“In the first place, the various and vague application of the term contagion has been the source of confusion. In foreign languages, as well as in English, it has sometimes been used for the plague itself, sometimes as synonimous with infections; sometimes for the virulent effluvia issuing from the sick, or from substances infected, and sometimes as a property common to various diseases.” He is of the decided opinion, that plague is communicated, by contact of the body, with the poison, which is properly understood by the word contagion. He says—“The second mode of contagion is by the medium of the air. The effluvia arising from the diseased, received into the ambient air, form a pestiferous atmosphere, more or less impregnated with these effluvia, as it recedes from their source. That contagion is thus communicated in the chamber of the sick, appears from persons being infected without touching the diseased body, or any thing in the room that may be supposed to harbour infection. “To what distance the tainted atmosphere extends is not yet known, but recent facts render it probable that the effluvia, when once transmitted into the air, are soon dispersed, blended with the common mass, or otherwise suffer such alteration as render them innocuous at no great distance from their source. It is probable, also, that those effluvia arise, in an active state, to no great height in the atmosphere.” He adds, that the contagion by fomites, that is, impregnated clothes, is the most extensive in its operation; and that it spreads disease, not only in all quarters of a town, but also to remote regions. He asserts that the plague is conveyed into different streets, remote from one another, by the Jewish salesmen, and that he has known Armenian washerwomen infected by tainted linen. The infectious air of plague, according to him, when it adheres to substances not exposed to free ventilation, and closely packed, retains its vigour for along time, and in that state is transported to other countries: and he held it as proven that it retains its activity in a three months’ voyage from the coast of Syria to Marseilles. He is disposed to think that the contagion of plague, rarely remains in the system longer than ten days, and that more danger is to be apprehended from the baggage of passengers who enter into lazarettoes, than from their persons. To Dr Joseph Adams we are indebted for an excellent treatise on animal poisons, one that is much valued for the information and clear views it contains. The following is an extract from the work in question.