=Tear Gases in Shrapnel.= We will probably use tear gas in most, if not all, of our shrapnel. The general idea now is that we should not put tear gas in all shrapnel because under certain conditions it will be blown back and harass our own troops. But as was said before, we must remember that the enemy will be using gas at all times as well as ourselves, and hence if we limit ourselves in any line we give the enemy an advantage. This use of gas by the Artillery will extend to all classes of guns—seacoast, field, turret and what not. =Use of Gas by Air Service.= _Bombs._ Let us next consider the Air Service. We naturally think of dropping gas in bombs when we speak of the use of gas by the Air Service. Gas will so be used and it will be used in bombs of perhaps a thousand pounds or even a ton in weight, at least 50 per cent of which will be gas. Such gases, however, will be of the non-persistent type—phosgene or similar ones. They will be used against concentration camps and cross-roads, on troops on the road in columns; against railroad centers and rest areas; in other words, against groups of men or animals. _Sprinkling._ But that is not even the beginning of the use of gas by aeroplanes. Mustard gas, which is one-third again as heavy as water, and which volatilizes far slower than water, may be sprinkled through a small opening such as a bung hole in a tank that simply lets liquid float out. The speed of the aeroplane will atomize it. In this way, gas can be sprinkled over whole areas that must be crossed in battle. The Lewisite, of which we have heard considerable, will be used. It is less persistent than the mustard gas, but like mustard gas it produces casualties by burning. Unlike mustard gas, however, the burns from a quantity equal to three drops will usually cause death. The material can be made up by hundreds, even thousands, of tons per month. We are working on clothing that will keep it out just as we have been and are working on clothing that will protect against mustard gas. But these gases are so powerful that if any opening be left in the clothing the gas will get through, so that even if we get clothing that will protect, it must cover every inch of the skin from head to foot. Besides the mask must be worn at all times. Consider the burden put on any army in the field that would have to continually wear such complete protection. What a strain on the mentality of the men! As before said, to endure it at all we must train our men to think of such conditions, to face them in peace, and in order to do so we must actually use gas. Just as in the World War the highly trained Caucasian outdistanced the savage in endurance, just so will the most highly trained men in the future outdistance all others in endurance.