BONES. 



203 



litmus-paper to a distinct blue color, for they are 

 very rich in carbonate of ammonia. The heating 

 when air is excluded causes the safne change as pu- 

 trefaction; that is, it converts the nitrogen of the 

 gelatine contained in the bone into ammonia. 

 Should it be desired to condense the vapors by cool- 

 ing, and to mix the ammoniacal solution so obtained 

 with the bone-black left behind, a mixture might 

 be exhibited which acts in the same way as putre- 

 fied manure or guano, and is of very rapid opera- 

 tion ; whereas, fresh bones act like unputrefied ma- 

 nure, and more slowly in the mass, when they are 

 coarsely broken or imperfectly pulverized. 



The following analyses of several kinds of bone- 

 dust employed in Saxony disclose the chemical 

 composition of this material as it is found in com- 

 merce. 



In consequence of the great demand in Saxony 

 daring the last few years, the market-price has con- 

 siderably advanced, and may be assumed to average 



