knoweth, that except he do it, nothing will be done: men are so set to despise the means of their own good. And as for the baseness of many of the experiments; as long as they be God's works, they are honourable enough. And for the vulgarness of them, true axioms must be drawn from plain experience and not from doubtful; and his lordship's course is to make wonders plain, and not plain thing wonders; and that experience likewise must be broken and grinded, and not whole, or as it groweth. And for use; his lordship hath often in his mouth the two kinds of experiments; experimenta fructifera, and experimenta lucifera: experiments of use, and experiments of light and he reporteth himself, whether he were not a strange man, that should think that light hath no use, because it hath no matter. Further his lordship thought good also to add unto many of the experiments themselves some gloss of the causes; that in the succeeding work of interpreting nature, and framing axioms, all things be in more readiness. And for the causes herein by him assigned; his lordship persuadeth himself, they are far more certain than those that are rendered by others; not for any excellency of his own wit, as his lordship is wont to say, but in respect of his continual conversation with nature and experience. He did consider likewise, that by this addition of causes, mens minds, which make so much haste to find out the causes of things, would not think themselves utterly lost in a vast wood of experience, but stay upon causes, such as they are, a little, till true axioms may be more fully discovered. I have heard his lordship say also, that one great reason, why he would not put these particulars into any exact method, though he may these that looketh attentively into them shall find that they have a secret order, was, because he conceived that other men would now think that they could do the like; and so go on with a further collection: which, if the method had been exact, many would have despaired to attain by imitation. As for his lordship's love of order, I can refer any man to his lordship's Latin Book, "De Augmentis Scientiarum ; " which, if my judgment be any thing, is written in the exactest order that I know any writing to be. I will conclude with an usual speech of his lordship's: That this work of his Natural History is the World as God made it, and not as men have made it; for that it hath nothing of imagination. W. RAWLEY. This epistle is the same, that should have been prefixed to this book, if his lordship had lived. NATURAL HISTORY. CENTURY I. Experiments in consort, touching the straining and passing of bodies one through another; which they call Percolation. DIG a pit upon the sea-shore, somewhat above the high water-mark, and sink it as deep as the low-water mark; and as the tide cometh in, it will fill with water, fresh and potable. This is commonly practised upon the coast of Barbary, where other fresh water is wanting. And Cæsar knew this well when he was besieged in Alexandria for by digging of pits in the sea-shore, he did frustrate the laborious works of the enemies, which had turned the sea-water upon the wells of Alexandria; and so saved his army being then in desperation. But Cæsar mistook the cause, for he thought that all sea-sands had natural springs of fresh water: but it is plain, that it is the sea-water: because the pit filleth according to the measure of the tide; and the sea-water passing or straining through the sands, leaveth the saltness. 2. I remember to have read, that trial hath been made of salt-water passed through earth, through ten vessels, one within another; and yet it hath not lost its saltness, as to become potable: but the same man saith, that, by the relation of another, salt-water drained through twenty vessels hath become fresh. This experiment seemeth to cross that other of pits made by the sea-side; and yet but in part, if it be true that twenty repetitions do the effect. But it is worth the note, how poor the imitations of nature are in common course of experiments, except they be led by great judgment, and some good light of axioms. For first, there is no small difference between a passage of water through twenty small vessels, and through such a distance, as between the low-water and high-water mark. Secondly, there is a great difference between earth and sand; for all earth hath in it a kind of nitrous salt, from which sand is more free; and besides, earth doth not strain the water so finely as sand doth. But there is a third point, that I suspect as much or more than the other two; and that is, that in the experiment of transmission of the sea-water into the pits, the water riseth; but in the experiment of transmission of the water through the vessels, it falleth. Now certain it is that the salter part of water, once salted throughout, goeth to the bottom. And therefore no marvel, if the draining of water by descent doth not make it fresh besides, I do somewhat doubt, that the very dashing of the water, that cometh from the sea, is more proper to strike off the salt part, than where the water slideth of its own motion. 3. It seemeth percolation, or transmission, which is commonly called straining, is a good kind of separation, not only of thick from thin, and gross from fine, but of more subtile natures; and varieth according to the body through which the transmission is made: as if through a woollen bag, the liquor leaveth the fatness; if through sand, the saltness, etc. They speak of severing wine from water, passing it through ivy wood, or through other the like porous body; but non constat. 4. The gum of trees, which we see to be commonly shining and clear, is but a fine passage or straining of the juice of the tree through the wood and bark. And in like manner, Cornish diamonds, and rock rubies, which are yet more resplendent than gums, are the fine exudations of stone. 5. Aristotle giveth the cause, vainly, why the feathers of birds are of more lively colours than the hairs of beasts; for no beast hath any fine azure, or carnation, or green hair. He saith, it is because birds are more in the beams of the sun than beasts; but that is manifestly untrue; for cattle are more in the sun than birds, that live commonly in the woods, or in some covert. The true cause is, that the excrementitious moisture of living creatures, which maketh as well the feathers in birds, as the hair in beasts, passeth in birds through a finer and more delicate strainer than it doth in beasts: for feathers pass through quills; and hair through skin. 6. The clarifying of liquors by adhesion, is an inward percolation; and is effected, when some cleaving body is mixed and agitated with the liquors; whereby the grosser part of the liquor sticks to that cleaving body; and so the finer parts are freed from the grosser. So the apothecaries clarify their syrups by whites of eggs, beaten with the juices which they would clarify; which whites of eggs gather all the dregs and grosser parts of the juice to them; and after the syrup being set on the fire, the whites of eggs themselves harden, and are taken forth. So hippocras is clarified by mixing with milk, and stirring it about, and then passing it through a woollen bag, which they call Hippocrates's Sleeve, and the cleaving nature of the milk draweth the powder of the spices, and grosser parts of the liquor to it; and in the passage they stick upon the woollen bag. 7. The clarifying of water is an experiment tending to health; besides the pleasure of the eye, when water is crystalline. It is effected by casting in and placing pebbles at the head of the current, that the water may strain through them. 8. It may be, percolation doth not only cause clearness and splendour, but sweetness of savour; for that also followeth as well as clearness, when the finer parts are severed from the grosser. So it is found, that the sweats of men, that have much heat, and exercise much, and have clean bodies, and fine skins, do smell sweet; as was said of Alexander; and we see commonly that gums have sweet odours. Experiments in consort, touching motion of bodies upon their pressure. 9. Take a glass, and put water into it, and wet your finger, and draw it round about the lip of the glass, |