500 MR. J. B. LAWES, DR. GILBERT, AND DR. PUGH ON 
tive result. The mass was then re-exhausted with water, and the extract submitted to 
precisely the same process as before, when the presence of nitric acid was made manifest. 
In the following Table are given the numerical results of the six experiments :— 
Taste VII.—Showing the Numerical results of experiments on the Decomposition of 
Nitrogenous organic matter, made in 1857. 
Substances submitted to experiment. Nitrogen after Decomposition. 
Ouand Onisniily Not recovered. 
Description of sug 7 pantity uae Total by 
F Description of Matrix.| of * Meal” of - 
Organic matter. B teen Sirogen, Soda-lime. Actual ere 
quantity. 
grammes. || grammes. | grammes. | grammes. 
1. Wheat-meal.../Ignited pumice ...| 2°0585 | 0-0370 | 0-0338 0:0032 8°51 
2. Wheat-meal...|Ignited soil ......... 2°1282 || 0°0383 | 0°0335 | 00048 12°53 
3. Barley-meal...|I[gnited pumice ...| 2°2495 | 0-0380 | 0-0368 0-6012 3-16 
4, Barley-meal...|Ignited soil ......... 20980 | 00355 | 0-0309 0°0046 12-96 
| 
5. |Bean-meal ...|Ignited pumice ... 2°0650 | 0-0803 | 0-0741 0-0062 7-72 
6. Bean-meal .../Ignited soil ......... 20800 0-0809 | 0-:0823 ((+0°0014) |+ (1°73) 
The last two columns of this Table, which exhibit respectively the actual amount of 
Nitrogen not recoverable by the soda-lime process in the substance after decomposition, 
and the percentage proportion of this loss upon the Nitrogen submitted to experiment, 
are the most important to consider for our present purpose. 
With one exception (the gain of Nitrogen in which is quite within the range of the 
error of analysis), all the experiments point to the fact, that a part of the Nitrogen of 
decomposing organic matter passes into a state in which it cannot be estimated by the 
soda-lime process. Neither did it exist as nitric acid. There appears, therefore, to be 
an evolution of free Nitrogen. 
It is not a little remarkable, that although so large a proportion of the total Nitrogen 
present is lost, doubtless passing off as free Nitrogen, yet scarcely a trace of ammonia 
was given off from the mass; for the oxalic acid in the bulb-apparatus C was, in each 
case, separately rendered alkaline with caustic potash and distilled, the distillate being 
collected and examined quantitatively for ammonia, when, in only one case—that of the 
Bean-meal and Pumice—was there any ammonia indicated, and then only equal in 
amount to 00002 gramme Nitrogen. This was the case, notwithstanding that the 
Nitrogen in the mixtures amounted to from 0:03 to 0-08 per cent. of their entire 
quantity. 
The questions here arise:—to what extent had the decomposition of the organic sub- 
stance proceeded? what shall we accept as the measure of the amount of decomposition ? 
what are the intermediate stages through which the substance has passed? what is the 
character of the organic compounds remaining in the mass? what is the nature of those 
that have been evolved? and what part does water play in the matter? 
The subject of the character of the gradual changes which take place during the 
