very day when the river first riseth, great plagues in Cairo use suddenly to break up. Experiments in consort touching sleep. 744. Those that are very cold, and especially in their feet, cannot get to sleep: the cause may be, for that in sleep is required a free respiration, which cold doth shut in and hinder; for we see that in great colds one can scarce draw his breath. Another cause may be, for that cold calleth the spirits to succour; and therefore they cannot so well close, and go together in the head: which is ever requisite to sleep. And for the same cause, pain and noise hinder sleep; and darkness, contrariwise, furthereth sleep. 745. Some noises, whereof we spake in the hundred and twelfth experiment, help sleep: as the blowing of the wind, the trickling of water, humming of bees, soft singing, reading, &c. The cause is, for that they move in the spirits a gentle attention; and whatsoever moveth attention without too much labour stilleth the natural and discursive motion of the spirits. 746. Sleep nourisheth, or at least preserveth bodies, a long time, without other nourishment. Beasts that sleep in winter, as it is noted of wild bears, during their sleep wax very fat, though they eat nothing. Bats have been found in ovens and other hollow close places, matted one upon another: and therefore it is likely that they sleep in the winter time, and eat nothing. Query, whether bees do not sleep all winter, and spare their honey? Butterflies, and other flies, do not only sleep, but lie as dead all winter and yet with a little heat of sun or fire, revive again. A dormouse both winter and summer, will sleep some days together, and eat nothing. Experiments in consort touching teeth and hard substances in the bodies of living creatures. To restore teeth in age, were magnale naturæ. It may be thought of. But howsoever, the nature of the teeth deserveth to be inquired of, as well as the other parts of living creatures' bodies. 748. Bones, after full growth, continue at a stay; and so doth the skull: horns, in some creatures, are cast and renewed: teeth stand at a stay, except their wearing as for nails, they grow continually : and bills and beaks will overgrow, and sometimes be cast; as in eagles and parrots. 749. Most of the hard substances fly to the extremes of the body: as skull, horns, teeth, nails, and beaks: only the bones are more inward, and clad with flesh. As for the entrails, they are all without bones; save that a bone is, sometimes, found in the heart of a stag; and it may be in some other creature. 750. The skull hath brains, as a kind of marrow, within it. The back-bone hath one kind of marrow, which hath an affinity with the brain; and other bones of the body have another. The jaw-bones have no marrow severed, but a little pulp of marrow diffused. Teeth likewise are thought to have a kind of marrow diffused, which causeth the sense and pain; but it is rather sinew; for marrow hath. no sense; no more than blood. Horn is alike throughout; and so is the nail. 751. None other of the hard substances have sense, but the teeth; and the teeth have sense, not only of pain but of cold. But we will leave the inquiries of other hard substances unto their several places; and now inquire only of the teeth. 752. The teeth are, in men, of three kinds; sharp, as the fore-teeth; broad, as the back-teeth, which we call the molar-teeth, or grinders; and pointed teeth, or canine, which are between both. But there have been some men that have had their teeth undivided, as of one whole bone, with some little mark in the place of the division; as Pyrrhus had. Some creatures have over-long or out-growing teeth, which we call fangs, or tusks: as boars, pikes, salmons, and dogs, though less. Some living creatures have teeth against teeth; as men and horses; and some have teeth, especially their master-teeth, indented one within another like saws, as lions; and so again have dogs. Some fishes have divers rows of teeth in the roofs of their mouths; as pikes, salmons, trouts, &c. And many more in salt waters. Snakes and other serpents have venomous teeth; which are sometimes mistaken for their sting. 753. No beast that hath horns hath upper teeth; and no beast that hath teeth above wanteth them below: but yet if they be of the same kind, it followeth not, that if the hard matter goeth not into upper teeth, it will go into horns; nor yet e converso; for does, that have no horns, have no upper teeth. 747. There be five parts in the bodies of living creatures, that are of hard substance; the skull, the teeth, the bones, the horns, and the nails. The greatest quantity of hard substance continued is towards the head. For there is the skull of an entire bone; there are the teeth; there are the maxillary bones; there is the hard bone that is the instrument of hearing; and thence issue the horns; so that the building of living creatures' bodies is like the building of a timber house, where the walls and other parts have columns and beams; but the roof is, in the better sort of houses, all tile, or lead, or stone. As for birds, they have three other hard substances 754. Horses have, at three years old, a tooth put proper to them; the bill, which is of like matter forth, which they call a colt's tooth; and at four with the teeth for no birds have teeth: the shell years old there cometh the mark tooth, which hath of the egg and their quills: for as for their spur, a hole as big as you may lay a pea within it and it is but a nail. But no living creatures that have that weareth shorter and shorter every year; till shells very hard, as oysters, cockles, muscles, scal- that at eight years old the tooth is smooth, and the lops, crabs, lobsters, crawfish, shrimps, and especi-hole gone; and then they say, that the mark is out ally the tortoise, have bones within them, but only of the horse's mouth. little gristles. 