metal instead of hydros-en, they are called salts 
 of hydrochloric acid. From the metals they contain, tlie 
 one may he called a salt of iron, the other a zinc salt. 
 
 Care should he taken in experimenting with hydrogen 
 to use only small quantities and wide-mouthed hottles. 
 There is then no danger from the slight explosions which 
 may occur on account of an admixture of air. 
 
 Dissolve a little caustic soda in water. Taste the solu- 
 tion, and test it with litmus paper. Caustic soda is a 
 soluble base, and like other bases must contain a metal 
 or its equivalent. The metal in caustic soda is called 
 sodium. 
 
 Mix hydrochloric acid w^ith the solution of caustic soda 
 until the mixture has neither a pungent nor a sour taste, 
 and will neither turn blue litmus paper red nor red to blue, 
 i. e., until it is neutral to litmus. 
 
 There is now" dissolved in the water a substance which 
 tastes like common salt. To make sure that it is salt, set 
 aside some of the solution in a Hat dish until the water 
 has evaporated. The taste of the residue and the form 
 of its crystals will leave no doubt that it is conmion salt. 
 But no salt was put into the mixture. How shall we 
 account for its production ? We recollect that in the pre- 
 
Teachet'^s Manual of Nature Lessons. 37 
 
 piinition of liydrogen the metals used took the [>hice of 
 the hydrogen in the acid. The eonelusion is that in this 
 case the metal sodium of the ])ase acted in the same wav 
 — that it re})laeed the hydrogen in the aeid, forming by 
 its union with chlorine another salt, sodium chloride. If 
 this reasoning be correct, we have discovered the composi- 
 tion of common salt, and know its chemical name. 
 
 Taste a weak solution of aqua ammonite, and test it 
 with litmus paper. You will conclude that it is a base. 
 
 Make a mixture of the ])ase aqua ammonise with hydro- 
 <;hloric acid. When the solution has been made neutral 
 to litmns, put a few drops of it on a slip of glass and hold 
 the glass slantingly. As the water evaporates, crystals will 
 form on the glass. These are the crvstals of another salt, 
 iimmonium chloride, often called sal ammoniac. 
 
 Why is not the displaced hydrogen set free when a base 
 and an acid are mixed as well as when a metal and an acid 
 are brought in contact with one another ? 
 
 Let us now trv to find out, as far as our means will 
 permit, the composition of the minerals we examined some 
 time ago. 
 
 We have learned that heat tends to break up compounds, 
 and that when some substances are treated with acids, 
 chemical changes set in. Let us take advantage of these 
 facts in endeavoring to find the composition of limestone. 
 
 Put a small handful of bits of marble, chalk, or ordinary 
 limestone into a bottle. The bottle should have a moutVi 
 large enough to receive a cork, with two tubes through it — 
 a small one, reaching only through the cork, to be con- 
 
38 Teacher\s Manual of Nature Lcftsons. 
 
 nected witli a ruljbcr (iolivery tube, ainl a larger one, 
 tlirougli vvliich, by meuns of u funnel, acid is to ])e [toured. 
 This tube should roach down nearly to the limestone in tlie 
 bottle. I'our water down the larjj^er tube until it covers 
 the limestone and reaches a short distance up the tnbe. 
 
 Add enough hydrochloric acid to produce a lively effer- 
 vescence, and collect over water a bottle of the gas wliicli 
 is evolved. Then put the end of the delivery tube into 
 the mouth of a bottle of air standing mouth upward. 
 Add acid whenever necessary to keep up effervescence in 
 the generating bottle. In two or three minutes, the flame 
 of a burning match will be promptly' extinguished when 
 held in the mouth of the receiving bottle, but the gas 
 itself does not take fire. Tliis i>;as then is neither com- 
 bustible nor a supjtorter of ordinary combustion. What 
 does the fact that it sank tlirough and replaced the air 
 show ? 
 
 Empty it upon a candle flame. Account for the result? 
 
 Leave an open bottle of this heavy gas sitting on the 
 table for a short time. Then plunge a lighted match into 
 it. If the flame be extinguished, try again a few mimites 
 later. Explain the result. 
 
 Push a glass slip under the mouth of the first bottle, 
 turn its mouth upward, pour in lime-water, and shake the 
 gas and lime-^vater together. This gas produces the same 
 ^^8ible effect upon lime-w^ater that carbon dioxide did. 
 Since it resembles carbon dioxide in being incombustible 
 and a non-supporter of combustion, we conclude with cer- 
 tainty that it is the same gas which we obtained by 
 burning charcoal in oxygen. 
 
Teacher^ 8 Manual of Nature Lesmris. 39 
 
 AVhence did tlie carbon dioxide come? Since iieitlior 
 the wiiter nor the acid put ir^to tiie «i^eneratinn- bottle con- 
 tain its elements, tiie inference is that it came out of the 
 limestone. 
 
 Repeat the experiment of heating a thin slice of lime- 
 stone in a wire coil, and dami»en the residue on red litmus 
 paper. It acts like a base, and has a puntz:ent taste. 
 
 How shall we account for the formation of this ])ase? 
 We prepared our first ])ase by treating the oxide of a metal 
 with water. Our explanation, then, is that the residue 
 which remaijis after heating the calcite is the oxide of a 
 metal. It is evidently not a metal, as it does not })0sse8s 
 metalli(; lustre or the other distinctive properties of metals. 
 This oxide is called qalckUtne^ or simply lime. And lime has 
 V)een found to consist of oxviyen and a beautiful metal called 
 calcium ; hence, lime may be called caldiun oxule. 
 
 On each desk place a small lump of lime. Since it is the 
 oxide of a metal, with water it should form a base. Let us 
 try it. Slowly pour upon the lime as much water as it will 
 absorb, turning it over as this is done. Curiously enough, 
 the cold water seems to make it hot. Light a match in the 
 crumbling mass. The lime is now said to be water-slaked. 
 Rub some of it on dampened red litmus paper. It acts like 
 a base. Taste it. 
 
 Put the water-slaked lime, or caustic lime, as it is called, 
 into large bottles, until each is about one-third full. Fill 
 them up with water, and shake. When the water has 
 become clear again, try red litmus paper in it. The effect 
 will convince you that a part of the caustic lime has been 
 
40 Teacher 8 Manual of Nature Lessons. 
 
 (lisHolvod in the water. This solution of caustii' lime in 
 water is called /intc-irafrr. Cork tlie bottles and set them 
 aside. 
 
 Put a lari:;er lump of unslaked lime in one pan of a 
 balance, and wei^^hts enou*2;h to equal it in the other pan. 
 Slake this lum[) of lime in a dish, and when the resulting 
 caustic lime has become cool and i»erfectly dry, put it into 
 the same pan of the balance in which it was before it was 
 slaked. Does it weigh more or less than the original lime ? 
 You will be forced to conclude that, although the lime is 
 perfectly dry, the increase in weight must be due to the 
 water having united with the lime. This is another ex- 
 ample of chemical union. 
 
 The heat which was evolved while the lime was beino* 
 slaked Avas doubtless due to the comim:: toiirether of the 
 atoms. 
 
 The base, caustic lime, consists, then, of the metal cal- 
 cium, hydrogen, and oxygen, and may be called calcium 
 hydrate. 
 
 We have found that the lime which remains after heat- 
 ing limestone contains a metal (calcium, we were told) and 
 oxygen. We had previously found that limestone contains 
 carbon dioxide. Therefore limestone must contain the 
 elements of both lime and carbon dioxide, viz., calcium, 
 carbon, and oxygen. We see now what happens to calcite 
 when it is heated, and why chemists call it carbonate of 
 lime or calcium carboimte. 
 
 Call attention to the fact that although limestone con- 
 tains the black element carbon yet, when pure, it is either 
 colorless or white. 
 
Teachcr^s Manual of Nature Lessom. 41 
 
 Since luairiietite is {ittractuhle bv tlio iiiaiiiiet, wo imiv 
 be quite sure tliiit it contains iron. Its lianlness, black- 
 ness, and brittleness sliow tbat it is not pure iron. 
 
 We renienil)er tliat it resenil^les tbe black i>'lol)iiles of 
 oxide of iron wliicb were produced by burniuij; iron wire 
 in oxygen, and, indeed, tbe composition is tbe same. 
 
 Heat a tliin frai;inent of bematite in a wire coil. It 
 becomes dark and maii;nt'ti(' like mai>:netite. Hematite is 
 evidently anotber oxide of iron. It is called from tbe 
 color of its powder red oxide <>/' h'o?). 
 
 Heat some u'rains of limonite in a closed tu1)e. It yields 
 water and becomes reddisb. Heat a sliee of it more 
 strongly in a wire coil. It becomes dark and magnetic. 
 We must tliink tbat limonite is a compound of red oxide 
 of iron witb ^vater. From its yellow streak it is called 
 yelloio oxide of iron. 
 
 Heat powdered pyrite in a closed tube. A yellow deposit 
 appears on tbe inside of tbe tube. Open tbe tube and con- 
 tinue heating. Wbat do you now smell ? AVbat was tbe 
 jellow solid wbicb was at first deposited? Heat a bit of 
 pyrite in a Avire coil. It becomes magnetic. What have 
 we established concerning its composition? Its chemical 
 name is sulphide of iron. 
 
 Heat a slice of clay iron stone (impure siderite) in a wire 
 coil, and test the residue with the magnet. 
 
 Put a teaspoonfal of fragmetits of siderite into a test tube. 
 Cover with water, add hydrochloric acid, and insert a cork 
 litted with a delivery tube. Apply heat, and pass, by means 
 of a rubber tube, the gas which is evolved into lime-water. 
 
42 Tfacher\s Manual of Nnbirc Lessons. 
 
 Account for tlie eft'oct. Inter the coni])Osit*H)n ot' sidcritc. 
 What is itH chcniiciil niiinc ? 
 
 Il(!at i^ypsuiii in a closed tube until the water is expelled. 
 The residue can })e shown to consist of the metal calcium — 
 the metal of which lime is the oxide — toi^ether with sul- 
 phur and oxyt^en. llenco, gypsum is ktiown as hydrous 
 (Gr. lufdor, water) calcium sulphate or sul[»hate of lime. 
 We have not the means, however, to demonstrate its com- 
 position. 
 
 These are the oidv minerals we have studied vet which 
 hydrochloric acid, or the heat of the spirit lamp without a 
 blow-i)i[»e, will readily decompose. It will he interestinic 
 to know, however, some thing's which liave been found 
 out about the composition of the others. 
 
 Quartz is the oxide of an element, silico)), which resem- 
 bles carbon. ITence, cjuart/ may be called oxif/e. of silicon, 
 or brietlv silica. Since it is the oxide of a non-metal, it 
 miglit be expected that with water it would form an acid. 
 Water, however, under ordinary' conditions, as can be 
 easilv shown bv exi)eriment, does not even dissolve it. 
 But by indirect processes their elements can be got to 
 unite, thus forming silicic acid. The salts of this acid are 
 called silicates, since they contain a metal with silicon and 
 oxvijen. 
 
 Feldspar, mica, and hornblende are silicates. Each of 
 them contains aluminum, the most abundant of the metals, ; 
 and one or two other metals besides. 
 
 Rock salt is chemically the same as table salt, as can 
 be inferred from comparison. 
 
Tmchtr'a Manual of Nature Lensom. 43 
 
 All tlio liiiiKTiils we luivo considtTi'd are eonipomwls — 
 eitliei' salts or oxides — exeept lirapliite. Altlioiiirl' tl'i-^ 
 miiu'i-al has a nietallir lustre, it is oiilv a I'oriii of the non- 
 metal carlx)!!. Note how it ditfers in its properties from 
 chareoal. 
 
 Section C: Tiik Phincipal Constituents of the Soliiv 
 
 Kakth. 
 
 R(tr/,s. — Visit the sea-shore or the hanks of a river, ln'ook, 
 or lake. Seek out a hed of (/rfirl. ^'ou will tind in it 
 several minerals voii know, and others of whieh vou are 
 ignorant. The jiieccs of <|uartz and other minerals will 
 sometimes he eolored red or vellow. Tlieso eolors are 
 ii'enerallv due to an admixture of red or of vellow oxide of 
 iron, (travel, it is plain, is not a mineral, but a mixture 
 of various minerals. It is a rork. 
 
 Visit a hed of samf. Vou will tind that it, too, is a, mix- 
 ture of several minerals. (Quartz, opa<iue or transparent^ 
 will prohahly he the most abundant, but others will be 
 found in i::reater or less amount. 
 
 Examine da// next. Take a lump of stiff elay to the 
 school-house, and cover it with water. When thoroughly 
 soaked, stir it through the water. Tour off the '-vater 
 above the clav as soon as it becomes clear. When the 
 remaining water has eva[»orated sutHciently to allow the 
 clay to be handled, it will be found to be (piite plastic. 
 Mould pieces of it into a variety of small models. 
 
 Put water into a saucer just made from damp clay. If 
 the water does not pass through the clay, empty it out, 
 and set the saucer and other clay models in a drv place. 
 
44 Teacher s Manual of Nature Lessotis. 
 
 "When dried, the clay will he found to have become 
 <{uite rigid, thon2;h still soft. Bake the clay models in an 
 oven or in a metal vessel set on a stove. The heated 
 clay will he both rigid and liard. The leaking may be 
 <lone at home by the pupils. 
 
 These experiments illustrate the most important projter- 
 ties of clay, and show its fitness for the manufacture of 
 bricks and earthenware. 
 
 But is clav a single mineral, or a mixture of minerals? 
 Heat thorouii'ldv a little piece of ordinarv clay in a wire 
 coil, ^ote the change of color. Hold a magnet Hrst near 
 some particles of clay which have not lieen heated ; then 
 near some broken from the heated jdece. The latter will 
 be attracted. Explain the facts. 
 
 Ordinarv clavs usujdlv owe their color to the presence of 
 iron compounds. But they consist mainly of silicates of 
 alumina. l*ure white clav is aluminum silicate. AVe can- 
 not see the diftcrent minerals whicli make up oar common 
 clays on ac(!ount of the fineness of the particles. 
 
 The masses of mineral matter which make up the solid 
 earth are called rocks^ no matter how loose or finely pulver- 
 ized they may be. Each pupil should take to the field a 
 knife or file, and the party should have a bottle of hydro- 
 chloric acid to aid in determining the minerals which the 
 Tocks contain. 
 
 Find a bed of gravel which is now accumulating. Such 
 beds occur onlv where there is flowing water. Examine 
 the pebbles. They are of various sizes, but all are more or 
 less smooth and rounded. Seek for an explanation. You 
 
S 
 
 Tcacho-'s Manual of Nature Lessons. 45 
 
 will conehule that these are result?^ due to the pebblet* 
 bein^i:; rubbed together as the water carried them alonic 
 to the hea[) of gravel, and rolkMJ them over one another 
 after thev ijot there. 
 
 A'isit also growing deposits of sand and elay. They 
 will be found onlv where there is water. The u'rains of 
 sand are water-worn like the pebbles in the gravel. 
 
