« PreviousContinue »
Experiment solitary touching the condensing of air
in such sort as it may put on weight, and yield nourishment.
29. Onions, as they hang, will many of them shoot forth ; and so will penny-royal ; and so will an herb called orpin; with which they use in the country to trim their houses, binding it to a lath or stick, and setting it against a wall. We see it likewise, more especially, in the greater semper-vive, which will put out branches, two or three years: but it is true, that commonly they wrap the root in a cloth besmeared with oil, and renew it once in half a year. The like is reported by some of the ancients, of the stalks of lilies. The cause is; for that these plants have a strong, dense, and succulent moisture, which is not apt to exhale; and so is able, from the old store, without drawing help from the earth, to suffice the sprouting of the plant: and this sprouting is chiefly in the late spring, or early summer; which are the times of putting forth. We see also, that stumps of trees lying out of the ground, will put forth sprouts for a time. But it is a noble trial, and of very great consequence, to try whether these things, in the sprouting, do increase weight; which must be tried, by weighing them before they be hanged up; and afterwards again, when they are sprouted. For if they increase not in weight, then it is no more but this ; that what they send forth in the sprout, they lose in some other part: but if they gather weight, then it is magnale nature; for it sheweth that air may be made so to be condensed, as to be converted into a dense body; whereas the race and period of all things, here above the earth, is to extenuate and turn things to be more pneumatical and rare; and not to be retrograde, from pneumatical to that which is dense. It sheweth also, that air can nourish; which is another great matter of consequence. Note, that to try this, the experiment of the semper-vive must be made without oiling the cloth; for else, it may be, the plant receiveth nourishment from the oil.
Experiment solitary touching the commixture of flame
and air, and the great force thereof. 30. FLAME and air do not mingle, except it be in an instant; or in the vital spirits of vegetables and living creatures. In gunpowder, the force of it hath been ascribed to rarefaction of the earthy substance into flame; and thus far it is true: and then, forsooth, it is become another element; the form whereof occupieth more place; and so; of necessity, followeth a dilatation : and therefore, lest two bodies should be in one place, there must needs also follow an expulsion of the pellet; or blowing up of the mine. But these are crude and ignorant speculations. For flame, if there were nothing else, except it were "in very great quantity, will be suffocate with any hard body, such as a pellet is; or the barrel of a gun; so as the flame would not expel the hard body; but the hard body would kill the flame, and not suffer it to kindle or spread. But the cause of this so potent a motion, is the nitre, which we call otherwise saltpetre, which having in it a notable crude and windy spirit, first by the heat of the fire suddenly dilateth itself; and we know that simple air, being preternaturally attenuated by heat, will make itself room, and break and blow
up that which resisteth it; and secondly, when the nitre hath dilateth itself, it bloweth abroad the flame, as an inward bellows. And therefore we see that brimstone, pitch, camphire, wild-fire, and divers other inflammable matters, though they burn cruelly, and are hard to quench, yet they make no such fiery wind as gunpowder doth: and on the other side, we see that quicksilver, which is a most crude and watery body, heated, and pent in, hath the like force with gunpowder. As for living creatures, it is certain, their vital spirits are a substance compounded of an airy and flamy matter; and though air and flame being free, will not well mingle; yet bound in by a body that hath some fixing, they will. For that you may best see in those two bodies, which are their aliments, water and oil; for they likewise will not
well mingle of themselves ; but in the bodies of plants, and living creatures, they will. It is no marvel therefore, that a small quantity of spirits, in the cells of the brain and canals of the sinews, are able to move the whole body, which is of so great mass, both with so great force, as in wrestling, leaping ; and with so great swiftness, as in playing division upon the lute. Such is the force of these two natures, air and flame, when they incorporate. Experiment solitary touching the sacred
nature of flame. 31. TAKE a small wax candle, and put it in a socket of brass or iron; then set it upright in a porringer full of spirit of wine heated : then set both the candle and spirit of wine on fire, and you shall see the flame of the candle open itself, and become four or five times bigger than otherwise it would have been; and appear in figure globular, and not in pyramis. You shall see also, that the inward flame of the candle keepeth colour, and doth not wax any whit blue towards the colour of the outward flame of the spirit of wine. This is a noble instance; wherein two things are most remarkable: the one, that one flame within another quencheth not; but is a fixed body, and continueth as air or water do. And therefore flame would still ascend upwards in one greatness, if it were not quenched on the sides : and the greater the flame is at the bottom, the higher is the rise. The other, that flame doth not mingle with flame, as air doth with air, or water with water, but only remaineth contiguous; as it cometh to pass betwixt consisting bodies, It appeareth also, that the form of a pyramis in flame, which we usually see, is merely by accident, and that the air about, by quenching the sides of the flame, crusheth it, and extenuateth it into that form ; for of itself it would be round : and therefore smoke is in the figure of a pyramis reversed; for the air quencheth the flame, and receiveth the smoke. Note also, that the flame of the candle, within the flame of the spirit of wine is troubled; and doth not only open and move upwards, but moveth waving, and to and fro; as ii flame of its own nature, if it were not quenched, would roll and turn, as well as move upwards. By all which it should seem, that the celestial bodies, most of them, are true fires or flames, as the Stoics held; more fine, perhaps, and rarified than our flame is. For they are all globular and determinate; they have rotation; and they have the colour and splendour of flame : so that flame above is durable and consistent, and in its natural place; but with us it is a stranger, and momentany, and impure; like Vulcan that halted with his fall. Experiment solitary touching the different force of flame in the midst and on the
sides. 32. TAKE an arrow, and hold it in flame for the space of ten pulses, and when it cometh forth, you shall find those parts of the arrow which were on the outsides of the flame more burned, blacked, and turned almost into a coal, whereas that in the midst of the flame will be as if the fire had scarce touched it. This is an instance of great consequence for the discovery of the nature of flame; and sheweth manifestly, that flame burneth more violently towards the sides than in the midst : and, which is more, that heat or fire is not violent or furious, but where it is checked and pent. And therefore the Peripatetics, howsoever their opinion of an element of fire above the air is justly exploded, in that point they acquit themselves well: for being opposed, that if there were a sphere of fire, that encompassed the earth so near hand, it were impossible but all things should be burnt up; they answer, that the pure elemental fire, in its own place, and not irritated, is but of a moderate heat.
Experiment solitary touching the decrease of the natu
ral motion of gravity, in great distance from the earth; or within some depth of the earth.
33. It is affirmed constantly by many, as a usual experiment; that a lump of ore, in the bottom of a
mine, will be tumbled and stirred by two men's
in bulk, by the mixture of the more liquid body with
34. It is strange how the ancients took up experiments upon credit, and yet did build great matters upon them. The observation of some of the best of . them, delivered confidently, is, that a vessel filled with ashes will receive the like quantity of water, that it would have done if it had been empty. But this is utterly untrue, for the water will not go in by a fifth part. And I suppose, that that fifth part is the difference of the lying close, or open, of the ashes; as we see that ashes alone, if they be hard pressed, will lie in less room : and so the ashes with air between, lie looser; and with water, closer. For I have not yet found certainly, that the water itself, by mixture of ashes or dust, will shrink or draw into less
Experiment solitary touching the making vines
more fruitful. 35. It is reported of credit, that if you lay good store of kernels of grapes about the root of a vine, it will make the vine come earlier and prosper better. It may
be tried with other kernels laid about the root of a plant of the same kind; as figs, kernels of apples, etc. The cause may be, for that the kernels draw out