508 MR. J. B. LAWES, DR. GILBERT, AND DR. PUGH ON 
suggested, to ascertain the causes of the difference of effect, in order, if possible, to con- 
trol them. ‘The results also point to the insignificance of the loss of Nitrogen in the 
form of ammonia, a supposed evil to which the attention of agricultural chemists has 
specially been directed in order to find means of preventing it, though nothing has as yet 
been done to avoid the loss, in apparently much larger quantity, of free Nitrogen. But 
as these questions are more appropriate for consideration in a purely agricultural paper, 
we shall not follow them further in this place. 
Other investigations, to which we have to call attention, will throw some light upon 
the character of the molecular forces by which the decomposition of nitrogenous organic 
compounds is effected under such circumstances as we have been considering. These 
forces might be one or both of two kinds. 
1. They might be of an oxidizing character, analogous to that of the action of chlo- 
rine upon ammonia by which free Nitrogen is evolved. 
2. They might be of a reducing character, similar to that of a great number of sub- 
stances upon the oxygen-compounds of Nitrogen, by which the oxygen of the latter is 
appropriated, and free Nitrogen given off. 
3. These two actions may operate in succession the one to the other. 
It is well known that an oxidizing action may be so intense as to deprive a nitro- 
genous organic compound of all its carbon and’hydrogen, converting it into oxygen com- 
pounds, as is done by permanganic acid. The converse action of the transformation of 
oxygen-compounds of Nitrogen into ammonia is also very well known. An intermediate 
stage in either of these converse actions may give free Nitrogen. 
There can be little doubt that the Nitrogen in the organic substances which we have 
submitted to decomposition existed in them in a condition more analogous to a hydro- 
gen than to an oxygen compound of it. The able researches of Hormanwn into the 
nature of compounds formed upon the ammonia type, would lead us to suppose that the 
Nitrogen compounds upon which we have been operating are of the ammonia class. They 
are more difficult to oxidize into nitric acid than is ammonia; yet their transition into 
ammonia is so easy, that it is effected in almost all the chemical changes to which they 
are ordinarily subjected. And, since ammonias yield free Nitrogen under the influence 
of oxidizing forces, it may be inferred that it has been under the influence of such forces 
that Nitrogen has been set free in the cases recorded above. PxrLouzE has remarked* 
that salts of nitric acid are converted into ammonia, in contact with decomposing organic 
matter. Experiments of our own have shown that, during the decomposition of organic 
matters in contact with nitrates, free Nitrogen is not evolved. The evolution of free 
Nitrogen in the experiments quoted above must, therefore, be referred to the action of 
oxidizing forces. 
The experiments next referred to bear upon these points. 
* Comptes Rendus, xliv. p. 118. 
