JULY 15, I19P5] 
NATURE 
54 

hitherto relied on imported ores for raw material, 
their own deposits being very inadequate. 
To sum up, the position may be stated broadly 
as follows :—Of the ten munition metals, the chief 
sources of production and uses of which have 
been passed in review, the enemy countries can 
certainly produce five without having recourse to 
imports, viz., iron (the basis of the various steels 
used for war purposes), manganese, chromium, 
zinc, and lead; on the other hand, it is doubtful 
whether they can produce sufficient nickel, copper, 
aluminium, tin, and antimony from domestic ores. 
In view of the fact, however, that they prepared 
for this war with extreme care and foresight, it 
may safely be concluded that large stocks, either 
of ores or the corresponding metals, or both, will 
have been accumulated in those countries. How- 
ever confident the Higher German Command may 
ostensibly have been of a rapid victory, they will 
quite certainly have laid their plans to wage a pro- 
longed war if it should prove to be necessary, and 
such plans will have included the accumulation of 
munition ores and metals of which their countries 
produced an insufficient amount. There is 
accordingly no adequate reason for concluding that 
the enemy countries are likely—in spite of the pro- 
digious scale upon which the war is being conducted 
—to run short of metals which are essential for 
war purposes for some time to come. Moreover, it 
may safely be concluded that their technical’ 
metallurgists will have been mobilised in the 
direction of discovering substitutes for any of the 
above metals of which a shortage is liable to occur 
in a long war. 
The Allies for their part can produce from their 
own resources all the iron, manganese, nickel, 
chromium, tin, and most of the aluminium they 
require; their command of the seas enables them 
to obtain, principally from the United States, their 
deficiencies in aluminium, copper, and lead; China 
furnishes the requisite antimony. Zinc is the only 
important munition metal of which there is a 
shortage, in spite of the great speed with which 
the American furnaces are being operated. Wher- 
ever it is possible to substitute zinc by another 
metal it is of national importance that it should 
be done. 
It is satisfactory to note that on July 7 Mr. 
Lloyd George, in answer to a question in the 
House of Commons, stated that “the necessary 
steps have been taken to stop the export of lead, 
spelter (zinc), antimony, and nickel, and other 
metals necessary for the manufacture of munitions 
of war. The four metals named cannot be ex- 
ported except to places in the British Empire.” 
H. C. H. Carpenter. 

THE PRODUCTS OF COAL DISTILLATION. 
SS a paper before a conference recently held at 
Cardiff on the extension of British trade, 
Mr. W. J. A. Butterfield dealt with the many 
important aspects of this question, which has 
become of vital national importance to us now 
that supplies from Germany are cut off. We 
NO. 2385, VOL. 95 | 


probably scarcely yet realise how dependent we 
have been on Germany for many raw and finished 
products ; indeed with many coal tar derivatives 
it has amounted to a German monopoly. 
The output of coal in the United Kingdom 
in 1913 was 287,430,473 tons; in Germany 
188,485,000 tons, but in addition to the ordinary 
coal 86,093,000 tons of brown coal or lignite 
were raised. England retained 189,092,369 tons 
for home consumption in 1913; Germany retained 
about 155,503,000 tons and 93,455,000 tons of 
brown coal, part of which was imported. These 
figures show a mean consumption of coal of 
4108 tons per head in the United Kingdom and 
3°68 tons of coal and brown coal in Germany. 
Broadly speaking, the coal consumption is a 
measure of the industrial activity of the two 
countries, and on this basis it is gratifying to 
note the greater consumption in England. 
In order to arrive at some idea of the products 
available from distillation, the amounts of coal 
carbonised for gas and coke making, and the 
quantities treated in recovery plant in the latter 
case, must be considered. It is estimated that, 
in 1913, 37,483,944 tons of coal were used in the 
manufacture of gas and coke in this country; 
something above 16,000,000 tons being carbon- 
ised in gas works. In Germany the total quantity 
carbonised was 62,613,000 tons; only about 
9,000,000 tons being used in gas works. There 
is, however, a difference of considerable import- 
ance so far as the utilisation of products is con- 
cerned, that whereas in the United Kingdom 
27 per cent. of the total coal carbonised is 
treated in gas works, primarily for the production 
of coal gas, in Germany the corresponding figure 
is only 144 per cent., the larger bulk being 
treated primarily for the production of coke. 
Owing to the larger proportion carbonised in 
ovens in Germany, the quantity of some crude pro- 
ducts which are of primary importance in 
chemical industries—such as benzol, which is 
recovered only to a very small extent in gas 
works—is very much greater in Germany, 
relative to the total amount of coal carbonised, 
than in the United Kingdom. The output of 
pig iron, which dominates the question of coke 
production, is clearly an important factor. 
Germany derives a further advantage from the 
more extensive use of by-product recovery plant. 
Benzol recovery is now a matter of national 
importance, since toluene, which forms from 10 
to 25 per cent. of the benzol, is in large demand 
for the manufacture of trinitrotoluene. In 
recovery oven practice the gas is stripped of the 
whole of the benzol content, but in gas making 
only the toluene content of the benzol is removed 
permanently from the gas. It has been proved, 
however, that at least one-third of the benzol 
content of the gas can be removed without 
reducing its calorific value below the standard of 
500 B.Th.U. per cubic foot. The possible supply 
from coke ovens, if the whole of the gas pro- 
duced in them were debenzolised in recovery plant, 
would probably amount to 60,000,000 gallons; in 
