150 AMERICAN MANURES. 



We shall now show what soluble phosphoric 

 acid costs the manufacturer, when he uses South 

 Carolina mineral phosphate as a raw material. 

 To illustrate this, we will take for example No. 

 12 on the Table of Analyses, page 142. This an- 

 alysis is very near the general average, and 100 

 Ibs. of such phosphate will require the following 

 amount of sulphuric acid ; the amount of gas 

 liberated is also shown. 



These analyses are very imperfectly rendered, 

 the carbonates of lime and magnesia, and the 

 phosphates of iron a,nd alumina being given alto- 

 gether, with no statement of the amount of phos- 

 phoric acid combined with them. As these gu- 

 anos contain but a small amount of magnesia, 

 we shall estimate the carbonates as carbonate of 

 lirne, and estimate the phosphate of iron and alu- 

 mina given, as phosphate of iron. 



Sulphuric Acid. Gas liberated. 



50-07 Ibs. Phosphate of Lime, require 34-448 

 0-69 " " " Iron, " -730 



10-14 " Carbonate of Lime, " 10-819 4-46 

 39*10 " Organic matter, Sand, etc., 



100-00 " 45-997 



A ton of superphosphate of lime manufactured 

 from this guano, would cost, as follows; as in the 

 case of dry bones, should this guano be in a very 

 dry state, about the same amount of water should 

 be used : 



