E. J. RUSSELL, D.Sc. (Lond.)

GOLDSMITH COMPANY'S SOIL CHEMIST, ROTHAMSTED EXPERIMENTAL STATION

Cambridge: at the University Press 1911

PREFACE

The Syndics of the Cambridge University Press propose to issue a Nature Study Series of which this is the first volume.

We count ourselves fortunate in securing Dr E. J. Russell as author and Soil as subject. The subject is fundamental, for, just as the soil lies beneath the plant and animal life we see, so is a knowledge of the soil necessary for all understanding of flora and fauna. The real complexity of the apparently simple element "Earth," and the variety of methods required for exploring it, are typical of the problems which the tout ensemble of the outdoor world presents to the naturalist.

Dr E. J. Russell has not only acquired a first-rate and first-hand knowledge of his subject at Wye and at Rothamsted; his own researches have recently extended our knowledge of the micro-organisms in the soil and their influence on fertility. Further, what is very much to our purpose, he has himself had practical experience in teaching at an elementary school in Wye and at a secondary school in Harpenden.

Just at the present moment, County Councils are trying to push rural education and to awaken the intelligence of country children by interesting them in their surroundings. It is, therefore, a favourable opportunity to offer these pages as a concrete suggestion in model lessons and object lessons, showing exactly what can be done under existing conditions.

The book is intended to help children to study nature; there is no attempt to substitute book study for nature study. Hence, whilst there are passages of continuous reading, it is not a mere "reader." Many teachers, myself among them, have felt the difficulty of organising practical work for large classes. Dr Russell has written so that, whilst nominally showing the pupil how to learn, he is secretly scattering hints for the teacher who is learning how to teach.

Abundant and varied practical exercises have been suggested, and careful instructions have been given so that the book shall seem intelligible even in the absence of a teacher. The proposed practical work is not only what might be done by eager boys and girls on half-holidays, but what can be done by every scholar in the course of ordinary school work. The pictorial illustrations are intended as aids to observation, not as substitutes. Drawing is one form of practical exercise, and the preparation of corresponding illustrations in the scholars' notebooks from the apparatus used in the classroom and the fields around the school may afford exercises in artistic work with pen, brush or camera.

Sufficient directions are given for the supply of necessary materials and apparatus. The apparatus proposed is of the simplest character.

It is suggested that the book will be found most useful in the higher standards of elementary schools, in preparatory schools and in the lower forms of secondary schools, that is, where the ages of scholars average from 12 to 14.

HUGH RICHARDSON YORK, 7 January 1911

CONTENTS

CHAP. PAGE

I. WHAT IS THE SOIL MADE OF? 1

II. MORE ABOUT THE CLAY 9

III. WHAT LIME DOES TO CLAY 19

IV. SOME EXPERIMENTS WITH THE SAND 22

V. THE PART THAT BURNS AWAY 33

VI. THE PLANT FOOD IN THE SOIL 41

VII. THE DWELLERS IN THE SOIL 53

VIII. THE SOIL AND THE PLANT 64

IX. CULTIVATION AND TILLAGE 82

X. THE SOIL AND THE COUNTRYSIDE 100

XI. HOW SOIL HAS BEEN MADE 116

APPENDIX 128

INDEX 132

[Transcriber's note: The page numbers below are those in the original book. However, in this e-book, to avoid the splitting of paragraphs, the illustrations may have been moved to the page preceding or following.]