755. The teeth of men breed first, when the child is about a year and half old and then they cast them, and new come about seven years old. But divers have backward teeth come forth at twenty, yea, some at thirty and forty. Query, of the manner of the coming of them forth. They tell a tale of the old Countess of Desmond, who lived till she was seven score years old, that she did dentire twice or thrice; casting her old teeth, and others coming in their place. 756. Teeth are much hurt by sweetmeats; and by painting with mercury; and by things over-hot; and things over-cold; and by rheums. And the pain of the teeth is one of the sharpest of pains. 757. Concerning teeth, these things are to be considered. 1. The preserving of them. 2. The keeping of them white. 3. The drawing of them with least pain. 4. The staying and easing of the toothache. 5. The binding in of artificial teeth, where teeth have been strucken out. 6. And last of all, that great one of restoring teeth in age. The instances that give any likelihood of restoring teeth in age, are the late coming of teeth in some; and the renewing of the beaks in birds, which are commaterial with teeth. Query, therefore, more particularly how that cometh. And again, the renewing of horns. But yet that hath not been known to have been provoked by art; therefore let trial be made, whether horns may be procured to grow in beasts that are not horned, and how ? And whether they may be procured to come larger than usual; as to make an ox or a deer have a greater head of horns? And whether the head of a deer, that by age is more spitted, may be brought again to be more branched? for these trials, and the like, will show, whether by art such hard matter can be called and provoked. It may be tried also, whether birds may not have something done to them when they are young, whereby they may be made to have greater or longer bills; or greater and longer talons? And whether children may not have some wash, or something to make their teeth better and stronger? Coral is in use as a help to the teeth of children. Experiments in consort touching the generation and bearing of living creatures in the womb. 758. Some living creatures generate but at certain seasons of the year; as deer, sheep, wild conies, &c. and most sorts of birds and fishes: others at any time of the year, as men ; and all domestic creatures, as horses, hogs, dogs, cats, &c. The cause of generation at all seasons seemeth to be fulness: for generation is from redundance. This fulness ariseth from two causes; either from the nature of the creature, if it be hot, and moist, and sanguine; or from plenty of food. For the first, men, horses, dogs, &c. which breed at all seasons, are full of heat and moisture; doves are the fullest of heat and moisture amongst birds, and therefore breed often ; the tame dove almost continually. But deer are a melancholy dry creature, as appeareth by their fearfulness, and the hardness of their flesh. Sheep are a cold creature, as appeareth by their mildness, and for that they seldom drink. Most sort of birds are of a dry substance in comparison of beasts. Fishes are cold. For the second cause, fulness of food; men, kine, swine, dogs, &c. feed full; and we see that those creatures, which being wild, generate seldom, being tame, generate often; which is from warmth, and fulness of food. We find, that the time of going to rut of deer is in September; for that they need the whole summer's feed and grass to make them fit for generation. And if rain come early about the middle of September, they go to rut somewhat the sooner; if drought, somewhat the later. So sheep, in respect of their small heat, generate about the same time, or somewhat before. But for the most part, creatures that generate at certain seasons, generate in the spring; as birds and fishes; for that the end of the winter, and the heat and comfort of the spring prepareth them. There is also another reason why some creatures generate at certain seasons; and that is the relation of their time of bearing to the time of generation; for no creature goeth to generate whilst the female is full; nor whilst she is busy in sitting, or rearing her young. And therefore it is found by experience, that if you take the eggs or young ones out of the nests of birds, they will fall to generate again three or four times one after another. 