146 AMERICAN MANURES. 



manufacturer using an insufficient quantity of 

 acid. (See page 55.) 



Sulphuric acid being the agent used to render 

 phosphoric acid soluble, we shall now show how 

 much is required. Oil of vitriol, or the strongest 

 sulphuric acid of commerce, known as 66 acid, 

 contains 75 per cent, of anhydrous sulphuric 

 acid. 



Each per cent, of the following compounds 

 will require, to render them soluble, the follow- 

 ing amounts of 66 acid, or oil of vitriol : 



1-00 Carbonate of Lime requires 1*066 Sulphuric Acid. 



TOO Bone Phosphate of lime 0'688 



TOO Basic Phosphate of Magnesia. 0-810 



1-00 Fluoride of Calcium 1'367 



1-00 Alumina 3-110 



1-00 Protoxide of Iron 1-480 



1-00 Peroxide of Iron 2'000 



The above Table is very valuable both to the 

 manufacturer and the farmer. The manufacturer 

 can readily calculate how much acid is required 

 by bones or any mineral phosphates, of a known 

 composition, to render all the phosphoric acid 

 soluble. And when a superphosphate of lime is 

 represented to contain a certain percentage of 

 soluble phosphoric acid, the farmer can very 

 nearly estimate the amount of sulphuric acid 

 used, and also the expense incurred by the 

 manufacturers. The application of sulphuric 

 acid to carbonate of lime or fluoride of calcium, 



