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MONTHLY JOURNAL OF AGRICULTURE. 



own natural affinities. Tlie chemicnl changes 

 which take place between the sulphuric acid 

 and the organic portion of the bones are, no 

 doubt, very complicated. Sugar is one result, 

 and probably sulphate of ammonia is another ; 

 but I cannot venture to state what quantity 

 of sulphuric acid may be necessary to eflect 

 these changes. If we presume that one-third 

 is the proportion of sulphuric acid employed, 

 then there will remain 17 lbs. to act on the 

 organic portion of tlie 4 bushels of bones — the 

 remainder having been required by the 

 earthy portion. 



We find that manufacturing chemists, in 

 the preparation of phosphorus from bones 

 (now largely required for lucifer matches), 

 first destroy the org;mic part of the bones by 

 means of fire, and then mix the remainder 

 with half its weight of sulpliuric acid. Thus, 

 if we suppose 180 lbs. to be the quantity em- 

 ployed, by burning it will be reduced to 120 

 lbs., requiring 60 lbs. of acid to foiTU super- 

 phosphate, which would be one-third the 

 weight of the bones previous to burning. I 

 suppose, however, that in this case an excess 

 of acid is required to render the process com- 

 plete, as one-half would otherwise appear to 

 be more tluin the quantity demanded. 



From these and other reasons we may 

 justly consider that the jiroportion of acid to 

 the bones should never be less than one-third 

 nor more than one-half The former, I think, 

 is the most economical, but probably the pre- 

 cise quantity most desirable will be 42 jier 

 cent, of acid. I may, however, observe that 

 in an experiment during the last season, in 

 which one portion of the land was manured 

 v*ath bones and acid in difterent proportions, 

 that which had more bones and less acid 

 proved to be a somewhat better crop than 

 where fewer bones and more acid were used ; 

 the expense being the same in both instances. 



3. The proportion of water to be mixed 

 with the acid will next receive our attention. 



Wlien one part by weight of water is mixed 

 with four of acid, the temperature is raised 

 to 300° Fahr. It is, therefore, veiy desira- 

 ble that sutiicient water shoidd be used to 

 produce this gi-eat heat, which facilitates the 

 dissolving process ; and tlic (piantity above 

 stated, or, if moi-e convenient, the same meas- 

 ure of water as of acid, which will be rather 

 more than half the weight, will be a very 

 good proportion. More should not be used, 

 as no useful j)urpose will be acconiplislie<l. 

 In an experiment tried last year with ditVer- 

 ent proportions of water, I could not detect 

 any difference in the result. The water 

 should be api)lied first by means of a water- 

 ing-pot, so that it may be intimately combined 

 with every portion t>f the bones. This is an 

 important point, and gieally facilitates the 

 dissolving process, which without it is very 

 likely to be imperfectly acc()ni])lished. 



Another reason for ap[)lying th<> water first 

 is, that the bones becoming partially sHlunited, 

 the acid, from its gi-eat atlinity fur it, rashes 

 as it were into the pores of the bones in seaich 



(568) 



of the water, and thus the bones become 

 more rapidly and perfectly mixed with and 

 acted on by the acid. When no water is em- 

 ployed, and the bones are not entii'ely in the 

 state of fine dust, as they never are unless 

 purposely sifted, the surfaces of the small 

 pieces of bone become acted on by the acid, 

 and a coat forms around them which seals up 

 the interstices of the bones, and prevents the 

 acid from penetrating. I have no doubt this 

 is often the case likewise from careless or im- 

 perfect niixture, and the good effects of the 

 manure are thus materially diminished. 



4. Mode of mixing the bones with the acid, 

 and of preparing the compost. 



It has been reconnnended that a large heap 

 of a.shes or mould should be made with a hole 

 or depression on the top, in which the bones 

 are to be placed, the acid poured over them, 

 and after some time the whole shoveled up 

 and mixed together. Now, if we examine 

 into the effects of this mode of procedure, we 

 shall readily perceive the objection to which 

 it is subject. The ashes, no doubt, contain a 

 considerable portion of carbonate of lime, be- 

 sides other salts, for which sulphuric acid has 

 a very sti-ong affinity. Thus the bones are 

 robbed of a large proportion of the acid, of 

 which they ought to have exclusive posses- 

 sion. And even if common moidd is used, 

 or any other substance \vhich has no particu- 

 lar chemical affinity for tlie acid, still this 

 mould will mechanically absorb much of the 

 acid, and thus deprive the bones of it.* I hold 

 it, therefore, as a point of much importcUice 

 that the whole of the acid should be directly 

 applied to the bones, and that no other sub- 

 stance should l)e allowed to uitercept or ab- 

 stract their mutual affinities. 



A very convenient and cheap vessel for 

 manufactming the mixture is a sugar hogs- 

 head, having its hole stopped with plaster of 

 Paris. It is verj^ desirable to avoid if possi- 

 ble any measuring or weighing of the acid, as 

 it is so very dangerous a substance to liandle. 

 Many serious accidents occurred to my knowl- 

 edge during the last ye;u', and it is very dif- 

 ficult to impress farm servants with a siifli- 

 cient degree of caution, or even to convince 

 them that a liquid which ajipears so colorless 

 will burn their skin and clothes. In emptA'- 

 ing a carboy of acid even into a tub it is diffi- 

 cult to ])rcvent a little slo]iping about and 

 damaging the clothes of the attendants, as 

 well as the basket, vK:c., which contains the 

 carboy. To jirevent these unpleasant conse- 

 cpiences I have adopted the fi)llowing plan : 

 The carboy is ])laced on a stage or cask the 

 same bight iis the sugar hogshead, into which 

 is put the ])recis(^ quantity of bone-dust we 

 intend mixing with the carboy of acid. The 

 water is now added with a watering-pot hav 



* I have not found thai any considerable quantity 

 of the acid passes through the bones into tlie heap 

 of ashes or earth ; and though Mr. 8pooner'a is the 

 better plan, where his apparatus eiin be easily pro- 

 cured, I still think that the exjiedicnt I nientioned. 

 may be found souu limes convenient. [Pit. Pusiy 



