iindergoes -when in contact with Vegetables. 239 



vious experiments, was rather the effect of the growth of the 

 plant than the commencement of decomposition.* 



4i/i Experiment. — A number of small mushrooms, havin<y the 

 shape of little blue-bells, and congregated, of the species Agari- 

 cus dlgitaliformis, weighing together 60 grains, were placed 

 under a receiver inclosing 18.37 cubic feet of air, the thermo- 

 meter standing at 72°. At the end of nine hours its volume had 

 not sensibly changed. Analysis supplied the following results : 

 — The receiver enclosed, before the experiment, of nitrogen 

 14.53, of oxygen 3.84, = 18.37; after the experiment, of nitro- 

 gen 14.43, of oxygen 1.14, of carbonic acid 2.80, = 18.37 



It is here to be observed, that the mushrooms employed in 

 this experiment are very short-lived, that they are of a very soft 

 consistence, and begin to deliquesce in a very, short time. 



5th Experiment. — This experiment, which I regard as the 

 most conclusive of the series, was made upon the Boletus versi- 

 color. This species of mushroom usually grows upon decayed 

 trunks of trees, and old stumps of wood ; it is of a very touo-h 

 consistence, and, even when detached from the wood to which 

 it adheres, it exhibits no signs of decomposition for many days. 

 Fo-ur individuals of this variety, weighing together 140 grains, 

 were detached from the trunk of an oak, in such a way that 

 along with each mushroom there was removed that portion of 

 the wood by which it was nourished. In this way these mush- 

 rooms could be subjected to experiment, without in the slio-ht- 

 est degree altering their natural condition. They were intro- 

 duced under a receiver inclosing 35.00 cubic feet of air, the 

 thermometer being at 70° Fahr., and they were left exposed du- 

 ring the day-time for an interval of twelve hours. At the ex- 

 piration of this time, the volume of air in the receiver had in- 

 creased to 36.46 cubic feet. The result of the analysis was as 

 follows : — The receiver enclosed, before the experiment, of ni- 

 trogen 27.66, of oxygen 7.34, = 35.00 ; after the experiment, 

 of nitrogen 27.63, of oxygen .18, of carbonic acid 8.36, = 

 36.17. 



• In often repeating the above experiment I have remarked, that when 

 putrefaction had decidedly commenced in the mushroom employed, there was 

 generally a small quantity of hydrogen evolved. I have never, however, oh- 

 .served this result when it was fresh. 



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