SejMration of Nitrogen from the Atmosphere. 
437 
tlon the following paper, developing his ideas, with a plan of the 
machine by which he thinks they may be carried into effect. 
1 hope some member of our Society, possessing the requisite 
combination of chemical knowledge with mechanical skill, will 
be induced to try the experiment. 
James Caird. 
The important functions in fertilization performed by nitrogen 
have been thoroughly established by those who have investigated 
the cause or active element in manures derived fi'om animal 
substances. 
Nitrogen, although a most abundant constituent element in 
our atmosphere, does not appear to act so readily as a fertilizer 
as when it is presented to the roots of plants in combination 
with some other substance, from which combination plants abstract 
the nitrogen in a manner most effectually conducive to their 
fertility. 
All animal substances, especially when such are in a state of 
decomposition, are well known to be very effective as manures. 
This arises from the fact that in that condition they contain 
ainmorda, which, being composed of hydrogen and nitrogen, the 
roots of the plants decompose the ammonia and appropriate 
the nitrogen greedily, as their most favourite food, and hence its. 
efficacy as a fertilizer. 
Reasoning on this subject full forty years ago, and con- 
sidering the inexhaustibleness of the store of nitrogen we possess 
in our atmosphere, it occurred to me that, could we but devise 
some means of laying hold of this nitrogen of the atmosphere, 
and fixing it in combination with some other element, so as to 
enable us to present the result directly to the roots of plants, we 
should, in that way, supply them with their most effective food 
as manure, derived from an inexhaustible source around us, 
instead of having to obtain the desired nitrogen, as we do at 
present, by going all the way to Peru for it in the form of guano, 
which owes its efficacy as a fertilizer chiefly to the presence 
of ammonia, from which the plants, by means of their roots, 
abstract their favourite nitrogen. Reasoning on this subject, 
as I have said, it occurred to me that if by some medianico- 
chemical process we could manage to knock the nitrogen and 
oxygen of the atmosphere into chemical combination, and at the 
same moment combine the so produced nitric acid with some 
mineral substance which would permanently fix the combination 
in a portable form, we should thereby get hold of a source of 
fertilizing power as inexhaustible as it would be effective. In 
following out this train of reasoning, I called to mind the fact 
