136 FERMENTATION, 



taste, of a peculiar penetrating odour, and it is 

 very inflammable and volatile. It dissolves resins, 

 essential oils, camphor, sulphur, phosphorus, &c. 

 It is composed of hydrogen, carbon, and a small 

 quantity of oxygen. 



Strong acids and alkohol have a considerable 

 action on each other, and this produces ether, which 

 is a fluid still more highly volatile, inflammable, 

 and odorous. Nitric acid with alkohol produces 

 nitric ether, and sulphuric acid in the same way 

 produces sulphuric ether. 



When wine, or any fermented or vinous liquor 

 is exposed to a heat, from J5 to 85S Fahr., and 

 access of air is permitted, the fluid becomes turbid, 

 and a new change of principles takes place. It 

 loses its taste and smell, it becomes sour, and is 

 converted into vinegar, or acetous acid. Though 

 vinegar is chiefly prepared from fluids which have 

 undergone the vinous fermentation, yet this is not 

 necessary to the production of vinegar, for simple 

 mucilage is capable of passing into the state of 

 acetous fermentation. When the saccharine prin- 

 ciple predominates in any substance exposed to 

 the necessary conditions of fermentation, alkohol 

 is produced ; when mucilage is most abundant, 

 vinegar or acetous acid is the product ; and when 

 gluten is predominant, ammonia will be discovered, 

 and putrefaction will take place. 



Common vinegar may be purified, or concen 

 trated by distillation, and it is then called distilled 

 vinegar. This, however, still consists of the acetic 

 acid and water. To free the acid from the water, 

 distilled vinegar is saturated with some metallic 

 oxide, and an acetate is thus formed. The acetate 

 is then heated red hot in a retort, by which it is 

 decomposed, and the acetic acid passes over pure, 



