proper alternation, series, and succession of all Any bodies, however, can easily be suspended these, or at least of some of them.

I. With regard to the first; common air, which is always at hand, and forces its admission, as also the rays of the heavenly bodies, create much disturbance. Whatever, therefore, tends to exclude them, may well be considered as generally useful. The substance and thickness of vessels in which bodies are placed when prepared for operations may be referred to this head. So, also, may the accurate methods of closing vessels by consolidation, or the latum sapientiæ, as the chymists call it. The exclusion of air by means of liquids at the extremity, is also very useful; as, when they pour oil on wine, or the juices of herbs, which, by spreading itself upon the top, like a cover, preserves them uninjured from the air. Powders, also, are serviceable, for, although they contain air mixed up in them, yet they ward off the power of the mass of circumambient air, which is seen in the preservation of grapes, and other fruits, in sand and flour. Wax, honey, pitch, and other resinous bodies, are well used in order to make the exclusion more perfect, and to remove the air and celestial influence. We have sometimes made an experiment, by placing a vessel or other bodies in quicksilver, the most dense of all substances capable of being poured round others. Grottos and subterraneous caves are of great use in keeping off the effects of the sun, and the predatory action of air, and, in the north of Germany, are used for granaries. The depositing of bodies at the bottom of water may be also mentioned here, and I remember having heard of some bottles of wine being let down into a deep well in order to cool them, but left there by chance, carelessness, and forgetfulness, for several years, and then taken out; by which means, the wine not only escaped becoming flat or dead, but was much more excellent in flavour; arising (as it appears) from a more complete mixture of its parts. But, if the case require that bodies should be sunk to the bottom of water, as in rivers, or the sea, and yet should not touch the water, nor be enclosed in sealed vessels, but surrounded only by air, it would be right to use that vessel which has been sometimes employed under water, above ships that have sunk, in order to enable the divers to remain below and breathe occasionally by turns. It was of the following nature. A hollow tub of metal was formed, and sunk so as to have its bottom parallel with the surface of the water; it thus carried down with it to the bottom of the sea all the air contained in the tub. It stood upon three feet, (like a tripod,) being of rather less height than a man, so that when the diver was in want of breath, he could put his head into the hollow of the tub, breathe, and then continue his work. We hear that some sort of boat or vessel has now been invented, capable of carrying men some distance under water.

under some such vessel as we have mentioned, which has occasioned our remarks upon the experiment.

Another advantage of the careful and hermetical closing of bodies is this; not only the admission of external air is prevented, (of which we have treated,) but the spirit of bodies also is prevented from making its escape, which is an internal operation. For any one operating on natural bodies must be certain as to their quantity, and that nothing has evaporated or escaped; since profound alterations take place in bodies, when art prevents the loss or escape of any portion, whilst nature prevents their annihilation. With regard to this circumstance, a false idea has prevailed, (which, if true, would make us despair of preserving quantity without diminution,) namely, that the spirit of bodies, and air when rarefied by a great degree of heat, cannot be so kept in by being enclosed in any vessel, as not to escape by the small pores. Men are led into this idea by common experiments of a cup inverted over water, with a candle or piece of lighted paper in it, by which the water is drawn up, and of those cups which when heated draw up the flesh. For they think that in each experiment the rarefied air escapes, and that its quantity is therefore diminished, by which means the water or flesh rises by the motion of connexion. This is, however, most incorrect. For the air is not diminished in quantity, but contracted in dimensions,* nor does this motion of the rising of the water begin till the flame is extinguished, or the air cooled, so that physicians place cold sponges, moistened with water, on the cups, in order to increase their attraction. There is, therefore, no reason why men should fear much from the ready escape of air: for, although it be true that the most solid bodies have their pores, yet neither air nor spirit readily suffers itself to be rarefied to such an extreme degree; just as water will not escape by a small chink.

