94 AGRICULTURE 



than of common burned lime, for whereas, 

 in the latter case, impurities like ashes and 

 stones can be readily detected, in the former 

 case everything is ground up into an im- 

 palpable powder, so that it is impossible 

 by mere inspection to determine, even 

 approximately, the extent of the impurity. 

 Ground lime should therefore be brought 

 under a specific guarantee of purity, which 

 generally falls somewhere between 80 and 90 

 per cent. 



Another form of lime, extensively em- 

 ployed in agriculture, is Gas Lime which, when 

 thoroughly weathered so that the poisonous 

 substances (sulphides) are rendered innocuous, 

 has a distinctly beneficial effect on many 

 classes of soil, though experiments go to 

 show that as a preventive or cure of finger- 

 and-toe it is much less effective than burned 

 lime. 



More recently, ordinary unburned lime- 

 stone as it comes from the quarry has been 

 passed through disintegrators, and may now 

 be purchased in the form of powder, but it 

 is doubtful whether in most cases this form 

 of lime is effective enough to be profitable. 



In certain districts of England great 

 quantities of chalk have in past years been 

 applied to agricultural land with, it may 



