NUTRITIVE MANURES. 59 



These parts of animals are principally composed of phos- 

 phate of lime and of gelatine. Those bones which are 

 most usually employed, contain about equal quantities of 

 phosphate and gelatine. The bones of the ox yield from 

 fifty to fifty-ftve per cent, of gelatine ; those of the horse 

 from thirty-six to forty ; and those of the hog from forty- 

 eight to fifty. 



The bones of young animals contain more gelatine than 

 those of older animals, and have a less compact texture. 

 The bones of the feet of the elk, the roe-buck, stag, and 

 hare afford, upon analysis, from eighty to ninety per cent, 

 of phosphate. 



When bones are to be employed as a manure, they 

 should be ground fine, and thrown into a heap to ferment. 

 As soon as this action shall have commenced, so as to 

 give out a penetrating odor, the mass should be spread 

 upon the earth, and be afterwards mixed with it; or it 

 may be thrown upon the seed, and buried in the ground 

 with it. When seeds are sown in furrows, it is a good 

 method to place some of the ground bones in the furrows 

 with them. 



In some countries the fat and a great part of the gela- 

 tine are extracted from bones, by boiling them in water, 

 before selling them for agricultural purposes. But by this 

 operation they are deprived of a great part of their fertil- 

 izing powers. Upon carefully observing the appearance 

 of a mass of bones under fermentation, I found the sur- 

 face of a part of them to be covered with a thin coating 

 of an unctuous substance, sharp and biting to the taste. 

 This appeared to me to be formed by the combination of 

 gelatine with ammonia ; this last being always developed 

 during the decomposition of all animal substances. The 

 observations of M. D'Arcet, lo whom we are indebted for 

 a very valuable work upon gelatine, support this opinion. 



It is possible, that, when the ground bones are em- 

 ployed without having been first submitted to the com- 

 mencement of a fermentation, the gelatine is gradually 

 decomposed in the ground, and the same result at length 

 produced ; or, we can conceive that water, acting upon 

 the bones, will dissolve the gelatine, and transmit it to 

 plants ; and in both these cases the influence of the bones 

 upon vegetation is very great, whether it be considered 

 as a purely nutritive manure, or in the double connexion 

 of a nutritive and stimulating substance. 



