268 SCIENCE PROGRESS. 



the disorder have been completely preserved by being 

 heated to 6o° C, and that warming them only to 55° C. 

 materially helps them to resist it. He has further extracted 

 normal wine by the alcohol method, and side by side with 

 it samples of the same wine after being heated to 6o° C. 

 The precipitate in the latter case had no oxidising power, 

 while that in the former was very active. Further investiga- 

 tion showed him that the nature of the medium exercised a 

 great influence on the destruction. When the enzyme was 

 treated in an aqueous solution of neutral reaction it with- 

 stood all temperatures below 72. 5 C, but when 10 per 

 cent, of alcohol or "5 per cent, of tartaric acid was present 

 destruction was complete at 52*5° C. If double these per- 

 centages of alcohol or acid were present, the necessary 

 temperature was reduced 5° C. He agrees with Martinand, 

 however, in saying that it can be destroyed by prolonged 

 heating in neutral media at 6o° C. 



Dealing with the action of various reagents upon 

 cenoxydase, Bouffard has ascertained that it is destroyed by 

 the action of very dilute sulphurous acid, the necessary 

 amount being '02 gm. per litre of the solution of the 

 enzyme. 



Cazeneuve (23) has extracted the enzyme from unsound 

 Beaujolais, and examined many of its properties. He pre- 

 cipitated the wine by excess of strong alcohol, and found 

 the deposit was of a gummy consistency. He took up the 

 gummy precipitate with water, and reprecipitated it with 

 alcohol, collected the deposit rapidly, and dried it in vacuo. 

 He found the precipitate chiefly gum, impregnated with 

 cenoxydase. 



In most respects Cazeneuve's results agree with those 

 already quoted, but he finds further that it acts slightly on 

 alcohols and ethers, and on the essences which give wines 

 their peculiar bouquet (24). In its action on the wine he 

 observes that it causes a disengagement of carbonic dioxide, 

 and that after its action there is a diminution of the quantity 

 of alcohol and acid.. He attributes the noticeable effects 

 produced to the action of the enzyme on the tannins. As 

 stated above, Martinand has shown that if these are re- 



