VALUATION OF FERTILIZERS. 147 



dissipates the carbonic acid and fluorine gases, 

 causing a loss of weight, as follows : 



1-00 Carbonate of lime loses 0'44 Carbonic Acid. 



1-00 Fluoride of Calcium 0-512 Hydrofluoric Acid. 



To illustrate this matter fully, we will take 

 for example 100 Ibs. of ox bones, which have the 

 following composition : 



'Gelatin 30'58 Ibs. Sulphuric Acid. Loss in gas. 



Phosphate of Lime 58-30 " require 40*165 Ibs. 



Carbonate of Lime .... 7-07 " " 7'536 " 3'11 Ibs. 



Fluoride of Calcium.... 1-96 " " 2'689 " I'OO " 



Phosphate of Magnesia. 2-09 " " 1-692 " 



100-00 Ibs. 52-082 Ibs. 4-11 Ibs. 



The resulting compounds, formed by the addi- 

 tion of the sulphuric acid, are as follows : 



Hydrated Sulphate of Lime or Plaster 81-17 Ibs. 



Superphosphate of Lime 44-00 " 



Superphosphate of Magnesia 1-73 " 



Hydrated Sulphate of Magnesia 3-91 " 



Gelatin J^j. " 



Carbonic Acid gas liberated and lost 3-11 " /& t 



Hydrofluoric Acid " " " 1 ; 00 " 



The above fully explains the theory of con- 

 verting insoluble phosphates into superphos- 

 phates. 



The following Table shows the average cost 

 of the materials, and the weight produced. As 

 the sulphate of lirne produced requires two 

 equivalents of water for its formation, if the 

 bones be perfectly dry, it would be necessary to 

 add water in about the proportion shown below. 



