SCIENCE IN SECONDARY SCHOOLS. 163 
measures). Experimental graduation of a thermometer by placing it in hot 
and cold water together with a thermometer already graduated. 
2. Expansion as a phenomenon generally accompanying heating. Rough 
estimates of expansion of water and of metal rods. Expansion and pressure- 
increase of heated air. Geographical applications. 
3. Examination of the steady heating and cooling of water; discovery of 
constancy of temperature during boiling and freezing. 
Definite melting and boiling points of substances. Freezing of sea-water. 
Melting-points of alloys, &c. Change of volume on solidification : ice, type- 
metal, dentist’s filling, &c. 
4, Maximum and minimum thermometers; construction of temperature- 
charts. (Records of wind-directions and rainfall should also be kept throughout 
the year.) 
Second YEAR. 
[Section I. must be taken, as before, in seasonal order. Section II., E., is 
closely related to it and should be begun in the autumn term.] 
I. Biological Section. 
A. Autumn Term. 
1. Animal life in the garden. Individual observations, guided by question 
papers, directions for practical work, reference books, &c., supplemented by 
class-work. The following are suitable subjects: snail and slug, earthworm, 
uae and millipede, earwig, green-fly, lady-bird, hover-fly, lace-wing fly, 
crane-fly. 
2. Soil: general characters of clay, sand, chalk, peat, &c.; closer study of 
local soil; subsoil. Simple experiments to ascertain proportions of water, clay, 
sand, silt, grit, and organic matter in a sample of soil. 
3. The ingredients of soil. Clay : why called ‘ heavy’; impervious to water 
and air; comparison of growth of seeds in pure clay and garden soil; experiments 
on effects of ‘liming.’ Experiments to test properties of sand and chalk. Leaf- 
mould and humus: origin and distribution. 
4, Biology of soil. Adaptations of animals that inhabit soil. Why the 
farmer thinks soil itself ‘ alive ’; demonstration of activity by respiration within 
the soil. Soil bacteria and protozoa needing air, water, and food. 
B, Spring Term. 
Relation of plant life to soil. 
1. Soil-water ; comparison of retentive power of different soils. Rise of water 
in soils; capillarity (see II., C., 3). Importance of hoeing and mulching. 
2. Local differences in water-supply of soil; effects on plant forms studied 
in. situ. 
3. Differences in form of leaves of plants from dry and wet localities. 
Experimental investigation of differences directed to (i) absorption of water by 
roots, (ii) loss of water by leaves. Hale’s experiments. Construction of 
potometer. Microscopic examination of leaf-epidermis; stomata, water-pores. 
Ascent of water in stem; osmosis (see ITI., C., 4). 
4. Mineral substances in soil as food for plants. 
(a) Soil-water shown by evaporation (II., E., 1) to contain dissolved mineral 
matter; comparison with transpired water suggests that the matter is retained 
by the plant. Suggestion confirmed by examination of ash of burnt plant. 
The more important constituents. Practical preparation of water and sand 
cultures. Selective absorption by roots. 
(b) Rotation of crops. The nodules on roots of leguminous plants; fixation 
of nitrogen by bacteria. Bottomley’s researches. ‘Symbiotic’ relations 
between green plants and fungi. 
C. Summer Term. 
Studies in plant physiology. f : y 
1. Respiration. | Germinating seeds found, like human beings, to emit 
carbon dioxide. Probability (in spite of negative experimental tests) that the 
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