PREPARATION OF THE ALCOHOLIC LIQUID. 109 



The strength of commercial alcohol varying considerably it is 

 of importance to the manufacturer to be able to calculate in a 

 simple manner how many gallons of water have to be added to 

 alcohol of known strength in order to obtain an alcoholic liquid 

 with the desired percentage of alcohol. The calculation is exe- 

 cuted as follows : 



Suppose : 



P = per cent, of alcohol in the spirits to be used. 



E = per cent, of alcohol in the alcoholic liquid to be prepared, 

 the quotient obtained by dividing P by E gives the volume to 

 which the spirits have to be reduced by the addition of water in 

 order to obtain alcoholic liquid with the desired percentage of 

 alcohol. 



Example : 



From spirits of 86 per cent. Tralles' alcoholic liquid with 11 

 per cent, of alcohol is to be prepared. 



P 

 P= 86; E= 11 = 7.818. 



Hence one volume of the spirits to be used has to be brought 

 to 7.818 volumes, or to 1 gallon of spirits 6.818 gallons of water 

 have to be added. 



Examples of the composition of alcoholic liquid : 



A. Alcoholic liquid from alcohol, water, and vinegar : 



For vinegar with about 7 per cent, of acetic acid. Alcohol of 

 90 per cent. Tr. 10 parts by volume, water 107, vinegar with 7 

 per cent, of acetic acid 12. 



For vinegar with about 12 per cent, of acetic acid. Alcohol of 

 90 per cent. Tr. 10 parts by volume, water 65, vinegar with 12 

 per cent, of acetic acid 7. 



It is advisable to add about 1 per cent, of the entire volume of 

 beer to the above alcoholic liquids. 



B. Alcoholic liquid from alcohol, water, vinegar, and beer. 

 For vinegar with about 5 per cent, of acetic acid. Alcohol of 



90 per cent. Tr. 10 parts by volume, water 107, vinegar with 

 5 per cent, of acetic acid 13, beer 14. 



C. For vinegar with about 8 per cent, of acetic acid. Alcohol 

 of 90 per cent. Tr. 10 parts by volume, water 92, vinegar with 

 8 per cent, of acetic acid 10, beer 9. 