 Gravel, sand, and elav are evidentlv formed throutJ-h the 
 agency of water. They are irater-formed or aqueous (Lat. 
 aqua^ water) rix-ks. But why are they mainly laid down 
 in separate places? Upon investigation you will find that 
 the gravel is de})Osite(l where the water is not moving 
 with sufficient force to push along the pebbles, but if 
 moving rapidly enongh to carry along particles of sand 
 and clay. Similarly, the sand settles where the water i* 
 moving too fast to allow the clay to settle. The clay 
 sinks at last in still water. 
 
 Search for l)eds of gravel, sand, and clay at a distance 
 from water. You will often find them far above the 
 present level of the waters, even on the tops of high hills. 
 What does this teach ? Tt show^s that once these places 
 were covered l)v water, swiftlv flowiiiir, srentlv Howing, or 
 quite still, according to the charaeter of the deposit. 
 
 You will be sure in the course of your exploration to 
 come upon a rock which looks like consolidated gravel, 
 the pebbles being lield in place by the finer material of 
 the rock. This is coiKjloiiHrate or pndding-stone. The 
 rounded pel)bles tell you that it is a water-formed rock. 
 But it must have been loose gravel once, else the pebbles 
 
46 Teacher^s Manual of Nature Lessons. 
 
 <jould never liiive 1)een worn and rounded as thev are. 
 Try to find out how it was consolidated. 
 
 Rocks will also be found which are evidently made up 
 mostlv of "crains of sand all coherini»" too'ether. These are 
 sandsiones. 
 
 Shale is consolidated clay. Account for the consolidation 
 of the cla}' and sand. 
 
 Sometimes in steep banks you will see aqueous rocks 
 lying one above the other in layers or strata (sing-, 
 stratum). Account for this arrani!:ement. Which of the 
 layers was the oldest, that is, which was first deposited ? 
 Why did the one cease to be deposited and tlie other 
 besrin ? It will be seen that the arranii-ement of the rocks 
 one above the other is a means of determining their 
 relative ages. 
 
 There may be no granite rocks in situ in your neigh- 
 borhood, but you will at least, be able to find boulders 
 which have been ])rought from some district farther 
 north where jj-ranite abounds. IIow were these boulders 
 transported? They are too large and heavy to have 
 been brought by water. The only explanation we can 
 think of is that our country was once covered with 
 glaciers, and that these boulders were borne by the ice 
 as it slowly moved southward, as similar boulders are 
 now being transported in the mountains of Switzerland 
 and Alaska. 
 
 Break up some pieces of granite. You will find, upt»n 
 testing the minerals it contains, that it is a mixture of feld- 
 spar, quart/, and mica, varying, however, in relative amount 
 
Teacher^ s Manual of Nahire Lessons. 47 
 
 in (lifi'erent f^pccimens. The Iiard glassy-lookin*:: minoral 
 is evidently rock-erystal. Tlie less hard one, which has 
 glisteiiini"^ cleavage planes, and is nearly wliite, or more or 
 less strongly tinged with red oxide of iro!i, is feldspar. The 
 dark soft mineral which cleaves into thin elastic sheets is 
 black mica. Yon will be strnck by the fact that these 
 minerals show no signs of having been water-worn except, 
 perhaps, at the surface of the rock. The pieces are {ingn- 
 lar, and are evidently imperfect crystals — having crowded 
 upon each other during their formation, and thus interfered 
 with eacli other's development. 
 
 But how were the minerals li(pietied or softened suffi- 
 ciently to emible the molecules to group themselve.' into 
 crystals? It must have been through the action of heat 
 and, perhaps, heated water. The granite may once have 
 been a bed of sand or pel)bles. In that case it is a meta- 
 morp/u'r (Gr. vieia, change ; )iiorphe, form) rock. When 
 an aqueous rock has ])een hardened and crystallized to a 
 greater or less degree through the influence of lieat, it is 
 called a metamorphic rock. 
 
 The granite, however, ma^^ never have been an aqueous 
 rock. Its material may have been ejected in a liquid state 
 from the interior of the earth. In that case it is an ifpitovs 
 (Lat. ig)iis, Are) rock. C^uite likely you will not be able to 
 decide whether your specimens are metamorphic or igneous. 
 
 Examine the weathered surface of a granite boulder. 
 Does the weather have any visible effect on either of its 
 minerals? Scrape off' some of the soft friable substance 
 produced by the decomposition of the feldspar. 
 
48 Teacher's Manual of Nature Lessoris. 
 
 We were once told that felcLsjtar is a silicate containing 
 two metals, that is, a double silicate. The soft residue is 
 a sinirlc silicate — the oidy metal in it being aluminum. 
 The metal potassium, in combination of course with other 
 elements, has beer washed awav. 
 
 I'ulverize a litt'e of the decomposed feldspar and hejit 
 it for several minutes in a closed tube. You have been 
 told that the feldspar lo.'^cs something by weathering; this 
 experiment sliows 3'ou what it (jams. 
 
 The chemical name, then, of the substance we have 
 just been heating is h/drous aluminum silicate. You will 
 have noticed its resemblance to white clay. And, indeed, 
 it is the same. It contributes largely to the formation of 
 beds of clay. Other double silicates besides feldspar 
 decompose in a similar manner. 
 
 Slate is one of the commonest of metamorphic rocks. Its 
 composition and iineness of grain go to show that it was 
 once clay. Its stratitication, and the remains of animals 
 and plants frequently found between its layers, demon- 
 strate its aqueous origin. Relics of ancient life, found in 
 rocks, are called fossils. 
 
 You will find that the thin even sheets into which slate 
 cleaves are not, as you will probably suppose at tirst, differ- 
 ent la^'ers de[)Osited by water. ^ote that the lines of 
 cleavage are, generally speaking, crosswise to the layers 
 of bedding. And, further, the fossils do not rest upon 
 the cleavage surfaces, as they would do if these were the 
 layers of deposition. This slaty cleavage did not exist in 
 the clay at tirst, as it is not found in modern clays. 
 
Teacher'' s Manual of Nature Lessons. 49 
 
 Much as heat converts clay into hard and rigid hricks 
 and earthenware, so long continued pressure, accompanied 
 hy a moderate heat, has changed the original clay into 
 slate. Often, too, crystals, more or less distinct, have been 
 produced. The cause of slaty cleavage ia more difficult to 
 understand. Perhaps, however, the teacher will be able 
 to show experimentally that steady pressure upon a body 
 composed of particles of unequal diameters tends to 
 arrange the particles with their longer diameters at right 
 angles to the direction of the pressure. 
 
 The slate rocks, originally deposited in horizontal layers 
 in still waters, as clay is being deposited at the present 
 time, have often been tilted and curved by disturbances in 
 the earth's crust. Frequently, also, seams and veins, filled 
 with quartz, calcite, or some other mineral, which has fil- 
 tered into them, cross the beds. 
 
 About the sites of old volcanoes and where there have 
 been fissures in the earth's crust, vou will find rocks which 
 were never, so far as we know, deposited by water, but 
 which were produced by the solidification and crystal- 
 lization of molten matter from the depths of the earth. 
 One of the commonest of these rocks is basalt, usually 
 known as trap. A piece of massive trap might be taken 
 for a fragment of sandstone. The little grains composing 
 it, however, are crystalline and not water-worn. It is 
 heavier, too, and harder to break than sandstone. You will 
 sometimes find light basaltic rock containing many cavities 
 formed by the expansion of the gases present in it when 
 in the melted state. The rounded cavities are frequently 
 
 D 
 
50 Teacher^s Manual of Nature Lessons. 
 
 filled with minerals which look like pebbles. Upon break- 
 ing them, however, you will find that they are composed 
 of crystalline minerals which have filtered in from the 
 surrounding rock. This variety of trap is called int^yg- 
 daloid (Lat. amyfjdalum^ an almond). Account for the 
 name. 
 
 We have divided rocks into three classes : Ist, Aqueous 
 Rocks, the materials of which were brought together by 
 water, and which, although often consolidated by pressure 
 since their deposition, have not been altered perceptibly by 
 heat; 2nd, Metamorphic Rocks, originally deposited by 
 water, but afterward altered by pressure and heat; and 3rd, 
 Igneous Rocks, the solidified products of volcanic and 
 fissure eruptions. 
 
 Along the lower course of a stream, beds of clay, sand, 
 and gravel are found. Follow the stream upward and 
 you will find, near its mouth, the source of the deposits — 
 the older rocks from which the materials for the deposits 
 have been taken. They may be older aqueous rocks, or 
 they may be the fragments at the base of a promontory 
 of igneous rock. Upon reflection it will become evident 
 that the first aqueous rocks were composed of materials 
 derived from igneous rocks — that these fire-formed rocks 
 must have constituted the foundation upon which the water 
 did its work. Does it follow that all the ligneous rocks 
 are older than any of the aqueous rocks ? Remember that 
 volcanic action in the earth has not ceased. 
 
 Try to find, by actual study of the rocks in localities 
 where 'he fragments lie close to the masses from which 
 
Teacho'^s Manual of Nature Lessons. 51 
 
 they were broken, the prineipal agencies in tlieir disinte- 
 gration. 
 
 In the finer-<j;raine(l water-formed roeks, vou have 
 sometimew met with tlie remains of phmts and animals. 
 If you closely observe how stems, leaves, shells, etc., are 
 now being buried in the accumulating mud-beds of sea- 
 shore and river, you will be able to picture out the 
 conditions which existed long ago when the plants and 
 animals, of which fossils are the relics, were buried in 
 the stony graves in which they have lain for long ages. 
 
 Do not suppose that the stony fossil stem has been 
 produced by the conversion of wood into stone. That 
 could not have been, for the stone is not composed of the 
 same elements as wood and other vegetable matters. But 
 as the plant gradually decayed, stony particles took the 
 place of the vegetable matter. There is but little of the 
 original material of the plant left. Some of the carbon 
 usually remains, enough to blacken the outside of the 
 fossil. 
 
 The hard parts of animals — their bones or shells — 
 persist in their fossil remains. Touch a clam or oyster 
 shell with hydrochloric acid. Scratch it with a knife. 
 Examine the shells in a piece of fossiliferous limestone in 
 the same way. What do you infer? 
 
 Limestones may be found which are made up almost 
 entirely of fossil shells. When fossils are not to be found, 
 the limestones have probably undergone alteration. Lime- 
 stones, then, are aqueous rocks which accumulated in 
 waters aboundino- in corals, shell fish, and other animals 
 
52 Teacher's Manual of Nature Lessons. 
 
 with hard parts contiiinino; much carhoiiate of lime. 
 Thev thus difter from the other water-formed rocks with 
 which we have met in deriving their material immediately 
 from animals. 
 
 Soils. — The loose earth through which the roots of 
 plants spread, and from which they ahsorb a part of the 
 plant-food, is called the soil. 
 
 Procure about a quart of ordinary soil. If there arc 
 lumps in it, break them up thoroughly. Separate the 
 pebbles and little stones from it by means of a wire sieve. 
 
 Put the soil which passes through the sieve into a small 
 pail half full of water. Stir the soil through the water, 
 then allow it to come to rest. Empty the muddy water 
 into a large pail. Pour fresh water upon the residue, and 
 proceed as before. Continue to pour the water off until 
 it is no longer rendered muddy by the residue of the soil 
 in the small pail. Examine the sediment. What name 
 mav be sjiven to it ? 
 
 Set the large pail aside until the water no longer looks 
 muddy. Pour off the clear water, and leave the pail in a 
 dry room until the remainder of the water has evaporated. 
 Examine the residue in the large pail. What name may 
 you give it? 
 
 If the two residues be nearly equal in weight the soil was 
 a loam. If the part in the small pail considerably exceed 
 the other, the soil was a sandy loam ; but if the contrary 
 be the case, it was a clay loam. 
 
 It should be noted, however, that the fertility of a loam 
 depends largely on the amount of decaying organic matter 
 mixed with the sand and clay. 
 
Teacher's Manual of Nature Lessons. 53 
 
 Heat a little red earth in a wire coil; also a l»it of 
 yellow earth. N'ote the change of color. Test them with 
 the magnet. Explain the facts. 
 
 Procure a lump of hlack earth, such as is usually 
 known as black mud. Some may suppose that, since the 
 red and yellow colors of soils are due to the red and 
 yellow oxides of iron, that the blackness in this case is 
 owing to the presence of the black oxide of iron. Since 
 the latter is magnetic, the magnet will at once decide the 
 question. 
 
 Heat a small jjiece of this black soil in a wire coil 
 until only a light ashy-looking residue is left. It is 
 evident that the black substance so largely present in 
 this soil is combustible. What must it be ? After further 
 examination and discussion, the conclusion will certainlv 
 be reached that it is carbon. 
 
 But whence came the carbon ? We know that when a 
 piece of wood is held in a flame the charred end is 
 composed mostly of carbon which remains behind after 
 the other elements of the wood are mostly expelled. 
 
 Visit any boggy place within reach. It will be noticed 
 on the way that plants which decay above ground m dry 
 places disappear without leaving behind any black residue : 
 but in boggy ground, where the oxygen of the air is 
 mostly excluded by water, a large part of the carbon of 
 decaying plants remains behind. Soils containing a large 
 proportion of this carbonaceous matter are ^^ea^j/ soils. 
 
 Examine also the vegetable mould in the forest produced 
 by the decay of fallen leaves. 
 
64 Teacher s Manual of Nature Lenmns, 
 
 All excursion is now in order for the purpose of examin- 
 ing the elianicter and deptli of the soils in the neiu;hhour- 
 hood. 
 
 S|)ots will he found where there is no soil at all — nothinu: 
 but bare solid rock; others where the soil is very shallow — 
 only a few inches deej). Upon inquirinti^ of those who have 
 dry cellars and wells, you will be able to decide whether 
 the soil is always underlaid by solid rock. 
 
 Examine the alluvial soil of an intervale and compare it 
 with the soil of the adjoinin<!; uplands. Account for the 
 diiierence. 
 
 Visit places where rocks are plainly crumbling away and 
 forming soil. 
 
 Find whether upland soils are usually or alwa^'s formed 
 from the underlvins; rocks. Account for the ftict when 
 decided. Do not forget the glacial boulders in attempting 
 an explanation. 
 
 Coal. — Our studies of peaty soils will enable the pupils 
 to understand how peat is formed in bogs. 
 
 It should be shown by means of fossils from the rocks 
 underlying the coal beds that plants grew in their vicinity 
 previous to their formation. These rocks, as well as those 
 overlying the coal are water-ff»rmed rocks. 
 
 Such considerations as these will lead the pupils to- 
 think it highly probable that coal-beds were once accumu- 
 lations of decaying vegetable matter in swampy lands 
 which have since been buried beneath sediments deposited 
 by overflowing waters. 
 
Teacher's Manual of Nature Lessons. 55 
 
 Skctiox D: The Properties and Composition of the Air. 
 
