Toh. XXI, Second Skries. 



ROCHESTER, N. Y., FEBRUARY, 1860. 



No. 2. 



SONES AS A FESTILIZES. 



We have received several inquiries in regard to 

 he value of bones as a fertilizer, and the best 

 lethod of preparing and applying them. 



The value of bones depends almost wholly on the 

 hosphate of lime and gelatine which they contain, 

 f we burn bones the gelatine is driven off, while 

 tie phosphate of lime remains as ashes. Dry bones 

 ontain, in one hundred lbs., about fifty lbs. of 

 hosphate of lime, and gelatine equal to about five 

 ounds of ammonia. The commercial value of 

 he former is about one cent per lb. ; of the latter, 

 welve cents per lb. This would make one bund- 

 ed lbs. of bones worth, $1.10 — the phosphate be- 

 ig worth fifty cents, and the gelatine sixty cents. 

 Q burning, therefore, we destroy more than half 

 he value of the bones. 



The great question is, how can bones be applied 

 that the phosphate and the gelatine shall be 

 oth retained. Plow them in whole, is the first 

 Ian that suggests itself. This certainly retains in 

 he soil all the virtue there is in the bones ; but 

 hey are so slow to decompose and give up their 

 jrtilizing matter, that little' or no immediate bene- 

 t is derived from their application. Place them 

 a moist unleached wood ashes, or in horse dung, 

 r other fermenting material, and they will decom- 

 ose and fall to pieces, is another way recommended, 

 'his plan has had many able advocates. It has 

 .oubtless in many cases proved effectual. There 

 3, however, this objection to it : a considerable 

 »ortion of the ammonia formed during the decom- 

 S)osition of the bones escapes ; and if, in order to 

 retain the ammonia, we surround the heap with 

 cam, peat, etc., fermentation proceeds so tardily, 

 rom lack of air, that the object is but half accom- 

 ilished. Better, however, treat bones in this way, 

 i:han allow them to lie bleaching in the summer's 

 Bun, an eyesore to every passer-by. 

 : Phosphate of lime, as found in bones, is compar- 

 atively insoluble in water ; and, as plants can take 

 up their food only in solution, it is yery desirable 



that this insoluble phosphate should be converted 

 into a soluble phosphate. This can be done simply 

 by the addition of the proper quantity of sulphuric 

 acid and water to the insoluble phosphate of the 

 bones. The value of this change niay be under- 

 stood by the consideration of the fact that, while 

 the insoluble phosphate sells in Lqndon for less 

 than one cent per lb., the soluble phosphate sells 

 readily, as a manure for turnips, at eight cents 

 per lb. 



Knowing the increased value of the soluble phos- 

 phate, and the great difficulty of reducing bones 

 to a powder, many scientific men have recommend- 

 ed farmers to dissolve whole bones in sulphuric 

 acid, and thus " kill two birds with one stone." 

 We have experimented not a little on this subject, 

 and have come to the conclusion that it is practi- 

 cally impossible to make a good superphosphate of 

 lime from whole bones. We have used twice the 

 quantity of acid necessary for the conversion of 

 the phosphate into superphosphate, and allowed it 

 to act on the bones for several months, yet only a 

 very small proportion of the bones was decom- 

 posed. Equally unsuccessful, too, have we been in 

 dissolving coarsely crushed bones. The acid, it is 

 true, decomposed the outside portions of the bones, 

 but left by far the greater part of the bones un- 

 touched. We have never yet succeeded in making 

 a good superphosphate of lime without grinding the 

 bones quite fine before mixing them with the acid. 



We conclude, therefore, that while bones may 

 be disintegrated by moist, unleached wood-ashes, 

 or by fermentation, the only method of obtaining 

 all their fertilizing properties is by grinding. We 

 should be sorry to discountenance experiments hav- 

 ing for their object the decomposition of whole 

 bones ; but at the same time we could wish that 

 some of the intelligence, ingenuity and skill, which 

 have hitherto been unsuccessfully employed in this 

 matter, were turned to devise a cheap and efficfi- 

 cious bone-miU, and that one was erected in evorv 

 town of the country. 



