AMOUNT OF ALCOHOL IN WINE. 153 



Each of these temperatures is higher than given 

 by water, in consequence of the fixed ingredients 

 which remain in wine when freed from alcohol. But 

 if these solid matters raise the boiling point of wine 

 which has been freed from alcohol and restored to its 

 original volume by the addition of water, they must 

 have the same effect upon wine in which alcohol still 

 exists. 



Fixed ingredients in wine raise the boiling point ; 

 the alcoholic contents, if deducted from it, will be 

 estimated too low, and that in proportion to the 

 amount of the extractive matter. 



Pohl,* like Groning and Brossard-Yidal, has made 

 use of the ebullioscope, and, according to him, even 15 

 per cent, sugar has no effect upon the boiling point of 

 water; and a mixture of 10 parts alcohol, 15 parts 

 sugar, and 75 parts water, boils at the same tempera- 

 ture as a mixture of 10 parts alcohol, and 90 parts 

 water. We learn from his statements that a mixture 

 of alcohol and water, when it first boils only remains 

 stationary at a fixed point for a short time, it then 

 rises gradually a little, and afterwards (supposing the 

 liquid mixture to contain 146 grammes, (2253 grains)) 

 remains at a fixed temperature for from 4 to 16 seconds. 

 It is in this last period, during which the thermo- 

 meter remains stationary, that Pohl gives us the 

 weight per cent., of alcohol in the mixture, at 760 

 millimetres. (29 9 inches) barometric pressure. 

 * Liebig and Kopp, Jahresber, 1850, s. 455. 



