310 LOUIS PASTEUR 



Ordinary fungi likewise require large quantities of oxy- 

 gen for their development, as we may readily prove by 

 cultivating any mould in a closed vessel full of air, and 

 then taking the weight of plant formed and measuring the 

 volume of oxygen absorbed. To do this, we take a flask of 

 the shape shown in FIG. 8, capable of holding 

 about 300 cc. (io J /2 fluid ounces), and containing 

 a liquid adapted to the life of moulds. We boil 

 this liquid, and seal the drawn-out point after the 

 steam has expelled the air wholly or in part; we 

 then open the flask in a garden or in a room. 

 Should a fungus-spore enter the flask, as will in- 

 variably be the case in a certain number of flasks 

 out of several used in the experiment, except 

 under special circumstances, it will develop there 

 and gradually absorb all the oxygen contained in 

 the air of the flask. Measuring the volume of 

 this air, and weighing, after drying, the amount of plant 

 formed, we find that for a certain quantity of oxygen 

 absorbed we have a certain weight of mycelium, or of 

 mycelium together with its organs of fructification. In an 

 experiment of this kind, in which the plant was weighed a 

 year after its development, we found for 0.008 gramme 

 (0.123 grain) of mycelium, dried at 100 C. (212 F.), an 

 absorption that amounted to not less than 43 cc. (2.5 cubic 

 inches) of oxygen at 25. These numbers, however, must 

 vary sensibly with the nature of the mould employed, and 

 also with the greater or less activity of its development, 

 because the phenomena is complicated by the presence of ac- 

 cessory oxidations, such as we find in the case of mycoderma 

 vini and aceti, to which cause the large absorption of oxy- 

 gen in our last experiment may doubtless be attributed. 11 



11 In these experiments, in which the moulds remain for a long time in 

 contact with a saccharine wort out of contact with oxygen the oxygen 

 being promptly absorbed by the vital action of the plant (see our Memoire 

 sur les Generations dites Spontanees, p. 54, note) there is no doubt that 

 an appreciable quantity of alcohol is formed because the plant does not 

 immediately lose its vital activity after the absorption of oxygen. 



A 3OO-CC. (lo-oz.) flask, containing 100 cc. of must, after the air in it 

 had been expelled by boiling, was opened and immediately re-closed on 

 August 1 5th. 1873. A fungoid growth a unique one, of greenish-grey 

 colour developed from spontaneous impregnation, and decolorized the liquid, 

 which originally was of a yellowish-brown. Some large crystals, sparkling 

 like diamonds, of neutral tartrate of lime, were precipitated. About a year 







