The Dysenteric Disorders

gas is not destroyed but only dissolved, and care must be taken not to spread the contamination by allowing the solvent to run. lThorough washing with soap and water will complete the treatment. 3. T7horough washing with soap and water.-If some time has elapsed after contamination, the washing treatment should still be carried out at the first opportunity with the hopes of mitigating the degree of burning. Bleach ointment or paste should never be applied to a skin already showing signs of irritation, as it aggravates the condition. Speed is the essence of all preventive treatment, and a delay of three minutes with liquid contamination or twenty minutes following exposure to vapour before cleansing the skin is carried out will result in definite burns. The other important blister gas-Lewisite-is a vesicant compound containthg arsenic, and is America's principal contribution to the war gases. It was not used during the Great War, but twenty thousand tons of it were on the way to Europe when the Armistice was signed, and it was destroyed at sea. It is an oily liquid, colourless in the pure state, but darkening on standing. Pure Lewisite is odourless, but on contact with moisture or in the impure form it smells strongly of geraniums. Lewisite is more rapid than mustard in its action, producing more discomfort when breathed and more irritation when placed on the skin. It lacks the insidious character of mustard-gas, and its extreme pungency and penetrative odour renders it early of detection when similar concentraitons of mustard-gas would not be noticed. Broadly speaking, its effects on the body are similar to mustard. Lewisite can be neutralised by water, especially if it is hot and contains an alkali. So that preventive treatment consists essentially in rapid removal of clothing followed by washing in soap and water. Lewisite can also be neutralised by a five per cent. aqueous solution of sodium hydroxide or removed by solvents or destroyed by bleach.