42 EFFECT OF EVAPORATION ON 



has been added, the acetone retains no trace of 

 water. 



If we suppose, that of the two originally formed 

 strata of liquid, one of them, namely that which 

 sinks and contains chloride of calcium dissolved, is 

 in contact with a current of dry air, the water of 

 this solution will evaporate, the solution will thus 

 become stronger, and in consequence of its increased 

 concentration will be able to remove a new portion 

 of water from the mixture of acetone and water 

 above it ; and this will continue till the acetone is 

 entirely deprived of water. 



Effect of If in the place of the chloride of calcium we put 

 through i n a bladder, and, in place of the acetone and water, 

 diluted alcohol, we have the finest example of the 



lol< unequal attraction which the animal tissue exerts on 

 the two ingredients of the mixed liquid. 



It is known from the experiments of SOEMMERING, 

 that spirits of a certain strength inclosed in a blad- 

 der, which is exposed to the air, lose by evaporation 

 only water, and that at last anhydrous, or nearly 

 anhydrous (absolute) alcohol is left in the bladder. 

 When strong spirits of wine are used, the bladder 

 remains dry externally; when weaker spirits are 

 employed, it becomes moist, and alcohol evaporates 

 with the water. In virtue of the unequal affinity 

 of the bladder for alcohol and for water, a com- 

 plete separation is here effected. The water of the 

 mixture is absorbed and evaporates from the outside 



