8G STUDIES ON FKRMENTATTOX. 



this kind, wrongly interpreted, that many errors have crept into 

 our knowledge of the lower organisms, and that we are con- 

 stantly seeing old discussions crop up, both on the subject of 

 so-called spontaneous generation and on that of the theory of 

 fermentation. At every step in the course of this work we 

 shall see the trace of these complications, as well as the 

 influence they have had on the progress of our knowledge. 



In opposition to these results, we will study the case of wort 

 sown directly with germs distinctly of one kind, unmixed witli 

 any other. 



§ I. — Growth of Penicillium Glaucum and Aspergillus 

 Glaucus in a State of Purity — Proofs that these 

 Fungoid Growths do not become Transformed into 

 THE Alcoholic Ferments of Beer or Wine, — Pre- 

 liminary Enquiry into the Cause of Fermentation. 



Let us again take one of the flasks furnished with two necks 

 such as we have already described, and let it be supposed that 

 this flask contains a quantity of saccharine wort, brewed some 

 considerable time ago, which has undergone no change what- 

 ever, except in colour, the slow process of oxidation having 

 gradually darkened the original colour of the liquid. What 

 we have to do is to drop into this unchanged and fertile liquid 

 some grains or spores of penicilliiim which are free from the 

 slightest trace of the spores or germs of other microscopic 

 organisms. 



One means of effecting this consists in taking up with a pair of 

 metallic forceps, previously heated, a piece of platinum wire, one 

 or two centimetres (about J in.) in length, which we also pass 

 through the flame of a spirit lamp, and with which, as soon as it is 

 cold, we touch a mass of sporanges of a growth of penicUliam, 

 No matter how few spores ma}- be taken up on the end of the 

 platinum wire, we shall liave far more than we require for the 

 impregnation of the liquid. At the moment of charging the 



