MECHANICS AND L'SEFUL AKTS. 79 



A vacuum being created, the gases contained in the wine are re- 

 leased from atmospheric pressure, and, as they are essentially 

 elastic, expand sufficiently to break the cells of vegetable filjrine 

 enclosing them and escape. These gases are dissolved to such an 

 extent that the withdrawal of 30 or 40 litres of gas occasions no 

 sensible decrease of liquid. The theory of the decomposition of 

 grape-juice and other organic substance rests on a very element- 

 ary fact, namely, on the power of double decomposition. Gas- 

 eous products of the fermentation do not remain inert, but ener- 

 getically induce tiie fermentation or decomposition of free bodies. 

 These products are the most active in inducing decomposition ; 

 they alter wines indefinitely when enclosed in the fibrine culls, 

 which M. Pasteur calls mycodermes. White wines owe their 

 great superiorit}' in preservation over red wines to their different 

 condition as regards this point. Under the treatment by the 

 vacuum, fermentation does not occur, or, if in progress, entirely 

 ceases. — Chem. News. 



AIR TREATMENT OF WINE. 



Mons. R. D'Heureuse, the patentee of the new process by which 

 new wine is ripened in a few weeks, instead of, as in the old 

 method, years, gives us the following resume of his method. He 

 says : — 



In all " must" are certain nitrogenous substances, the cause of 

 fermentation, if called into action by some impulse. The contact 

 with air, and the germs of fermentation therein constituting the 

 impulse, causes in *' must" the vinous fermentation, — generally 

 termed "the fermentation," — which eliminates a portion of the 

 deleterious substances by oxidation in shape of yeast. To prevent 

 later fermentation and diseases of the wine inherent therein, all 

 the nitrogenous substances have to be eliminated. This can be 

 done slowly, tediously, expensively, and imperfectly, by fre- 

 quently drawing the wine from cask to cask for years, or it may 

 be done in a few weeks, thoroughly, easily, and economically, by 

 impelling the air into the " must" or 3'oung wine. The air it is, 

 which in either case acts, oxidizing and eliminating the nitroge- 

 nous substances, and the wine is constant and sound only when 

 free from all these substances, which also carry with them all that 

 bad or earthy taste which vitiates nearly all American wines. 



An air-pump is used by M. D'Heureuse for the purpose. In 

 some cases it is desirable that the air be previously heated. 

 The heater has a pipe and faucet, and the heated air may be 

 mingled with that of ordinary temperature at will in a reservoir 

 arranged for the purpose. 



From this the air is passed through a cotton filter of simple con- 

 struction, and then conducted through some pipe or rubber hose 

 to which a perforated mouth-piece of tin, copper, or gutta-percha 

 is attached. This mouth-piece, mostly in shape of a pipe or pipes 

 to suit the vat, is sunk to the bottom of the ferment-vat, and re- 



