THE SOUTHERN PLANTER. 



259 



acid used ; these should be enough to 

 convert all of the neutral into superphos- 

 phate ; less than that would leave a por- 

 tion of the neutral phosphate unacted 

 upon and more than sufficient for this 

 would only involve the maker in unneces- 

 sary expense. It is also important to at- 

 tend to the state of division of the bone, 

 or other phosphate acted onj some works 

 upon Chemistry applied to agriculture, re- 

 commend the use of whole or broken 

 bones, if ground ones cannot be had, and 

 say that by the use of more acid, the bones 

 will soon crumble. This is a mistake ; 

 the material should always be in a fine 

 state of division to insure complete re- 

 action between the substances ; and even 

 then great care in mixing them is neces- 

 sary. 



Again, it is necessary in the prepara- 

 tion of the manure, to dilute the acid with 

 a certain portion of water ; first, to pre- 

 sent the acid's charing the animal mat- 

 ter 5 and second, to make the mixture of 

 such a consistence, that the materials may 

 be thoroughly incorporated, so as to in- 

 sure the most intimate contact between 

 the acid and the phosphate. After the 

 reaction is complete, this water must be 

 gotten rid of by drying the manure in the 

 air, or by artificial heat ; or it may be 

 absorbed by the addition of some other 

 substance, which substance may give ad- 

 ditional value to the manure, or may be 

 worthless. 



So variable is the composition of this 

 manure, that no two brands are alike, 

 and very few of them come up to any- 

 thing like what should be the proper stan- 

 dard of excellence. This results from ig- 

 norance and want of skill on the part of 

 some manufacturers ; but in very many 

 cases it results from design. The man- 

 ufacturer deliberately prepares an infe- 

 rior or adulterated article, knowing that 

 very few persons can detect the fraud for 

 themselves, or will take the trouble to 

 have the manure analyzed before pur- 

 chasing. Many manufacturers and agents 

 publish analysis of their manures, made 

 by distinguished chemists ; but their anal- 

 ysis are not always to be relied on, — not 

 that the chemists are parties to the fraud, 

 but- the manufacturer supplies them with 

 one article, and the consumer with an- 

 other. 



Let us now see in what proportions the 



acid and bone dust should be used, and 

 what would be the composition of a ma- 

 nure so prepared ; then we shall be better 

 prepared to decide upon the results of the 

 superphosphates now in the market. 



The composition of neutral phosphate 

 of lime is — 



Phosphoric acid, 48^ 

 Lime, 51^ 



100 



That of superphosphate of lime is — 

 Phosphoric Acid, 71£ 

 Lime, 28£ 



100 



Now let us suppose that we wish to con- 

 vert 100 parts of neutral phosphate into 

 superphosphate. In this there are 48J 

 parts of phosphoric acid ; thus : 



71 J; 48^; 100: 68 very nearly. That is, 

 100 parts of Neutral phosphate, will yield 68 

 parts of Superphosphate, which will re- 

 quire the removal of 32 parts of lime. 



Lime and sulphuric acid will unite with 

 each other in the proportion of 41| parts 

 of the former to 58 j of the latter ; to form 

 plaster, therefore,. the thirty two parts of 

 lime which is to be removed from the 100 

 parts of neutral phosphate, will require 45 

 parts of absolute sulphuric acid, or 55 

 parts of the best commercial acid. If 

 now we refer to the original composition 

 of bones, we find that 100 parts of bone 

 dust contain about 46 per cent of neutral 

 phosphate of lime, hence, according to 

 our calculation, this will require for its 

 complete conversion into the superphos- 

 phate, about 25J parts of the last commer- 

 cial acid. The bones also contain about 

 four per cent of carbonate of lime, which 

 is decomposed with the formation of sul- 

 phate of lime the moment the acid and 

 bone dust come in contact with each 

 other; this will consume about 4^ parts 

 of acid. The whole amount of acid, then, 

 necessary to effect the transformation of 

 the neutral phosphate in 100 parts of bone 

 dust into superphosphate, need not exceed 

 30 per cent of the whole ; or say, any 

 amount of bone dust, can, by proper 

 treatment, be converted into superphos- 

 phate of lime by the addition of one third 

 of its weight of good sulphuric acid. 



The mixture of 100 parts of bone dust, 

 and 30 of sulphuric acid, would, after the 



