[UPON THE DARK THICK MIST HAPPENING ON THE 27TH OF NOVEMBER, 1674.]
Though it be not strange to see frequent mists, clouds, and rains, in England, as many ancient describers of this country have noted, yet I could not but take notice of a very great mist which happened upon the 27th of the last November, and from thence have taken this occasion to propose something of mists, clouds, and rains, unto your candid considerations.
Herein mists may well deserve the first place, as being, if not the first in nature, yet the first meteor mentioned in Scripture, and soon after the creation, for it is said, Gen. ii. that ‘God had not yet caused it to rain upon the earth, but a mist went up from the earth, and watered the whole face of the ground,’ for it might take a longer time for the elevation of vapours sufficient to make a congregation of clouds able to afford any store of showers and rain in so early days of the world.
Thick vapours, not ascending high but hanging about the earth and covering the surface of it, are commonly called mists; if they ascend high they are called clouds. They remain upon the earth till they either fall down or are attenuated, rarified, and scattered.
The great mist was not only observable about London, but in remote parts of England, and as we hear, in Holland, so that it was of larger extent than mists are commonly apprehended to be; most men conceiving that they reach not much beyond the places where they behold them. Mists make an obscure air, but they beget not darkness, for the atoms and particles thereof admit the light, but if the matter thereof be very thick, close, and condensed, the mist grows considerably obscure and like a cloud, so the miraculous and palpable darkness of Egypt is conceived to have been effected by an extraordinary dense and dark mist or a kind of cloud spread over the land of Egypt, and also miraculously restrained from the neighbour land of Goshen.
Mists and fogs, containing commonly vegetable spirits, when they dissolve and return upon the earth, may fecundate and add some fertility unto it, but they may be more unwholesome in great cities than in country habitations: for they consist of vapours not only elevated from simple watery and humid places, but also the exhalations of draughts, common sewers, and fœtid places, and decoctions used by unwholesome and sordid manufactures: and also hindering the sea-coal smoke from ascending and passing away, it is conjoined with the mist and drawn in by the breath, all which may produce bad effects, inquinate the blood, and produce catarrhs and coughs. Sereins, well known in hot countries, cause headache, toothache, and swelled faces; but they seem to have their original from subtle, invisible, nitrous, and piercing exhalations, caused by a strong heat of the sun, which falling after sunset produce the effects mentioned.
There may be also subterraneous mists, when heat in the bowels of the earth, working upon humid parts, makes an attenuation thereof and consequently nebulous bodies in the cavities of it.