The Toxicity of Atmospheres containing Hydrocyanic Acid Gas

The lethal dose of an ordinary pharmacological preparation is expressed in a simple statement of quantity. The lethal dose of a poisonous gas cannot as a rule be so expressed. The majority of such gases are rapidly destroyed in the body, and the building up of a lethal concentration in some critical portion of the organism is a race between the rate at which the gas is inhaled and the rate at which it is destroyed. Even in the cases of such gases as arsenuretted hydrogen which are destroyed only very slowly, and which are therefore cumulative poisons, the attainment of a lethal concentration in the body is a function not only of the concentration of the gas in the atmosphere, but of the time during which that atmosphere is breathed.