 Fit a cork, wliicli bus a JK-iit (leliverv tube piissing throui^li 
 it, into u tent tube full of air. Hold tlie a|>i>anitiis so tliat 
 tlie ond of tlio deliverv tube will be under water, and beat 
 the confined air. Part of the air will be forced from the 
 tube, and will ascend iti bubbles throui»:h the water. Ac- 
 count for this. ITow, besides in teiii[»erature, does the air 
 in the tube now differ from the air which was there at first? 
 
 IIt)ld your hand in the air two or three inches al)Ove the 
 flame of a lanqt. Then hold a bit of down or fine cotton- 
 wool in the same place, and suddenly release it. If care- 
 fully done, it will rise vertically for several feet. Kxplain 
 its ascent. Account for winds on the same principle. 
 
 Confine a portion of air bv corking a tube tio;htlv at both 
 ends. Hold one end against a firm surface, and push in 
 the cork at tlie other end with a blunt rod. Although the 
 air cannot escape from the tube, the cork can easily be 
 driven in, thus diminishing the volume of the air without 
 lessening its mass. This experiment shows that air is 
 Ijighly compressible. On removing the rod, the cork, if no 
 air has escaped around it, will be driven back nearly to its 
 original position. Since the air was not able to push the 
 cork out at first, we must conclude that the compression 
 endowed it with more ability to do work — more energy. 
 
 Hold the tube horizontally, leaving the farther end free, 
 and push the nearer cork in quickly. Explain the result. 
 
 Place a piece of paper over the mouth of a tumbler of 
 water. Keeping the paper in its place, invert the tumbler. 
 Something pushes or pulls upon the paper with sufficient 
 
1^6 Teachtr^s Manual of Nature Lessons. 
 
 force to h()l<l u}» tlio wator in o^tposition to gravity. Sliow 
 by oxi>oriiiiont that tlic paj'tT is not held up by adhesion, 
 i^oniething presses ifpirard, then against tlie paper. What 
 <*an it be ? There is nothing touching the lower side of the 
 paper except the air. It must l)e the air, then, that pushes 
 against the })aper. 
 
 Stand a small tube, which is open at both ends, with 
 the lower end in water. Then, pressing the thui..'> against 
 the ui)per end, raise the tube. Some water is maintained 
 in the tube without the intervention of paper. Lift the 
 thumb. The water drops out of the tube. Explain. 
 
 By using a bent tube, it may be shown that the air 
 exerts pressure laterally. 
 
 What else does the air press against besides the things 
 we liave noticed? How do 3'ou know? What compresses 
 the air in the room and pushes it against the surfaces 
 with which it is in contact? It must be the upper air, 
 pressing downward with all its weight, which compresses 
 the lower air and gives it this energy; just as in a former 
 experiment, the })ressure of the air in a closed tube 
 increased its cxjMnsivc force. 
 
 If the school possesses a pound of mercury and a glass tube about three 
 feet long, the pressure of the air per square inch may be calculated, and 
 the principle of the barometer explained. 
 
 The Constituents of the Air. — Repeat the experiments and 
 arguments by which we were formerly led to conclude that 
 there is oxygen in the air. 
 
 Show th^-t the air cannot be entirely composed of 
 oxygen. It is our business then to find what other gas 
 or gases are present in it. How shall we begin ? 
 
leacha^'fi Manual of Nature Lessons, bl 
 
 Let \X9< remove the oxvircti from a confiiu'd portion of 
 air, and try to tind what the residue is. AVe know that 
 when suhstaneeH hurn in tlie air, tliey eond)ine witli its 
 oxygen. We may remove the oxygen, tlien, from some 
 air by ])urning something in it. Let us try aleohoh 
 
 We have })een Imrning alcohol in a spirit lamp. The 
 oxides produced by its eond)Ustion are invisible to us, but 
 we may catch them in a bottle. 
 
 ITold the wide mouth of a bottle rather closely over the 
 flame. Drops of water will condense on the inside of the 
 bottle. In about a minute, close the mouth of the bottle 
 with a Blip of glass and invert it. 
 
 As soon as the mouth of the bottle is cool enough, pour 
 in a little lime-water and shake it through the gases in 
 the closed bottle. A striking change takes place in the 
 lime-water. By argument based on these experiments 
 show what two oxides are produced by the combustion 
 of alcohol, and demonstrate the presence of two elements 
 in it. Besides these, alcohol has been found to contain 
 some oxvjTfen, but not nearly enouo-h to oxidize the two 
 other elements in its molecule. 
 
 Wrap a bit of cotton jiround the end of a brass wire, 
 into a loose ball as large as a grape. Bend the wire into 
 a shape resembling that of the radical sign in algebra, 
 but rounded at the angles. Saturate tlie cotton with 
 alcohol. Hold the wire so that the bend below the cotton 
 rests upon the bottom of a small pan containing lime-water 
 to the depth of three inches. Ignite the alcohol in the 
 ^cotton with a match ; then quickly lower a wide-mouthed 
 
58 Teacher's Manual of Nature Lessons. 
 
 bottle over the cotton until its mouth rests upon the 
 bottom of the pan. The lime-water will rise in the bottle. 
 
 The part of tlie wire bearing the cotton should reach more than half- 
 way up the bottle. There must be enough lime-water in the dish, otherwise 
 air will be forced into the bottle from the outside after the alcohol has 
 ceased to burn. This would spoil the experiment. 
 
 Raise the bottle a little, but not till its mouth is out of 
 the lime-water, and draw out of it the Avire and cotton. 
 Then put one hand into the water and slide the palm under 
 the mouth of the bottle. Turn the bottle up and shake it 
 thorouii;hly, keeping the hand constantly pressed upon its 
 mouth. 
 
 Plunge a lighted match or stick into the gas wdiich now 
 remains over the lime-water. If the experiment has been 
 properly done, the flame will be immediately extinguished. 
 The gas itself does not take fire. What gas previously 
 prepared does this agree with so far ? How shall we deter- 
 mine whether it is that gas or not? By finding whether 
 it \N\\\ have the same effect on lime-water. 
 
 Repeat the preceding experiment with the exception of 
 putting a burning stick into the gas. Instead, as soon as 
 it has been shaken through the lime-water, still keeping 
 the hand tightly over it, lower the bottle into a deep pan 
 or pail full of water. Remo\'e the hand, and tip the mouth 
 of the bottle containing the gas under the mouth of a much, 
 smaller bottle which has been filled with water and inverted 
 in the vessel. The gas will rise into the smaller bottle, 
 displacing the water. Turn the bottle up in the usual w^ay. 
 Remove the hand, pour in lime-water, and shake it through 
 the gas. The water should remain clear. 
 
Teacha-^s Manual of Nature Lessons. 5i> 
 
 Show that this gas differs from any before preparech Its 
 name is nitrogen. Show that there is nitrou:en in the air. 
 Explain why lime-water was used in the preceding experi- 
 ment rather than pure water. 
 
 Phosphorus may be used instead of alcohol in this experiment, but it 
 is so inflaramable and poisonous that the latter is to be preferred in the 
 common schools. However, by using phosphorus it is easy to show that 
 about four-fifths of the air is nitrogen, and about one-fifth oxygen. Direc- 
 tions for performing the experiment with phosphonis may be found in any 
 text-book on chemistry. 
 
 Leave some clear lime-water standing in a bottle tightly 
 closed, and beside it some more in an open dish. Tn a few 
 days a scum will have formed upon the surface of the water 
 in the latter dish. Break a little piece of it away from the 
 rest. It sinks through the water. Skim off the rest of it, 
 and remove the water which adheres to it. Toucli it with 
 hydrochloric acid. This substance displays the distinctive 
 properties of a mineral well known to us. What is it ? 
 
 If it is carltonate of lime, the gas evolved must be carl)on 
 dioxide. Tliis may l)e established by treating a consider- 
 able quantity of the scum with hydrochloric acid in a test 
 tube provided with a delivery tube. The gas, when passed 
 into lime-water, will produce the same effect as carbon 
 dioxide. 
 
 Whence came the carbon dioxide? It is not present in 
 water or hydrochloric acid ; neither did it come from the^ 
 caustic lime dissolved in the water, for, as w^e remember^ 
 that is a compound of lime (calcium oxide) and water. 
 Hence it must have come from the air. But whv did it 
 leave the air and become part of this scum? We can 
 
60 Teacher^ s Manual of Nature Lessons. 
 
 only explain this by supposing that the lime has a stronger 
 iiiiinity for carbon dioxide than for the water with which 
 it is combined in the caustic lime (calcium hydrate) in the 
 lime-water. The lime then, we believe, gave up the water 
 and united with carbon dioxide out of the air, thus form- 
 ing a compound of calcium, carbon, and oxygen (calcium 
 carbonate). 
 
 The teacher must be careful to keep the distinction 
 clear between the water which is eoinbined with the lime 
 to form caustic lime, and the water in which the caustic 
 hme is dissolved to form lime-water. The latter is onlv a 
 mixture, not a compound of caustic lime and water. 
 
 By shaking lime-water through a bottle of air it can be 
 shown that there is but a small amount of carbon dioxide 
 present there. Give the argument. 
 
 Pass carbon dioxide, obtained from carbonate of lime in 
 the manner described in Section B., into a small bottle of 
 lime-water. Take the delivery tube out of the water as 
 soon as the substance which forms in the water has made 
 it opaque. 
 
 Allow this newlv formed solid to settle until the water 
 has become quite clear. Prove the elementary composition 
 of this solid. 
 
 Shake the solid through the water, and pass in more 
 <;arbon dioxide. In a short time the watc' will become 
 olear again although the solid does not settle to the 
 bottom. Account for this. You will probably conclude 
 that the carbon dioxide has made the opaque body more 
 soluble in water. This will explain its disappearance from 
 sight. 
 
Teacher s Manual of Nature Lessons. 61 
 
 Bring a cold glass vessel into a warm room. Drops of 
 water collect on the outside of it. The water could not 
 come out of the i:;lass. Whence did it come ? Give other 
 proofs that there is invisible water vapour (steam) in the 
 air. 
 
 We have now shown that the air contains nitrogen^ 
 oxygen, carbonic acid gas, and water — two elements and 
 two compounds. Besides these, it has been shown to con- 
 tain a very small amount of ammonia and of oxides of 
 nitrogen. Ammonia is a compound of nitrogen and 
 hydrogen. It may be smelled as it issues from a bottle of 
 aqua ammonia^ or in the idr of a stable before it has been 
 cleaned out in the morning;. 
 
 Show that there is little if any hydrogen in the air. 
 
 Section E: The Constituents of the Waters of the 
 Earth, and some of their Properties. 
 
 Water, we already know, is by far the most abundant 
 constituent of our seas, lak' s, and rivers. 
 
 Allow some sea-water, if obtainable, to evaporate, or boil it in a test tube 
 until the water disappears. Of what does the residue mainly consist ? 
 
 Scratch a piece of coral, or the shell of an oyster or 
 mussel, with a knife, and then touch it with hydrochloric 
 acid. Collect some of the <.:as, in the manner described 
 for calcite, and allow it to pass through lime-water. 
 
 Heat a sliver of this shell or coral, and note the eliect of 
 the dampened residue upon red litmus paper. 
 
 Touch the bone of a sea-iish with hydrochloric acid. 
 The mineral part of the bone is evidently different from 
 
62 Teacher's Manual of Nature Lessons. 
 
 that of the shell and coral. It consists mainlv of a salt 
 ■called, from its composition, calcium phosphate or phosphate 
 of lime. 
 
 Touch a fresh-water shell and the bone of a fresh-water 
 lish with hydrochloric acid. 
 
 Examine the deposit on the inside of a kettle or boiler 
 which has ))een in use for some time. 
 
 These experiments will show that not only sea-water, but 
 fresh water, holds in solution various saline matters. In- 
 deed, we might be sure without examination that the 
 rains would dissolve out of the soil and rocks such com- 
 pounds as are soluble in rain-water, and carry them into 
 the rivers and seas. 
 
 But how shall we explain the fact that shells and bones 
 remain for a very long time undissolved in the waters ? 
 We once showed that carbonic acid eras in water has the 
 power of making carbonate of lime soluble. And since 
 rain-water contiiins a considerable amount of carbon 
 dioxide taken from the air, it is a better solvent than 
 waters which contain a less amount of the gas. 
 
 Similarly, it has been found that carbon dioxide renders 
 phosphate ot lime soluble in water. 
 
 Take a sip of rain-water and of water artificially dis- 
 tilled. Are they more or less palatable than ordinary 
 spring or river water ? Account for the difference. 
 
Teachev^s Manual of Nature Lessons. 63 
 
 CHAPTER II. 
 
 THE ORGANIC WORLD. 
 
 DIVISION I. — PLANTS. 
 
 Section A : The DeveloPxMent of the Plant — Root, 
 
 Stem, and Leaves. 
 
 Collect a number of larije seeds. Select some which 
 contain albumen, as those of the ash and of Indian corn ; 
 some wliich have no albumen, as those of the maple, the 
 bean, and the pea; some whose embryos have tleshy 
 cotyledons, as beans, peas, and apple-seeds ; some whose 
 embryofe have one cotyledon, as those of the Indian corn ; 
 others with dicotyledonous embryos ; and seeds with poly- 
 cotyledonous embryos, as those of the white pine and 
 most other members of the IMne Family. 
 
 Plant a sufficient number of each kind of seeds in boxes 
 in a moderately warm room, and water them regularly, but 
 not too frequently. As soon as each kind begins to germi- 
 nate, dissect some seeds (previously soaked, if too hard) of 
 that kind, comparing its parts with those of the germinating 
 plantlet. 
 
 The pupils will learn what parts grow larger in germina- 
 tion, what parts become smaller — they will note the uses 
 of the different parts — and then the teacher will give them 
 their names. Make drawings of the embryo, giving the 
 names of its parts — the radicle, the seed-leaves or cotyle- 
 dons, and the plumule if apparent. 
 
 Leave at least as many young plants in the earth to 
 continue their growth as there are pupils in the class. 
 
64 Teacher^s Manual of Nature Lessons. 
 
 TCeep tliem in the school-room and let the children observe 
 their growth from day to day, noting any interesting 
 changes which are observable. Measnre their height from 
 time to time, and calculate the rate of increase. Why 
 can we not sec them grow ? 
 
 01)serve particularly the manner of growth, the forma- 
 tion of nodes and mternodes, the growth of the leaves and 
 their arrangement on the stem. Xame the different parts 
 of the leaves — the blade, the foot-stalk, the stipules, and 
 notice which of them are sometimes wantino;. 
 
 Observe and name the different shapes of the leaves, 
 and distinguish between simple and compound leaves. 
 
 Watch the formation of buds, and their position — axillary 
 oY ter)tiinal. Compare those which are not intended to 
 live through the winter with those which are, and account 
 for the difference. 
 
 Require the pupils to make drawings illustrating all 
 the important facts and new terms. 
 
 If the plants enumerated cannot all be had, or are not 
 found sufficient to bring out all the necessary points, other 
 seeds and growing plants may be brought in from the 
 fields or gardens. 
 
 The propagation of plants by seeds is called reproduction. 
 
 Section B : The Development of Flowering Plants 
 Continued — The Flower, Fruit, and Seed. 
 
