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 if flame of his 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 his 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.

of ten

32. Take an arrow, and hold it in flame for the space 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 his own place and not irritate, is but of a moderate heat.

Experiment solitary touching the decrease of the natural motion of gravity in great distance from the earth, or within some depth of the earth.

33. It is affirmed constantly by many, as an usual experiment, that a lump of ore in the bottom of a mine will be tumbled and stirred by two men's strength, which if you bring it to the top of the earth, will ask six men's strength at

The real reason is, that the air has freer access to the external parts of the wood, VOL. II.

A A

the least to stir it. It is a noble instance, and is fit to be tried to the full. For it is very probable that the motion of gravity worketh weakly both far from the earth and also within the earth: the former, because the appetite of union of dense bodies with the earth, in respect of the distance, is more dull: the latter, because the body hath in part attained his nature when it is some depth in the earth. For as for the moving to a point or place (which was the opinion of the ancients) it is a mere vanity.'

Experiment solitary touching the contraction of bodies in bulk, by the mixture of the more liquid body with the more solid.

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.2 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 room.

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, &c. The cause may be, for that the kernels draw out of the earth juice fit to nourish the tree, as those that would be trees of themselves, though there were no root; but the root being of greater strength, robbeth and

1 Bodies weigh less at the bottom of a mine than on the earth's surface, though of course the difference is not so great as Bacon supposed. The explanation is, that the shell external to the body exerts no attraction on it, and the body may therefore be conceived of, as lying on the surface of a smaller ellipsoid. This at least would be the case if the shell were perfectly homogeneous.

2 Arist. Prob. xxv. 8. It has been found by Messrs. Playfair and Joule that the solution of many salts in water, e. g. of alum, increases the volume of the water simply by that of the water of crystallisation they contain; which is a curious approximation to Aristotle's notion.

devoureth the nourishment, when they have drawn it; as great fishes devour little.

sent.

Experiments in consort touching purging medicines.

36. The operation of purging medicines, and the causes thereof, have been thought to be a great secret; and so according to the slothful manner of men, it is referred to a hidden propriety, a specifical virtue, and a fourth quality', and the like shifts of ignorance. The causes of purging are divers: all plain and perspicuous, and throughly maintained by experience. The first is, that whatsoever cannot be overcome and digested by the stomach, is by the stomach either put up by vomit, or put down to the guts; and by that motion of expulsion in the stomach and guts, other parts of the body (as the orifices of the veins, and the like) are moved to expel by conFor nothing is more frequent than motion of consent in the body of man. This surcharge of the stomach is caused either by the quality of the medicine, or by the quantity. The qualities are three: extreme bitter, as in aloes, coloquintida, &c.; loathsome and of horrible taste, as in agaric, black hellebore, &c.; and of secret malignity and disagreement towards man's body, many times not appearing much in the taste; as in scammony, mechoacham2, antimony, &c. And note well, that if there be any medicine that purgeth, and hath neither of the first two manifest qualities, it is to be held suspected as a kind of poison; for that it worketh either by corrosion, or by a secret malignity and enmity to nature; and therefore such medicines are warily to be prepared and used. The quantity of that which is taken doth also cause purging; as we see in a great quantity of new milk from the cow; yea, and a great quantity of meat; for surfeits many times turn to purges, both upwards and downwards. Therefore we see generally, that the working of purging medicines cometh two or three hours after the medicines taken; for that the stomach

That is, an occult quality not explicable by the combination of the primary qualities of the elements of which the body is composed. Occult qualities are often called tertiary, but Bacon apparently supposes that tertiary qualities are those which result from combinations of the secondary, and therefore ultimately from the four primary or elementary qualities, namely hot, cold, moist, and dry.

2 Mechoachan is the root of an American plant; it takes its name from the district of Mexico from which it is brought. See Frampton's Joyful News out of the new found World, (1577) p. 23. Frampton's work is only a translation of that of Nicolas Monardes, of which a Latin translation by Clusius was published in 1574. I have not seen the original work, which is in Spanish. The title of Clusius's translation is De simplicibus medicam. ex occident. India delatis.

first maketh a proof whether it can concoct them. And the like happeneth after surfeits, or milk in too great quantity.

