capable of dilution in the atmosphere, so as to be rendered at length innoxious. The contagion of the plague will be entirely prevented from spreading if all access to, and all intercourse with, the sick be strictly prohibited: whence the following forms a safe and infallible prophylactic of the disease: [110] Medical Review, vol. iii, p. 257. “Mox, longe, tarde, cede, recede, redi. _Go_ quick, _fly_ far, _and_ slow _return again._” “No change in the habit takes place previous to the action of the contagion, but the body is from the first equally susceptible of it as of the itch, or any other infectious disease. Whilst the plague ceases in the civilized parts of Europe spontaneously, or by human precautions, its revival is prevented, from the care that is bestowed in purifying or destroying every infected substance. In the east, on the contrary, this precaution is totally neglected; whence it is probable that the disease is not reproduced anew, but that it is perpetuated by the former fomes, as happens with us in the small-pox. The matter producing the ordinary epidemics is widely diffused in the atmosphere, and capable of infecting through a widely extended space. The pestilential poison, on the contrary, is confined to the vicinity of the affected body, and becomes so dilute at the distance of a few paces only as to be incapable of further action. Hence it appears that the plague is much easier avoided than epidemic disorders. The more abundant the contagious matter is, the further probably is the power of its infection carried. This is the reason that the mere separation of the sick and suspected from the healthy is so much more efficacious in destroying it at its commencement than at a later period. To restrain epidemics within bounds is impossible; but with the contagion of the plague, it is certain that it can be confined by art to a narrow spot.”