He was a powerful, well-formed, and laborious man, was in good general health up to the moment of his being affected in the grave,—and it was not ascertained that he had been in a situation to receive infection from any other source. Vitiated air arising from persons in a state of disease, is found in those situations only where the apartment is close and confined, where the person and clothes are allowed to remain in a state of impurity, where the secretions and excretions are left to ferment; and, in short, where no attention is paid to cleanliness, the removal of respired air, and the introduction of a fresh atmosphere. The production of vitiated air is thus only occasional, while, in the contagious diseases, the specific poisons are produced in every case of their respective diseases, and were they capable of being diffused in the atmosphere, there would be present as constantly an atmospheric contagion. When vitiated air is produced, its removal can readily be accomplished, as daily experience, and the testimony of Dr Haygarth, given at the beginning of this work, amply prove. AIR VITIATED WITH EFFLUVIA FROM DEAD ANIMAL MATTER. There is still another source whence effluvia of a pestiferous nature arise. Dead animal matter, during putrefaction, exhales gases which taint the atmosphere, and render it unwholesome. When these materials are exposed to heat and moisture, the decomposition is rapid, and the air becomes more obviously tainted than when that process is retarded by cold, breezy weather, and some other circumstances. When the decomposition takes place in the open air, and when that is kept in motion, the quantity of decomposing materials not being very great, the bad effects are not so serious. When, however, buried along with a sufficient quantity of atmospheric air, to allow of the play of the chemical affinities, and kept there a considerable time, if they be exhumed previous to their total digestion or complete assimilation with surrounding objects, effluvia are exhaled, having the most intolerable stench, causing instant sickness, faintness, and giddiness, and eventually producing disease. “Thus, we are told by Fourcroy, that in some of the burial-grounds of France, whose graves are dug up sooner than they ought to be, the effluvium from an abdomen, (belly), suddenly opened by the stroke of the mattock, strikes so forcibly upon the grave-digger, as to throw him into a state of asphyxy, if close at hand; and if at a little distance, to oppress him with vertigo, fainting, nausea, loss of appetite, and tremors for many hours: whilst numbers of those who live in the neighbourhood of such cemeteries labour under dejected spirits, sallow countenances, and febrile emaciation.”[5] Footnote 5: Good’s Study of Medicine, vol. ii. page 65.