44 ETHYL ALCOHOL. 



anhydride stands in the closest relation to the growth 

 of these vegetable organisms in the saccharine solution. 

 It has been proven with certainty, that the formation 

 of alcohol and carbonic anhydride only takes place in 

 the interior of the plant cells, but, regarding the de- 

 tails of this process and the character of the chemical 

 reaction, nothing is positively known. 



Fermentation only takes place between 3-35, it 

 progresses most rapidly at 25-30. The character of 

 the ferment (the variety of vegetable organism) that 

 is undergoing development in the saccharine solution, 

 exerts the most marked influence upon the products of 

 the fermentation. Under certain circumstances, which 

 appear to be unfavorable to the development of yeast- 

 cells, the germs of another ferment are developed, and 

 now entirely different products result (see Lactic Acid). 



Yeast loses its efficacy by being thoroughly dried, 

 by being heated up to 60, by being immersed in alco- 

 hol, and by being acted upon by acids and alkalies. 

 Various substances, particularly the volatile oil of 

 mustard, sulphurous, nitrous, and arsenious acids, mer- 

 cury chloride, prevent the beginning of fermentation, 

 when added in exceedingly small quantity to a fer- 

 mentable liquid. 



Starch is not fermentable, but, as it can be readily 

 converted into sugar, alcohol can also be obtained from 

 substances containing starch, such as potatoes, grain, etc. 



Preparation. By partial distillation of a fermented 

 liquid, the alcohol goes over still mixed with more or 

 less water. Such a mixture containing between 30 

 and 40 per cent, of alcohol is brandy. Subjected again 

 to distillation, it is separated into water, which remains 

 behind, and an alcohol containing less water (spirits of 

 wine), which distils over. The last portions of water 

 cannot be removed from this by means of distillation, 

 but only by means of desiccating agents, such as fused 

 calcium chloride, fused potassa, quicklime, etc., most 

 efficiently, however, by means of anhydrous baryta, 

 which is brought in contact with the alcohol, and the 

 latter afterward distilled off from it. 



Properties. Colorless, thin liquid; in a perfectly 



