76 SECTIONAL ADDRESSES. 
The claim of munitions on sulphuric acid also materially reduced the 
quantity of ammonium sulphate as well as of superphosphate by about 
40 per cent., and chemists had to devise means for using nitre-cake in its 
place in the manufacture of these fertilisers. 
Anxiety as to the want of capacity of the country for fixation of atmo- 
spheric nitrogen had led in June 1916 to the foundation of the Nitrogen 
Products Committee, the results of whose labours will be found in a massive 
Blue Book full of information on statistics, on processes, and on the com- 
parative merits of methods for developing power. A staff of chemists and 
physicists attached to the laboratory of this Committee were actively 
engaged on investigations on the conditions of manufacture of ammonia 
by the Haber process, as well as in determining the physico-chemical 
constants of the gases involved. Much valuable work was accomplished 
both on the combination of hydrogen and nitrogen and also on the oxidation 
of the product to nitric acid, so that the Committee was able to recommend 
the erection of a trial plant in February 1917, and by October of that year 
the Department of Explosives Supply recommended the process worked 
out for adoption in a national factory, and a start had been made towards 
its erection at the end of the war. 
This project was taken over by Synthetic Ammonia and Nitrates, Ltd., 
which has continued the research work and erected the large-scale plant. 
It is satisfactory to be able to announce that, instead of being about the 
only great nation not engaged in the fixation of nitrogen from the air, we 
have now in Great Britain a plant producing at the moment 150 tons of 
synthetic ammonia a week. From the point of view of agriculture as well 
as of national defence, this cannot fail to afford a fresh, if somewhat 
delayed, confidence. 
The shortage of potash supplies was apparent soon after war broke out, 
since nearly all potash came from Germany. Attention was immediately 
drawn to other possible sources of supply and to means whereby the potash 
in stable combination in the soil might be made available. Russell at once 
called attention to the potash salts in the ash of seaweed, bracken, hedge- 
clippings, wood-waste, and similar substances, and advised as to the best 
methods for utilising them. He also advised the use of lime, and in certain 
circumstances of sodium salts, whereby potash in the felspars and clays 
became available. 
Numerous suggestions put forward as to possible sources of supply of 
potash were inquired into. In one interesting case, where a small-scale 
plant was put into operation under the supervision of the Government 
Laboratory, a good yield of potash was obtained from felspar, but the 
process involved the production as a by-product of so large a quantity of 
an inferior quality of cement that unless a market could be obtained for 
this there was no possibility of working the process successfully. 
A source of supply that was used to a certain extent was the flue-dust of 
furnaces, which was found to contain a fair though variable quantity of 
potash. Considerable developments were made by Mr. Kenneth Chance, 
of the British Cyanides Co., in the direction of obtaining from the ores 
dealt with in the United Kingdom a large supply of potash, and an 
extensive scheme of operation was contemplated before the Armistice. 
Another direction in which supplies became restricted was in respect of 
phosphatic manures. Importation of bones, mineral phosphates, and guanos, 
