M. I^atour^s Observations on the Cause and 



k)''ks'to produce a very considerable augmentation of new 

 ferment 



M. Cagniard Latour inquired if the globular vegetables of 

 the yeast were limited, as it regards their organization, to a 

 maternal vesicle capable of reproducing and multiplying itself 

 by small seeds, produced by extension, either from the external 

 surface, or, what is more probable, from the internal; or whether, 

 placed in a somewhat more elevated order of organization, they 

 do not represent in the mass of the ferment, simple reproducing 

 bodies, of that kind which germinate and advance to minute 

 vessels of a somewhat more complicated nature. 



The author made many attempts to arrive at a more certain 

 knowledge of the organization and physiology of these mi- 

 croscopic vegetables. The first, not very adroitly executed, or 

 possibly conducted on too small a scale, did not produce any 

 vegetation, — the yeast decayed, and became decomposed. But 

 it was very different with another attempt, though long and 

 troublesome, which was made during the night in the English 

 brewery of M. Leperdriel, in a vat containing about S60 gallons 

 of the wort of porter. 



This wort, when first examined in the microscope, only exhi- 

 bited a great number of very slender particles without any de- 

 terminate form ; but after the yeast had been introduced for 

 about half an hour, about ten o'clock at night, between 6 and 7 

 pounds of ferment having been added, the wort, when again 

 examined, exhibited solely the vesicular globules of the ferment 

 which had been employed, the number of which in the field of 

 the microscope might amount to about eighteen. After this, 

 specimens were taken from the vat every hour until six o'clock 

 in the morning, the time required for the fabrication of the 

 porter ; and these presented successively the following trans- 

 formations : — 



In the first, all, or nearly all, the simple globules of the 

 yeast which had been introduced into the wort, were observed 

 to be supplied with one or two small buds, more transparent 

 than the maternal globule, of which, however, they seemed ex- 

 tensions. Some of them had not as yet produced their bud, 

 whilst others, more advanced than those first mentioned, were 