II. With regard to the second of the seven above mentioned methods, we must especially observe, that compression and similar violence have a most powerful effect either in producing locomotion, and other motions of the same nature, as may be observed in engines and projectiles, or in destroying the organic body and those qualities which consist entirely in motion, (for all life, and every description of flame and ignition are destroyed by compression, which also injures and deranges every machine;) or in destroying those qualities which consist in position and a coarse difference of parts, as in colours; for the

* Part of the air is expanded and escapes, and part is consumed by the flame. When condensed, therefore, by the cold application, it cannot offer sufficient resistance to the external atmosphere to prevent the liquid or flesh from being forced into the glass.

master of violent motions than of any other means.

colour of a flower when whole differs from that it presents when bruised, and the same may be observed of whole and powdered amber; or in III. The third of our seven methods is referred taste, for the taste of a pear before it is ripe and to that great practical engine of nature as well as of the same pear when bruised and softened is of art, cold and heat. Here man's power limps, different, since it becomes perceptibly more sweet. as it were, with one leg. For we possess the heat But such violence is of little avail in the more of fire, which is infinitely more powerful and innoble transformations and changes of homoge-tense than that of the sun (as it reaches us) and that neous bodies, for they do not, by such means, of animals. But we want cold,* except such as acquire any constantly and permanently new we can obtain in winter, in caverns, or by surstate, but one that is transitory, and always rounding objects with snow and ice, which, perstruggling to return to its former habit and free- haps, may be compared in degree with the noondom. It would not, however, be useless to make tide heat of the sun in tropical countries, increased some more diligent experiments with regard to by the reflection of mountains and walls. For this; whether, for instance, the condensation of this degree of heat and cold can be borne for a a perfectly homogeneous body (such as air, water, short period only by animals, yet it is nothing oil, and the like) or their rarefaction, when effected compared with the heat of a burning furnace, or by violence, can become permanent, fixed, and, the corresponding degree of cold. Every thing as it were, so changed as to become a nature. with us has a tendency to become rarefied, dry, This might at first be tried by simple perse- and wasted, and nothing to become condensed or verance, and then by means of helps and harmo- soft, except by mixtures, and, as it were, spurious nies. It might readily have been attempted, (if methods. Instances of cold, therefore, should be we had but thought of it,) when we condensed searched for most diligently, such as may be found water (as was mentioned above) by hammering by exposing bodies upon buildings in a hard frost, and compression until it burst out. For we in subterraneous caverns, by surrounding bodies ought to have left the flattened globe untouched with snow and ice in deep places excavated for for some days, and then to have drawn off the that purpose, by letting bodies down into wells, water in order to try whether it would have im- by burying bodies in quicksilver and metals, by mediately occupied the same dimensions as it did immersing them in streams which petrify wood, before the condensation. If it had not done so, by burying them in the earth, (which the Chinese either immediately or soon afterwards, the con- are reported to do with their china, masses of densation would have appeared to have been which, made for that purpose, are said to remain rendered constant; if not, it would have appeared in the ground for forty or fifty years, and to be that a restitution took place, and that the con- transmitted to their heirs as a sort of artificial densation had been transitory. Something of the mine,) and the like. The condensations which same kind might have been tried with the glass take place in nature by means of cold should also eggs; the egg should have been sealed up sud-be investigated, that by learning their causes they denly and firmly, after a complete exhaustion of the air, and should have been allowed to remain so for some days, and it might then have been tried whether, on opening the aperture, the air would be drawn in with a hissing noise, or whether as much water would be drawn into it when immersed, as would have been drawn into it at first, if it had not continued sealed. For it is probable (or at least worth making the experiment) that this might have happened, or might happen, because perseverance has a similar effect upon bodies which are a little less homogeneous. A stick bent together for some time does not rebound, which is not owing to any loss of quantity in the wood during the time, for the same would occur (after a larger time) in a plate of steel, which does not evaporate. If the experiment of simple perseverance should fail, the matter should not be given up, but other means should be employed. For it would be no small advantage, if bodies could be endued with fixed and constant natures by violence. Air could then be converted into water by condensation, with other similar effects; for man is more the

may be introduced into the arts; such as are observed in the exudation of marble and stones, in the dew upon the panes of glass in a room towards morning after a frosty night, in the formation and the gathering of vapours under the earth into water, whence spring fountains, and the like.

