Imágenes de páginas
PDF
EPUB

swelling for the size of the wound; but that from the bite of a serpent is still greater.

16. Nettles, bryony, and some other things raise the skin, and make blisters on it.

17. It is accounted an evident sign of poison (especially of that kind which operates by malignancy, not by corrosion) if the face or body be swollen.

18. When blisters are applied to the neck or any other part for the cure of diseases, there rises a watery humour, or ichor, which flows out when the skin is cut or pricked.

19. All pustules from an internal cause, and the like excrescences and abscesses, produce apparent swellings, and raise the skin.

20. A sudden burst of anger in some inflates the cheeks, as likewise does pride.

21. Frogs and toads swell; and many other animals when angered erect their combs, hair, and feathers. And this proceeds from a contraction of the skin by the swelling of the spirits.

22. Turkey-cocks swell greatly when angry, and raise their feathers like a mane. Birds while they sleep, the spirit being dilated by the reception of heat into the inner parts, are somewhat swollen.

23. In all decay and putrefaction the native spirits of the body begin to swell; and when they hasten to come forth, they loosen and alter the framework of the body. And if this framework be somewhat tenacious and viscous, so that they cannot escape, they try new forms, as in worms generated from corruption. But the commencement of the action proceeds from the dilatation of the spirits.

24. And the spirit confined in putrefaction produces

not only animal, but also vegetable life; as is seen in moss and the hairiness of some trees. I remember that in summer time I once left by chance a cut lemon

in a close room, and two months afterwards. I found a putrefaction growing on the cut part; tufts of hair an inch high at least; and on the top of each hair a kind of head, like the head of a small snail, plainly beginning to imitate a plant.

[ocr errors]

25. In like manner rust is formed on metals, glass, and the like, from a dilatation of the native spirit, which swells, and presses on the grosser parts, driving and propelling them before it that it may get out.

26. Whether the earth swells in its surface, especially where the soil is spongy and hollow, is a point to be inquired. Certainly in soils of this kind there are sometimes found trees like the masts of ships, lying sunk and buried in the ground several feet deep; so it would seem that these trees had been blown down by storms long ago, and afterwards covered up and buried by the earth gradually raising itself over them.

27. But in earthquakes the earth swells suddenly and manifestly; and oftentimes there burst forth springs of water, wreaths and balls of flame, and strong and strange winds; and stones and ashes are hurled up into the air.

28. But yet earthquakes do not all take place quite suddenly, for it sometimes happens that the earth trembles for several days; and in our time in Herefordshire there was a very small, slow, and partial earthquake, in which some acres of land continued to move gradually for a whole day, and transferred themselves to another place not far off, which lay a little lower, and there rested.

29. Whether the body of waters in the seas sometimes swells is a matter to be inquired. For the tides must needs be caused either by a progressive motion, or by the rising of the water upwards through some magnetic virtue and consent; or lastly by some swelling or relaxation in the waters themselves. And this last (if it be one of the causes of any tide) belongs to the present inquiry.

30. The water in some fountains and wells swells and falls again, so that it would appear to have certain tides.

31. Springs of water likewise sometimes burst out in certain places without any earthquake, at intervals of some years, from causes not known. And such eruption generally occurs during great droughts.

32. It has likewise been remarked that sometimes the sea swells, not at the time of the flood, and with no external wind; and this generally precedes somc great storm.

Injunction.

It would be worth trying whether there is not sometimes some relaxation in the body of water, even in a small quantity. But if water be exposed to the sun or air, it will more likely be consumed; and therefore the experiment should be made in a closed glass. Take then a glass with a large belly and a long and narrow neck, and fill it with water up to the middle of the neck. But do this in a dry season with a north wind, and leave it till the wind changes to the south and turns wet, and see if the water rises at all in the neck of the glass. Inquire likewise carefully of the swellings of water in wells, whether they take place rather by night than by day, and at what season of the year.

[blocks in formation]

pegs

33. In wet weather the wooden of violins swell and become harder to screw. So likewise wooden drawers are harder to pull out, and wooden doors open with more difficulty.

34. The strings of violins break if they are stretched tight in wet weather.

35. Humours in the bodies of animals in wet weather and south winds are found to be relaxed and swell, and to run, and oppress and obstruct the passages

more.

36. It is a received opinion that not only in animals, but also in plants, humours and juices swell and fill up the cavities more about the time of the full moon.

37. Salts in damp places dissolve, open, and dilate themselves, as also in some degree do sugar and preserves; which if they are not stored in a room where a fire is sometimes lighted, grow mouldy.

38. All things likewise which have felt the fire and been a good deal contracted are somewhat relaxed by time.

39. The swellings and relaxations of the air should be carefully inquired into, and how far the causes of winds (in any great part) are concerned therein, when vapours are neither collected easily into rain nor dissipated into clear air, but induce swellings in the body of the air.

Transition.

So much then with respect to the dilatations of bodies by the native spirit, whether in maturations or in rudiments of generations, or in excitation by motion, or in natural or preternatural irritations, or in putrefactions, or in relaxations, being but a few particulars taken out of the heap of nature. I must now

pass on to the openings and dilatations produced by fire and actual external heat.

THE DILATATIONS AND OPENINGS OF BODIES WHICH

ARE CAUSED BY FIRE, AND ACTUAL, SIMPLE, AND EXTERNAL HEAT.

Admonition. The openings of bodies by heat or fire (whereof I shall now inquire) belong properly to the titles of Heat and Cold, the Motion of Hyle, and Separations and Alterations. Nevertheless some

touch and taste of them must be given in the present title; for without some knowledge of these the inquiry concerning Dense and Rare cannot proceed aright

The History.

1. Air is dilated simply by heat. For there is nothing separated or discharged, as in tangible bodies, but a simple expansion takes place.

2. Cupping glasses are applied to the skin, the glass and the air contained in it having been first heated; presently the air, which has been dilated by heat, begins to cool, and to be gradually contracted into its former state; and then the flesh is attracted by the motion of connection. But if you wish the glass to draw stronger, take a sponge dipped in cold water, and place it on the belly of the glass; thus the air will be further contracted by the coolness, and the attraction will be more powerful.

3. Take a glass and heat it, and afterwards put it into water; it will attract the water so as to fill at least a third part of the space within, which shows that the air was rarefied likewise by the heat as much as a

« AnteriorContinuar »