37. A second cause is mordication of the orifices of the parts; especially of the mesentery veins; as it is seen that salt, or any such thing that is sharp and biting, put into the fundament, doth provoke the part to expel; and mustard provoketh sneezing; and any sharp thing to the eyes provoketh tears. And therefore we see that almost all purgers have a kind of twitching and vellication, besides the griping which cometh of wind. And if this mordication be in an over-high degree, it is little better than the corrosion of poison; and it cometh to pass sometimes in antimony, especially if it be given to bodies not replete with humours; for where humours abound, the humours save the parts.

38. The third cause is attraction: for I do not deny, but that purging medicines have in them a direct force of attraction; as drawing plaisters have in surgery: and we see sage or bettony bruised, sneezing-powder, and other powders or liquors (which the physicians call errhines) put into the nose, draw phlegm and water from the head; and so it is in apophlegmatisms and gargarisms, that draw the rheum down by the palate. And by this virtue, no doubt, some purgers draw more one humour, and some another, according to the opinion received: as rhubarb draweth choler; sean melancholy; agaric phlegm, &c. But yet (more or less) they draw promiscuously. And note also, that besides sympathy between the purger and the humour, there is also another cause why some medicines draw some humour more than another. And it is, for that some medicines work quicker than others: and they that draw quick, draw only the lighter and more fluid humours; they that draw slow, work upon the more tough and viscous humours. And therefore men must beware how they take rhubarb and the like, alone, familiarly; for it taketh only the lightest part of the humour away, and leaveth the mass of humours more obstinate. And the like may be said of wormwood, which is so much magnified.

39. The fourth cause is flatuosity: for wind stirred moveth to expel: and we find that (in effect) all purgers have in them a raw spirit or wind; which is the principal cause of tortion in the stomach and belly. And therefore purgers leese (most of them) the virtue, by decoction upon the fire; and for that cause are given chiefly in infusion, juice, or powder.

40. The fifth cause is compression or crushing; as when water is crushed out of a sponge; so we see that taking cold moveth looseness by contraction of the skin and outward parts; and so doth cold likewise cause rheums and defluxions from the head; and some astringent plaisters crush out purulent matter. This kind of operation is not found in many medicines. Myrobalanes have it; and it may be the barks of peaches for this virtue requireth an astriction; but such an astriction as is not grateful to the body; (for a pleasing astriction doth rather bind in the humours than expel them): and therefore such astriction is found in things of an harsh'

taste.

41. The sixth cause is lubrefaction and relaxation. As we see in medicines emollient; such as are milk, honey, mallows, lettuce, mercurial, pellitory of the wall, and others. There is also a secret virtue of relaxation in cold; for the heat of the body bindeth the parts and humours together, which cold relaxeth; as it is seen in urine, blood, pottage, or the like; which, if they be cold, break and dissolve. And by this kind of relaxation, fear looseneth the belly: because the heat retiring inwards towards the heart, the guts and other parts are relaxed; in the same manner as fear also causeth trembling in the sinews. And of this kind of purgers are some medicines made of mercury.

42. The seventh cause is abstersion; which is plainly a scouring off, or incision of the more viscous humours, and making the humours more fluid; and cutting between them and the part. As is found in nitrous water, which scoureth linen cloth (speedily) from the foulness. But this incision must be by a sharpness without astriction: which we find in salt, wormwood, oxymel, and the like.

43. There be medicines that move stools, and not urine; some other, urine and not stools. Those that purge by stool, are such as enter not at all, or little, into the mesentery veins ; but either at the first are not digestible by the stomach, and therefore move immediately downwards to the guts; or else are afterwards rejected by the mesentery veins, and so turn likewise downwards to the guts; and of these two kinds are most purgers. But those that move urine, are such as are

Harrish in the original, both here and in several other places; though no always. But 1 u, pose it is only another way of spelling harsh.-J. S.