60 CHYMISTRY APPLIED TO AGRICULTURE. 



When bones are calcined in a close vessel, they yield 

 oil and carbonate of ammonia ; the proportion of the 

 phosphate is not sensibly diminished ; but the gelatine is 

 decomposed. There remains after the operation from six- 

 ty-six to seventy-two per cent, of the weight of the bones 

 employed. This residue, broken and pulverized with care, 

 is of great use in the process of refining sugar. After 

 having been used in this process, and become impreg- 

 nated with ox-blood and animal carbon, I have found it 

 to be one of the best manures which I could employ for 

 trefoil and clover. It should be scattered with the hand 

 upon the plants, when vegetation begins to be developed 

 in the spring. 



Some of the dry parts of animals, as the horns, hoofs, 

 and claws, approach closely to bones in the nature of their 

 constituent principles ; but the proportions of these va- 

 ry prodigiously. In such parts, gelatine constitutes the 

 largest portion ; and for this reason they are more es- 

 teemed as manure than the bones. M. Merat-Guillot has 

 found but twenty-seven per cent, of phosphate of lime in 

 the horn of a stag, and M. Hatchett, by an analysis of 

 five hundred grains of the horn of an ox, gained only one 

 fifth part of earthy residuum, of which a little less than 

 one half was phosphate of lime. 



The clippings and parings of horns form an excellent 

 manure, of which the effect is prolonged during a suc- 

 cession of years, owing to the difficulty with which water 

 penetrates them, and the little tendency they have to fer- 

 ment. 



A very good manure is likewise formed from wool. Ac- 

 cording to the ingenious experiments of M. Hatchett, hair, 

 feathers, and wool are only particular combinations of gela- 

 tine with a substance analogous to albumen; water can 

 only dissolve them by means of fermentation, which takes 

 place slowly, and after a long time. 



One of the most surprising instances of fertile vegeta- 

 tion that I have ever seen, is that of a field in the neigh- 

 bourhood of Montpellier, belonging to a manufacturer of 

 woollen blankets. The owner of this land causes it to be 

 dressed every year with the sweepings of his work-shops ; 

 and the harvests of corn and fodder which it produces, 

 are astonishing. 



It is well known, that the hairs of wool transpire a fluid 

 which hardens upon their surface, but which possesses 