 In the early spring, bring to the school-room several 
 young trees — birches, maples, apple-trees, etc., which bear 
 living buds, but as yet no branches. Keep as much of 
 
Teacher's Manual of Nature Lessons. 65 
 
 the native esirth about tlieir roots as possible. Briiii:; also 
 l)raiK*lies of older trees or shrubs, including!: some with 
 two forms of buds. Set the jjlants aud l)ranelies in vessels 
 of damp eartli or sand. AVateh the buds from (hiy to 
 dav as they swell and leiiii'then out. Into what do the 
 axillary buds on the vouui^ trees develop? — the terminal 
 buds. These buds are called kaj-hnih. Observe that leaf- 
 buds develop not into leaves but into branches, or con- 
 tinuations of the stems, with ordinary or folkufc leaves 
 upon them. 
 
 Some of the buds on the branches from the older trees 
 will develop into a kind of modified branches bearing 
 several sets of moditied leaves set closely together at the 
 top of the branches, or branchlets. These are fower-bads. 
 Each Hower with its stalk constitutes a modified branch, 
 the iioincr-leavi's corresponding to the foliage leaves, but set 
 much more closely tv^gether. Theoretically, then, every 
 bud which develops at all becomes a branch of some kind 
 (or a continuation of the stem, which is e(piivalent to a 
 branch). 
 
 Distinguish and name the different sets of parts which 
 make up a flower, using large flowers at first. Xame the 
 different sorts of flower-leaves — sepals, petals, stamens (fila- 
 ment and anther), carpels. Lead the pupils to see that the 
 carpels are ovule-hearing leaves, and the stamens pollen-bearing 
 leaves. 
 
 Investigate the history of the pollen after its discharge 
 by the anther. It will be found that the stigma is specially- 
 fitted to retain it. After careful observations in the field, 
 
 E 
 
66 Teacher^ 8 Manual of Nature Lessoua. 
 
 it will be cojK'luded that insects and winds are the chid" 
 agents in conveying pollen from the anther to the stigniu — 
 that is, in eftecting pollination. 
 
 Discover at least one plant in which pollination could 
 not be effected by the wind; also, a flower in which it is 
 impossible, or nearly so, for the pollen from its own anthers 
 to reach its stigma. 
 
 Carefully exclude [)ollen from the stigmas of some large 
 flowers. Keep a plant of the same species under similar 
 conditions except those for preventing pollen from reaching 
 the stigma. Tt will not be long until the use of the pollen 
 becomes evident. The eft'ect produced by the pollen upon 
 the ovules is called fertilization. 
 
 Study the means by wliich cross fertilization is secured in 
 the common iris (blue-flag), and find what insect plays a 
 j>rominent part in its pollination. 
 
 Follow the history of the flower on, either in the fields 
 or by bringing specimens into the school-room from time 
 to time. The maple, cherry, apple, strawberry, tomato, 
 and Indian corn will present an instructive variety. Notice 
 what parts of the flower perish, and what parts continue 
 to live and grow. 
 
 When growth has ceased, we have the full-grow^n fruit. 
 The plants mentioned above furnish examples of some of 
 the principal kinds of fruit — the achene, pome^ berry, stove- 
 fruit, (jrain, and key-fruit. The fruit may be defined as the 
 ripened pistil together with any part of the flower which 
 may adhere to it. 
 
 Prove that the little seed-like bodies on the outside of 
 
leachers Manvnl of Nature Lesfions. 67 
 
 the jiiicv ro(H'i)ta('lo of the str:i\v])orrv arc not seeds hut 
 the true fruits. 
 
 Finally, c)j)en the rijK'ned ovary (the seed-vessel), take out 
 the seeds, open one of them, and examine the embryo 
 within. 
 
 We have now followed the life-history of the plant from 
 embrvo to end)rvo. 
 
 Section C: Anxtals, Biennials, and Perennials, Herbs, 
 
 Shrubs, ani> Trees. 
 
 Collect several wild and several cultivated ftlants which 
 grow from the seed, blossom, and die, all in one year. 
 These are annnats (Lat. annus, a year). Learti the names 
 of those you tind. 
 
 Set out in a box or bed a cabbage, turnip, carrot, beet, 
 parsnip, and onion which were grown from the seed last 
 year. ^Sow near them some seeds of each ]>lant. Should 
 the seeds of any of them fail to germinate, young plants 
 grown from the seed can be obtained trom gardeners or 
 farmers, and be planted in boxes or pots in the school- 
 room. Compare the growth and development of the first 
 year with that of the second 3'ear, Xotice the change in 
 the bulb of tlie onion, the thick leaves of the cabbage- 
 head, and the Heshv roots of the other iilants as the u'rowth 
 of the second year proceeds. Draw the inference as to 
 the use of these parts. 
 
 Such of the plants as die outright on ripening their seed 
 at the end of tlieir second year's grow^th are called 
 biennials (Lat. Ins, twice; annas, a year). Plants which 
 
68 Teachei-^8 Manual of Nature Lessoiia, 
 
 ('C)iitiiHU' to live and iz;row tor iiioro tluiii two voiirs ure 
 called perennials (Lat. pcr^ throngh ; annifs, a year). 
 
 Distinguish Ijctween AhVav, s/>ri'hs^ and tires. Discover 
 and name some annual, some biennial, and some perennial 
 herbs. Find how our native perennial herbs provide 
 against tlie cold of winter, what i»arts of them die in tlie 
 autumn, and what parts retain their vitality tlirougli the 
 winter. 
 
 Learn to distinguish our principal forest trees and 
 shrubs — the maples, cherries, birches, alders, the oak, the 
 hazel, the ashes, the elm, the poplars, willows, pines, 
 spruces, the hemlock, larch, or tamarack, and cedar, and 
 in localities where they grow, the linden or basswood, the 
 butternut, and the hornbeam. Note the time and order of 
 their flowering; \vhich of them blossom before their leaves 
 appear; which of them have flowers with l)oth stamens 
 and pistils ; which have on the same tree some flowers with 
 stamens and no pistils {staminatc Jiowcrs), and others with 
 }iistils but no stamens {pistillaie flowers) ; and which bear 
 the pistillate and the stand nate flowers on diflerent trees. 
 Make a collection of their leaves and fruits. Compare 
 them, and make illustrative drawings. Find which of 
 them are deciduous and which are evergreen. 
 
 Section D : Forms and Properties of Roots, Stems, Buds, 
 _ AND Branches. ^ 
 
 Make a collection of j)lanvs illustrating fleshy and tibrous 
 roots, and the principal modifications of stems and branches 
 — as the rmmers of the strawberry; the tendrils of the grape- 
 
Teacher s Manual of Nature Lessons. 60 
 
 vine, the Yirginiii crcoper, or the s<|usish ; tlio suckers of tlie 
 rose or tlie ra8j>borry; the rootsloch- of the couch-gniss ; 
 the tuber of tlie potato or of the spring beauty; the bulbs 
 of tlie onion and lily; and the fhonis of the hawthorn. 
 Allow the ]>upils to identity each of these moditieations as 
 a 8teni, or branch of a stem, giving proofs. The clearest 
 proof in most cases is that they bear leaves, which is a 
 peculiarit}' of stems. Sometimes, however, the leaves are 
 very small and scale-like, as in the case of the potato 
 tuber. The position and origin of thorns show that they 
 are branches, although other evidence may occasionally be 
 found. 
 
 Propa<j(tf.lon bij Cuttiiujs, — At any time when the leaves 
 are off the trees, cut vigorous shoots from voung branches 
 of last year's growth. Among others, get some from the 
 gooseberry, the currant, and the willow. Keep them in a 
 damp cellar, or rolled in damp moss, until early spring. 
 Then set them in prepared earth, well packed around them, 
 leaving several buds above the ground. Keep the earth 
 moderatelv moist, and free from weeds. Also l)urv in the 
 earth short })ieces of the underground stems of couch-grass, 
 each piece having but one bud. If successful, you will tiiul 
 that little branches, or portions of branches, will develop 
 roots, so that each will become a complete and independent 
 plant with root, stem, and leaves. These experiments de- 
 monstrate the remarkable power of striking root which 
 branches possess. We must show how this property may 
 be taken advantage of in the propagation of plants. 
 
 Layeiiyig. — Bend a branch of a gooseberry or currant 
 
70 
 
 Tcacher\ Manual of Nature Lessons. 
 
 liiisli down to u little hollow in the oiirtli, and iiiaki' a notch 
 j)iirtly throuu:h the wood with a knife at the plaee where it 
 touches the gronnd. Tin the ln-anch (hnvn with a hooked 
 stick aiUk eover tile part near the noteh with earth, leavins^ 
 the en<l ol' the hrsmeh ahove L!;round. Wtieii it han taken 
 root, sever it i'roni the main plant and set it out in another 
 place. 
 
 (Tvaftiiyj. — .\telt toi^ether some resin, hees-wax, and tal- 
 low, usinu; ahont one-third more resin than of either of the 
 
 other in,ii:redients. Tear 
 a piece of calico into nar- 
 row strips. Roll them up 
 and sojik them tln^roughly 
 in the liquid mixture. 
 
 In autumn, after the fall 
 of the leaf, or in winter, 
 cut some short pieces of 
 last season's growth, with- 
 out Hower-buds, hut hear- 
 ing leaf-buds, from the 
 ends of the branches of a 
 healthy apple-tree. Keep 
 these shoots in a cool, 
 moist place, with their cut 
 ends in damp earth or moss. If the work is to be done 
 in the school-room, we must bring in, wl?en spring arrives, 
 some young apple-trees about two years old, taken up root 
 and all. With a very sharp knife, cut the stem oft' obliquely 
 close to the root. Make the cut as smooth and even as 
 
 ROOT-GRAFTING. 
 
 a. The Stock, b. The Scion, c. The Union of 
 Stock and Scion. 
 
Teaclier^s Manual of Nature Lctmoua. 71 
 
 |»osrtil)lo. At tlu' middle of tlu* cut siirt'aci', by iiuikint? u 
 downward slit, ju'odticc u tonn'iic of wood iirojcctinii- up- 
 wards. Cut oft*ol>li(jiU'ly the lower end ot" one of the sliootK 
 previously iiieiitioTU'd, and make in it a totiicue i»roje<;tinL^ 
 downwards, so that it will tit exjietly upon the end of the 
 root cut as described. Then tit th(>in toi^ether tightly, 
 taking care that the inner hark of the one is in close con- 
 tact with that ol" the other, at least on one side. F'inish 
 hy wrai»})ing a strip of calico, saturated with the grafting 
 mixture, tirndy around the parts wliere the joining was 
 made. 
 
 The process just described is called //'v/./'///?y ; the })lant 
 upon which the shoot is grafted is called the .s7or/i ; and the 
 shoot itself the scioti. If properly done, the two will unite, 
 and growth will ))roceed in the ordinary wav. 
 
 One or two of the plants should be set out in good 
 earth in the school grounds. The others may be planted 
 at home in the garden bv the children, to he afterward 
 transferred to the orchard. 
 
 If it is not convenient to do the work in tlie school-room, 
 the grafting may be done in the orchard upon an older 
 tree. Cut off' the ends of some of the lower branches, and 
 graft upon them shoots from other trees. If the teacher 
 should he conscious of a lack of skill, a lesson from some 
 one who has a practical knowledge of grafting will over- 
 come the difficulty. 
 
 Budding. — If a single bud be cut smoothly from the new 
 wood in the summer, before the tree has completed its 
 growth for the year, it will, if inserted under the bark of 
 
72 
 
 Teacher^s Manual of Nature Lessons. 
 
 another tree of the same kind, grow out and l)ecome a 
 hranch. A portion of bark and a very little wood at the 
 hase of the bud should be cut out wiHi the bud. A cross- 
 shaped incision is made in the bark so that it can be raise*! 
 to receive the bud beneath it. A piece of tape, soaked in 
 the graftini; mixture, is then tightly wound about it. 
 
 BUDDING. 
 
 o. Removal of bud. b. Method of slilHiig the bark. c. The bud inserted. 
 
 d. The same tied up. 
 
 Find whv the different varieties of orchard fruits are 
 usually pro[»agated by grafting or l)udding. 
 
 Encourage the children to experiment further in this 
 line and report their failures and successes. 
 
 Transplantmg 7)rcs. — Xo school, in country or city, 
 should allow arbor day to pass without planting one or 
 more trees. If there is no room in the school grounds for 
 more trees, city schools may find vacant spaces in the 
 public parks nnd along the streets; country schools, by 
 the roadside near the school, or before the house of a poor 
 
Teacher's Manual of Nature Lessons. 73 
 
 or infirm resident of the district. In the country, too, 
 the cliildren should he encouraged to plant trees ahout 
 their homes. 
 
 But the trees must he taken up and planted in an intelli- 
 gent manner, and ])e cared tor and piotected afterward, 
 else only disappointment will follow. The proper time to 
 transplant trees is Just hefore the huds hcgin to swell. In 
 selecting trees for trans[)lanting, prefer those which grow 
 at some distance from others. They will hear the chauire 
 to an exposed situation hetter than those which liave heen 
 growing in the dense shade. 
 
 Small thrifty trees will hear transplanting hetter than 
 hirger ones and will soon surpass them in size. 
 
 Great care should he taken not to destroy the iihrous 
 roots. As soon as the tree is out of the earth its roots 
 should he dipped in, or dauhed with, rich mud, or covered 
 with very damp earth. It is important that the rootlets 
 be kept moist until the tree is set out. 
 
 The ground into which the tree is set should be well 
 spaded. Sift loose rich carta about the roots when the 
 young tree has been set in place. Shake the tree up and 
 downi a little as tlie roots become covered to assist in 
 working the earth into all the cavities. Finally press the 
 earth down, but not too compactly, to the level of the 
 surrounding soil. A pail of water thrown on the earth 
 before the last is put in will aid in bringing the tine soil 
 close to the rootlets. 
 
 If the soil be clayey, the tree must not be planted deep, 
 as water would collect and sta«>:nate around it. In the case 
 
74 Teacher^s Ilanual of Nature Lessom. 
 
 of very clayej' soil, a little dniin filled with sand or sandy 
 earth should he digged to earry off the surplus water. 
 
 In most eases, unless the tree is quite small, the ends of 
 the branehes should he lopped off in order to balance the 
 loss of roots. In doing this the future symmetry of the 
 tree should he kept in view. 
 
 Sometimes it would l)e better to saw off the top of the 
 main stem, and cut off all the branches quite short. It 
 is well to cover the wounds with paint or tar. 
 
 The earth around the tree should be covered, especially 
 if the season be dry, with a mulching of straw, decaying 
 chips, or other loose material. The trees will need to be 
 watered in case of a drought. 
 
 In the country, if not protected from cattle by a fence, 
 each tree must be separately guarded by stakes or palings 
 set around it and joined by cross-pieces. 
 
 Section E : Structural Relations and Classification 
 
 OF Plants. 
 
 Collect a set of plants, in bloom at the same time, illus- 
 trating the various degrees and forms of cohesion and 
 adhesion in the flower. The buttercup, plum, apple, 
 adder's tongue, trillium, dwarf raspberry, fiy-lioneysuckle, 
 and dandelion will make a good set, but a closely related 
 plant may be substituted for either of them. 
 
