THE SOURCES OF THE NITEOGEN OF VEGETATION, ETC. 509 



E. — Experiments on the action of the oxidizing and reducing forces, as manifested 

 in the decomposition of organic matters containing Nitrogen. 



Several qualitative experiments showed that when cereal grains and leguminous 

 seeds were placed in water, over mercury, an evolution of gas took place, after about 

 thirty-six to forty-eight hours. This went on rapidly for a week or two, after which 

 all action appeared to cease, no more gas being evolved. The total quantity of gas 

 evolved varied between 20 and 50 cub. cent, from 3 to 4 grammes of the seeds. An 

 examination of the gas proved it to be almost entirely carbonic acid and hydrogen, the 

 quantity of Nitrogen being very small. 



To examine this action more thoroughly, about half a pound of a mixture of Wheat, 

 Barley, and Beans was taken, put into a long narrow glass vessel (fig. 7, Plate XII.) of 

 about 500 cub. cent, capacity, which was then filled with well-boiled water, and closed 

 with a cork, through which two glass tubes [a and b) passed. The external ends of 

 these tubes were fitted with caoutchouc tubing, for closing with pinch-cocks, or con- 

 nexion with the Torricellian exhauster as described at p. 487. One of the tubes being 

 so connected with the exhauster, it was allowed so to remain for several hours, in order 

 to remove all the gaseous Nitrogen from the seeds. The vessel was then inverted in 

 mercury, with one of the tubes (b) open under that fluid, and the whole placed in 

 sunlight to favour the decomposition. This was done on the 28th of August, 1858. 

 The seeds commenced swelling very soon, and on the 30th of August well-marked 

 decomposition had set in. 



On September 13th the vessel was about two-thirds full of gas, the displaced water 

 having passed out through the quicksilver. Part of the seed was now above the water, 

 in the gas, which commenced bubbling out through the tube (b). The arrangement 

 was allowed so to remain until October 5, when 400 cub. cent, of gas were collected, of 

 which the percentage composition was as follows : — 



Carbonic acid. Hydrogen. Nitrogen. 



Experiment 1 .... 64-87 34-83 0-30 



Experiment 2 .... 64-54 35*46 traces. 



The quantity of the gas evolved points to the extent of the decomposition ; the amount 

 of carbonic acid and hydrogen shows how great must have been the reducing force 

 exerted ; and the small quantity of Nitrogen, which was probably due to accident, 

 indicates that free Nitrogen was not a product of the action. 



The vessel was again filled with boiled water, again connected for some time with the 

 Torricellian exhauster, and again placed in its former position in the sunlight. 



October 9. — A small bubble of gas collected in the top of the vessel. 



November 3. — Only a few bubbles of gas at the top of the vessel. 



November 17. — The vessel was removed into the laboratory and placed in a room, the 

 temperature of which varied from a few degrees above the freezing-point to about 24° C. 



December 1. — Very little gas evolved. 



December 12. — The gas collected without exhaustion measured only 6T cub. cent, of 



