PLANT PRODUCTS. FERMENTATION AND FUELS 419 



It is of service in the purification of many natural organic products, 

 such as turpentine, and in the preparation of many synthetic 

 organic products, such as dyes. It is also rapidly coming into 

 use as a fuel, its smokeless flame and efficiency of combustion 

 making it of special importance for aeroplane and motor engines. 

 ^solidified alcohol, chained by the_ad^'*i'rm nf P^I in 10^^-00^^ 

 ? (p. 480), i&jnow largely employed for cooking purposes. Another 

 new development is the catalytic production of ethylene for cut- 

 ting and welding purposes (p. 352). 



\Alcohol. as used in the industries, is denatured, or rendered 

 unsuitable fordrinkingj)urDOses. by fl.HHit.ipTi of small qnp.Tit.it.ifta 

 of~ben^ine Jp. 345J7pyridine bases, nr nt,hp r Hian.grftftn.|^e_ and 

 non-removable organic liquids. The exact formula of denatured 

 alcohol depends upon the use for which it is intended. 



The cheap production of industrial alcohol is rendered possible 

 by the utilization of certain waste materials rich in carbohydrates. 

 When the price of food is high, grains are employed in the 

 manufacture of alcohol only when a crop has been damaged in 

 some manner so that it cannot be sold as a food material. 

 xain-dii.st.^r^wood refuse is heated with Hil^t.p sulphuric 



3onerted int 



sugars by hydrolysis (compare p. 401). At the present time, 

 however, the most important source of industrial alcohol in the 

 United States is molasses. Only a few years ago the dis- 

 posal of molasses furnished a very troublesome problem to the 

 sugar mills, but in 1918 nearly 120,000,000 gallons of industrial 

 alcohol were obtained from this " waste product " in the United 

 States alone. 



Acid CH 3 COOIL^- This acid is formed by the partial 

 oxidation of alcohol (p. 348). Vinegar (crude acetic acid) is 

 manufactured by oxidizing alcohol with atmospheric oxygen, 

 using a bacterium (B. Aceti, " mother of vinegar "), or more 

 probably an enzyme which it secretes, as a contact agent. The 



