undergoes when in contact with Vegetables. 235 



vented the effects of a speedy fermentation. %d, The experi- 

 ment never lasted longer than a few hours, usually from eight 

 to twelve ; and I was always particular in remarking, at the end 

 of every experiment, if the mushrooms which had been em- 

 ployed exhibited, by their smell or otherwise, the slightest ap- 

 pearance of decomposition ; and if this were the case, that ex- 

 periment was not regarded. 3c?, I took care in removing the 

 mushrooms from the soil, never to cut the tendrils of the root, 

 and also to preserve round the stalk a very small quantity of 

 mould, in the hope of prolonging vegetation as long as possible.* 

 When I was experimenting on those kinds which grow on wood, 

 I always removed a piece of wood with the mushroom, in fact 

 the bed in which it grew, so that in this case the experiments 

 were conducted without in the slightest degree removing them 

 from their natural condition. 



I now proceed to give an account of the results obtained, by 

 successively introducing different kinds of mushrooms : 1st, 

 into atmospheric air; %d, into oxygen ; and, 3c?, into nitrogen. 



Sect. I. On the Action of Mushrooms on Atmospheric Air. 



Before introducing the mushrooms under the bell-glasses filled 

 with atmospheric air, I carefully noted the weight and the num- 

 ber of the individual plants which I meant to submit to ex- 

 periment. I then introduced them into a receiver, of a long- 

 ish form, about three-fourths of which was filled with air. This 

 receiver, which was graduated, was then placed in the mercu- 

 rial trough. After allowing the mushrooms to remain a cer- 

 tain number of hours, and after having noted the change in- 

 duced in the volume of the air in the receiver, I submitted this 

 air to analysis, by means of Volta's eudiometer. Now, then, for 

 the experiments. 



1st Experiment. — Three mushrooms, of the species Lycoper- 

 don bovista (the fuzz-ball), weighing together 130 grains, were 

 introduced under a receiver containing about 32.37 cubic feet of 

 air, at the temperature of 65° Fahr. Here they remained, fully 



* I had previously determined, by direct experiment, that a trifling quan- 

 tity of earth does not evolve any appreciable quantit} r of carbonic acid gas, 

 after the lapse of twenty-four hours. 



