To see how chemical weapons are likely to be used in future we must study their employment in the late war. Lachrymatory gas was only once used under ideal conditions――by the Germans in the Argonne in 1915. They captured a fairly extensive French trench system and about 2,400 prisoners, almost all unwounded, but temporarily blind. When they gave the number of prisoners, the French authorities not unnaturally protested that this number was practically equal to the total of their casualties. And this was quite true. The French were unprotected. They were deluged with shells giving off a vapour which temporarily blinded them. They could not even run away. The Germans walked across, removed their rifles, and formed them up in columns which marched back, each led by a German in goggles. In order to make future wars humane it would only be necessary to introduce the two following rules:―― 1. No goggles or other eye protection shall be worn; 2. No shells shall be used containing any other substances save ethyl iodo-acetate (or other lachrymatory compound) and a small bursting charge. Certainly it is unlikely that such rules will ever be adopted, but I do contend that to forbid the use of such substances is a piece of sentimentalism as cruel as it is ridiculous. Gases of the first group were used in clouds discharged from cylinders, sometimes on a front of several miles. They probably caused at least 20,000 casualties among unprotected or inadequately protected British troops. At least a quarter of these died, and that very painfully, in many cases after a struggle for breath lasting several days. On the other hand, of those who did not die almost all recovered completely, and the symptoms of the few who became permanent invalids were mainly nervous. Apart, however, from the extreme terror and agitation produced by the gassing of uneducated people, I regard the type of wound produced by the average shells as, on the whole, more distressing than the pneumonia caused by chlorine or phosgene. Besides being wounded, I have been buried alive, and on several occasions in peacetime I have been asphyxiated to the point of unconsciousness. The pain and discomfort arising from the other experiences were utterly negligible compared with those produced by a good septic shell-wound.