Structure of Simpler Organic Compounds. 75 



Methyl alcohol, as already stated, is one of the products 

 of the destructive distillation of wood. It is largely 

 employed both in the laboratory and in manufacturing 

 processes as a solvent. 



Ethyl alcohol, or more simply, alcohol, is the typical 

 substance which has given its name to the whole class. 

 It is produced, together with carbon dioxide, from sugar 

 by the action of various micro-organisms, such as the 

 yeasts. The action, which was first definitely shown to 

 be due to the presence of living organisms by Pasteur, is 

 known as " fermentation," and is due to the presence in 

 these organisms of substances known as " enzymes " or 

 " ferments," the action of which will have to be discussed 

 in detail later. The chemical reaction when a simple 

 sugar, such as glucose (dextrose), is employed may be 

 represented by the equation 



Alcohol can also be obtained from more complex " carbo- 

 hydrates " (see p. 2 1 4 and seq.) such as starch, sucrose (cane- 

 sugar), etc., which first undergo hydrolysis to yield the 

 simpler carbohydrates. The actual mechanism of fermenta- 

 tion processes may be best discussed when dealing with the 

 chemistry of the carbohydrates. For the manufacture of 

 alcohol on a large scale starch from potatoes and other 

 cheap raw materials is employed. The alcohol contained 

 in beer and wines is derived from the carbohydrates 

 contained in the malt or grapes. 



Propyl Alcohol. In alcoholic fermentation there is 

 produced, in addition to alcohol, small quantities of other 

 products with higher boiling points, which can be separated 

 by a process of fractional distillation. The higher boiling 

 portion of the volatile fermentation products is known 

 as fusel oil. The separation from the "raw spirit," as 

 the crude fermentation product is called, is accomplished 



