BONES FOR MANURE.

Lyttelton Times, Volume LIII, Issue 5918, 13 February 1880, Page 6

BONES FOR MANURE.

TO THE BDITOE. Sib, —In reply to your correapondent in this morning’s Times, who signs himself “ Agricola,” requesting some of your agricultural readers “to explain the method of decomposing bones with diluted sulphuric acid, and what quantity per acre should be used, and how applied.” Having had considerable experience in the manipulation, as well as the use of a large variety of hand and patent manures, I shall with your permission furnish the required information. The method of preparing bones of any hind for treatment with splphuric acid, is to have them broken up small, either by hammers or ground in a mill for the purpose; the finer the bones are broken the less acid will be required. To every 1001 b of bones should be added an equal weight of water poured over’ them and well mixed. To avoid waste an old case may be used for the mixture. The usual quantity of acid used for dissolving half-inch bones is 501bs to every lOOlbs of bones. The acid should be poured over the bones and well mixed, great care being used in handling the carbon, as the acid burns the skin or clothes wherever it touches.

The theory of wetting the bones first is explained in the fact that sulphuric acid has a great affinity for water, and therefore more readily finds its way through the moistened pores of the bones, which thus become more easily acted upon by the acid. It may be interesting to explain the chemical changes (according to agricultural chemists) which take place in the bones when treated by sulphuric acid. First the carbonate of lime is converted into sulphate of lime, and this explains the violent effervescence or escape of carbonic acid gas observed during the process. Again, the insoluble phosphate of lime loses a portion of its lime, forming with the acid sulphate of lime, thus the cause of the presence of so large an amount of gypsum in vitriolised bones, and the lime remaining unappropriated by the acid, forms with the phosphoric acid a compound readdy soluble in water. Vitriolised bones or superphosphate may be used either in drills preceding the seed or sown broadcast at the rate of from two to three hundredweight per acre, one hundredweight being equal to double the quantity of half-inch bones for the first season, but being rendered soluble there remains little in the soil for the after crop. The great advantage derived from the use of super-phosphate, particularly with the turnip crops, is that its immediate action has the effect of forcing the young plants into the rough leaf, and beyond the fly. In conclusion, I must state that the present price of acid, 4d per lb, renders the _ profitable manufacture of super-phosphate impossible. One cwt of bones at 7s 6d, and 661 b of acid

at 4d, and our mixture will coß 4^f. P l r ft vl)o without the cost of labo ur - Bomb xaey rendered sufficiently soluble by k 01 “8 B / m P crushed, mixed with ashes, peat« earth, put into a heap, wetted occasionally, and a to remain so for two or three months before use. Active fermentation will set m, and for all ordinary purposes will be equal to super-phosphate, with the advan g of having been prepared at a nominal cost. I am, &0., . >TTT ,, Feb, 12. SOI'ANPM.