The sprayers previously mentioned were originally suggested for use against the gas cloud itself, the idea being that chemicals should be sprayed at the cloud so as to neutralise the poisonous gas and thereby purify the air. Nearly everybody with even a nodding acquaintance with chemistry wrote in suggesting ammonia for this purpose, oblivious of the fact that the chemical reaction between chlorine and ammonia in these circumstances produces a dense cloud which is most irritating to the eyes and throat, and that this together with the excess of ammonia would be almost as bad as the original gas.
In any case it is impossible to deal with the gas cloud by spraying, because of the enormous amount of chemicals and apparatus that would be required to neutralise the attack. A cloud of chlorine from one thousand cylinders, for example, would require more than forty tons of the strongest ammonia solution obtainable to kill all the gas, even if none of the spray were lost in the ground. Besides this the spraying might have to be continued for hours, some of the attacks having lasted intermittently for more than three hours.
It was quickly seen that this was an utter impossibility, but experiments showed that a spray of the hypo solution was quite capable of removing what remained of the gas cloud out of trenches and shell holes and from dugouts into which the gas had penetrated. This of course applied only to chlorine. Arrangements were therefore made for supplying a large number of these sprayers, which are exactly the same as those used for spraying fruit trees and potatoes with fungicides, and men were specially trained in their use so that they could be employed after an attack was over. These men were officially known as the “Vermorel sprayer men,” and were popularly supposed to preface all their operations with the words “Let us spray.”
The solution to fill the sprayers was kept in all the trenches in corked rum jars, and there were many amusing incidents rising out of the dual purpose to which these revered vessels were put. It is stated that a certain battalion on going into the line for the first time saw these rum jars safely ensconced in niches in the parapet and immediately thought that they contained the rum ration concerning which they had heard so much before they came out. Some of the more adventurous ones surreptitiously tried out the supposed rum and drank a few mouthfuls of the nauseous liquid before discovering their mistake. The real joke lay in the fact that even after they realised that the liquid was not rum they continued to drink it, and by the time they finished their two days’ tour of instruction there was not a drop of Vermorel sprayer solution left in any of the trenches.
The sprayers were somewhat delicate pieces of apparatus to keep in good condition in the trenches, and were apt to get crusted with mud and out of order unless they were well looked after. Like everything else connected with the defence against gas, their condition in the trenches varied with different regiments according as they were well trained and disciplined or otherwise, but as a rule the sprayers were well enough looked after, and proved extraordinarily useful on many occasions after their first appearance in the line.
As stated before, the long interval of the summer and autumn of 1915 gave the chemists and the army plenty of opportunity for thinking about the gas question, developing organisation and methods to meet attacks in the future, and making arrangements for the training of the troops so that they should be thoroughly prepared when the next attack should arrive.
One of the most important things that was done was to start a big field laboratory for dealing with questions of gas warfare. And as it had already been realised that the whole basis of defence against gas was going to lie in the hands of the troops themselves by increasing their steadiness, developing their discipline, and generally accustoming them to the idea that gas was now an ordinary method of warfare, chemists and instructors were appointed for attachment to each of the British armies.
These men were all chosen from the line. For the most part they were infantry officers who could realise the real needs and limitations of the troops, but they were picked in each instance because they had, at any rate, some chemical knowledge and could translate into practice for the benefit of the troops various chemical measures which had been adopted for the latter’s safety. Their first chief job was to see that respirators and smoke helmets were issued in sufficient number; to see that they were in good condition; and then to arrange for the training of all the troops in the army in their use. This was a heroic task, to be accomplished in as short a time as possible, but by dint of speaking to large bodies of officers and men at the same time it was so far completed that all ranks were given practical instruction in the use of the helmet.
When it is realised that each of these officers had to deal with at least one hundred thousand troops it will be seen that it was no mean feat that was accomplished. What was started then has never been completely accomplished, partly because of the continual development of gas warfare and partly because it is a matter of education—which is always slow—but very largely also because of the continually changing personnel and the enormous numbers of men that have had to be trained.