234 
NATURE 
[APRIL 29, 1915 

typhoid. Early in the war, the bad news came of 
many cases of tetanus; the heavily manured soil 
of France was full of tetanus; the very earth 
that our men were helping to defend was their 
enemy. It is a great blessing that a wounded 
man may indeed be safeguarded, with a dose of 
anti-tetanic serum, against this disease; and a 
great blessing that our men now are on soil which 
is fairly free from it. 
But typhoid, after all, is the supreme test of 
the efficiency of an army medical service. We 
have learned of late years that the infection may 
be conveyed by flies, and by clouds of dust; we 
have learned also the danger of infection from 
mild, unsuspected cases, and from _ typhoid- 
carriers; we have left off thinking that typhoid 
cannot be spread without the help of a “polluted 
water supply.” The present control of typhoid 
for our Army in France has been won by the 
bacteriologists; all honour to them :— 
Mobile bacteriological laboratories have been in- 
stalled expressly for this purpose (the early detection 
of cases). Each laboratory consists of a motor-lorry 
fitted with a complete bacteriological equipment, and 
is in charge of a specially-trained officer, and an 
attendant of the Royal Army Medical Corps. 
Moreover, it is the bacteriologists who dis- 
covered the protective treatment against the 
disease. On March 5 we learned what our Army 
owes to that treatment. Of fifty deaths from 
typhoid fever among our men on active service, 
forty-eight had occurred among the non-protected, 
one in a man protected, and one in a man partly 
protected. Nobody in his proper senses can 
doubt that Nature finds it easier to kill the non- 
protected than to kill the protected. 
It must not be forgotten that by far the most 
potent weapon in our armoury against typhoid fever 
has been forged by pathologists, before the war. 
Inoculation is the surest defence: and to its extensive 
use must chiefly be attributed the low incidence of 
this terrible disease in the British Army. 
But the whole article ought to be read care- 
fully, not in fragments. 
Doubtless, when the hot weather comes, the 
work of safeguarding the Army’s health will be 
no less arduous than it is now. For the present, 
let us be thankful for the splendid services ren- 
dered by men of science to our defenders, through 
all the bitter hardship and perils of the past nine 
months. STEPHEN PAGET. 

THE USE OF ASPHYXIANTS IN 
WARFARE. 
“PRE use of asphyxiating gases by the Germans 
in forcing back the French lines to the north 
of Ypres has given rise to much conjecture as to 
the nature of the gases employed, and in a long 
article in a Sunday paper it is surmised that the 
gas used was carbon monoxide. The only founda- 
tion that can exist for such an opinion is that 
carbon monoxide is one of the most virulent 
gaseous poisons known, and that less than 1 per 
cent. in air rapidly proves fatal, but inasmuch as 
all the explosives in general use produce it in 
large quantities, the smokeless powders in use by 
NO. 2374, VOL. 95] 

England, France, and Germany, giving approxi- 
mately 50 per cent. of the permanent gases formed 
as carbon monoxide, it is hard to believe that the 
enormous volume produced by firing the charge 
in the gun should have no deleterious effect on 
those using it, whilst the much smaller quantity 
given on the bursting of the shell should asphyxi- 
ate the enemy. The fact is, that carbon mon- 
oxide is slightly lighter than air, and when driven 
out by the explosion in a heated condition diffuses 
upwards so rapidly that scarcely a trace can be 
found at the breathing level, but when evolved 
underground in a confined space many accidents 
have been caused by its poisonous properties. 
Moreover, carbon monoxide is in no sense of 
the word an asphyxiant, “and one of its greatest 
dangers lies in the fact that air containing a 
poisonous amount can be readily breathed. 
Later reports received on Monday and Tuesday 
make it evident that it was a true asphyxiant, 
such as sulphur dioxide, chlorine, or a mixture 
of the two that was employed, and that the fumes 
generated in front of the German trenches were 
borne down by a northerly wind upon the Allies. 
Some descriptions speak of the burning of some 
substance which gave a yellowish smoke and 
gases; others that the gases were contained in 
steel cylinders, the gases being conducted by hose- 
pipes some little distance in front of the trenches, 
whilst the men manipulating the cylinders wore 
divers’ helmets, and the first German troops to 
charge over the gassed area wore smoke helmets 
or respirators. It is further probable that some 
shells containing a liquid giving gases of an 
asphyxiating character were ‘also employed. 
It seems to be clear from various descriptions 
that the gases floated close to the ground for a 
considerable distance, producing an effect of 
asphyxiation, which was felt as far as the Allies’ 
second lines. 
Both sulphur dioxide and chlorine would have 
produced the effects described, and the cylinders 
spoken of might have contained these gases in a 
liquefied form, whilst it is probable that shells 
used for asphyxiating purposes would be charged 
with chloride of sulphur which would itself decom- 
pose in moist air or in contact with water into 
sulphur dioxide, hydrochloric acid, and sulphur, 
or, if fired by the bursting of the shell, would give 
sulphur dioxide and chlorine. 
Both sulphur dioxide and chlorine satisfy the 
requirements of being more than double the weight 
of air, and so might remain near the ground, 
diffusion being only slow, but it is difficult to 
understand how sufficient quantities of either gas 
were produced to render the air irrespirable at the 
distance of the Allies’ lines from the German 
trenches. 
RICHARD LYDEKKER,. FURS. 
Bose zoologists and geologists lament the 
death on April 16 of Mr. Richard Lydekker, 
who had been for more than thirty years one of 
the most active workers in the natural history 
sciences. Born in 1849, of Dutch descent, he 
was educated at Cambridge, where he graduated 