759. Of living creatures, some are longer time in the womb, and some shorter. Women go commonly nine months; the cow and the ewe about six months; does go about nine months; mares eleven months; bitches nine weeks; elephants are said to go two years; for the received tradition of ten years is fabulous. For birds there is double inquiry; the distance between the treading or coupling, and the laying of the egg; and again, between the egg laid, and the disclosing or hatching. And amongst birds, there is less diversity of time than amongst other creatures; yet some there is; for the hen sitteth but three weeks, the turkey-hen, goose, and duck, a month: Query, of others. The cause of the great difference of times amongst living creatures is, either from the nature of the kind, or from the constitution of the womb. For the former, those that are longer in coming to their maturity or growth are longer in the womb; as is chiefly seen in men: and so elephants, which are long in the womb, are long time in coming to their full growth. But in most other kinds, the constitution of the womb, that is, the hardness or dryness thereof, is concurrent with the former cause. For the colt hath about four years of growth; and so the fawn; and so the calf. But whelps, which come to their growth, commonly, within three quarters of a year, are but nine weeks in the womb. As for birds, as there is less diversity amongst them in the time of their bringing forth; so there is less diversity in the time of their growth: most of them coming to their growth within a twelvemonth. 760. Some creatures bring forth many young ones at a burden: as bitches, hares, conies, &c. Some ordinarily but one; as women, lionesses, &c. This may be caused, either by the quantity of sperm required to the producing one of that kind; which if less be required, may admit greater number; if more, fewer or by the partitions and cells of the impulsion there is requisite the force of the body womb, which may sever the sperm. Experiments in consort touching species visible. 761. There is no doubt, but light by refraction will show greater, as well as things coloured. For like as a shilling in the bottom of the water will show greater; so will a candle in a lanthorn, in the bottom of the water. I have heard of a practice, that glowworms in glasses were put in the water to make the fish come. But I am not yet informed, whether when a diver diveth, having his eyes open, and swimmeth upon his back; whether, I say, he seeth things in the air, greater or less. For it is manifest, that when the eye standeth in the finer medium, and the object is in the grosser, things show greater: but contrariwise, when the eye is placed in the grosser medium, and the object in the finer, how it worketh I know not. that moveth, and the resistance of the body that is moved and if the body be too great, it yieldeth too little; and if it be too small, it resisteth too little. 765. It is common experience, that no weight will press or cut so strong, being laid upon a body, as falling or strucken from above. It may be the air hath some part in farthering the percussion ; but the chief cause I take to be, for that the parts of the body moved have by impulsion, or by the motion of gravity continued, a compression in them, as well downwards, as they have when they are thrown, or shot through the air, forwards. I conceive also, that the quick loss of that motion preventeth the resistance of the body below; and priority of the force always is of great efficacy, as appeareth in infinite instances. Experiment solitary touching titillation. The 766. Tickling is most in the soles of the feet, and under the arm-holes, and on the sides. cause is the thinness of the skin in those parts, joined with the rareness of being touched there : for all tickling is a light motion of the spirits, which the thinness of the skin, and suddenness and rareness of touch do farther: for we see a feather, or a rush, drawn along the lip or cheek, doth tickle; whereas a thing more obtuse, or a touch more hard, doth not. And for suddenness, we see no man can tickle himself: we see also that the palm of the hand, though it hath as thin a skin as the other parts mentioned, yet is not ticklish, because it is accustomed to be touched. Tickling also causeth laughter. The cause may be the emission of the spirits, and so of the breath, by a flight from titillation; for upon tickling we see there is ever a starting or 762. It would be well bolted out, whether great refractions may not be made upon reflexions, as well as upon direct beams. For example, we see, that take an empty bason, put an angel of gold, or what you will, into it; then go so far from the bason, till you cannot see the angel, because it is not in a right line; then fill the bason with water, and you shall see it out of its place, because of the reflexion. To proceed therefore, put a looking-glass into a bason of water; I suppose you shall not see the image in a right line, or at equal angles, but aside. I know not whether this experiment may not be extended so, as you might see the image, and not the glass; which for beauty and strangeness were a fine proof: for then you should see the image like a spirit in the air. As for example, if there be a cistern or pool of water, you shall place over against it a picture of the devil, or what you will, so as you do not see the water. Then put a look-shrinking away of the part to avoid it; and we see ing-glass in the water: now if you can see the devil's picture aside, not seeing the water, it would look like a devil indeed. They have an old tale in Oxford, that Friar Bacon walked between two steeples; which was thought to be done by glasses, when he walked upon the ground. Experiments in consort touching impulsion and percussion. 