 First examine the flowers for examples of union between 
 the parts of the same circle, i. e., for cohesion. In the 
 butteiA'Up no cohesion will be found; but in the others the 
 parts of the calyx are more or less united, the lower part, 
 
Teacher s Manual of Nature Lessons. 7 5 
 
 us far as the coliesioii extends, forniijig tlie tnhe of tlie 
 calyx, iiiid the n|)per part tlie llitif). The numl)er of lobes 
 or teeth in tlie limb indicate the number of sepids except 
 in the florets of tlie dandelion in wliicli the limb of the 
 calyx is made np of numerous bristles so that we can oidy 
 infer the numl»er of }»arts of which the calyx is formed, 
 from the numbei' which make up the stamens and corolla. 
 Among the flowers will be found cases in which the petals 
 are distinct, and in which they are more or less united: 
 cases of distinct stamens, and of stamens united by tlicir 
 anthers; of distinct car])els, and of carpels coherent. 
 
 Next look for examples of union between different circles, 
 i. e., for adhesion. Here you will find the calyx quite free 
 from all the other circles; there vou will find it adherinu; 
 to — combined with — the ovarv. Sometimes the corolla 
 will be free from the other parts of the flower, and only 
 attached to — inserted on — the receptacle; sometimes it will 
 be inserted on the calyx tube. Agaiti, in the dandelion it is 
 seemingly inserted on the top of the ovary. Stamens will 
 be found inserted on the receptacle, on the calyx, and on 
 the corolla. 
 
 In this way, the pu[)ils will be led to see that flowers 
 differ widely in the degree and manner of the union be- 
 tween their parts — in the way they are put together — 
 that is, in their structure. 
 
 Compare the flowers as to the number of parts in the 
 <lifl*erent circles of the same flower, and in the correspond- 
 ing circles of difterent flowers. Also compare the veining 
 of their leaves, and sections of their stems. Draw any 
 general conclusions which seems to be justified bv the facts. 
 
76 Teacher^s Manual of Nature Lessons. 
 
 If this work be done after the =nminer vacation, a differ- 
 ent, but equally suitable, set of plants can be found. 
 
 Let the pupils find two or three plants in the field whose 
 flowers resemble those of the buttercup in having neither 
 cohesion nor adhesion, and in possessing several carpels 
 and numerous stamens. 
 
 Seek for resemblances in other parts as well as in the 
 flowers — in the form of the leaves; in the stipules, if pre- 
 sent; in the taste of the juice, and in the fruit. 
 
 On account of these resemblances, especially in the struc- 
 ture of the flowers, these plants are considered to be nearly 
 enough related to belong to one FaJiiUi/ or Order. It is 
 called the Crowfoot or Buttercup FamiO/. Find the origin 
 of both names. 
 
 The features, in which the plants of this family agree with 
 each other, but differ from the members of other families, 
 constitute the characteristics of the Crowfoot Familv. Enu- 
 merate and record these characteristics. Make out tabular 
 <le8criptions of at least three plants of this family, displaying 
 clearly to the eye their common features, and at the same 
 time their individual differences. 
 
 Do not require of the children, at this stage, the use of 
 the technical terms used by botanists for expressing the 
 lack of cohesion and adhesion, and the different modes of 
 them. Encourage a clear statement of the facts by the use 
 of ordinar3" language. 
 
 The pupils should make drawings of the plants to 
 accompany their written descriptions. These drawings 
 should exhibit the plant as a whole, and also sections of 
 
THE HAREBELL. 
 a. Section of Flower. 
 
78 Teacher's Manual of Nature Lessons. 
 
 tlio flower and fruit. The pluiit may l)e drawn eitLer as 
 it appears in life, or after it has been dried under pressure. 
 .Siuall phmts may ])e dried in old books. Larger ones 
 should be placed between tliiek sheets of drying paper, or 
 several thicknesses of old newspapers. I^ressure is applied 
 by laying a board on the top bearing a number of bricks 
 or .ones. Tlie paper should be changed every day at 
 first; less frequently afterward. If carefully done, the 
 leaves and flowers will retain their natural colors. 
 
 In the manner previously described, the pupils should 
 make out for themselves the characteristics oi the Hose 
 iind Lily Families, with descriptions and drawings. 
 
 Make out the structure of the flower in tlie blue-flag or 
 iris and in the lady's slipper or some other member of 
 the Orchis Familv, notins; the structural differences between 
 them and the Lily Family. 
 
 In examining plants, if the seed be so small that the 
 parts of the embryo cannot be made out distinctlv, its 
 general form and the number of cotyledons can be learned 
 by allowing the seed to germinate. 
 
 Section F: Structural Delations and Classification of 
 
 Plants — Continued. 
 
 During the next season make out, as before, the charac- 
 teristics of tlie Cress, Aster, Buckwheat, Willow, i*ine, and 
 Grass Families, Avith accomi)anying drawings and descrip- 
 tions. 
 
 In selecting representatives of the preceding families, 
 iilways include one or more cultivated plants if possible. 
 
leacho'^s 3Ianual of Nature Lesi^ons. 79 
 
 Make out, at least, tlic t'ainily relations of the eabbauv, 
 turnip, l)eet, carrot, radish, apple, cherry, strawberry, plum, 
 raspberry, currant, bean, clover, onion, oat, wheat, and 
 timothy. The pupils will be pleased when they discover 
 that those cultivated plants, which are mostly descendants 
 of immigrants from the Old World, liave near relations 
 among the native American [dants which grow and pro}>a- 
 gate tlieir species without man's care. 
 
 In the spring-time, watch the curion. way in which the 
 leaves — fronds — of ferns unfold. Xothing but the leaves 
 rise above the ground. The stem and root must be beneath 
 its surface in our ferns. Dig some up and examine them. 
 If they grow at a long distance from the school take up two 
 or three kinds, with a good share of their native soil, and 
 wet them in boxes in the school-room. Allow them enough 
 water and not too much light. 
 
 Follow the growth of the rei)roductive organs on tlie 
 back of the fronds. 
 
 Compare the ferns with re]>resentatives of some of the 
 other families of lowering plants — the Club-mosses, 
 Mosses, Horsetails, Lichens, and Mushrooms or Fungi. 
 Note such differences as will enable the pupils to refer 
 ordinary tlowerless plants to their proper families. 
 
 In autumn, collect a quantity of the ripe spoi'es of ferns 
 or of club-mosses. Demonstrate, by imitating the natural 
 conditions as closely as possible in the school-room, that 
 they possess vitality and the power of growth. The s[)ores 
 may be sown upon pieces of brick placed in a saucer con- 
 taining water. The brick will absorb water to keep the 
 
80 Teacher\s Manual of Nature Lessons. 
 
 spores sufHcieiitly moist. Cover the saucer witli a glass 
 jar, aiul keep it \iiere the teini)erature will be as even us 
 possible and tlie light not too strong. 
 
 [{' time and opportunity permit, a small area of damp 
 earth nuiy he prepared in a suitable place, ajid then be' 
 sown with spores. The spot should be protected so that 
 rains will not wash the s[)ores away. The sowers may 
 succeed in growing new plants. 
 
 The pupils are now able to arrange all the }»lants they 
 have met with in two divisions which will include the 
 whole, viz., plants which bear Howers and seeds (each of 
 which contains, when mature, an emI>ryo): and plants 
 which do not l)ear Howers or seeds, but reproduce them- 
 selves by means of mimite reproductive bodies called 
 spores. These great divisions of plants are called Series — 
 the former the Flowering Series, the latter the Floivcrless 
 Series. 
 
 Similarlv, divide the Flowering ISeries into two Classes 
 — the Exogenous Class or Dicotyledons, and tlie Endo- 
 genous Class or Monocotyledons. Inquire into the appro- 
 priateness of these terms. Enumerate {ind record the 
 features common to all plants of each class. These are 
 Class characteristics. Refer the families of Howering 
 plants whose characteristics have been made out to one 
 or the other of these classes, giving the reasons. Consider 
 whether part of a famih^ ever belongs to one class, and 
 the other species of the family to another class. 
 
 Divide the Exogens into two groups — Sub-classes — 
 Covered-Seeded plants and Naked-Seeded plants, and write 
 out the characteristics of each sub-class. 
 
Teacher^s Manual of Nature Lessons. 81 
 
 AiTanir<^' tlu' families ol' Ex()i::tMis with wliich voii arc 
 acquainted under one or tlie other of the ahove sub-ehisscs. 
 
 The pupils are to work out the above classitieation 
 themselves. A set of specimens illustratiuiz; these natural 
 divisions of plants should be arran«^ed before them while 
 thus enii'a«!:ed. 
 
 Description of Bed Clover. — The main root is large, firm, 
 and tough. Its principal divisions are long and fleshy, 
 with flbrous branches extending a great way in various 
 directions. 
 
 The stem is exogenous, contains only a small amount of 
 wood, and is slightly hairy. 
 
 The leaves are net-veined, compound, alternate. The 
 blade is composed of three oval leaflets, each of which has a 
 pale spot on its upper surface. Each leaf has a pair of broad 
 stipules which adhere to the foot-stalk except at the tips. 
 
 The flowers grow in dense roundish clusters, or heads. 
 They are pleasantly sweet-scented. Each flower is on a 
 little receptacle of its own. 
 
 The lower part of the calyx forms a narrow cup, which 
 is hairy at the mouth. The cup bears five slender teeth, 
 which show that the calyx is composed of five sepals united 
 at the base. 
 
 The corolla is composed of five petals of different sizes 
 and shapes. It is of a purplish color. The upper petal is 
 the largest. There are two smaller petals at the sides, and 
 between them two small petals are united at one edge. All 
 the petals are united below in a long, slender tube. Upon 
 splitting this tube, without pulling it out of the calyx, two 
 
 F 
 
82 TeaQher\^ Manual of Nature Lessoiifi. 
 
 slender tliread-like parts will be found insido of it. "When 
 traeed downward, one of tliem will be found to end in 
 the snndl, ij^reen ovary, and is therefore the style. When 
 traced upward, the other will be found to ))ear an anther 
 on the top, and is therefore a tilainent. Xine other stamens 
 show their anthers, but their filaments unite in the loiiic 
 tube, which seems to consist of tlie tilaments of nine sta- 
 mens and the lower parts of the petals, i(ro\vn together. 
 This tube, when [Milled out, is seen to have been fastened 
 to the base of the calvx-tube. We niii^ht have thoun'ht it 
 grew from the receptacle had we not noticed that the tlower 
 closely resembles, in structure, those of the Pea and Bean. 
 And since there is nothing to show that the pistil has more 
 than one carpel, we conclude that, like the }»istils of its near 
 relatives, it is formed from onlv one ovule-bearino; leaf. 
 
 The fruit is verv small, and remains liidden within the 
 calyx. It seems most often to contain only one seed. The 
 .seed contains nothimj: l)u.t an embrvo, whicli has two cotv- 
 ledons. 
 
 We do not know yet how long the Red Clover lives, but 
 I shall raise some plants from the seeds, and count the 
 years until they die. 
 
 .^^OTE. — The above description will show that a plant may be elescribed 
 with exactness, including the structure of the flower, without the use of any 
 of the more difficult technical terms employed in text-books on Botany. 
 
 Section Ct: The Composition of Plants. 
 
 We know something about the composition of the earth, 
 the ocean, and the air. To discover what plants are 
 chiefly composed of is our next undertaking. 
 
Teacher s Manval of Nature LeHnons. 83 
 
 IMiU'c ill the bottom of si'pjirato test tulu'^ ji little 
 cotton fibre, u hit of uiiit(> linen, iiiul a pieci' of tlie pith 
 of I'l snntlower, and cover them witli water. Xote the 
 effect, if any; then pour otT' the water and eover them 
 with alcoliol. Km[)ty the alcohol, and cover tliem with 
 hvdrochloric acid. 
 
 Slowly heat a dry piece of each of the suhstancies ahove 
 mentioned in a test tnhe closed V)y th(> fini!:er. dear drops 
 of water collect on the inside of the tube, while a hlack 
 mass of charcoal remains in the bottom. 
 
 Eacli of these substances, then, must contain carbon and 
 the elements of water — hvdro<i;en and oxvi^en. This 
 means that the molecule of each contains one or more 
 atoms of carl)()n, hydrogen, and oxygen, respectively. The 
 wood oi' ]>lants is mainly composed of a substance called 
 cellulose, consisting' of these three elements. Cotton and 
 linen tibre and dry sunflower ]>ith are nearly [lure 
 cellulose. 
 
 With a knife or grater, reduce a small potato to a Hne 
 pulp. Place the [>ulp in the middle of a piece of t/iut 
 cotton, and draw together the edges so as to form a little 
 l)ag with the pnlp in the bottom. Take a saucer of water, 
 and ])y alternate di[)i»ing and squeezing, without using 
 much force, try to get out of the pulp anything soluble 
 which it mav contain, or anvthing which is in a sufHcientlv 
 fine state of division to pass through the meshes of the 
 cotton. 
 
 When this has been well done, stir the water, and jtour 
 it, and evervthinir which it contains, into a slender bottle 
 
84 Teacher's Manual of Nature Lessons. 
 
 or into test tubes. Soon a white solid substance will have 
 settled to the bottom. This is evidontlv insoluble in cold 
 
 « 
 
 water. 
 
 Pour off the lic^uid over it into test tubes. Boil a little 
 of this white substance with fresh water, in a test tube. 
 Mix with water a small portion of the jelly-like mass 
 which results. Put in two or three drops of tincture of 
 iodine — a solution of iodine in alcohol. A new and bright 
 color should appear. 
 
 Treat a bit of starch in a similar way with cold and hot 
 water, and tincture of iodine. Facts will justify the infer- 
 ence that the white solid which came out of the potato is^ 
 starch. How, being insoluble, did it pass through the 
 coUon? It is granular — made up of little grains small 
 enough to make their way through the meshes. 
 
 Heat slowdy a piece of thoroughly dry starch in a 
 closed tube. AVhat collects above the starch on the 
 inside, and what is the dark substance which remains 
 in the bottom ? You will conclude that each molecule 
 of starch contains one or more atoms of carbon, of 
 hydrogen, and of oxygen. 
 
 Cellulose and starch are ternary compounds ; they are 
 called, from their elementary composition, carboh/drates — 
 the first part of the word denoting carbon, the middle 
 part hydrogen, and the termination ate oxygen. 
 
 Warm with the fiame of the spirit lamp, in a test tube, 
 some of the liquid which was poured from over the 
 starch. Before the water has begun to boil, a substance, 
 which evidently was dissolved in the cold waiter, will 
 
Teacher'' s Mariual of Nature Lessomt. 85 
 
 solidify in the warm water. This substance, so pLiinly 
 different from starch in its properties, must also have 
 come out of the potato. It is known as albumen (Lat. 
 albas, white), although, from the presence of foreign sub- 
 stances, it does not appear to be quite white. 
 
