A process for destroying contagious miasmata or effluvia, by the fumes of various substances. The most efficacious substance for this purpose is chlorine, which may be readily applied in the state of gas by placing in the apartment to be fumigated an earthen pan, containing sea salt and black oxide of manganese, and pouring dilute oil of vitriol upon the mixture; but a solution of chloride of lime is generally preferred. Next to chlorine in efficiency is the vapour of nitric acid; and, lastly, of muriatic acid; but the fumes of heated vinegar, burning sulphur, or exploded gunpowder, deserve little confidence.