CHEMISTRY 



one year from coal tar a quantity of indigo dye which under 

 the natural process of plant extraction would have required 

 a quarter million acres of indigo plant. 



The abundance and cheapness of newspapers, coarse 

 wrapping papers, etc., is due to the fact that man has learned 

 to substitute wood for rags in the manufacture of paper. In- 

 vestigation brought out the fact that wood contained the sub- 

 stance which made rags valuable for paper making. Since 

 the supply of rags was far less than the demand, the problem 

 of the extraction from wood of the paper-forming substance 

 was a vital one. From repeated trials, it was found that 

 caustic soda when heated with wood chips destroyed every- 

 thing in the wood except the desired substance, cellulose; 

 this could be removed, bleached, dried, and pressed into 

 paper. The substitution of wood for rags has made possible 

 the daily issue of newspapers, for the making of which suffi- 

 cient material would not otherwise have been available. 

 When we reflect that a daily paper of wide circulation con- 

 sumes ten acres of wood lot per day, we see that all the 

 rags in the world would be inadequate to meet this demand 

 alone, to say nothing of periodicals, books, tissue paper, etc. 



Chemistry plays a part in every phase of life ; in the arts, 

 the industries, the household, and in the body itself, where 

 digestion, excretion, etc., result from the action of the bodily 

 fluids upon food. The chemical substances of most interest 

 to us are those which affect us personally rather than indus- 

 trially; for example, soap, which cleanses our bodies, our 

 clothing, our household possessions; washing soda, which 

 lightens laundry work ; lye, which clears out the drain pipe 

 clogged with grease ; benzine, which removes stains from 

 clothing ; turpentine, which rids us of paint spots left by 

 careless workmen ; and hydrogen peroxide, which disinfects 

 wounds and sores. 