 Mix wheat flour with enough water to make a lump of 
 stiff dough as large as a small apple. 
 
 Put this dough into a thin cotton bag. Dip it in water 
 and squeeze it repeatedly in the same manner as the 
 potato pulp. Stir the water and pour it into a test tube. 
 Identify the substance which settles to the bottom. Spread 
 the bag open, and examine the part of the flour which did 
 not pass through into the water. Although it is insoluble 
 like the substance which passed out, it differs from it in 
 being sticky, and in admitting of being drawn out into 
 strings wliich contract when they break. This substance 
 is called fjlutin or vegetable fbrin. These names, it will be 
 noticed, were suggested by its properties. Upon slowly 
 heating dry albumen and gluten, it will be found that 
 they both contain carbon. We shall not be able to show 
 experimentally what other elements are in them. They 
 have, however, been found to contain (besides carbon) 
 hydrogen, oxygen, nitrogen, and a little sulphur, i. e., the 
 elements of the carbohydrates and two more. They are 
 called albuminoids, nitror/enoKs substances, or proteids. Note 
 the suitability of the first two names ; that of the third is 
 not so apparent in the present state of our knowledge. 
 
 Call attention to the fact that sugar is another substance 
 found in plants. Treat a little sugar with hot and cold 
 
86 Teacher''' s Manual of Nature Lessons. 
 
 water. Ileiit a few ij;raiiis of it slowlv in a closed tube. 
 What elements must be in it ? It is plainlv another 
 carl )oli yd rate. 
 
 The pupils will be able to mention substances found in 
 [tlants which difler in some of their properties from anv we 
 liave examined. Indeed, there are many other vegetable 
 substances — some carbohydrates, some albuminoids, some 
 oils, some acids, etc. ; but those we have considered make 
 up the greater part of most plants. 
 
 Hold a green leaf by one edge, keeping the farther part 
 in the tlame of a s[)irit lam[>, and carefully observe the 
 visible changes. The part of the leaf ex[)Osed to the fire 
 first dries, then blackens, and lastly whitens. Do your best 
 to burn the white tilm which remains. This incombustible 
 material, or inorganie matter, is the ash of the plant. Burn 
 other portions of plants in the same way. 
 
 Procure some ash from a stove. Mix the ash with water, 
 A part of it settles to tlie bottom. Dip a piece of red 
 litmus paper into the water above it. The effect shows 
 that part oi' the ash is soluble in water, and also that this 
 soluble part contains a metal. 
 
 The ashes of plants have been found, by analysis, to con- 
 sist mainl V of the salts and oxides of various metals. Hence 
 we speak of the ash as saline matter. 
 
 But what became of the carbohydrates, albuminoids, oils, 
 etc., when the plants were exposed to the fire. They must 
 have been consumed. These combustible substances are 
 called organic matter. Wliat was the black substance which 
 was the last to burn ? Which is greater in amount in the 
 plant — the organic matter or the ash ? 
 
leacher^s Manual of Nature Lessons. 87 
 
 Sectiun 11 : The Food of Plants ani> its Assimilation. 
 
 Ul>oii inquiry, your pupils will tell you tliiit a I'ull-growii' 
 lilaut luis much more mutter in it than when it began its 
 existence, and that this matter must have been obtained 
 from its surroundinics — from its enciroHnicitt. 
 
 They will also notice that the soil and air, with the water 
 whi(;h falls from the air, constitute the whole material sur- 
 rouiidinii^s of the phmt. They will tell you that the organic 
 substances in the |>lant — the starch, sugar, cellulose, albu- 
 men, gluten, etc. — are not found either in the air, water, or 
 soil. It must be that the substances which the plant took 
 in — liA food. — underwent cliemical changes within the plant 
 by which these organic couipounds were produced. The 
 changes which the i)lant food undergoes are denoted collec- 
 tively by the term as.^imdlafmi, since by them substances 
 which differ from those in tlie plant are transformed into 
 substances which are s'mi.'dav to them. 
 
 The pu[>ils can easily oe led to see that the food of the 
 jtlaut must contain the elements of starch, sugar, ceUulose, 
 and the other organic compounds which are the products 
 of assimihition. 
 
 Examine a young plant — root, stem, and leaves. No 
 openings can be seen through which the smallest particle 
 of solid matter could enter. It is evident that a plant 
 can only take in — absorb — liquid or gaseous matter. 
 
 Let us try to find out some of the substances which 
 plants absorb. To make starch and the other carbo- 
 hydrates the substances taken in must contain their ele- 
 ments — carbon, hydrogen, and oxygen. They cannot 
 
88 Teach&i'''s Manual of Nature Lessons. 
 
 take ill carbon l)y itself since it is quite insoluble. But 
 the air contains carbon dioxide, a gaseous compound of 
 carbon. Hydrogen is not, by itself, a constituent of either 
 the soil or air. Water, however, whicli contains hydrogen 
 and oxygen, is present in both the liquid and gaseous 
 states. 
 
 These two compounds, carl)on dioxide and water, con- 
 tain, taken together, the same elements as starch. And 
 further, water contains hydrogen and oxygen in the [»ro- 
 portions in which they exist in starch. We remember that 
 Avhen starcli was hented in a closed tube its hydrogen and 
 oxj-gen immediately began to pass off together in the form 
 of water, leaving carbon behind. 
 
 It is probable, then, that the plant absorbs carbon 
 dioxide and M^ater, and out of their elements forms the 
 carbohydrates. Let us put this supposition to the test of 
 experiment. 
 
 Twist the end of a small wire around a short piece of 
 a taper. Fill a pan with water to the depth of about 
 three inches. Set a pickle bottle, or other wide-mouthed 
 bottle, with it:^ mouth down into the water, and let it 
 stand thus on the bottom of the pan. Bend the wire in 
 the manner described for the pre[)aration of nitrogen by 
 the combustion of alcohol. Rest the bends below the end 
 which bears the taper, on the bottom of the pan. The 
 taper should reach a short distance above the water. 
 Light the taper, and set the bottle mouth downward over 
 it. As the taper burns, water will rise into the bottle. 
 When combustion has ceased, quickly raise the bottle, and 
 
Teacher^8 Manual of Nature Lessons. 89 
 
 as soon as thu water wliich lias risen into it (Iroj)s out, 
 place the palm of the hand closely over the niontli of the 
 bottle and turn its mouth upward. Kemove the hand, 
 pour in lime-water until the bottle is one-fourth full; close 
 it tightly again aiid shake the lime-water through the gases. 
 
 The effect will show that carbon dioxide was produced 
 by the combustion of the taper, which means that the 
 taper contains carbon which united with the oxj'gen of 
 the air in the bottle. The air, then, now contains little 
 oxygen, but, instead, much carbon dioxide. 
 
 Burn the tai»er in two other bottles as before; but this 
 time leave the bottles standing with their mouths under 
 water. Get the taper out of the bottle by raising the 
 latter in the water and drawing the taper out by the wire. 
 Be careful not to raise the mouth of the bottle out of 
 the water. 
 
 Prepare another bottle in the same way, and after remov- 
 ing the taper, push up into it, without raising its mouth 
 above the surface of the water, a sprig of mint, or some 
 other plant, with rootlets attached. Most of the leaves 
 should reach above the water, atid the roots should be 
 immersed in the water. The plant may be as tall as the 
 bottle. 
 
 It will be well to prepare three other bottles, using 
 another pan, in the same way. Take two plants of one 
 species, and two of another. 
 
 Set two of the bottles containing plants of the same 
 species in a place where they will receive plenty of sunlight. 
 Set the other two in a totally dark, but not a cold place, as 
 
90 leacher^s Manual of Nature Lesftons. 
 
 in a trunk or close box. Let all the bottles remain with 
 their nioutlis under water for six or eight <hiys, then [)usli ji 
 slip of glass under a bottle which had no plant in it, and 
 turn its mouth u]>ward. Lower into it ])y it wire a burning 
 ta|»er. It will be at once extinguished. Shake up lime- 
 water in it, and in the other bottle wdiich was left without 
 a plant. The effect on the lime-water will be tlie same as 
 in the l)ottlc in which the taper had just been burned. 
 Explain the results. 
 
 Kemove the plant, without allowing air to enter, out of 
 one of the bottles which was left cx[)ose(l to the light. 
 Then slip the hand under the mouth of the bottle and 
 invert it, allowing the water in it to fall to the bottom 
 of the bottle. Quickly lower a lighted tai)cr into it by 
 means of a wire. The ta[)er should continue to burn for 
 some time. Remove the plant in the same way from the 
 companion bottle ; but raise it above the water before 
 placing the hand upon its mouth that any water which is 
 in it mav fall out. Then shake through it some lime- 
 water. The water should remain clear. Account, as far 
 as you are able, for these results. 
 
 Since the carbon dioxide remained in the bottles which 
 contained no plants, and disappeared from tliose in which 
 plants had been placed, we must conclude that, in the latter 
 case, the plants absorbed that gas. And since there was 
 oxygen enough in the latter case to enable a taper to burn, 
 although all, or nearly all of it, had been previously re- 
 moved by the combustion of the taper, we are led to 
 conclude that the plant gave out oxygen. 
 
Teacher 8 Manual of Nature Lessons. 91 
 
 Fill ji 1)()ttle, in which ji niiiiiixu- of tK'isli loiivus hnvv 
 been plticod, with niiii-wutor or water from a stream, 
 which, since carhon dioxide is sohil)k' in water, must have 
 taken in some of that n'as from tiie air. Invert the hottle 
 with its mouth down in Ji saucer of water, and expose it 
 to direct sunlijj^ht. Bubhles of gas will collect uj^on the 
 leaves and will readilv ascend in small huhbles to the 
 surface. What gas is \t'i 
 
 Prepare another hottle similarly, using water from which 
 the carhon dioxide has been expelled hv hoilinu'. Xcr 
 bubbles of oxygen will be given ofi* from the leaves. 
 
 When the leaves, then, can get no carbonic acid gas 
 tliev cease to ij^ive ofi' oxviren. 
 
 It seems that the oxygen which is evolved from a plant 
 comes from the carl)onic acid gas which it absorbs; that 
 is, the plant decomposes carbon dioxide and gives off its 
 oxygen, retaining the carbon. By careful manipulation, 
 the oxygen from the leaves may be em})tied upward into 
 a vial or small test tube. If a hardwood s[)linter, with a 
 glowing tip, l)e plunged into it, active combustion will 
 set in. 
 
 A leafy water-plant immersed in rain-water in an 
 inverted test tube, will give off oxygen rapidly when held 
 in the light. 
 
 Examine the gas now in the bottles which were Fot awav 
 in darkness. Find whether a taper will burn in one of^ 
 them. Shake lime-water through the other. Account 
 for the difference between these results and those obtained 
 in the bottles left under the influence of suuliorht. 
 
92 Teacher a Manual of Nature Lemontt. 
 
 Set a yoiinu; c'tibbaii:L', bean, or otlitT plant, in a i)()ttlo, 
 Avitli its roots inmiersud in a solution of red ink or aniline 
 ilye. Aceount for the effects observable in the plant on tin.' 
 following day. 
 
 Allow the earth about the roots of two potted plants to 
 become very dry. Water the leaves of one of them regu- 
 hirly for several days without wetting the earth. Apply 
 the water to the earth about the roots of the other plant. 
 AVhat inferences mav be drawn ? 
 
 Stand a plant with only its roots in water. Set another 
 top downward in a bottle. Tut water enough into the 
 bottle to cover the top and upper leaves, leaving the rest 
 of the plant, including the root, immersed in air. Notice 
 which of the leaves wither first, and draw the obvious in- 
 ferences. 
 
 We have established pretty conclusively, by experiments 
 iiiid arguments, that plants absorb carbon dioxide out of 
 the air by tlieir leaves; that they absorb water by their 
 roots, and but little, if any, by their leaves ; that they take 
 in b}' their roots substances dissolved in water; and that 
 the}^ exhale oxygen from tlieir leaves. We have also found 
 that the absorption of carbon dioxide and exhalation of 
 oxygen only go on under the action of light. 
 
 It is now reasonably clear that the plant makes starch 
 and the other carbohydrates out of carbonic acid gas and 
 water. But these two substances contain more oxygen 
 than is necessary for that purpose, since they both contain 
 it, wdiile in starch there is only enough oxygen to form 
 water with the hydrogen. That is, there is sufficient 
 
Teacher s Manual of Nature Lesaons. 93 
 
 hv(lr()i::en iind oxvirt'ii in tlic water alone for tho iiiakinir 
 of starch, and onlv tlio oarlfon of tlio carhon dioxide is 
 re(iuired. //>• oxyiren is exhaled hy tlic ]>lant. 
 
 But tlie alhnniinoids contain two elements, nitroj^en and 
 8ul})liur, neitlier of wliicli are present in earhon dioxide 
 or water. 
 
 Now, so far as we know, the i)lant cannot build up 
 eh'/nenfs into compounds. Tlie food of plants consists of 
 compounds, most of which the plant decomposes and 
 builds up aii:ain into others more complex. 
 
 Althouiih there is an abundance of nitrogen in the air 
 it is of no direct use to the plant. l*lants derive their 
 supply of nitrogen mainly from the ammonia and oxides 
 of nitrogen in the air, and salts of nitric acid — nitrates — 
 present in the soil in small amount. The sul[)hur required 
 for the production of albuminoids is supplied by the 
 soluble sulphates. The most important of these is sul- 
 phate of lime (gypsum), which is slightly soluble, and is 
 present in tine [)articles in most soils. These sulphates 
 must be decomposed in the plant in order that their 
 sulphur may be worked into the forming albuminoids. 
 
 Fill a small wide-mouthed bottle nearly to the neck with 
 water. Make a hole through its cork just large enough 
 to receive the stem of a plant of suitable size. Split the 
 cork from one side into the hole, and push the stem of 
 the plant through the cleft into tlie hole made to receive 
 it. Close the cleft and lower the root of the plant into 
 the water. Fit the cork tightly into the neck of the 
 bottle. Turn a glass jar, or a larger bottle mouth down- 
 
D4 Teachrs Manual of Nature Lr^miis. 
 
 Avard over the l)()ttl(' containinu; \]\v [>lant. Wliat colk'cts 
 on the inside of tlje larutT hottlc. WIh'IU'c docs it come':' 
 Kxplain tlic facts and reconcile tlieni witli what \vc liad 
 provionyly learned about the use of water as food foi' 
 jdants. 
 
 Tlie pujtils are familiar with the nuiin facts of res}»ira- 
 tion in animals. Tiiey iidiale oxy_i;'en and exhale carbon 
 dioxide produced by the oxidation i;"oing on in nearly all 
 parts of the body. 
 
 It can be demonstrated that a similar process, wliich 
 mjiy be termed vcf/tiahic ri'Sfura.tion^ goes on in plants. They 
 absorb oxy<j!;en, which promotes oxidation in the plant, 
 slightly raising its tem[)erature ; and carbon dioxide, [»ro- 
 <lueed by the oxidation of carl)on in the ])lant, is exhaled. 
 
