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. CHAPTER III