SUGAK-HOUSE BONE-BLACK. 377 



applying finely-ground mineral phosphates as previously 

 specified. 



Bone-black Waste. 



This sample was bought of a Boston dealer, and consisted 

 of a very fine, dry powder; it contained 36.2 per cent., or 

 724 pounds of phosphoric acid per ton. 



Taking its wholesale price at $25 to $30 per ton, it is not 

 only one of the best but also one of the cheaper materials 

 for the manufacture of superphosphates. The above sample 

 of bone-black is, in all probability, the fine dust produced in 

 the preparation of granulated bone-black, from burnt bones, 

 for the use of sugar-refiners. Its supply is very limited. 

 The larger bulk of bone-black waste used for fertilizers comes 

 from sugar-houses, and consists of the daily waste resulting 

 from the screening of the reburnt bone-black. As the latter 

 has passed through repeated calcinations, in consequence of 

 a repeated use for the decoloration of sugar solutions, it is 

 frequently not only strongly impregnated with gypsum and 

 other mineral matters, but also very compact; it contains 

 usually from 32 to 34 per cent, of phosphoric acid, and, for 

 obvious reasons, ought only to be used in form of a super- 

 phosphate. 



Ground Bones. 

 I. — Ground Bones of the Cumberland Co. (Portland, Me.). 



8.18 parts. 



Moisture at 100° C, 

 Moisture and organic matter, 

 Ash constituents, . 

 Phosphoric acid, in ash, . 

 Nitrogen in animal matter, 



444.2 pounds insoluble phosphoric acid, . 

 90.8 " nitrogen, .... 



$53 90 



It was a coarsely-ground article, resembling in size that 

 which is sold commonly as chicken-bone ; it sold at $40 per 

 ton. 



48 



