Epidemic, in general, denotes a spreading disorder which, as is supposed, arises from some corruption or malignity in the air, and attacks great numbers of people at certain seasons.

Mankind have always been more inclined to search for the most distant causes, in order to explain physical events, rather than to avail themselves of those which are within their reach. Thus the yellow-fever, which in 1793 ravaged the city of Philadelphia, was doubtless generated by the immense quantities of damaged coffee, and other putrescible substances, exposed in the heat of summer oil the muddy banks of the river, In like manner the plague, which formerly destroyed great numbers in London, was not always imported, but probably originated at home, where, in those ages, c/eanliness was not so generally attended to as it is at present. Hence this domestic virtue has guarded us against many epidemics, to which other less cleanly nations have been sub-ject. But there is still great occasion for improvements, especially in the houses of the narrow courts and alleys of the metropolis, where the progress of a contagious malignant fever has lately excited considerable alarm. The Society for bettering the Condition of the Poor (according to the printed Report of the philanthropic T. BERnard, Esq.) have proposed another benevolent institution, to check the ravages of contagious distempers among that class of persons, who are most liable and exposed to their influence. Farther particulars relative to this interesting subject we propose to give under the head of Infection: See also Contagion.