Mention should be made also of that other chemical secret of the war, Lewisite. In one sense Lewisite can be termed a development of mustard gas, for the laboratory process of making mustard suggested to Captain Lewis certain analogous chemical reactions, out of one of which came the hitherto unknown liquid which was named after him. Like mustard, Lewisite is a so-called vesicant, a substance which blisters the skin, but it is much more powerful; for, whereas mustard gas merely burns, Lewisite is absorbed through the skin into the system. Three drops of this chemical placed on the belly of a rat will kill the animal in two or three hours, and it is believed that this would be the effect of a similar quantity sprinkled on the skin of a man. Like mustard, too, Lewisite gives off fumes slowly, and these fumes have a burning, deadly effect. Before and since the armistice there have been other developments of war gases in this country, and for some of these, as well as for some of the better known gases, there is, or can be, civilian use. Believing that chemical warfare has come to stay as long as there shall be wars, the Chemical Warfare Service has sought since the armistice to develop peace-time uses for war gases in order that there may be a continuous production of them, with a simultaneous training of chemists on whom the Government can rely in time of war. A new tear gas which has been developed is called chloracetophenone. The presence of a minute quantity of this gas in the air has a blinding lachrymatory effect upon the eyes of one caught in it; yet the gas is non-toxic. Various metropolitan police forces are experimenting with this gas to determine its effect in dispersing mobs. Another distressing, but not dangerous, gas bears the staggering chemical name of diphenylaminechlorarsine. It is temporarily blinding and causes nausea and vomiting, but it is not regarded as a lethal gas. It is proposed to use this in protecting vaults in which valuables are stored. Phosgene is used in making brilliant dyes, and it can also be used to exterminate rats. Chlorine is a widely used disinfectant. With other war gases it is proposed to exterminate numerous sorts of weevil and other insect pests which annually cause great damage to American crops.[12] SIGNAL SUPPLIES Signal corps contracts on the day of the armistice were 1,244 in number. They contemplated a production of supplies worth upwards of $45,000,000. Telephones, telegraph equipment, radio, field glasses, photographic cameras, pigeons, wrist watches--these were the sorts of things the Signal Corps procured.