 It will be remembered here that plants absorb {'arbon 
 ilioxide, decompose it in assimilation, and give ofl' its oxy- 
 gen. But tins process ceases in darkness, wliereas respira- 
 tion continues through the night. It is plain, liowever, 
 that plants absorb more carbon dioxide for assimilation 
 than they exhale as a product of resj)iration. 
 
 Explain why the presence of plants in a bedroom man 
 be injurious to health. 
 
T€acher\s Munual of Nature Lctt8o}is. !>") 
 
 CHAPTER III. 
 
 TirK ()K(;AXir world. 
 
 DIVISION II. — ANIMALS. 
 S'.:CTIOX A: TiIK nKVKLOI'.MIlNT AND LiFK IIl.STOHV OK AN 
 
 Animal. 
 
 Wo luivt' tullowed a )>lant t'roiii its iK'^-iiining- as an 
 embryo tliruiiu'li tlio successive stages of its existence. In 
 ii similar manner we propose to trace the lite liistorv of an 
 iinimal. Of all kinds of animals, an insecjt will best suit 
 our pnr[»ose. Its development is easily followed, and since 
 its life is usnallv brief we shall not be wejiried ])y waitiiiii". 
 
 Caterpillars of various kinds are easil}- obtained. They 
 may be brought to the school in bottles with some leaves 
 from the [dant on which they were found. This will prob- 
 ably be the plant — or one of the plants — upon whicb they 
 feed. 
 
 A breeding cage may be made from a wooden box, each 
 side of which is about a foot s(piare. 
 
 Set the box with the open end in a vertical position. 
 Cut a hole about four inches square in the side which is 
 then uppermost. Cover tlie open end with wire netting 
 or gauze, and nail a strip of wood, about three inches 
 wide, at the bottom. Put in enough sandy earth to cover 
 the bottom to the depth of three inches, and put in some 
 dry twigs. 
 
96 Teacher^s Manual of Nature Lessons. 
 
 The caterpillars kept in thin cage inust be provided 
 from time to time with fresh leaves from their food-plants. 
 The earth should be kept sliglitly moist. 
 
 If properly cared for some of the caterpillars will 
 shortly begin to make a little case, called a cocoon, \n 
 which to stay during the next stage in their development. 
 If the insect constructs its cocoon above ground, it will 
 be easy to watch its progress. Find wliere the caterpillar 
 gets the material of which its cocoon is made. 
 
 Examine the contents of some of the cocoons. Com- 
 pare the new form which the insect has assumed with 
 that of the caterpillar. 
 
 Some cater})illars do not make a cocoon, but attach 
 themselves to a stick or other support, and there undergo 
 the change to the pupa state in open sight. In this 
 inactive state the insect remains often for onlv two or 
 three weeks, sometimes until the following spring. Then 
 its final transformation into the winged state takes place. 
 
 If these winged insects be kept in the case for a while, 
 and provided with suitable food, they may be induced to 
 lay eggs. 
 
 We have now seen the four principal stages in the 
 development of an insect. You will understand, how^ever, 
 that the egg, which has been mentioned last, is really the 
 lirst state. The second form of an insect, of which the 
 caterpillars are examples, is called the larva (plural, larva'). 
 The term caterpillar, strictly, is only applied to the larvae 
 of butterflies and moths. The larvse of Hies are called 
 maggots, and those of beetles grabs. 
 
Teachei-'s Manual of Nature Lessons. 97 
 
 The form into which the larva changes is called the 
 pupa (plural, pupti) or rlin/salis. 
 
 The fourth state, in which the insect is usually provided 
 witli win*!:s, is the miago. 
 
 If unsuccessful in carrying any one species through all 
 these transformations, the whole history of the typical in- 
 sect must ])e learned by piecing together the partial histories 
 of two or more. 
 
 If it is desired to keep one species by itself, it may })e 
 kept in a pasteboard box, having a glass cover, and small 
 holes in the sides for ventilation. A glass jar with a pie(;e 
 of gauze placed over the mouth also answers well. The 
 bottom of the box or jar should be kept covered with damp 
 earth. 
 
 In which of its stages does an insect partake of food ':* 
 In which does it eat most greedily? In which does it 
 grow? In what ways does it obtain its food in difterent 
 stages? How does the food of the same insect vary in its 
 different stages ? What ditlering habits sometimes make 
 an insect harmful to man in one of its states and useful in 
 another ? How many legs and wings has an insect in the 
 imago state ? Compare the eyes of an insect with human 
 eyes. Find the row of little holes on each side of the body 
 of an insect, which are the openings to its breathing organs. 
 Allow the pupils to find, by individual observation, the 
 answers to the preceding questions. 
 
 In country and village schools, at least, the life history 
 of several species of insects may be traced. Four are 
 selected as examples, the lirst for its size and beauty, the 
 a 
 
98 
 
 Teacher\ Manual of Nature Lessons. 
 
 others rather on account of their fondness for human food- 
 plants. 
 
 In the autumn, there may be found feeding on the leaves 
 of the apple-tree a large green caterpillar, three or four 
 inches long when full-grown, having its l)ack set with warts 
 or tubercles, some red, some yellow. If it cannot be found 
 on the apple, it may be looked for on the plum, cherry, 
 alder, and lilac. This is the larva of the Emperor Moth. 
 
 THE COrooN OF THE 
 EMPEROU MOTH. 
 
 THE LARVA (W THE 
 EMPEROR MOTH. 
 
 Place several of those caterpillars in the breeding cage, 
 and sup])lv tlicin with leaves. Soon thev will be^'in to build 
 cocoons. The cocoon is double, of a brownish or ici'avisli 
 color, about three inches long, and an inch broad at the 
 widest part. The space between the outer and the inner 
 cocoon is occupied by til)res of silk. If you should not 
 succeed in securing any of the caterpillars, the cocoons 
 
Teache/s Manual of Nature Lessons. 
 
 99 
 
 may be found upon tlie trees at any time during tlie 
 winter or early spring. The chrysalis may be taken out 
 of one of them for examination. The cocoons should be 
 kept out of doors, or in a shed, during the winter. When 
 winter is over, they should be brought into the school- 
 room and placed in a breeding cage. About the last of 
 May, the imago will come forth in all its beauty. Let 
 
 IMAGO OF EMPEROR MOTH. 
 
 the pupils watch its exit from the cocoon and the expansion 
 of its wini>;s. It is now a maiirnificent creature with winii-s 
 extending, when spread out, six or seven inches from tip 
 to tip. jN'ote the colors and arrangement of the wings. 
 
 This insect is closely related to the silk'-worm moth, from 
 whose cocoon is obtained the silk of commerce. 
 
 On visitinc; the iirarden, some morninii" in June, vou will 
 find the tops of certain young plants — cabbages, beans, or 
 onions perhaps — lying on the ground looking as if they 
 had been cut ott near its surface. Slowly scrape away the 
 earth about the stum}) and you will find the culprit — a 
 
100 Teacher^ s Manual of Nature Lessons. 
 
 greasy-looking, brownish or grayisli caterpillar. It coils 
 itself up as soon as it is disturbed. It is known as a Cut- 
 worm^ for a reason now plain to you. Leave it lying ou 
 the surface of the ground, but keep your eye on it. 
 Notice the course it pursues when it sets out to escape. 
 Before it has entirely disappeared, take it again ; and, with 
 some of its kind, put it into a glass jar which has a little 
 earth in the bottom. 
 
 Provide them wuth leaves from their food-plants. After 
 a while they will cease to eat. Upon examining the earth 
 in the bottom of the bottle, you will find that they have 
 made cells for themselves, in which thev have become 
 transformed into pupjc. Take one of the pupa^ by the 
 head and note the behaviour of the other end. Leave 
 the others undisturbed in their cells. 
 
 In a few weeks the imagos will appear. Note the dis- 
 tinctive characteristics of these moths, s) that you will 
 know them from others when you see them out of doors, 
 or when they fly into the house at night attracted by the 
 light. Find w^iether cut-worms ever destroy w^eeds. Wheu 
 do they do their work ? 
 
 The Potato Beetle, improperly called a bug, is easily fol- 
 lowed through all its transformations. The imagos may 
 be seen upon the potato plant early in June. They deposit 
 their yellow eggs in clusters on the under side of the leaves. 
 The larva is yellowish in color, and has a row of black dots 
 ou each side. If allowed to live, it will descend into the 
 earth to become a pupa. Put some well-grown larva? into 
 a bottle partly filled with earth, and feed them with potato 
 
Teacher s Manual of Nature Lessons. 
 
 101 
 
 leaves until they pupate. Take some of the piipse out of the 
 earth. Notice whether the traiisforruation is more or less 
 marked than in the case of a hutterily or moth. Leave 
 some of them in a bottle until Jiey become perfect beetles. 
 Trace the life history of the insect whose larva is so des- 
 tractive to apples by eatiuii; holes through them. Find 
 where tiie larva enters the ai)ple, and where it makes its 
 exit. In autumn, before the apples are ripe, procure some 
 fruit infested by these larvae. Put a number of the apples 
 into a box or jar aloni^ with some bits of wood. Examine 
 the cocoons when finished, and then set them away in a 
 cool place till spring. 
 
 This cut shows the transformations of the Codling Moth, 
 its cocoon, and its burrowings in the apple. 
 
 The beautiful little moths which emerge from the cocoons 
 will enable you to identity those of the same species which 
 you will find flying about the apple trees, if you visit them 
 
102 Teacher^ 8 Manual of Nature Lessons. 
 
 at night with the lamp about the time the blossoms are 
 
 opening in the spring. Find where, upon the young apple, 
 
 this insect, the Codlmc/ Mot/i, deposits its egg. Also discover 
 
 where they make their cocoons, and remain during the 
 
 winter. 
 
 The honey-bee, the ant, and the mosquito, afford interesting subjects 
 for study. 
 
 Section B: The Adaptation of Form to Function in 
 
 AnIxMALS. 
 
 The domestic animals ofter the best opportunity of 
 studying the admirable correspondence of form to function 
 in organized beings. Our observations will include the 
 horse, cow, sheep, pig: the hen, turkey, goose, duck; the 
 cat and dog. 
 
 Below will be found a list of topics and questions 
 indicating the extent and character of the investigations 
 to be made. 
 
 THE DOMESTIC ANIMALS: 
 
 Their Food and Clothing. 
 
 How do they take their Food ? 
 
 How do they procure Food when not provided by Man ? 
 
 How do they feed their Young? 
 
 In what position do they Eat ? 
 
 How do they Drink? 
 
 How do they get Up and iie Down ? 
 
 Which of them spend most time in Eating? 
 
 Which of them Ruminate? 
 
 What is the Cud, and what is its Use? 
 
Teachei'^s Manual of Nature Lesfions. 103 
 
 Which of them can Swim, Climb Trees, Fly, Perch? 
 
 Compare the Teeth of those which sul)sist on Vegetable Food 
 
 with the Teeth of those which feed on Animal Food, and 
 
 account for the difference. 
 
 Which of them have both upper and lower Front Teeth ? 
 
 Compare the . Feet, Toes, Ears, Eyes, and Noses of each species 
 
 with the Corresponding Organs of all the others. 
 Which of them have relatively much longer Necks than the 
 
 others? Of what advantage is this to them? 
 
 Which of their Limbs correspmnd (are homologous) to Human 
 
 Arms, Legs, Hands, and Feet? 
 
 How do they < xpress Pleasure, Anger, Grief, Fear? 
 
 In what Position do they Rest and Sleep? 
 
 How do they call their Companions? 
 
 How do they Attack other Animals? 
 
 How do they Defend themselves against Attack ? 
 
 In making the observations indicated above, encourag'O 
 tlie children to note for themselves the adaptation of form 
 to fnnetion, and that for every diiference in the habits of 
 animals tliere is a corresponding difference in form. 
 
 Section C: The Distinguishing Characteristics and 
 Habits of the Common Wild Birds. 
 
 The birds enumerated below are so common and easily 
 distinguished that every child, both in country and city 
 schools, mav learn to recos-nize them. It will not be 
 necessary to kill any of them in order to identify them. 
 Patient observation will overcome all the difficulties, and 
 at the same time call forth patience, tact, and keenness of 
 
104 Teacher s Manual of Nature Lessonn. 
 
 sight and cur; not to speak ot'tlic direct and indirect moral 
 effects. 
 
 If four or five birds are learnt each year, the list will he 
 inarttered before tlie pupil leaves the common school. 
 
 City schools may take advantage of natural history col- 
 lections to supplement their Piore limited opportunities for 
 ■field work. 
 
 Jjcarn to recognize the different species in as many ways 
 as possible — by their plumage, their songs, their modes of 
 flight", etc. 
 
 Observe closely the nestinji; and feedins: habits of each 
 species, the difference (if any) in [)lumage between the males 
 and females, and discover which are migratory, and which 
 resident throui^hojit the vear. 
 
 1. The American Kobin is so well known that no des- 
 cription is necessary. 
 
 Our Robin is a member of the Thrush Family, of which 
 two or three other species are quite common. 
 
 The Swamp Robin, or Hermit Thrush, is much shyer than the common 
 Robin, and does not frequent the open fields. Its under parts are mostly 
 white, but the throat and breast are speckled with dusky spots. 
 
 The Robin of England — "Redbreast" — is quite a diflerent bird from 
 ours. 
 
 2. The Black-capped Chickadee lives with us through- 
 out the year. It is a small bird, mostly ash-colored above, 
 with the top of the head, the chin, and throat black. The 
 Chickadees prefer to go in small companies. The usual 
 note, Chick-a-dee, dee, dee, is quite familiar. 
 
 Find what it is looking for as it inspects the stems of 
 trees bo carefully. Is it doing good to itself alone, or to the 
 
Teacher^s 3fanual of Nature Lessons. 
 
 105 
 
 trees also ? Does it ever run 
 about on the ii^round ? 
 
 The Chickadee l)elon_ii:s to 
 tlie Titmouse Family. 
 
 The lIiulHoniaii Chickadee is less 
 coiunion with iih than the Black -capped. 
 It is b^o^vnish above, without any black 
 on the head. 
 
 •3. Tlie Summer Warbler, or 
 Golden Warbler, is abundant 
 amonjj: the willows and low- 
 shrubbery along the l)aid<s 
 of streams. It is common, 
 too, in the trees and bushes 
 about houses, and in the parks 
 and streets in towns and vil- 
 lages. It is the yellowest l)ird we have. Its back is 
 olive-yellow ; under parts mostly golden-yellow, streaked 
 with oranu'e-brown on the breast and sides. The wino-s 
 and tail are duskv, but there is no black about the bird. 
 
 We have sev ./al other species of the Warbler Family during the summer. 
 They are all small birds, generally not more than five or six inches in length. 
 As a rule, they spend mor.t of their time in trees or shrubbery, attracting but 
 little attention from man notwithstanding the bright colors which adorn 
 •most of them. 
 
 4. The Cedar Waxwiuii* is a beautiful and i^entle bird. 
 Its plumage is very soft and smooth. The fore parts ot 
 the body, both above and below, are of a brownish-ash 
 -color, which acquires a pale reddish cast towards the bill, 
 and behind shades otf into clear ash above and into yellow 
 
 BLACK-CAPPED cniCKADKE. 
 
