Phosphatic Materials used for Agricultural Purposes. 33 



In the next table is given the composition of 



No. 1. Sound foreign bones. 



2. Decayed foreign bones. 



,, 3. Decayed and sound foreign bones mixed. 



4. London bones. 



In decayed bones the proportion of organic matter is not quite 

 so great as in sound bones, and the phosphates are rather higher. 

 But the differences are not sufficiently striking to require any 

 comment. In the preceding analyses, the lime which is left in 

 solution after the phosphates have been removed has likewise 

 been determined quantitatively. Calculated as carbonate of 

 lime, it amounts in the four analyses to 8'60, 8*71, 7*50, 7'78, 

 respectively. 



b. Boiled Bones. 



The bones from which glue-makers have extracted a certain 

 portion of gelatine and nearly all the fat are known in commerce 

 under the name of boiled bones. It must not be supposed, how- 

 ever, that boiled bones do not contain any organic matter, nor 

 furnish on decomposition any ammonia. The following two 

 analyses show the contrary : 



Composition of Two Samples of Boiled Bones. 



Moisture 8'06 



"Organic matters 25'45 



Phosphates of lime and magnesia (bone-earth) 60'48 



Carbonate of lime 3-251 



Alkaline salts -43J 



Sand 2-33 



7-70 

 25-27 

 43-73 



9-77 

 13-53 



* Containing nitrogen 

 Equal to ammonia . . 



100-00 



1-84 

 2-24 



100-00 



2-78 

 3-37 



