[124] Synopsis, vol. i, p. 80.
[125] Earthquakes, as we have already seen, might be accounted rather a sign or cause of the beginning of pestilence, than of its departure. A great quantity of electricity in the atmosphere has accordingly been enumerated among the signs of an approaching pestilence. Thus in Burnet’s Thesaurus, p. 699, we find among the previous signs of a plague, “plurima et fere continua nocturna fulgora, sine pluviis et tonitruis, cœlo non nubiloso existante.” Very much and almost continual lightning at night, without rain or thunder; the sky in the mean time not being covered with clouds.
[126] Before we can attach any degree of probability to either of these suppositions, it must be proved that plagues arise out of the earth. But this, though as plausible as many other hypotheses, is not yet supported by any direct proof.
[127] Medicina Nautica, p. 173, et seq.
[128] In the plague, Dr. Russel has observed, that those who die in a very short time are much less ready to communicate infection, than those who live longer. He also takes notice, that “the plague, though a contagious disease, is not equally contagious in every period of the pestilential season. In the beginning those frequenting the sick often escape unhurt, or one only, out of several, is infected. The escape of persons employed about the sick, proves a frequent cause of misleading the popular opinion of the disease, and has in many instances occasioned much mischief, by encouraging the neglect of due precautions till too late.”
[130] Here, I hope, it will not be thought unreasonable to digress a little in favour of the sensations of humanity which on all occasions ought to predominate in our minds. Birds are the natural enemies of that hateful class of beings we call insects, and which in general are the natural enemies of man. In proportion to the havock we make among the former, the latter will multiply upon us whether we will or not. The wanton, indiscriminate, and I may add provoking destruction exercised among this useful as well as beautiful and agreeable part of the creation, must certainly be sometimes attended with bad consequences. Though birds feed on many different kinds of insects, yet there are exceptions. If then we totally exterminate a species of birds, is it not probable that a species of insects might appear, the mischief done by which we could not be able to counteract? Quere. Is it not possible that the Hessian fly may have made its appearance from this cause?
[131] Diemerbroeck, Hist. 17, lib. 4.
[132] Annals of Medicine for 1797, p. 373.
[133] The opinion of those physicians whom Mr. Howard consulted upon this subject are given at large in the APPENDIX.