1887.] 



PUBLIC DOCUMENT — No. 83. 



117 



The diflference in the mechanical condition of the steamed 

 bones causes the variation in the valuation of the phosphoric 

 acid and of the nitrogen: The first sample was of a good 

 average fineness ; the second consisted largely of coarse yet 

 porous pieces ; the phosphoric acid in the latter is valued at four 

 cents per pound, and the nitrogen thirteen cents, whilst five 

 and fifteen respectively are allowed in case of the former. 



Ground Bone. 



[I. Fine-ground bone sent on from Concord, Mass. II. Fine-ground bone compost 

 sent on from Concord, Mass.] 



The above samples of rendered, ground bones, and of a bone 

 compost prepared from the former by mixing with wood ashes, 

 were sent on to ascertain the exact changes which the material 

 had suflfered after a few months' keeping. The analyses show 

 less soluble phosphoric acid, and also less nitrogen for the same 

 amount of phosphoric acid in the bone compost, when compared 

 with the original bones. 



The operation of composting bones with wood ashes 

 proved in the present case a decided loss, for more than one- 

 fourth of the original nitrogen had been lost in the form of am- 

 monia. A sample of the material, sent on for examination, 



