72 CONTEMPORARY SCIENCE 



possible to neutralize a part of the infantry by cutting 

 down their supplies and ammunition. 



The use of a gas shell to force a man to put on his mask 

 is practically neutralization. If at the same time you can 

 hurt him, so much the better. Hence the change in gas- 

 shell tactics, which consists in replacing the purely lachry- 

 matory substance by one that is also poisonous. 



One substance used for this method of simultaneously 

 harassing and seriously injuring was dichloro-diethylsul- 

 fide (mustard gas). Its use was begun in July of last 

 year at Ypres, and it was largely used again at Nieuport 

 and Armentieres. A heavy bombardment of mustard-gas 

 shells of all calibers was put on these towns, as many as 

 50,000 shells being fired in one night. The effects of 

 mustard gas are those of a "super-lachrymator." It has 

 a distinctive smell, rather like garlic than mustard. It 

 has no immediate effect on the eyes, beyond a slight irri- 

 tation. After several hours the eyes begin to swell and 

 inflame and practically blister, causing intense pain, the 

 nose discharges freely, and severe coughing and even 

 vomiting ensue. Direct contact with the spray causes 

 severe blistering of the skin, and the concentrated vapor 

 penetrates through the clothing. The respirators of course 

 do not protect against this blistering. The cases that went 

 to the hospitals, however, were generally eye or lung 

 cases, and blistering alone took back very few men. 

 Many casualties were caused by the habit that some of the 

 men had fallen into of letting the upper part of the mask 

 hang down so as not to interfere with seeing. The Ger- 

 mans scored heavily in the use of this gas at first. It was 

 another example of the element of surprise in using a 

 new substance that produces new and unusual symptoms 

 in the victims. 



Up to the present time there had been no material 

 brought out on either side that can be depended on to go 

 through the other fellow's respirator. The casualties are 

 due to surprise or to lack of training in the use of masks. 



