of the retort. I therefore
considered it necessary to use retorts with very thin walls, but I did
not succeed in obtaining retorts of this description which would
resist the very high temperatures which the process requires, and for
this reason I abandoned these experiments. I was at that time not
acquainted with the excellent quality of clay retorts used in zinc
works, with which I have since experimented for a different purpose. I
have no doubt that with such retorts the production of cyanides by
this process can be carried out without great difficulty.

I believe that the process will prove remunerative for the manufacture
of cyanogen products, which, if produced more cheaply, may in the
future play an important role in organic synthesis, in the extraction
of noble metals, and possibly other chemical and metallurgical
operations.

The process certainly also offers a solution of the problem of
obtaining ammonia from the nitrogen of the atmosphere, but whether
this can be done with satisfactory commercial results is a question I
cannot at present answer, as I have not been able to secure the data
for making the necessary calculations.

I am the more doubtful about this point, as in the course of our
investigations I have found means to produce ammonia at small cost and
in great abundance from the immense store of combined nitrogen which
we possess in our coal fields.

Among the processes for obtaining ammonia from the nitrogen of the air
which we investigated, was one apparently of great simplicity,
patented by Messrs. Rickman and Thompson. These gentlemen state that
by passing air and steam through a deep coal fire, the nitrogen so
passed through is to a certain extent converted into ammonia. In
investigating this statement we found that the process described
certainly yields a considerable quantity of ammonia, but when we
burned the same coal at a moderate temperature by means of steam
alone in a tube heated from the outside, we obtained twice as much
ammonia as we had done by burning it with a mixture of air and steam,
proving in this case, as in all others, the source of the ammonia to
have been the nitrogen contained in the coal. The quantity of ammonia
obtained was, however, so large that I determined to follow up this
experience, and at once commenced experiments on a semi-manufacturing
scale to ascertain whether they would lead to practical and economic
results.

I came to the conclusion that burning coa