Mance: Quarrij Industry of Southern Indiana 



163 



The uses of lime in the agricultural industry are many, but by 

 far the largest part used is as a soil amendment, and this use is 

 thoroly discussed in the portion of this study dealing with crushed 

 limestone as a fertilizer. It was there shown that crushed lime- 

 stone would do the same work as lime and at a much smaller 

 cost. The onh' case in which lime is better adapted to soil 

 treatment is that of a soil very high in organic matter, as in the 

 case of drained lands where the soil is of a peaty nature and a 

 part of the organic matter in the soil can be sacrificed for quicker 

 returns. 



Lime is used in the preparation of nearly all of the insecticides 

 and fungicides used for protecting plants. Lime and iron stil- 

 phate, commonly known as copperas, and water are much used 

 as a spray under the name of Bordeaux mixture. This mixture 

 is used to kill fungus growths on vines and trees. A mixture of 

 about 20 pounds of sulphur, 15 pounds of common salt, 35 pounds 

 of lime, and 50 gallons of water Avill make when boiled a spray 

 that will destroy scale and other insects without doing damage to 

 the trees at any time of the year. Alany other mixtures of this 

 type are known. 



Slaked lime, when treated with an excess of chlorine gas, 

 forms calcium oxy-chloride (Ca(0Cl)2), commonly known as 

 "bleaching powder", much used in bleaching vegetable fibres 

 in the textile and paper industries. 



Quicklime is used in the manufacture of the alkaline hy- 

 droxides, such as sodium, potassium, and ammonium hydroxides. 

 The carbonate of the substance, when treated with quicklime 

 and water, gives calcium carbonate and the hydroxide of the 

 substance, as for example: 



CaO + XaoCOs + H,0 = CaC03 + 2Xa(0H) 



This means that quicklime plus sodium carbonate plus water 

 equals calciiun carbonate plus sodiiun hydroxide. 



Calciiun carbide, much used in the production of acetylene 

 gas, is made from a mixture of 100 parts of lime and 70 parts 

 of coke. This mixttu'e must be heated at the temperatiuT of the 

 electric furnace for some time, and as a consequence plants for 

 its manufacture must have cheap sources of power. The carbide 

 breaks up slowly in the air, but rapidly when treated with water 

 according to the following reaction: 



CaCo + 2H2O = CH. + Ca(0Hj2 



