Improving the Condition of the Soil 



combinations — is much more prominent than its 

 value, which is in reality nothing to boast about. 



Slag from Sugar Manufacture. 



This consists of the residue of the lime employed 

 in sugar factories for precipitating the organic 

 matters of the juice which impede the crystallisation 

 of the sugar. After the precipitation of these organic 

 matters the excess of lime is next precipitated by 

 saturating the boiling juice with carbonic anhydride 

 — the result being carbonic calcium. These slags, 

 therefore, are composed of precipitates of organic 

 matter and impalpable carbonate of lime [CaCOs]. 

 The value of slags is partly attributable to the fine- 

 ness of the insoluble calcium present in an impal- 

 pable form, and partly to the nitrate and phosphoric 

 acid it contains. Wolif gives the following analysis 

 of its important constituents : — 



Water .. .. .. .. .. .. 43*3 percent. 



Insoluble carbonate of lime . . . . . . o"35 ,, 



Organic matters .. .. .. .. .. I'j'z „ 



Phosphoric acid .. .. .. .. .. o"i ,, 



JNitr3>X6 •• •• •■ •• «• «a O* ^ 1^ 



The carbonate of calcium in the form of impal- 

 pable elements is the most active of all the carbonates 

 of calcium. Its action will be rapid and not long- 

 lasting. Its use is recommended in the neighbour- 

 hood of sugar works, but it does not justify the 

 heavy cost of transport. 



It would cost probably from is. 6d. to 2S. a 

 ton. 



140 



