164 



Indiana University Studies 



The manufacture of acetate of lime from which pure acetic 

 acid is prepared, and the purification of wood alcohol and acetone 

 are carried on along the same line. Milk of lime is used to take 

 up the acid from the impure wood spirits, while the alcohol and 

 acetone are carried over and condensed. Much lime is used in 

 these reactions. The only method of obtaining wood alcohol of 

 high purity is by distillation over lime. 



In the manufacture of soaps the lime is used to obtain the 

 alkaline hydroxides from the carbonates, as described earlier. 

 The action of the lime on tallow or on a grease forms organic 

 salts of calcium. The calcium is easily replaced by sodium or 

 potassium, from some of their compounds, to form the soluble 

 soaps of commerce. Saponification with lime is a necessary 

 step in the manufacture of candles, glycerine, and the explosives 

 derived from glycerine. The milk of lime is used also to remove 

 any trace of acid that might be present in the pure products. 



Lime plays a very important part in the manufacture of 

 paper. The first use of lime in this industry is in the cleansing 

 of the materials and the removal of foreign substances. This 

 method is employed in the case of rags, straw, etc., that are to be 

 used in paper manufacture. If wood pulp from soft woods is 

 to be used, the pulp is boiled in a solution of sodium carbonate 

 which has been rendered alkaline by the addition of pure lime 

 oxide. In the sulphite process the wood of spruce, hemlock, 

 etc., is boiled with sulphurous acid and milk of lime until the 

 tars and oils are removed and the pulp softened. The paper 

 pulp is usually bleached with chloride of lime before rolling. It 

 will thus be seen that lime plays one of the most important parts 

 in this industry. 



The uses of lime in sanitation are so numerous and so well 

 known that space will not be given here to a discussion of them. 



Lime is used in sugar manufacture in the process known as 

 ''Defecation". The lime here removes the excess of organic acids 

 and coagulates the albumen and mucous. Lime, altho only 

 slightly soluble in water, is more soluble in sugar water, and the 

 lime unites with the sugar to form an insoluble compound in which 

 form it can be washed with alcohol and water. The calcium 

 from this sugar of lime compound can be removed by passing 

 carbon dioxide thru the solution. 



Lime is used in tanning hides, in which process a strong solu- 

 tion of milk of lime is used to remove the hair from the hides. 

 The lime also dissolves the fatty matter and the coriin, loosening 



