From some such Commotions of the Air I imagine it is, that at Grand Cairo the Plague immediately ceases, as soon as the Nile begins to overflow; although Mr. Boyl attributes it to nitrous Corpuscles. Determ. Nat. of Effluv. Chap. 4.
Nulla enim propemodum regio est, quæ non habeat aliquem flatum ex se nascentem, & circa se cadentem.
Inter cætera itaq; Providentiæ opera, hoc quoq; aliquis, ut dignum admiratione suspexerit. Non enim ex unâ causâ Ventos aut invenit, aut per diversa disposuit: sed primum ut aera non sinerent pigrescere, sed assiduâ vexatione utilem redderens, vitaiemq; tracturis. Sen. Nat. Quæst. l. 5. c. 17, 18.
All this is more evident, from the Cause assigned to malignant epidemical Diseases, particularly the Plague, by my ingenious, learned Friend, Dr. Mead; and that is, an hot and moist Temperament of the Air, which is observed by Hippocrates, Galen, and the general Histories of Epidemical Diseases, to attend those Distempers. Vid. Mead of Poisons, Essay 5. p. 161. But indeed, whether the Cause be this, or poisonous, malignant Exhalations or Animalcules, as others think, the Winds are however very salutiferous in such Cases, in cooling the Air, and dispersing and driving away the moist or pestiferous Vapours.
[c] July 8. 1707, (called for some time after the Hot Tuesday,) was so excessively hot and suffocating, by reason there was no Wind stirring, that divers Persons died, or were in great Danger of Death, in their Harvest-Work. Particularly one who had formerly been my Servant, a healthy, lusty, young Man, was killed by the Heat: And several Horses on the Road dropped down and died the same Day.
In the foregoing Notes, having Notice of some Things relating to Heat, although it be somewhat out of the way, I hope the Reader will excuse me, if I entertain him with some Observations I made about the Heat of the Air under the Line, compared with the Heat of our Bodies. J. Patrick, who, as he is very accurate in making Barometrical and Thermometrical Instruments, had the Curiosity for the nicer adjusting his Thermometers, to send two abroad under the Care of two very sensible, ingenious Men; one to the Northern Lat. of 81; the other to the Parts under the Æquinoctial: In these two different Climates, the Places were marked where the Spirits stood at the severest Cold and greatest Heat. And according to these Observations he graduates his Thermometers. With his Standard I compared my Standard Thermometer, from all the Degrees of Cold, I could make with Sal Armoniack, &c. to the greatest Degrees of Heat our Thermometers would reach to. And with the same Thermometer (of mine) I experimented the greatest Heat of my Body, in July 1709. First in an hot Day without Exercise, by patting the Ball of my Thermometer under my Armpits, and other hottest Parts of my Body. By which means the Spirits were raised 284 Tenths of an Inch above the Ball. After that, in a much hotter Day, and indeed nearly as hot as any Day with us, and after I had heated my self with strong Exercise too, as much as I could well bear, I again tried the same Experiment, but could not get the Spirits above 288 Tenths; which I thought an inconsiderable Difference, for so seemingly a very different Heat of my Body. But from some Experiments I have made (altho’ I have unfortunately forgotten them) in very cold Weather, I imagine the Heat of an healthy Body to be always much the same in the warmest Parts thereof, both in Summer and Winter. Now between those very Degrees of 284 and 288, the Point of the equatorial Heat falleth. From which Observation it appears, that there is pretty nearly an equal Contemperament of the Warmth of our Bodies, to that of the hottest Part of the Atmosphere inhabited by us.
If the Proportion of the Degrees of Heat be desired from the Freezing-Point, to the Winter, Spring, and Summer Air, the Heat of Man’s Body, of heated Water, melted Metals, and so to actual Fire; an Account may be met with of it, by my most ingenious Friend, the great Sir Isaac Newton, in Phil. Transact. Nᵒ. 270.
[d] In hoc Providentia ac Dispositor ille Mundi Deus, aera ventis exercendum dedit,——non ut nos classes partem freti occupaturas compleremus milite armato, &c. Dedit ille ventos ad custodiendam cœli terrarumq; temperiem, ad evocandas supprimendásq; aquas, ad alendos satorum atq; arborum fructus; quos ad maturitatem cum aliis causis adducit ipsa jactatio, attrahens cibum in summa, & ne torpeat, promovens. Dedit ventos ad ulteriora noscenda: fuisset enim imperitum animal, & fine magnâ experientiâ rerum Homo, si circumscriberetur natalis soli fine. Dedit ventos ut commoda cujusq; regionis fierent communia; non ut legiones equitemq; gestarent, nec ut perniciosa gentibus arma transveherent. Seneca, ibid.
[e] Sea-Breezes commonly rise in the Morning about nine a Clock.——They first approach the Shore gently, as if they were afraid to come near it.——It comes in a fine, small, black Curle upon the Water, whereas all the Sea between it and the Shore (not yet reached by it) is as smooth and even as Glass in Comparison. In half an Hours time after it has reached the Shore, it fans pretty briskly, and so encreaseth gradually till twelve a Clock; then it is commonly strongest, and lasts so till two or three, a very brisk Gale.——After three it begins to die away again, and gradually withdraws its force till all is spent; and about five a Clock——it is lulled asleep, and comes no more till next morning.
And as the Sea Breezes do blow in the Day, and rest in the Night; so on the contrary [The Land-Breezes] blow in the Night, and rest in the Day, alternately succeeding each other.——They spring up between six and twelve at Night, and last till six, eight, or ten in the Morning. Dampier’s Disc. of Winds, ch. 4.