THE SOURCES OF THE iSHTEOGEJS" OF VEGETATION, ETC. 
515 
involved. On the other hand, the facts adduced aiford a probable explanation of any 
small loss of Nitrogen which may occur when seeds have not grown, or when leaves, or 
other dead matter, have suffered partial decomposition. 
F . — The mutual relations of Gaseous J^itrogen and the Nascent Hydrogen evolved diiring 
the decomposition of organic matter. 
The importance attached by Muldee, and others after him, to the action of nascent 
hydrogen, evolved in the decomposition of organic matter, upon gaseous Nitrogen, as a 
som’ce of ammonia, is such as to require that we should refer to the subject here, in 
the course of the discussion of the conditions possibly affecting the supply of combined 
Nitrogen to our experimental plants. The results given in the last sub-section (pp. 509- 
511), leave no doubt of the evolution of hydrogen during the decomposition of organic 
matter. They suggest, therefore, the possibility that such an evolution may take place 
in any decomposition of organic matter involved in our experiments on the assimilation 
of free Nitrogen by plants, and hence prove a source of ammonia to them. 
That nascent hydrogen may, under certain circumstances, combine with gaseous 
Nitrogen, has long been admitted. But the view so prominently put forth by Muldee*, 
and some others, that those circumstances occur in the evolution of nascent hydrogen 
accompanying the decomposition of organic matter, requires confirmation. 
If only a veiy small part of the hydrogen evolved in the decomposition of organic matter 
were to form ammonia with the Nitrogen gas whicli must always be in most intimate con- 
tact with it, the amount of ammonia formed in this way would be enormous. Peat bogs, 
cesspools, and all stagnant water pregnant with organic matter, as well as many soils, 
would be constantly so accumulating ammonia. The extensive forests in different parts 
of the world, which have been annually depositing a coating of leaves upon the surface 
of the soil for thousands of years, must also have been a very fertile source of ammonia, 
as the leaves have gradually decayed under the infiuence of moisture and confined air 
beneath the succeeding layers. And when we contemplate the amount of decomposi- 
tion that must liave corresponded to the very exuberant growth of former geological 
periods, as manifested in the remains exhibited in our coal beds and limestones, we see 
a source of ammonia, if formed in the manner now under consideration, which would 
be incalculable. 
The results given in the last subsection (E), upon the decomposition of nitrogenous 
organic matter, favour the view that the hydrogen evolved in such decomposition does 
not foim ammonia with the Nitrogen of the air. The assumption that it did so, implies 
that the nascent hydrogen was capable of uniting with free gaseous Nitrogen (forming 
ammonia) under circumstances in which its affinities were not sufiiciently powerful to 
prevent Nitrogen compounds very similar to ammonias (and which are easily transformed 
into them) from giving up Nitrogen in the free state. It implies also, that the nascent 
hydrogen can act upon ordinary Nitrogen, when it cannot do so upon this nascent Nitro- 
* Chemistry of Vegetable and Animal Physiology, pp. 111-114, 149-152, &c. 