LIST OF ILLUSTRATIONS

FIGURE PAGE

1. Soil and subsoil in St George's School garden 2

2. Columns showing what 100 parts of soil and subsoil were made of 4

3. Columns showing what 100 parts of dried soil and subsoil were made of 8

4. Clay shrinks when it dries 11

5. Clay swells up when it is placed in water 12

6. Landslip in the Isle of Wight. Phot. Valentine & Son 13

7. Clay does not let water run through 14

8. Sand allows air to pass through but clay does not 15

9. A brick allows both air and water to pass through it 17

10. Lime added to turbid clay water soon makes the clay settle 20

11. Sand dunes, Penhale, Cornwall. Phot. Geological Survey 23

12. Blowing sand covering up meadows and ruining them. Phot. Geological Survey 25

13. Model of a spring 26

14. Foot of chalk hill at Harpenden where a spring breaks out. Phot. Lionel Armstrong 27

15. The little pool and the spring. Phot. Lionel Armstrong 28

16. Water spouting up from a bore hole, Old Cateriag Quarry, Dunbar. Phot. Geological Survey 29

17. Sandy soils in wet and in dry positions 31

18. Map of the roads round Wye 32

19. Peat bog in Hoy, Orkney: peat is being cut for fuel. Phot. Valentine & Son 39

20. Rye growing in surface soil, subsoil, and sand 42

21. Mustard growing in surface soil, subsoil, and sand 43

22. Mustard growing in soil previously cropped with rye, and in soil previously uncropped 45

23. Pieces of grass, leaves, etc. change to plant food in the surface soil lint not in the subsoil 50

24. Soil in which earthworms have been living and making burrows 55

25. Fresh soil turns milk bad, but baked soil does not 57

26. Soil contains tiny living things that grow on gelatine 58

27. Our breath makes lime water turn milky 59

28. Something in the soil uses up air and makes lime water turn milky 61

29. Soils are able to stick to water: clay or loam soils do this better than sands 65

30. Water can pass from wet to dry places in the soil, it can even travel upwards 66

31. Plants growing in soils supplied from below with water. All the water the plants get has to travel upwards 67

32. Mustard growing in soils supplied with varying quantities of water 69

33. Wheat growing in moist and in dry soils 71

34 a and b. Plants found on a dry soil had narrow leaves, those on a moist soil had wider leaves. Phot. S. T. Parkinson 72, 73

35. Plants give out water through their leaves 74

36. Stephen Hales's experiment in 1727 75

37. Hill slope near Harpenden showing woodland at top and arable land lower down. Phot. Lionel Armstrong 77

38. View further along the valley; woodland and arable above, rough grassland near the river. Phot. Lionel Armstrong 79

39. Rough grass pasture near the river. Higher up is arable land. Phot. Lionel Armstrong 81

40. After harvest the farmer breaks up his land with a plough and then leaves it alone until seed time. Phot. Lionel Armstrong 83

41. Rolling in mangold seed on the farm. Phot. H. B. Hutchinson 85

42. Soil sampler 88

43. Cultivation and mulching reduce the loss of water from soils 90

44 a and b. Maize cannot compete successfully with weeds 94, 95

45. A plot of wheat left untouched since 1882 at Rothamsted has now become a dense thicket. Phot. Lionel Armstrong 97

46. A badly drained wheat field 99

47. Highly cultivated sandy soil in Kent 103

48. A Surrey heath 105

49. Woodland and heather on high sandy land, Wimbledon Common. Phot. R. H. Carter 107

50. Poor sandy soil in Surrey, partly cultivated but mainly wood and waste 109

51. Open chalk cultivated country, Thanet 113

52. Cliffs at the seaside, Manorbier. Phot. Geological Survey 117

53. Cliffs in inland district, Arthur's Seat, Edinburgh. Phot. Geological Survey 119

54. Model of a stream 120

55. The bend of a river 121

56. The winding river--the Stour at Wye. Phot. R. H. Carter 123

57. Sketch map showing why Godmersham and Wye arose where they did on the Stour 126

58. Ford at Coldharbour near Harpenden. Phot. Lionel Armstrong 127

The photographs of the pot experiments are by Mr Lionel Armstrong.

INTRODUCTION

The following pages contain the substance of lessons given at the village school at Wye to the 4th, 5th, 6th and 7th standards (mixed) and at St George's School, Harpenden, to the 3rd form. There is, however, an important difference between the actual lessons and the book. The lessons had reference to the soils round about the village, and dealt mainly with local phenomena, general conclusions being only sparingly drawn; while in the book it has been necessary to throw the course into a more generalised form. The teacher in using the book will have to reverse the process, he must find local illustrations and make liberal use of them during the course; it is hoped that the information given will help him over any difficulties he may experience.

