330 FERMENTATION ASCRIBED TO THE 



which light is quite excluded, follow laws of nutrition different 

 from those governing green plants ; and it cannot be doubted that 

 their nourishment is derived from putrefying bodies, or from the 

 products of their putrefaction, which pass directly into this kind 

 of plants, and obtain an organized form by the vital powers re- 

 siding within them. During their growth they constantly emit 

 carbonic acid, increasing in weight at the same time, while all 

 other plants, under similar circumstances, would decrease in 

 weight. Hence it is possible, and indeed probable, that fungi 

 may have the power of growing in fermenting and putrefying 

 substances, in as far as the products arising from the putrefaction 

 are adapted for their nourishment. When a quantity of fungi are 

 exposed to the temperature of boiling water, their vitality, and 

 power of germinating become completely destroyed. If they be 

 now kept at a proper temperature, an evolution of gas proceeds 

 in the mass thus treated ; they pass over into putrefaction, and, 

 if air be admitted, into decay ; and at last nothing remains ex- 

 cept their inorganic elements. The putrefaction in this case 

 cannot be viewed as the act of the formation of organic beings, 

 but as the act of the passage of their elements into inorganic 

 compounds. 



Observations of another kind — for example, that flesh and other 

 animal bodies may be kept for several weeks without putrefying, 

 if placed in a vessel containing air previously heated to redness 

 — have gone far to support the opinion that the process of putre- 

 faction is effected by the growth of organic beings ; but all such 

 experiments are of very subordinate value in support of these 

 conclusions. In some experiments instituted by the author, for 

 the purpose of detecting quinine in the urine of a patient in the 

 habit of taking this medicine, he obtained the remarkable result, 

 that this urine kept for several weeks without passing into com- 

 plete putrefaction, although the urea of urine, under ordinary 

 circumstances, is often completely converted into carbonate of 

 ammonia in the space of six or eight hours. In the present case, 

 the urine effervesced only siightly with acids after fourteen days. 

 This seemed to give sufficient foundation for the opinion that the 

 quinine must be the cause of this delay in the putrefaction. But 

 further experiments proved that common urine introduced when 



