100 STU])IKS ON FERMENTATION. 



we niny obtain more alcohol from one plant than from another 

 weighing a hundred times as much. Often, however, when the 

 vegetation is abundant we cannot make out the occurrence of 

 alcohol in spite of the sensitiveness of the process described 

 (p. 78). 



What can be the cause of these varying results relating to 

 the production or non -production of alcohol in the vegetation 

 of the little plant ? The numerous experiments that we have 

 made seem to demonstrate positively that they are dependent 

 upon variations in the amount of air or oxygen that is supplied 

 to the fungoid growths, whether, that is, the vegetating my- 

 celium alone be submerged, or the whole plant with its organs 

 of fructification. When the plant has at its disposal an excess 

 of oxygen, as much as its vitality can dispose of, there is no 

 alcohol, or very little, formed. If, on the other hand, the plant 

 vegetates with difiiculty, in presence of an insufficiency of 

 oxj'gen, the proportion of alcohol increases ; in other words, 

 the plant shows a certain tendency to behave after the manner 

 of ferments. 



Some time ago, wishing to assure ourselves that the spores 

 of penicillium could not become transformed into ferment, we 

 sowed some pure spores in small flasks, holding from 50 c.c. to 

 100 c.c. (from 2 to 4 fl. oz.), which contained very little air, 

 and which were sealed hermetically after the sowing. Under 

 these conditions, the germination and growth of the spores 

 proceeded with great difficulty, and soon ceased through 

 want of air. The total weight of the little plant was too 

 small to be determined. In cases of this kind, if we distil the 

 whole of the liquid we shall often see the alcohol appear in the 

 second distillation, even though the weight of the plant may 

 have been scarcely appreciable. If, on the other hand, side by 

 side with experiments of this kind, we grow ^xxxq penicillium in 

 flasks containing air and having quantities of saccharine liquids 

 equal to the quantities in the small flasks of which we have been 

 speaking, the plant, in consequence of the large volume of air 

 at its disposal, will develop vigorously, and in the course of even 



