1882.] COMMERCIAL FERTILIZERS. 71 



salt cake added as a drier or make-weiglit, and some leaving little 

 to be desired as to fineness. 



The raw bones contain from 3^ to 4 per cent, of nitrogen and 

 from 20 to 25 per cent, of phosphoric acid. Steamed bone is gen- 

 erally a little poorer in nitrogen and richer in phosphoric acid, 

 while bone which has passed through the glue factories contains 

 often but a small fraction of one per cent, of nitrogen, and may run 

 as high as .30 per cent, of phosphoric acid. 



Now all the native phosphates previously noticed, with the ex- 

 ception of Peruvian guano, seldom come into the retail trade, being 

 used chiefly as the ba^sis of superphosphates. Bone, however, in va- 

 riety of forms is offered everywhere to the farmer, and is perhaps 

 more widely used with us than any other concentrated manure. It 

 has been used longer than any other, and those who have no faith in 

 commercial fertilizers as a rule make a mental reservation in favor 

 of bone. Yet bone varies in quality — as regards its mechanical con- 

 dition — as widely as other fertilizers vary in their chemical compo- 

 sition. A very fine-ground bone is quick-acting, but a coarsely- 

 ground or greasy bone is one of the slowest things to decompose 

 in the soil. 



Grease in bone or in fish is a decided disadvantage, as it shields 

 the other matters from the penetration of water and air, agencies 

 which produce decomposition. For this reason steamed bone is 

 more rapid in its action, and it is quite likely that our large bone 

 factories will sooner or later exhaust the fat almost completely 

 from bone, either with steam or with benzine. Besides the New 

 York market as a source of supply, we have bone-mills in a number 

 of places in this State. The general defect is carelessness in grind- 

 ing. Much of the bone is quite too coarse to secure the best ef- 

 fects, but when its mechanical condition is suitable I believe the 

 prices range a little lower than for New York bone. Those who 

 are on the lookout can at times get a limited amount of bone saw- 

 dust from manufacturing concerns at a very low figure. 



In our experience bone is a thing seldom adulterated with in- 

 tent to defraud. Some firms who deal in it, however, have a brand 

 of bone containing variable quantities (sometimes as high as 40 

 per cent.) of salt cake, sulphate of soda. This is added, as they 

 claim, to dry and keep the bone from rotting or to cheapen it to 

 meet a demand for a cheap manure I If a demand exists for a 

 cheap bone manure of that kind it is a most senseless one. Ton for 

 ton it contains not much more than half as much phosphoric acid 