This necessity for finding local illustrations constitutes one of the fundamental differences between Nature Study subjects and other subjects of the school curriculum. The textbooks in some of the others may be necessary and sufficient; in Nature Study it is at most only subsidiary, serving simply as a guide to the thing that is to be studied; unless the thing itself be before the class it is no better than a guide to a cathedral would be without the cathedral. And just as the guide is successful only when he directs the attention of the stranger to the important features of the place, and fails directly he becomes garrulous and distracts attention, so a Nature Study book succeeds only in as far as it helps in the study of the actual thing, and fails if it is used passively and is substituted for an active study. No description or illustration can take the place of direct observation; the simplest thing in Nature is infinitely more wonderful than our best word pictures can ever paint it.

The author recommends the teacher to look through the chapter before it has to be taken in class and then to make a few expeditions in search of local illustrations. It is not strictly necessary that the chapters should be taken in the order given. The local phenomena must be dealt with as they arise and as weather permits, or the opportunity may pass not to return again during the course. In almost any lane, field, or garden a sufficient number of illustrations may be obtained for our purpose; if a stream and a hill are accessible the material is practically complete, especially if the children can be induced to pursue their studies during their summer holiday rambles. Of course this entails a good deal of work for the teacher, but the results are worth it. Children enjoy experimental and observation lessons in which they take an active part and are not merely passive learners. The value of such lessons in developing their latent powers and in stimulating them to seek for knowledge in the great book of Nature is a sufficient recompense to the enthusiastic teacher for the extra trouble involved.

It is not desirable to work through a chapter in one lesson. Children unaccustomed to make experiments or to see experiments done, will probably require three or four lessons for getting through each of the first few chapters, and two or three lessons for each of the others.

The pot experiments of Chaps. VI., VII. and VIII. should be started as early in the course as possible. Twenty flower pots are wanted for the set; they should be of the same size, about eight inches being a convenient diameter, and should be kept together in a warm place. Three are filled with sand, seven with subsoil, and the remaining ten with surface soil. Three of the subsoil pots are uncropped, two being stored moist and one dry. Four pots of the surface soil are uncropped and moist, a fifth and sixth are uncropped and dry, one of these contains earthworms (p. 54). Four glazed pots, e.g. large jam or marmalade jars, are also wanted (p. 69). Mustard, buckwheat, or rye make good crops, but many others will do. Leguminous crops, however, show certain abnormal characters, while turnips and cabbages are apt to fail: none of these should be used. It is highly desirable that the pots should be duplicated.

The plots also should be started in the school garden as early as convenient. Eight are required for the set: their treatment is described in Chap. IX. Plots two yards square suffice.

A supply of sand, of clay, and of lime will be wanted, but it is not necessary to have fresh material for each lesson. The sand may be obtained from a builder, a sand pit, the sea shore or from a dealer in chemical apparatus. The clay may be obtained from a brick yard; it gives most satisfactory results after it has been ground ready for brick making. Modelling clay is equally satisfactory. A supply of rain water is desirable.

For a class of twelve children working in pairs at the experiments the following apparatus is wanted for the whole course:—

Six tripods and bunsen burners or spirit lamps [2] twelve pipe-clay triangles [4] twelve crucibles or tin lids [3] sixteen gas jars [4] twelve beakers 250 c.c. capacity [4] two beakers 500 c.c. two beakers 100 c.c. six egg-cups [2] twelve funnels [3] six funnel stands [1] six perforated glass disks [3] two tubulated bottles 500 c.c., four corks to fit cork borers 4 lbs. assorted glass tubing pestle and mortar twelve Erlenmeyer flasks 50 c.c. [3] six saucers twelve flatbottomed flasks 100 c.c., six fitted with India rubber stoppers bored with one hole [3], and six with ordinary corks [3] box as in Fig. 13 six glass tubes 1/2" diameter, 18" long [2] six lamp chimneys [3] six test tubes, corks to fit three thermometers soil sampler (p. 88) balance and weights two retort stands with rings and clamp.

The figures given in square brackets are the quantities that suffice when the teacher alone does the experiments, it not being convenient for the scholars to do much.

In conclusion the author desires to tender his best thanks to the Rev. Cecil Grant of St George's School, and to Mr W. J. Ashby of the Wye School, for having allowed him the use of their schools and appliances during the progress of these lessons. Especially are his thanks due to Mr Lionel Armstrong for much help ungrudgingly rendered in collecting material, taking photographs, and supervising the experiments.

E. J. R. HARPENDEN, February, 1911.