763. A weighty body put into motion is more easily impelled than at first when it resteth. The cause is, partly because motion doth discuss the torpor of solid bodies; which beside their motion of gravity, have in them a natural appetite not to move at all; and partly, because a body that resteth, doth get, by the resistance of the body upon which it resteth, a stronger compression of parts than it hath of itself: and therefore needeth more force to be put in motion. For if a weighty body be pensile, and hang but by a thread, the percussion will make an impulsion very near as easily as if it were already in motion. 764. A body over-great or over-small, will not be thrown so far as a body of a middle size: so that, it seemeth, there must be a commensuration, or proportion between the body moved and the force, to make it move well. The cause is, because to the also, that if you tickle the nostrils with a feather, Experiment solitary touching the scarcity of rain in 767. It is strange, that the river of Nilus overflowing, as it doth, the country of Egypt, there should be, nevertheless, little or no rain in that country. The cause must be either in the nature of the water, or in the nature of the air, or of both. In the water, it may be ascribed either unto the long race of the water; for swift-running waters vapour not so much as standing waters; or else to the concoction of the water; for waters well concocted vapour not so much as waters raw; no more than waters upon the fire do vapour so much after some time of boiling as at the first. And it is true that the water of Nilus is sweeter than other waters in taste; and it is excellent good for the stone, and hypochondriacal melancholy, which showeth it is lenifying; and it runneth through a country of a hot climate, and flat, without shade, either of woods or hills, whereby the sun must needs have great power to concoct it. As for the air, from whence I conceive this want of showers cometh chiefly, | periment concerning annihilation; namely, that if the cause must be, for that the air is of itself thin you provide against three causes of putrefaction, and thirsty; and as soon as ever it getteth any mois- bodies will not corrupt: the first is, that the air ture from the water, it imbibeth and dissipateth it be excluded, for that undermineth the body, and in the whole body of the air, and suffereth it not to conspireth with the spirit of the body to dissolve it. remain in vapour, whereby it might breed rain. The second is, that the body adjacent and ambient be not commaterial, but merely heterogeneal towards the body that is to be preserved; for if nothing can be received by the one, nothing can issue from the other; such are quicksilver and white amber, to herbs, and flies, and such bodies. The third is, that the body to be preserved be not of that gross that it may corrupt within itself, although no part of it issue into the body adjacent and therefore it must be rather thin and small, than of bulk. There is a fourth remedy also, which is, that if the body to be preserved be of bulk, as a corpse is, then the body that encloseth it must have a virtue to draw forth, and dry the moisture of the inward Experiment solitary touching clarification. 768. It hath been touched in the title of percolations, namely, such as are inwards, that the whites of eggs and milk do clarify; and it is certain, that in Egypt they prepare and clarify the water of Nile, by putting it into great jars of stone, and stirring it about with a few stamped almonds, wherewith they also besmear the mouth of the vessel; and so draw it off, after it hath rested some time. It were good to try this clarifying with almonds in new beer, or muste, to hasten and perfect the clarifying. Experiment solitary touching plants without leaves. Experiment solitary touching the materials of glass. body; for else the putrefaction will play within, though nothing issue forth. I remember Livy doth relate, that there were found at a time two coffins of lead in a tomb; whereof the one contained the body of king Numa, it being some four hundred years after his death: and the other, his books of sacred rites and ceremonies, and the discipline of the pontiffs; and that in the coffin that had the body, there was nothing at all to be seen, but a little light cinders about the sides; but in the coffin that had the books, they were found as fresh as if they had been but newly written, being written on parchment, and covered over with watch-candles of wax three or four fold. By this it seemeth that the Romans in Numa's time were not so good embalmers as the Egyptians were; which was the cause that the body was utterly consumed. But I find in Plutarch, and others, that when Augustus Cæsar visited the sepulchre of Alexander the Great in Alexandria, he found the body to keep its dimension; but withal, that notwithstanding all the embalming, which no doubt was of the best, the body was so tender, as Cæsar, touching but the nose of it, defaced it. Which maketh me find it very strange, that the Egyptian mummies should be reported to be as hard as stonepitch; for I find no difference but one, which indeed may be very material; namely, that the ancient Egyptian mummies were shrowded in a number of folds of linen, besmeared with gums, in manner of sear-cloth, which it doth not appear was practised upon the body of Alexander. Experiment solitary touching the abundance of nitre in certain sea-shores. 772. Near the castle of Caty, and by the wells of Assan, in the land of Idumea, a great part of the way you would think the sea were near at hand, though it be a good distance off: and it is nothing but the shining of the nitre upon the sea sands, such abundance of nitre the shores there do put forth. Experiment solitary touching bodies that are borne up by water. 