Lessons on Soil

by Edward J. Russell

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.

CHAPTER I

WHAT IS THE SOIL MADE OF?

Apparatus required.

Soil and subsoil from a hole dug in the garden. Clay. Six tripods and bunsen burners or spirit lamps [2]. Six crucibles or tin lids and pipe-clay triangles [2]. Twelve glass jars or gas cylinders [4]. Six beakers [2] [1].

If we talk to a farmer or a gardener about soils he will say that there are several kinds of soil; clay soils, gravel soils, peat soils, chalk soils, and so on, and we may discover this for ourselves if we make some rambles in the country and take careful notice of the ground about us, particularly if we can leave the road and walk on the footpaths across the fields. When we find the ground very hard in dry weather and very sticky in wet weather we may be sure we are on a clay soil, and may expect to find brick yards or tile works somewhere near, where the clay is used. If the soil is loose, drying quickly after rain, and if it can be scattered about by the hand like sand on the sea shore, we know we are on a sandy soil and can look for pits where builder's sand is dug. But it may very likely happen that the soil is something in between, and that neither sand pits nor clay pits can be found; if we ask what sort of soil this is we are told it is a loam. A gravel soil will be known at once by its gravel pits, and a chalk soil by the white chalk quarries and old lime kilns, while a peat soil is black, sometimes marshy and nearly always spongey to tread on.