AMOUNT OF ALCOHOL IN WINE. 145 



The simplest method of ascertaining the quantity 

 of alcohol contained in wine is to distil the spirit from 

 the wine, determine its specific gravity and quantity, 

 and compare it with the quantity of wine which has 

 been employed. 



Various instruments have been constructed to effect 

 this purpose, and one small apparatus was arranged by 

 Gray-Lussac ; but the simplest apparatus which can be 

 used is a retort, with a tubular refrigerator (consisting 

 of a glass tube fixed in the centre of a tin jar, so that 

 it may be kept filled with cold water). The tube 

 must be bent at a right angle, and terminate in a cylin- 

 drical measure-glass, shaped like a bottle, divided into 

 cubic centimetres, and be kept sufficiently cool. Care 

 must be taken to prevent the alcohol from evaporating, 

 as also that the apparatus be securely closed, and every- 

 thing except the retort be kept cool. 



Of course one of the first things to be considered 

 is, how much of the wine should be distilled over. 

 Some content themselves with one-third, and determine 

 the alcoholic contents from that. If, for instance, in 

 the distillate 33 parts out of 100 are composed of 

 alcohol, the quantity of alcohol in the wine will be 

 11 per cent, for ^- = 11. 



It is, however, advisable to distil over more than a 

 third, especially in the case of strong wines, and when a 

 glass retort and water bath are used in distilling. 

 If the wine does not boil, the alcohol evaporates 

 more slowly. I consider it better in general to allow 



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