FUNGI. 307 



of a'r, it was found that the vinegar-plant took 

 oxygen from the air, and therewith converted the 

 alcohol into acetic acid ; and that the mycoderm of 

 wine converted the alcohol into water and carbonic 

 acid. Thus both act as oxydizers, and it is well 

 known that if the vinegar-plant be left in fluid 

 after it has transformed the sugar or alcohol into 

 vinegar, it then burns up the vinegar and leaves the 

 housewife or other manufacturer, who had neglected 

 to remove it at the right period, only dirty water for 

 her pains." 



Spontaneous Generation. 



It is not so many years since many estimable men 

 were seduced by the superficial plausibility of the 

 theory then promulgated to give their adherence to 

 the doctrine of spontaneous generation. Down to the 

 seventeenth century it was imagined that certain 

 animal and vegetable forms did, in the process of 

 decomposition, originate or evolve insect life. All 

 this was done in perfect good faith ; it was accepted 

 as a hereditary tradition, without much thought or 

 investigation. For instance, it was held that if a 

 piece of meat was placed in the sun, and allowed to 

 undergo putrefaction, the grubs, which soon appeared, 

 were the result of a power of spontaneous reproduc- 

 tion which the meat possessed. Thus we could find 

 in old books various formulae for the manufacture of 

 animal or vegetable compounds, which would result 

 in the production of particular forms of animal life. 

 This is all matter of history and historical fact. 

 Amongst others a distinguished Italian, named Redi, 



