EXPERIMENT STATION. 41 



Analyses of Bone Manures. 



(See Tables on pp. 42 and 43.) 



Of the eighteen samples of ground bone here reported, hut 

 four fall in value seriously below their cost. These four are Lister's 

 Celebrated Ground Bone, and Rafferty & Williams' Bone Meal. 

 These two ai-ticles contain large and variable quantities of moist- 

 ture and salt-cake or sulphate of soda. (In 552 12.2 per cent, water, 

 and 38.3 soluble matters, mostly salt-cake; in 553 7.3 percent, 

 water and 17.2 sohible matter; in 607, 24 per cent, soluble 

 matters.) Doubtless the nitrogen and phosphoric acid in these 

 brands are more soluble and active than in raw bone, and 

 this fact should enhance the estimated value. On the other hand, 

 the pulverized salt-cake which passes the fine sieves by our mode 

 of reckoning tends to increase the estimated value, so that the 

 figures given for the latter are probably not far from correct. 



On soils which need or are benefited by sulphates, the salt-cake 

 in these articles has a value not to be overlooked. Perhaps they 

 may sometimes be strikingly useful because of the presence of 

 sulphate of soda, as might be expected on land in grass, where 

 plaster operates well, but they may also often work injuriously 

 from containing so much soluble salts, especially if applied with 

 seed in the hill or drill. 



"Peter Cooper's Pure Bone" contains so much less nitrogen 

 than other brands of pure bone, because it has been boiled or 

 steamed for the glue manufacture. The boiling has removed all 

 the fat or grease, and also a good share of the peculiar animal 

 matter of the bone (ossein) which dissolves in hot w^ater as glue 

 or gelatine, and which contains all the nitrogen. The residual 

 bone pulverizes easily, and, by the loss of animal matter, is ren- 

 dered relatively richer in phosphoric acid. 



Some entertain the notion that grease in ground bone is a sign 

 of goodness. This is true to a degree, since fresh raw bone is 

 greasy, while old bones that have been exposed to the weather 

 and bones which have been boiled or steamed are not greasy. 

 It is again true that weathered bones and boiled bones are not so 

 rich in nitrogen as fresh raw bones. On the other hand grease is 

 not a fertilizer, and while the extraction of grease is accompanied 

 4 



