STUDIES ON WINE. 117 



cause the escape of some bubbles of carbonic acid. 

 These bubbles, rising from the lower part of. the cask, 

 may disturb a portion of the deposit, which then mixes 

 with the wine and renders it turbid. But the real 

 cause of the disease is quite different. The turbidity 

 is without exception due to the presence of little fila- 

 ments of an extreme tenuity, about a thousandth part 

 of a millimeter in diameter. Their length is very 

 variable. It is these which, when the wine is agitated, 

 give rise to the silky waves just referred to. Often the 

 deposit of the casks leaves a swarm of these filaments 

 entangled in each other, forming a glutinous mass, 

 which under the microscope is seen to be composed 

 entirely of these little filaments. In acting upon 

 certain constituents of the wine, particularly upon the 

 tartar, this ferment generates carbonic acid. The 

 phenomenon of spurting is then produced, because 

 when the cask is closed the internal pressure of the 

 liquid augments. The sparkling and the crown of 

 little gas-bubbles, observed when the turned wine is 

 poured out into a glass, is similarly explained. In 

 a word, the disease of turned wine is nothing else 

 than a fermentation, due to an organised ferment 

 which, without any doubt, proceeds originally from 

 germs existing on the surface of the grapes at the 

 moment of gathering them, or on spoilt grapes such 

 as are found in every vintage. It is very rare 

 not to find this parasite of turned wine in the de- 



