Main Features of the Period.—It is difficult to generalise. But the following features appear to characterise the period under discussion. In the first place we see German policy tending towards the use of gas projectiles containing a variety of organic substances. Secondly, we have the British exploitation of cloud gas attack both in magnitude and method. The Livens Projector provides the third important feature. Fourthly, we note the somewhat tardy development of the British use of gas shell. A number of causes, no doubt, unite in responsibility for the above. But whether due to definitely framed policy on our part, or merely to the hard facts of the case, one important factor seems largely responsible. It is the relative ease of production by Germany as compared with ourselves. When German military opinion tended towards the development of gas shell, a variety of substances came quickly to hand, not only from German research sources, but in quantity from the dye factories. No such quick response could have met, or actually did meet, the demands of Allied military policy. Whatever ideas emanated from our research organisations, there was no quick means of converting them into German casualties. It is true that we could obtain chlorine and later phosgene in bulk and devote them to the exploitation of the older gas appliances in cloud methods. But British chemical supply was weak, owing to the absence of a strong organic chemical industry. In other words, German flexibility of supply meant flexibility in meeting the requirements of military policy, and, given sound military policy, this flexibility meant surprise, the essence of successful war.
CHAPTER IV
INTENSIVE CHEMICAL WARFARE
The chemical struggle became very intense in the Summer and Autumn of 1917. Projector attacks multiplied, the use of chemical shell increased on both sides, allied and enemy gas discipline was tightened up, officers and men acquired a kind of gas sense, a peculiar alertness towards gas. The home front was strengthened in England and France by reinforced and sounder organisations, and by the vigorous steps taken by America. The Germans began to reap the benefit of their gas shell policy. At the end of 1916, as a result of a review of the production situation, they had arrived at the so-called Hindenburg Programme. This included a large output of gas for shell, and from its realisation the Germans acquired a momentum which kept them ahead well into 1918. It is a very clear indication of the progress made by Germany in research, that the sudden expansion in manufacture required by the Hindenburg Programme found a number of new efficient war chemicals ready for production.
The Mustard Gas Surprise.—The next big surprise came from Germany. Units in the line at Nieuport and Ypres in July, 1917, were the first to experience it. Some were sprinkled and some deluged with a new type of German shell chemical which, in many cases, evaded the British gas discipline, and mustard gas, unrecognised, caused many serious casualties. Even those who wore the mask were attacked by the vesicant or blistering influence of the gas. The matter is vividly expressed in a letter, given below, which I received from an officer wounded in the Nieuport attack:
"I was gassed by dichlor-diethyl sulphide, commonly known as mustard stuff, on July 22nd. I was digging in (Livens Projectors), to fire on Lambartzyde. Going up we met a terrible strafe of H.E. and gas shells in Nieuport. When things quietened a little I went up with the three G.S. wagons, all that were left, and the carrying parties. I must say that the gas was clearly visible and had exactly the same smell as horseradish. It had no immediate effect on the eyes or throat. I suspected a delayed action and my party all put their masks on.
"On arriving at the emplacement we met a very thick cloud of the same stuff drifting from the front line system. As it seemed to have no effect on the eyes I gave orders for all to put on their mouthpieces and noseclips so as to breathe none of the stuff, and we carried on.
"Coming back we met another terrific gas shell attack on Nieuport. Next morning, myself, and all the eighty men we had up there were absolutely blind. The horrid stuff had a delayed action on the eyes, causing temporary blindness about seven hours afterwards. About 3000 were affected. One or two of our party never recovered their sight and died. The casualty clearing stations were crowded. On August 3rd, with my eyes still very bloodshot and weak and wearing blue glasses, I came home, and went into Millbank Hospital on August 15th."
These early mustard gas attacks caused serious gaps amongst the troops assembling for the Northern offensives. The gas was distinctly a new departure. Effective in low concentrations, with very little odour, and no immediate sign of discomfort or danger, very persistent, remaining on the ground for days, it caused huge casualties. Fortunately, its most fatal effects could be prevented by wearing a respirator, and only a very small proportion of mustard gas casualties were fatal.
The insidious nature of the gas and the way in which it evaded the gas discipline is shown in the following example from an official report: "A battery was bombarded by the new gas shell from 10 p.m. to 12 midnight and from 1.30 to 3.30 on the night of 23rd-24th July. The shelling then ceased and at 6 a.m., when the battery had to carry out a shoot, the Battery Commander considered the air free from gas, and Box Respirators were accordingly removed. Shortly afterwards several men went sick from gas poisoning, including the Battery Commander. On previous nights they had been fired at with gas shell in the same way, but found it safe to remove Box Respirators after a couple of hours. On the occasion in question the air was very still and damp." In another case an officer in the Boesinghe sector, during the gas bombardment on the night of the 22-23 July, adjusted the mouthpiece and nose-clip, but left the eyes uncovered. His eyes were seriously affected, but he had no lung symptoms on the morning of the 24th.