228 STUDIES ON FERMENTATION. 



de la Societe cliimique may be consulted. Now, these various 

 ferments mutually interfere with each other : whereas if sac- 

 charomyces apiculatvs were there alone it would multiply to 

 a greater extent, and with greater advantage to the fermenta- 

 tion of the must. This result is obtained by filtering the 

 must, as we have already observed. 



It is evident from what we have just said that the principal 

 part of the deposits of yeast in the sediment of fermented 

 grapes, at the time when the wine is first racked, which 

 in the Jura, is called VentonnaiHon, is composed of the ordinary 

 ferment of wine, the saccharomyces ellipso'ideus, and that the 

 cells of apiculated ferment are scarcely discoverable with 

 the microscope, being scattered amongst an infinite multitude 

 of other ferments.* 



We procured from Arbois, on Januar}' 20th, 1875, some wine 

 yeast taken from a large barrel of the preceding vintage, 

 racked on January 18th. The ferment was very irregular. 

 Some of its cells were very old, of a yellowish colour, and full 

 of granulations — amongst these a certain number formed 

 jointed segments, rather elongated, and probably belonging 

 to saccharomyces pastorianus. The other cells were transparent, 

 and apparently still young. This mixture of the two ferments 

 is represented in Fig. 57. No doubt if we had searched 

 carefully we should also have found some cells of saccharomyces 

 ajpiculatus. On January 21st y\e sowed a smaU quantity of this 



^ ^ ° o ,^ M 



Fig. 57. 



* We have reason to believe that the ratio of the proportions of these 

 ferments depends greatly on the climatic conditions preceding the period 

 of vintage, on the state of dryness or humidity, as well as the temperature 

 at the time of gathering the grapes, and also on the nature of the vines. 



