The use of fumigations, in a disguised form, was perhaps rendered necessary, as the purpose of purifying the atmosphere, might have seemed to cast reflections or imputations on the dead, which the vile, barbarous, and superstitious people, especially relatives, might have resented with acts of violence, or which might have thrown priest-craft into contempt and abhorrence. Perhaps it was in reference to this matter, as it was in many others of graver import, that the ignorant and superstitious condition of the people on the one hand, and the cunning, subtlety, despotism, and superior knowledge of the ministers of religion on the other, in early times, made it convenient that certain ends, thought to be desirable, should be accomplished without reasons, explanations, or intentions being given. There is, then, reason to believe, that the burning of oils and other fragrant substances, was used in very early times to purify the atmosphere from the effluvia of dead bodies. The products of the combustion of essential oils, tar, pitch, and the like, are carbonic acid gas and watery vapour, which, there is reason to think, cannot be useful in purifying the air, or in neutralizing hurtful effluvia. The permanently elastic gases which are used as fumigations, are the most potent agents of the kind, and they are generally used, and with much propriety and advantage, in all cases where disease is of a putrid character, and where, in short, the atmosphere is likely to be vitiated to a great extent. They form also the most useful fumigations for the purpose of purifying the atmosphere, and the walls and furniture of apartments lately inhabited by the sick, and their employment, in such cases, should never be neglected, even when there is no great reason to apprehend vitiation of the atmosphere, for when advantage is doubtful, there can exist no possibility of detriment. The agent now most commonly employed, is chlorine gas, and it is perhaps the most efficient in the list of fumigations. Chlorine gas has a greenish colour, and a most disagreeable and suffocating odour. Water impregnated with it, has the property of destroying colours, and chlorine is, on that account, much employed in bleaching, in the forms of “Bleaching Powder” and “Tennant’s Powder.” When chlorine gas is disseminated through an apartment, any stench, however strong and intolerable, which may have been present there, is no longer perceptible, the odour of the chlorine taking its place, or so completely covering it, as to render it no longer cognisable to the senses. Chlorine gas is employed both alone, and in combination with other bodies, as lime and soda. In combination with these alkalis, chlorine forms the chlorides of lime and soda. The former is well known in this country, and the latter, when dissolved in water, forms the “Liqueur disinfectante” of Monsieur Labarraque, which is much celebrated on the Continent.