452 

An expression of this kind, far from being an 
‘eccentricity,’ is a triumph of nomenclature. It is 
possible to mould language by logic; it is the only way 
to mould language that shall be truly scientific. It 
is this method which has given such power of expres- 
sion to the French language, not only in its magnifi- 
cent modern prose, but more especially in its incom- 
parable clearness when used for the exposition of 
science. Though our own language is somewhat less 
pliant, we cannot do better than imitate our more 
logical and enterprising neighbours in replacing con- 
fusing or ambiguous language by clear and rational 
terminology. ALBERT CAMPBELL. 
Teddington, June 19. 

Training for Scientific Research, 
I sHOULD like to say in regard to my letter on the 
above subject in Nature of June 17, that, owing to 
exceptional circumstances, I had not read Prof. W. H. 
Perkin’s presidential address to the Chemical Society 
which appeared in the Journal of the society for April, 
in which he makes precisely similar suggestions. 
This was unknown to me at the time of writing, and 
naturally I am very glad to find myself in agreement 
with so influential an authority. I can only add my 
hope that he, furnished with all the qualifications for 
the task, will succeed in persuading the universities 
to a reform upon which so much depends, and for 
which the time is favourable. T. S. Patrerson. 
Organic Chemistry Department, University of 
Glasgow, June 20. 

Extinguishing Fires. 
In reference to Sir W. A. Tilden’s article in NaTuRE 
of June ro, may I direct attention to the fact that 
an ordinary syphon of ‘‘soda-water ”’ is a very effective 
fire-extinguisher if used in the early stages of an out- 
break due to bombs, etc., and it is a wise precaution 
to keep a supply, of the larger size, in readiness. 
A small piece of rubber tubing may be slipped over 
the nozzle in order to direct the discharge, or the 
syphon may be inverted whilst held in the hands. 
C, Carus-WIrson. 
THE SYNTHETIC PRODUCTION OF 
NITRIC ACID. 
HE recent pronouncement of the German 
Chancellor, and the statements which have 
appeared from time to time in the daily Press 
and in technical journals, respecting the enorm- 
ous extension in the methods of transforming 
atmospheric nitrogen into ammonia and _ nitric 
acid, which are claimed to have been developed 
by German chemical engineers, have attracted 
such widespread attention at the present time on 
account of the necessary employment of this acid 
in the manufacture of explosives, that it may 
not be uninteresting to explain shortly, and in 
general terms, the main principles of the methods 
by which such transformation is effected. The 
actual details of the manufacturing processes now 
employed in Germany have not been published, 
and are not likely to be made known for some 
time to come. But there is little doubt that these 
processes are, in the main, merely extensions or 
refinements of methods already established, and 
‘in more or less successful operation, at Odda, 
NO. 2382, VOL. 95] 
NATURE 

[JUNE 24, 1915 

Notodden, and Christiansand in Norway, at 
Legnano, near Milan, at La Roche-de-Dame, in 
the south of France, and at Niagara Falls. Even 
before the outbreak of the war, factories for the 
utilisation of atmospheric nitrogen in the manu- 
facture of synthetic ammonia and nitric acid were 
at work in Westphalia, at Knapsack, near 
Cologne, at Spandau, and in one or two places in 
Austria-Hungary. Similar works have been 
erected, or are in course of erection, in the United 
States, Switzerland, and Japan. 
Although a considerable amount of British 
capital has been invested in Norwegian enter- 
prises, no attempts have hitherto been made in 
Great Britain to utilise the vast stores of potenti- 
ally combined nitrogen which exist in the air. It 
has been calculated that the air over a dozen acres. 
contains as much potential nitric acid as is annu- 
ally exported in the form of Chile saltpetre. The 
apparent apathy of the British manufacturer is 
probably due to the circumstance that hitherto we 
have not suffered to any appreciable extent from 
any shortage of nitrates or nitric acid, and that, 
so long as we have command of the sea, we are 
not likely to suffer for some time to come. But 
it must not be forgotten that the supply of Chile 
saltpetre is not inexhaustible. The rich deposits 
of Tarapaca are already worked out, and what is 
now obtained from the more inaccessible districts 
of Antofagasta, Toco, and Taltal is of much lower 
quality. On the other hand, we gather from the 
Chancellor’s statement in the Reichstag that the 
new industry in Germany is to be protected for 
at least a number of years, which would seem to 
imply that the manufacture cannot be worked on 
ordinary commercial lines. The probable effect of 
protection would be to limit, if not altogether to 
destroy, the importation of Chile saltpetre into 
Germany, and thereby to diminish its price to us 
unless German syndicates manage to obtain con- 
trol of the working's. i 
Another reason for the apparent lack of enter- 
prise on the part of the British chemical manu- 
facturer is the assumption that hitherto the com- 
mercially successful working of all such synthetic 
processes would seem to depend upon cheap 
water-power, of which this country has no very 
ample store. But it may be doubted whether this 
disadvantage is altogether insuperable, at least 
under certain conditions. At all events, it is 
certain that the German engineers have to look 
to other sources of energy. What will be the 
ultimate effect on the price of nitric acid remains 
to be seen. In the meantime, it is probable that 
its present cost to Germany ,is far higher than 
to us. 
The new methods of making nitric acid from 
atmospheric nitrogen are twofold in character; 
either direct, that is, by the direct combination of 
nitrogen and oxygen, or indirectly through the 
intermediate production and subsequent combus- 
tion of ammonia. The direct formation of 
ammonia by the union of its elements, nitrogen 
and hydrogen, has frequently been attempted, but 
hitherto with very limited success. It has long 
