WAR GASES 745 *The treatment consists in the prompt removal of contaminated clothing and wash- ing the body with soap and water. The eyes should be washed with warm water, normal saline or 2 per cent sodium bicarbonate solution and subsequently a drop or two of castor oil containing 1 per cent atropine should be instilled into them. The nose should be irrigated with 5 per cent sodium bicarbonate solution. Mustard gas should be re- moved from the skin by applying cotton wool swabs dipped in petrol, kerosene or methy- lated spirit and then by rubbing into the cleansed area bleach cream prepared by mixing one part of bleaching powder to two parts of water. Tannic acid jelly or solution should also be used. The respirator which will afford protection for the eyes, nose, face and lungs should be used. The respirator is a mask with valves for the intake of air and the escape of expired air, with a container in which are activated charcoal and a filter of celluloid through which the outer air has to pass before it enters the lungs. It will also give protection against any other type of gas. Protective clothing and boots which prevent the penetration of mustard gas should be worn. Lewisite is a heavy, oily, dark liquid, having an odour of geraniums. It is insoluble in water, but hydrolyses rapidly; this action is increased by heat and alkalies. It dis- solves in oil, benzene and ordinary organic solvents. It is both a vesicant and an asphyxiant, and is more rapid in action than mustard gas and produces more discomfort on inhalation and more irritation on coming into contact with the skin. It must be remembered that a vesicle caused by lewisite is clearly defined, covers the whole erythe- matous area and is filled with a cloudy fluid containing arsenic and leucocytes. While a blister produced by mustard gas is surrounded by a zone of erythema and contains a clear yellow serum but does not contain mustard.21 The treatment consists in the intramuscular injections of 2 ml. of a 5 per cent solu- tion of B.A.L, (British-Anti Lewisite) in arachis oil and benayl benzoate into the thigh and gluteal region. It is regarded as an antidote to the local and systemic damage caused by contamination of the skin or eyes with arsenical vesicant gases. II. Asphyxiants or Lung Irritants.—These are chlorine,22 phosgene (carbonyl chlo- ride or carbon oxychloride), diphosgene (trichloromethyl-chloroformate) and chloropi- crin (nit'rochloroform or trichloronitromethane). They exert their main action on the pulmonary alveoli through the upper respiratory passages. Phosgene is a colourless gas at ordinary temperature and pressure possessing a smell of musty hay. It is three times and a half as heavy as air and is decomposed by water into hydrochloric and carbonic acids. It is one of the most dangerous poison gases, being practically ten times more toxic than chlorine, but owing to its poor solubility its action is very slow. Hence it may sometimes produce poisonous symptoms a few hours after exposure and during the interval the patients may be able to carry on their work. Diphosgene is an oily liquid having a smell of phosgene. It is heavier than phos- gene, is as toxic as phosgene and is intensely lachrymatory. Both phosgene and diphosgene are known as "Green Cross". Chloropicrin is a yellow, oily liquid, smells like chlorine and is about four times more toxic than chlorine. It is destroyed by a solution of sodium sulphite in alcohol (50 per cent). When inhaled, these gases cause watering of the eyes, coughing, dyspnoea, feeling of pain and constriction in the chest, headache, retching and vomiting. These symptoms are followed by rapid and stertorous respirations, cyanosis and collapse. Death occurs from acute pulmonary oedema within twenty-four to forty-eight hours or later from broncho-pneumonia. The treatment consists in absolute rest, administration of oxygen by inhalation and venesection. Codeine may be given to relieve the irritating cough and intramuscular injections of calcium gluconate may be tried to prevent pulmonary oedema. On post-mortem examination the lungs are found heavy and oedematous, exuding frothy, dark fluid blood on section. There are petechial haemorrhages on the upper sur- face of the lungs and serous effusion in the pleural cavity. III. Lachrymators or Tea? Gases.—These are chiefly chlor-acetophenone (C.A.P.), ethyl-iodoacetate (K.S.K.) and bromobenzyl cyanide (B.B.C.). Chlor-acetophenone is a colourless, crystalline solid. It is very slightly soluble in water, but dissolves in ether, alcohol or benzene and in a hot aqueous solution of sodium carbonate, Ethyliodoacetate is a dark brown, oily liquid with a smell like that of "pear drops". Bromobenzyl cyanide is a heavy, oily, dark brown liquid, having a penetrating, bitter-sweet odour. It is very persistent. Exposure to the vapours of any of these substances causes intense irritation of the eyes with a copious How of tears, spasm of the eyelids and temporary blindness. When the 21, E. M. Cowell, Brit. Med, Jour., Oct. 14, 1939, p. 778. 22, Vide p. 477.