773. The Dead sea, which vomiteth up bitumen, is of that crassitude, as living bodies bound hand and foot cast into it have been borne up, and not sunk; which showeth, that all sinking into water is but an over-weight of the body put into the water in respect of the water; so that you may make water so strong and heavy, of quicksilver, perhaps, or the like, as may bear up iron; of which I see no use, but imposture. We see also, that all metals, except gold, for the same reason, swim upon quicksilver. Experiment solitary touching fuel that consumeth little or nothing. 774. It is reported, that at the foot of the hill near the Mare mortuum there is a black stone, whereof pilgrims make fires, which burneth like a coal, and diminisheth not, but only waxeth brighter and whiter. That it should do so is not strange : for we see iron red-hot burneth, and consumeth not; but the strangeness is, that it should continue any time so for iron, as soon as it is out of the fire, deadeth straightways. Certainly it were a thing of great use and profit, if you could find out fuel that would burn hot, and yet last long: neither am I altogether incredulous, but there may be such candles as they say are made of salamander's wool; being a kind of mineral, which whiteneth also in the burning, and consumeth not. The question is this; flame must be made of somewhat, and commonly it is made of some tangible body which hath weight: but it is not impossible perhaps that it should be made of spirit, or vapour, in a body, which spirit or vapour hath no weight, such as is the matter of ignis fatuus. But then you will say, that that vapour also can last but a short time: to that it may be answered, that by the help of oil, and wax, and other candle-stuff, the flame may continue, and the wick not burn. Experiment solitary œconomical touching cheap fuel. 775. Sea-coal lasts longer than charcoal; and charcoal of roots, being coaled into great pieces, lasts longer than ordinary charcoal. Turf and peat, and cow-sheards, are cheap fuels, and last long. Small coal, or brier-coal, poured upon charcoal, make them last longer. Sedge is a cheap fuel to brew or bake with the rather because it is good for nothing else. Trial would be made of some mixture of sea-coal with earth or chalk; for if that mixture be, as the sea-coal men use it, privily, to make the bulk of the coal greater, it is deceit; but if it be used purposely, and be made known, it is saving. Experiment solitary touching the gathering of wind for freshness. : 776. It is at this day in use in Gaza, to couch potsherds or vessels of earth in their walls, to gather the wind from the top, and to pass it down in spouts into rooms. It is a device for freshness in great heats and it is said, there are some rooms in Italy and Spain for freshness, and gathering the winds and air in the heats of summer; but they be but pennings of the winds, and enlarging them again, and making them reverberate, and go round in circles, rather than this device of spouts in the wall. Experiment solitary touching the trials of airs. 777. There would be used much diligence in the choice of some bodies and places, as it were, for the tasting of air; to discover the wholesomeness or unwholesomeness, as well of seasons, as of the seats of dwellings. It is certain, that there be some houses wherein confitures and pies will gather mould more than in others. And I am persuaded, that a piece of raw flesh or fish will sooner corrupt in some airs than in others. They be noble experiments that can make this discovery; for they serve for a natural divination of seasons, better than the astronomers can by their figures: and again, they teach men where to choose their dwelling for their better health. Experiment solitary touching increasing of milk in milch beasts. 779. It is reported, that in the valley near the mountain Carmel in Judea there is a sand, which of all other hath most affinity with glass: insomuch as other minerals laid in it turn to a glassy substance without the fire; and again, glass put into it turneth into the mother sand. The thing is very strange, if it be true: and it is likeliest to be caused by some natural furnace or heat in the earth: and yet they do not speak of any eruption of flames. were good to try in glass-works, whether the crude materials of glass, mingled with glass already made, and re-molten, do not facilitate the making of glass with less heat. Experiment solitary touching the growth of coral. It 780. In the sea, upon the south-west of Sicily, much coral is found. It is a submarine plant. It hath no leaves: it brancheth only when it is under water; it is soft, and green of colour; but being brought into the air, it becometh hard and shining red, as we see. It is said also to have a white berry; but we find it not brought over with the coral. Belike it is cast away as nothing worth: inquire better of it, for the discovery of the nature of the plant. Experiment solitary touching the gathering of manna. 781. The manna of Calabria is the best, and in most plenty. They gather it from the leaf of the mulberry-tree; but not of such mulberry-trees as grow in the valleys. And manna falleth upon the leaves by night, as other dews do. It should seem, that before those dews come upon trees in the val |