xc Agricultural Education — Examination Papers, 1874. 



8. Show how you detect (1) the phosphate in a mixture of calcium 

 phosphate and carbonate, (2) ammonia in rain water, (3) lead in tin 

 alloyed with lead. 



9. What is carbolic acid ? How is it obtained ? Describe its most 

 distinctive chemical characters, and explain how it is related to benzol, 

 and how to test its genuineness. 



10. Explain how to find (1) whether an organic substance contains 

 nitrogen, (2) how much it contains? 



II. Ageicultural Chemistry. 

 Wednesday, April 15th, from 2 jp.m. till 5 p.m. 



1. Give an account of the properties and composition of the various 

 constituents of milk. 



2. AVhat is the composition of blocd, and what is its value as a 

 manure ? 



3. "What is the composition of raw and boiled bones ? How do you 

 detect the adulteration of gypsum, crushed limestone, vegetable ivory, 

 and of sand in bone-dust ? 



4. If commercial nitrate of soda containing 95 per cent, of pure 

 nitrate cost 14Z. a ton, and commercial sulphateof ammonia containing 

 24 per cent, of pure sulphate 18Z. a ton, it is cheaper to use nitrate of 

 soda or suljjhate of ammonia as a source of nitrogenous plant food. 

 How much nitrogen is contained In 100 lbs. of sulphate of ammonia, 

 and in 100 lbs. of nitrate of soda ? 



5. In what states of combination does potash occur in soils ? In 

 what form is it best applied to the land? How may it be distin- 

 guished from soda, and the quantity of it in a mixture of chloride of 

 potassium and sodium be determined ? 



6. Mention some practical points on which you may obtain definite 

 information from soil-analyses. 



7. Describe briefly the characters of clay marls, chalk marls, peaty 

 and sandy marls. How do you proceed in analysing a marl with a 

 view of ascertaining its agricultural value ? 



8. Write a short paper on the changes which take place in the field 

 and stack in hay-making. 



9. Explain the fallacies involved in the so called Humus theory, 

 and at the same time point out in what way vegetable mould may 

 contribute to the fertility of the soil. 



