J^ QUESTIONS AND ANSWERS 35 



Name the principal salts of acetic acid and state which of the salts 

 named are used in veterinary medicine. 

 The acetates of potassium, lead, ammomum, sodium, zinc and 

 copper. The first five named are used in veterinary medicine. 

 What is vinegar? How made? 



Vinegar is dilute acetic acid (about 6 per cent.). It is made by 

 the oxidation of fermented juices (wine, cider). This oxidation is 

 greatly facilitated by the enzyme "Mycodermse aceti." Vinegar is 

 also made artificially by adding coloring and odoriferous substances 

 to dilute acetic acid. 



ALCOHOLS 



State briefly the method of preparation of alcohol. Give the properties 

 and the principal uses of alcohol. 



Ethyl alcohol is prepared by the fermentation of grape sugar 

 (glucose) . To a solution of grape sugar, a certain yeast (ferment) is 

 added which causes the decomposition of the sugar, yielding carbon 

 dioxide and ethyl alcohol. Alcohol boils at a much lower tempera-*' 

 ture than water and therefore it can be readily separated by dis- 

 tillation. 



CeHijOs = 2C'02 + 2C2HBOH (ethyl alcohol). 



Methyl alcohol (CH3OH) is obtained by the distillation of wood. 



Pure ethyl alcohol is a transparent, colorless, volatile liquid, of 

 a characteristic, rather agreeable odor, and a burning taste. It is 

 very soluble in water, for which it has a great affinity. It is used in 

 medicine in the preparation of tinctures, extracts and fluidextracts, 

 and widely used iu the arts. 



What is the difference between an alcohol and an aldehyde? 



An aldehyde is derived from an alcohol by dehydrating the 



latter, hence it contains less hydrogen than an alcohol. Aldehydes 



are unstable (except formaldehyde), very volatile liquids having 



a peculiar odor, e.g., liquor formaldehydi. 



Give the formula for (a) ethyl alcohol, (b) methyl alcohol. Which is 



used for internal purposes? 



(a) C2H5OH, used internally. 



(b) CH3OH. 



What is absolute alcohol? 



Alcohol containing not more than one per cent, of water. 



Compare wine and brandy in respect to composition. 



Wine, according to the variety, contains from 6 to 22 per cent. 

 alcohol. Brandy contains from 40 to 50 per cent, of alcohol. 



