54 auld: methods of gas ware'are 



over the same amount of gas as with gas clouds, say in five 

 minutes per thousand yards of front, would require a prohibi- 

 tive number of guns and shells. It becomes necessary to put 

 the shells on definite targets, and this, fortunately, the Germans 

 did not realize at the Somme, although they have found it out 

 since. 



The use of gas out of a projectile has a number of advantages 

 over its use in a gas cloud. First, it is not so dependent on the 

 wind. Again, the gunners have their ordinary job of shelling, 

 and there is no such elaborate and unwelcome organization to 

 put into the front trenches as is necessary for the cloud. Third, 

 the targets are picked with all the accuracy of artillery fire. 

 Fourth, the gas shells succeed with targets that are not accessible 

 to high explosives or to gas clouds. Take, for instance, a field 

 howitzer, dug into a pit with a certain amount of overhead cover 

 for the men, who come in from behind the gun. The men are 

 safe from splinters, and only a direct hit will put the gun out 

 of action. But the gas will go in where the shell would not. 

 It is certain to gas some of the men inside the emplacement. 

 The crew of the gun must go on firing with gas masks on, and 

 with depleted numbers. Thus it nearly puts the gun out of 

 commission, reducing the number of shots say from two rounds 

 a minute to a round in two minutes, and may even silence it 

 entirely. Another example is a position on a hillside with 

 dugouts at the back, just over the crest, or with a sunken road 

 behind the slope. Almost absolute protection is afforded by 

 the dugouts. The French tried three times to take such a posi- 

 tion after preparation with high explosives, and each assault 

 failed. Then they tried gas shells, and succeeded. The gas 

 flows rapidly into such a dugout, especially if it has two or more 

 doors. 



Among the effective materials used by the Germans for gas 

 shells were mono- and tri-chloromethyl-chloroformate. Prussic 

 acid never appeared; the Germans rate it lower than phosgene 

 in toxicity, and the reports concerning it were obviously meant 

 merely to produce fear and distract the provisions for protection. 



During the last five months the actual materials and the 

 tactics used by the Germans have undergone a complete change. 



