EXPERIMENT STATION. 51 



(( 



Rotted Bone." 



871. From stock of James H. Baker, 104 Clymer street,. 

 Brooklyn. Sent by E, Hoyt, New Canaan. 



Analysis and Valuation. 



Water, 29.04 



Sand and insoluble, 22.02 



Nitrogen, 2.65 



Phosphoric acid, 1.59 



Estimated value per ton, $14.10 , 



Cost in New York. $16.00 



On the Solubilitt of Bone in Ammonium Citrate. 



It is known that a very small part of the phosphoric acid ot 

 "bones may be extracted from them with cold water, while a large 

 amount is taken up by solution of ammonium citrate,* which is 

 used to remove the so-called " reverted " phosphoric acid from 

 superphosphates. Seventeen samples of bone have been extracted 

 with ammonium citrate solution in order to learn their average 

 solubility in it, and also to find out whether the phosphoric acid of 

 bone which has been mixed with salt or salt-cake is more soluble 

 than that of pure bone. Two grams of the bone, in the condition 

 in which it came to the Station, were digested with 100 c. c. of 

 neutral Am. Cit. solution (Sp. gr., 1.09) for half an hour at 40° C, 

 shaken every five minutes, and then filtered at once. The sam- 

 ples are arranged according to their fineness, and the results are 

 given on page 54. 



An examination of the figures shows that on the average 18.9 

 jjer cent, of the phosphoric acid in the pure bones was soluble, 

 81.1 per cent, insoluble in Am. Cit. The solubility was greater 

 in the finer bones on the average. In those which had no parti- 

 cles larger than one-twelth inch, the average solubility was 24.1 per 

 cent. Where all the particles were smaller than one-sixth inch it was 

 19.1 per cent. ; while in the coarser samples it was 10.2 per cent. 

 The solubility is doubtless afiected by other things than the fine- 

 ness. The amount of grease present, the character of the bone, 

 whether hard (from factories where bone is worked) or soft, and 

 the method of grinding, all have an effect in hindering or helping 

 the solvent action of water or ammonium citrate. 



* This is the substance formed by saturating or neutralizing the acid of lemons 

 by ammonia. 



