148 AMOUNT OE ALCOHOL IN WINE. 



and the of the scale placed exactly level with the 

 end of the column of mercury. In this manner the 

 instrument may be used to test wine. 



In order to determine the alcoholic contents of wine, 

 the thermometer (ebullioscope) should be dipped into 

 wine which is in a copper vessel, and then it should 

 be made to boil quickly. The point which the mercury 

 attains in the thermometer tube, gives directly the 

 amount of the alcohol. If this should reach the divi- 

 sion 15, then 15 per cent, absolute alcohol exists in 

 the wine. 



It will easily be understood that success depends 

 upon two points. First, that the solid matters which 

 exist in wine do not perceptibly raise the boiling point 

 (that is, not during the experiment) ; and secondly, 

 that when the wine begins to warm, and before it boils, 

 as much alcohol and water is evaporated as during the 

 experiment, which originally served for graduating the 

 tube. I will experimentally examine both points. 

 It is necessary to be very watchful and quick whilst 

 graduating the instrument and whilst examining any 

 wine, in noticing the height of the mercury. It is 

 reckoned that half a minute may elapse, and that the 

 temperature of wine containing 15 per cent, alcohol, 

 and of a mixture of 15 parts alcohol and 85 parts water, 

 may remain stationary for a minute. If the first half 

 minute be allowed to pass, the experiment must be 

 repeated with another liquid, since in that case too 

 much alcohol evaporates, and the experiment becomes 