106 Teacher^ 8 Manual of Nature Lchsoiih. 
 
 l)e]o\v. The l)ill is l)lack, and there is a hlaek wtrip 
 nniniiii^ haek to the eyes. The vviiii»- is rnostlv l>luekisli- 
 usli. The tail is tipped with yellow. From its crested 
 head, it is sometimes known among hoys as the " Top- 
 knot Bird." 
 
 Some of the win<r feathers are frequently tipped with 
 red waxy-lookinu^ appendages, not large enough, however^ 
 to be noticed unless the bird is quite close to the 
 observer. 
 
 The Waxwings usually go in flocks. Tn the spring a 
 oom])anv niav sometimes be seen rcixalini; themselves 
 upon the old but juicy fruits of the mountain ash. Later,, 
 they fre{{uent orchards, whence they are locally named 
 " Apple-birds." They are said to destroy large numbers- 
 of canker-worms and other insect enemies of the apple. 
 Spare them, then, even should they sometimes indulge iu 
 cherries and other small fruits. 
 
 5. The Purple Martin is about as long as the Waxwing, 
 The male is blue-black in color, very lustrous. The wing 
 is nearly as long as the body. The tail is forked. It 
 resides while with us in " martin-houses " erected by man 
 for its accommodation. 
 
 The Martin belongs to the Swallow Family. 
 
 We have four other species of swallows. The tall is usually plainly 
 forked ; their wings are always long and flight swift. The Cliff Swallow 
 usually huilds its mud nests under the eaves of barns, whence it is called 
 the Eaves Swallow. 
 
 The Barn Swallow nests inside of barns, fastening its nest to a beam 
 or rafter. 
 
 The Tree Swallow nests in holes in trees, fence-posts, etc. Its body i» 
 lustrous green above and white beneath. 
 
Teacher 8 Mmiiuil of Nature Lesnons. 107 
 
 High sandy banks may often be seen pierced with many rounded holes. 
 Tliese are the entrances to tunnels which lend to the nests of the Bank 
 Swallow. 
 
 f). The Soiiii' sparrow is one of the first t'eatlKTod siiiij^ers 
 to arrive in \.\w sprinir. ^^^ silvery notes may be lieanl on 
 sunny April niornino:s while tlie stiow still covers the forest 
 lands, and lies in [)atehes in the open fields. 
 
 Ti is a i2:ravish streaked bird, with usmdlv a brownish 
 blotch on the throat. There is no yellow about it, and but 
 little white is shown. It is conunonlv called a " u^rav-bird;'*^ 
 but that name is applied, by those who are not close ob- 
 servers, to several species of sparrows. 
 
 The "gray-bird" which is most likely to be confounded with the Song 
 Sparrow is the Vesper Sparrow or Grass Finch. It differs somewhat from/ 
 the Song Sparrow in size, color, and song, but may be most readily distin- 
 guished by the two white feathers which show at the sides of its tail wheii> 
 it flies. Both species frequent fields and roadsides. 
 
 7. The Chipping S[»arr()w is a very small "gray-bird."" 
 Its crown is reddish-l)r()wn. The throat and l)ellv are 
 grayish-wliite without streaks or other markifigs. Its song 
 is a mere chipping. It is very familiar in its habits, and 
 will allow the observer to approach, as it hoi)s about the 
 roadside, near enough to see its brown cap. 
 
 The Savanna Sparrow is another "gray-bird" smaller than the Song 
 Sparrow. It frequents intervales and lo«r meadows. It has no brown cap* 
 but a light streak over tlie eye, upon close approach, is seen to be yellow. 
 It has a musical, but very weak song, by which it may be easily distinguished. 
 
 8. The AVhite-throated Sparrow is familiarly known a* 
 Old Tom Peabody — a name suggested by the number and 
 grouping of the syllables in its song. It is mostly grayish 
 and reddish-brown above. The crown has two broad 
 
108 
 
 leacher'n Manual of Nature Lemms^. 
 
 MiU'k Wjinds, scparjitcil and honlcrcd hy narrow wliite 
 HtripcH. Tlic tliroat is juirc vvliiti-, Loiindcd l.y dark ash 
 oil tlu' breast and sides n\' neck. Tlie liu:l,t line in front 
 of ojieh eye and on tlie edge of the wings is, upon close 
 view, seen to be yellow. 
 
 9. The Knglish Sparrow is another "gray ])ird "; at 
 least, the female is. The black throat of the male dis- 
 tinguishes him at sight from tlie female. Tidike the 
 native sparrows, they reside with us through all the 
 seasons. They are very familiar, freipu-nting in Hoeks, 
 yjirds, and gardens, aiid the streets in towns and villages. 
 
 10. The Purple Finch is much smaller than a robin, 
 but slightly longer than the larger sparrows. Its pre- 
 vailing color is rose-red above and in front below. The 
 red deepens into eriiuson on the crown, and is striped 
 ■Nvith brown on the back. 
 
 The female and young are quite different in color, but 
 tliey may be known by the company they keep. The 
 Purple F'inch is a tine singer. 
 
 The male of the Pine Gross- 
 beak is also red, but is ranch 
 larger than the Purple Finch. 
 The Grossbeaks remain with us 
 during the winter, and mostly 
 go north in the spring, whereas 
 the Purple Finches leave for 
 the south before winter sets in. 
 
 11. The American 
 Gohlfinch is mostlv 
 
 t' 
 
 yellow above and be- 
 low. The crown is 
 
 AMERICAN GOLDFINCH. 
 
Teacher^ a Manual of Nature Leasons. I0i> 
 
 hlack. Till' \viiii::s aiv Itliu-k, with strips across thoiii 
 t()niu'<l l)v the wliite tips of tlie shorlcr t'catliiTs. 
 
 '^riii' (loldiiiu'li is tV(.'((UL'!itly known as tlie ''Thistlt'-l)inr* 
 or "Wild Canary." 
 
 VI. The shitt'-colori'd Junt'o resemhk's a sparrow in sliai)t'f 
 and size. It is of a dark asli color above, and on tlie throat 
 and l)reast. Tiie wliite of the nnder parts meets the dark 
 color of the hreast in a definite line. It shows two white 
 tail-feathers when it flies. 
 
 Junco returns to us very early in the sprin<^ — usually 
 near the first of April. It is often called the JJlue-hird, but 
 is very different from the true Blue-bird, which is rare with 
 us, at least in most localities. 
 
 The sparrows, (ioldtinch, i'urple Finch, and Junco belon<^ 
 to the sparrow Family. 
 
 13. The Bobolink, in spring plumage, is mostly black. 
 There is a cream-colored patch on the back of the neck. 
 The shoulders, and the back near the tail, are grayish 
 white. The tail-feathers have pointed tips. It is much 
 smaller than a robin, but larger than a sparrow. (See 
 illustration on next page.) 
 
 In this country, the Bobolitik frequents intervales, low 
 meadows, and river-islands. It belongs to the Black-bird 
 Family. 
 
 Three other species of the Blaek-bird Family are quite common. The 
 Red-winged Bhiek-bird and the Rusty Black-bird are birds nearly equal in 
 size to the Robin. The former has scarlet shoulders ; the latter is black 
 throughout in the spring, in autumn rusty-colored. The Crow Black-bird, 
 or Purple Graekle, is considerably larger than a Robin. Its head and neck 
 are blue, with a brilliant metallic lustre. 
 
Bobolink, male and female. 
 
Teachet'^s Manual of Nature Lessons. Ill 
 
 14. The Common Crow will speak for itself. 
 
 15. The lvini]:;-l)ird is blackish-ash above — darker behind 
 and on the head. A bright red spot on the crown is seldom 
 seen, being concealed by the dark feathers. The throat 
 and under parts are white. The tail is tipped with white. 
 
 The King-bird is smaller than a robin, but a little larger 
 than a bobolink. Observe its habits, and you will learn 
 how it got its name. It belongs to the family of Fly- 
 catchers. 
 
 We have several other species of Flycatchers, most of them considerably 
 smaller than the King-bird, and difficult to distinguish. 
 
 16. The Night-Hawk is a dark mottled bird with a 
 conspicuous white mark on each wing. It is usually 
 seen upon the wing — in the dusk of the evening, and on 
 cloudy days. It is not a hawk — not a bird of prey at all. 
 It belonsjs to the Goatsucker Familv. 
 
 The Night-Hawk is closely related to the Whip-poor-will — a bird we 
 seldom see, as it is strictly nocturnal in its habits. 
 
 17. The Chimney-Swift resembles a swallow so much 
 in its form, voice, and mode of flight that it is commonly 
 called the Chimney " Swallow." It is a brownish-black 
 bird, with a short blunt tail bv which it mav be distin- 
 guishcd from a swallow. It builds its nest in chimneys. 
 It is the only member of the Swift Family which visits us. 
 
 18. The Belted Kingflsher frequents lakes and wooded 
 streams. It is as long, or slightly longer, than the Crow 
 Black-bird. It is dull blue above, and has a band across 
 the breast of the same color. The rest of the under parts 
 is white. It has a long crest on the back of its head. 
 Its bill is long and stout. 
 
112 leacher^s Manual of Nature Lessons. 
 
 A fair knowledge of tl)R eighteen birds described above may be taken 
 as the minimum attainment. In favorable localities, something may be 
 learned about the birds referred to in the small print — also about the 
 Humming-bird, m^ Woodpeckers, Jays, Owls, Hawks, the Bittern, the 
 Heron, Gulls, Snipes, etc. 
 
 OxnER Animals. — Some acquaintance with our other native wild ani- 
 mals, inhabitants of land and of water, should be gained during natural 
 history excursions. 
 
 Classification of Animals. — It is not possible for the children in 
 attendance at the common schools to acquire a sufficiently extensive and 
 exact knowledge of animalp to enable them to make out a general classifi- 
 cation of them. The teachers, however, should frequently call their attention 
 to the more evident relationships among the animals they observe, and lead 
 them to notice that some are more higiily organized than others. 
 
 Section D: Kindness to Animals. 
 
 Happily, liuinan life is now held sacred among us, and 
 human suliering excites general sympathy; but we are 
 still, speaking generally, careless of the lives and feelings 
 of the lower animals. Soon, if man keeps up the needless 
 slaughter which is now going on, scarcely a remnant will 
 remain of the nobler wild animals of the earth, while its 
 birds of song and bright plumage will be practically ex- 
 terminated. 
 
 The gentler brute creatures have found in man not a 
 benevolent lord, but a sanguinary tyrant. The only friend 
 they can depend upon is God. " One of them shall not fall 
 to the ground without your Father." 
 
 Much of the cruelty practised by children is due to 
 thoughtlessness. In such cases the mild appeal of the 
 teacher will at once prove effectual. Sometimes ignor- 
 ance is the cause. For instance, snakes and salamanders 
 
Teacher^ s Manual of Nature Lessons. 113 
 
 are gencriilly looked upon as venomous reptiles. I*^one 
 of onr snakes, however, possess poison fangs. Salamanders 
 are not lizards, as they are often called, but harmless rela- 
 tives of the frog and toad. 
 
 But we may trace still more to heredity — to lamentable 
 survivals from barbarous ai>:es. Each of us can do some- 
 thinii: to hasten the time when men will cease to reufard the 
 pursuit and death of defenceless, terror-stricken animals 
 as " sport," and when women will no longer wear as orna- 
 ments the remains of harmless birds. The gentle deer may 
 yet roam our woodlands in peaceful security, and many 
 sweet-voiced birds, in happy confidence, build their nests 
 in the shrubs and trees about our homes. 
 
BOOKS FOR TEACHERS. 
 
 In iiddition to the prescribed texts, teachers will find the 
 hooks included in the following list very hel})tnl in ]tre- 
 paring themselves to deal with the Nature Lessons intelli- 
 fjjentlv and eftectivelv : 
 
 1. Common Minerals and Rocks, by W. O. Crosby. Paper, 25c.; 
 
 cloth, 60c. 
 Gives a brief account of the agencies throusj-h which rocks are 
 formed, describes the principal kinds of rocks, and the commoner 
 minerals found in them. 
 
 2. Tables for the Determination of Common Minerals, by W. O. 
 
 Crosby. Boston: J.Allen Crosby. Cloth, $1.25. 
 Contains, in a brief form, much useful infornuition about 
 minerals, and tables by which some two hundred minerals may 
 be determined mostly by easy physical tests. 
 
 3. A First Book in Geoloi^y, by N. S. Shaler. Boston: D. C. 
 
 Heath & Co. Boards, 70c. 
 A very plain and readable book, quite easily understood by 
 beginners. 
 
 4. A Compend of Geology, by Joseph LeConte. New York : 
 
 American Book Company. Cloth, $1.20. 
 A good book to get after reading No. 3. It uses more tech- 
 nical language, but is an excellent summary, and finely illustrated. 
 
 5. A Manual of Botany. Spotton's Botany, price $1, will answer 
 
 very well. 
 
 6. Gray's Manual of Botany with Lessons, price $3, describes a 
 
 greater number of plants, and the descriptions are more 
 
 detailed. 
 
 (114) 
 
Books for Teachei's. 115 
 
 7. Insects Injurious to Fruits, by William Saunders, Director of 
 
 the Experimental Farms in Canada. Philadelphia : J. B. 
 Lippincott & Co. Illustrated, S2. 
 Describes many of the commoner insects, and gives an account 
 of their habits. An excellent work. 
 
 8. My Saturday Bird Class, by Margaret Miller. Boston : D. C. 
 
 Heath & Co. Boards, 30c. 
 
 9. Some Canadian Birds, First Series, by Montague Chamberlain. 
 
 Toronto : The Copp, Clark Co. Boards, 30c. 
 These two cheap little books would be very useful to any one 
 beginning the study of birds. T'hey contain descriptions and 
 engravings of a good many of our commoner birds, including, 
 however, some not found in the Maritime Provinces, 
 
 10. Handbook of Birds of Eastern North America, by Frank M. 
 
 Chapman. New York : D. Appleton & Co. Cloth, $3. 
 Contains a very complete account of the birds of the eastern 
 part of the Continent, with keys to aid in their identification. It 
 is well illustrated. 
 
 11. A Popular Zoology, by Steele and Jenks. New York : Ameri- 
 
 can Book Company. Cloth, $1.50. 
 This book gives a general account of the Animal Kingdom. It 
 contains much interesting information, and is profusely illustrated. 
 
 12. Hand-book of Zoology, by Sir J. W. Dawson. Montreal: 
 
 Dawson Brothers. Cloth. This is a popular guide to 
 Canadian Zoology. It is fully illustrated. 
 
 13. Lessons in Elementary Physics, by Balfour Stewart. Mac- 
 
 millan & Co. Illustrated, SI. 50. 
 
 The author desires to convey his thanks to those friends who 
 so efficiently aided him in the preparation of this volume. Both 
 the author and publishers especially acknowledge their obligation 
 to Mr. G. U. Hay, editor of The Educational Review ^ of St. John.