CHEMISTRY. 207 



other words, in the destruction of their germs, or the suppression 

 of their vitality. 



" It is said that wine is a liquid whose diverse principles contin- 

 ually react upon each other by mutual slow affinities, as when 

 ether is slowly formed by the mixture of acid and alcohol. This 

 opinion of the nature of wine and the progressive changes of its 

 properties is altogether erroneous. New wine, shut up in close 

 vessels, out of contact with air, neither makes a deposit, nor 

 changes color, nor loses its bouquet. On the contrary, the same 

 wine, when submitted to the influence of the oxygen of the air, 

 whether in the dark or the light, but most rapidly in the light, de- 

 posits so much as to become turbid, and loses entirely its taste of 

 new wine, and its color becomes like that of wine ten or twenty 

 years old, and it acquires in a high degree the taste and bouquet 

 of the dry wines of Madeira and Spain, or of wines that have 

 been on voyages. All these exaggerated effects of the maturing 

 of wines by the action of the oxygen of the air may be realized in 

 a few weeks. 



" But the influence of oxygen is constantly joined, though in 

 different degrees, with the slow action of the cryptogamous vege- 

 tations in the wine, which are the cause of all its alterations. It 

 is indispensable to destroy the germs of these parasites, if we 

 would have the wine mature promptly and surely, without ever 

 deteriorating. 



"I have announced to the Academy that this desirable result 

 was easily obtained by heating the wine to a sufficiently high tem- 

 perature. But I have been reserved as to the industrial value of 

 this process, because I thought that my experience had not been 

 sufficiently long to be relied on. The communication which 1 now 

 have the honor to make to the Academy has for its principal object 

 to confirm my former views on this point. 



" It was necessary to resolve a previous question, that of the 

 immediate effect of the elevation of temperature. It was not easy 

 to believe in preserving wine by a process which might in some 

 respects impair the proper qualities of the wine. Now, multiplied 

 trials of French wines, of very diverse origins, enable me to say 

 with assurance that wine which has been heated and cooled has 

 not changed its color, nor lost any of its bouquet, nor made the 

 least deposit; and, finally, that it is so like the same winethathas 

 not been heated that it was necessary to submit them to a simul- 

 taneous comparison in order to perceive the least difference in 

 their properties. If that difference were against the wine that 

 had been heated, there would have been little hope of the success 

 of the process ; but an expert taster in seven samples out of nine 

 gave the preference to the wine that had been heated. The ar- 

 rangements were made by myself, so that the expert had not the 

 least idea of the nature of the wines of which he had to judge, 

 and in the two cases in which he preferred the wine that had not 

 been heated, he admitted that he was at a loss as to which was 

 best. Moreover, he did not perceive a taste of cooking, even 

 when his attention was called to the possibility of a flavor of that 

 nature. 



