2l6 On the Cultivation of the Vine, 



From the nature of the caufes which produce oilinefs in 

 wines, the phenomena exhibited by that malady, and the 

 means employed to cure it, it is evident that this alteration 

 ariles from the extractive principle, which has not been fuffi- 

 cicntly decomposed. 



AV e find a iimilar effect in beer, in the decoction of gall- 

 iot >, and in feveral other cafes where the extractive matter, 

 being very abundant, is precipitated from the liquor which 

 held it in folution ; and acquires the characters of fibrine 

 matter, unlefs burned by a fermentation or precipitated by 

 an acid, 



Acefcence of wine is however the mod common malady, 

 and, we may even fay, the moft natural, for it is almoft a 

 confequence of fpiritous fermentation; but by knowing the 

 caufes which produce it, and the phaenomena which accom- 

 pany or announce it, means may be taken to prevent it. The 

 antients admitted three principal caufes of the acidity of 

 wines: — ift, The humidity of the wine: 2d, The incon- 

 ftancy or variations of the atmofphere : 3d, Commotions. 



To know this malady exactly, we mult call to mind fome 

 principles, which can alone furnifh us with light on this 

 iubject. 



ift, Wine never turns four until the fpiritous fermentation 

 is terminated ; or, in other words, till the faccharine prin- 

 ciple is completely decompofed. Hence the advantage of 

 putting wine into cafks before all the faccharine principle 

 has difappeared ; becaufe the fpiritous fermentation then 

 continues, is prolonged, and removes every thing that can 

 pave the way for acetous decompofition. Hence the prac- 

 tice of putting a little fugar into the bottle to preferve the 

 wine without alteration; and hence the very general method 

 of baking a part of the mud at a (low and moderate heat, and 

 of mixing fome of it in the calks intended for embarkation. 

 In fome places of Spain and Italy all the muftis baked; 

 and Bellon fays that the wines qi' Crete would not keep at 

 fea unlefs the precaution were taken to boil them. 



2d, The lead fpiritous wines are thofe which fooneft be- 

 come four. We know, by experience, that when the feafon 

 is rainy, if the grapes be little faccharine, which confequently 

 give little alcohol, the wines readily turn four. The weak 

 wines of the north become four with great eafe ; while the 

 ftrong, generous, fpiritous wines obdinately refift acidity. 



It is however no lefs true, that the moft fpiritous wines 

 furnifh the ftrongeft vinegar, though their acetification is 

 more difficult, becaufe alcohol is neceffary to the formation 

 of vinegar, 



3d, Wine 



