18. To a fresh sample of soil add some hydrochloric acid. Is there any effervescence? If so, what conclusions do you draw?
19. Make a solution of soil in distilled water, and filter as before. Is this solution acid, alkaline or neutral? Are you quite certain of your result? Did you test the distilled water with litmus paper? And are you sure that your litmus does not contain excess of free acid or free alkali?
Peat.
20. Examine different varieties of peat collected (see Question 2) and describe the appearance of each.
21. Burn a fragment of each kind of peat on wire gauze. What do you notice?
22. Boil some peat with distilled water and filter the solution. What colour is it? Can you tell whether it is acid, neutral or alkaline? Evaporate some of the solution to dryness.
Out-of-doors.
23. Describe the appearance of the soil in the flower beds (a) during hard frost, (b) in the thaw which follows a hard frost, (c) after an April shower, (d) in drought at the end of summer, (e) in damp October weather when the leaves are beginning to fall.
24. Is the soil equally friable at different times of the year?