510 MR. J. B. LAWES, DR. GILBERT, AND DR. PUGH ON 
which 4:6 were absorbed by potash, and the remainder proved to be combustible. 
Hence, up to this date, there has been no appreciable evolution of free Nitrogen. In 
order to see whether the organic matter present would reduce a nitrate, with the evolu- 
tion of free Nitrogen, about 5 grammes of saltpetre were now put into the vessel, and 
it was replaced in the same room as before. 
May 3, 1859.—Several times since December 12, 1858, when the nitrate of potash 
was put in, the vessel has been warmed up to 30°C.; but up to this date very little gas 
has been evolved. 
May 25, 1859.—Still very little gas evolved; 4 cub. cent. only collected, one-fourth 
of which was carbonic acid, and the remainder was combustible. The vessel was now 
placed in the sunlight again, but up to the middle of June no further evolution of gas 
had taken place. The fluid still contained nitrate of potash. The vessel was then half 
filled with oxygen in order to see if this would cause a renewal of the decomposition. 
After ten days a portion of the gas was examined, when it was found that not one-fourth 
of the supplied oxygen had been consumed—a result which was quite unexpected. The 
total gas being removed, the vessel was again nearly filled with oxygen, driving out the 
greater part of the fluid, and leaving the partly decomposed seeds in an atmosphere of 
this gas. The apparatus so arranged was placed in the sunlight, and remained there 
during some very warm weather. 
July 12, 1859.—The gas collected contained in 100 parts— 
Carbonic acid. Oxygen. Nitrogen. 
20 re 1 
By accident a small quantity of air was admitted into the vessel, so that the analysis 
can only be taken to show how exceedingly slow was the oxidation of organic matter 
which had been treated as this had been. 
On the removal of the matters from the vessel, the Beans were found to possess much 
of their original firmness and solidity. The other seeds, though they retained their 
form, were softer, and they had evidently undergone a more complete decomposition. 
They emitted very little odour, which was not unpleasant. 
There can be no question as to the absence of any evolution of free Nitrogen during 
the long period that these three descriptions of seed were under experiment. A very 
small proportion of the combined Nitrogen present would, if set free, have been sufficient 
to fill the vessel with gas. But, as has been seen, only a few bubbles of gas were evolved 
during several months. 
Several other experiments were made upon the products of the decomposition of 
organic matter, in the first stages of the process. In Table X., which follows, are given 
the amounts, and the composition, of the gas obtained from decomposing organic matter 
in a few out of a number of cases in which we have had occasion to observe them— 
including, for comparison, some of the results already referred to. The decomposition 
took place in water, in vessels similar to that used in the experiments last described 
(fig. 7, Plate XII.). 
