404 



The Use of Lime. 



[OCT. 



lime, instead of the considerably higher rates now charged by 

 some of them. 



From 30 to 50 per cent, less ground lime: should be applied 

 than shell lime, as the distribution of the former can be more 

 perfectly carried out. It is usually applied by means of a 

 manure distributor. 



Ground limestone. — This must not be confused with ground 

 lime. It is difficult to grind, and has been found to be of 

 little advantage. 



Gas lime. — This is a by-product in the manufacture of coal 

 gas, for which lime is used as a purifying agent. Fresh gas lime 

 usually contains from 28 to 40 per cent, of water, and on the 

 average only about 34 per cent, of the equivalent of lime (CaO), 

 only a small proportion being caustic lime. It also contains 

 small amounts of sulphocyanides and sulphides, which are viru- 

 lent plant poisons. When, however, it is carefully spread on 

 the land and exposed to the air for at least two months (all 

 lumps being broken and spread) these are practically rendered 

 innocuous. Mr. Collins found that gas lime spread on the land 

 in a thin layer for about ten weeks had become safe, and had 

 also lost much of its moisture. The Glasgow Corporation now 

 use a plant for pulverising the gas lime produced at their gas- 

 works, and make a charge of 6d. a ton to purchasers who 

 desire it so pulverised. This form of lime is probably most 

 usefully applied to the hay stubbles in the autumn or early 

 winter, on which it should be carefully spread and not ploughed 

 in for at least eight weeks afterwards. The amount applied 

 may vary from two to four tons an acre. On soils poor in 

 lime the oat crop which follows may be considerably benefited. 

 Its value is low., At considerable distances from a town its use 

 is not profitable, and at moderate distances it is so only if rail- 

 way rates are low and the distance to cart is not excessive. 



CJialk. — This is really a soft limestone, and although it be- 

 comes hard on exposure, as on the face of chalk cliffs, it is 

 usually in a soft cheesy condition on the fresh surface of a 

 chalk quarry, and should be applied to the land in this con- 

 dition during late autumn or early winter, so that there is a 

 good chance of the water in the chalk being frozen so as to 

 pulverise the chalk lumps and insure distribution in the soil. 