Besides the substances which are cold to the touch, there are others which have also the effect of cold, and condense; they appear, however, to act only upon the bodies of animals, and scarcely any further. Of these we have many instances, in medicines and plasters. Some condense the flesh and tangible parts, such as astringent and inspissating medicines, others the spirits, such as soporifics. There are two modes of condensing

the degree of cold be of almost any required intensity.

*Heat can now be abstracted by a very simple process, till

It is impossible to compare a degree of heat with a degree of cold, without the assumption of some arbitrary test, to which the degrees are to be referred. In the next sentence Bacon appears to have taken the power of animal life to support heat or cold as the test, and then the comparison can only be between the degree of heat or of cold that will produce death.

The zero must be arbitrary which divides equally a certain degree of heat from a certain degree of cold.

the spirits, by soporifics or provocatives to sleep; the one by calming the motion, the other by expelling the spirit. The violet, dried roses, lettuces, and other benign or mild remedies, by their friendly and gently cooling vapours, invite the spirits to unite, and restrain their violent and perturbed motion. Rose-water, for instance, applied to the nostrils in fainting fits, causes the resolved and relaxed spirits to recover themselves, and, as it were, cherishes them. But opiates, and the like, banish the spirits by their malignant and hostile quality. If they be applied, therefore, externally, the spirits immediately quit the part, and no longer readily flow into it; but if they be taken internally, their vapour, mounting to the head, expels, in all directions, the spirits contained in the ventricles of the brain, and since these spirits retreat, but cannot escape, they consequently meet and are condensed, and are sometimes completely extinguished and suffocated; although the same opiates, when taken in moderation, by a secondary accident, (the condensation which succeeds their union,) strengthen the spirits, render them more robust, and check their useless and inflammatory motion, by which means they contribute not a little to the cure of diseases, and the prolongation of life.

The preparations of bodies, also, for the reception of cold, should not be omitted, such as that water a little warmed is more easily frozen than that which is quite cold, and the like.

for from their investigation, unless the discovery of forms and conformation be attained. With regard to animal bodies, it is not to be questioned that there are many internal and external medicines which condense by harmony, as we have before observed, but this action is rare in inanimate bodies. Written accounts, as well as report, have certainly spoken of a tree in one of the Tercera or Canary Islands (for I do not exactly recollect which) that drips perpetually, so as to supply the inhabitants, in some degree, with water; and Paracelsus says, that the herb called ros solis is filled with dew at noon, whilst the sun gives out its greatest heat, and all other herbs around it are dry. We treat both these accounts as fables; they would, however, if true, be of the most important service, and most worthy of examination. As to the honey-dew, resembling manna, which is found in May on the leaves of the oak, we are of opinion that it is not condensed by any harmony or peculiarity of the oak leaf, but that whilst it falls equally upon other leaves, it is retained and continues on those of the oak, cause their texture is closer, and not so porous as that of most of the other leaves.*

be

With regard to heat, man possesses abundant means and power, but his observation and inquiry are defective in some respects, and those of the greatest importance, notwithstanding the boasting of quacks. For the effects of intense heat are examined and observed, whilst those of a more gentle degree of heat, being of the most frequent occurrence in the paths of nature, are, on that very account, least known. We see, therefore, the furnaces, which are most esteemed, employed in increasing the spirits of bodies to a great extent, as in the strong acids, and some chymical oils; whilst the tangible parts are hardened, and, when the volatile part has escaped, become sometimes fixed; the homogeneous parts are separated, and the heterogeneous incorporated and agglomerated in a coarse lump; and (what is chiefly worthy of remark) the junction of compound bodies, and the more delicate conformations are destroyed and confounded. But the operation of a less violent heat should be tried and investigated, by which more delicate mixtures and regular conformations may be produced and elicited, according to the example of nature, and in imitation of the effect of the sun, which we have alluded to in the aphorism on the instances of alliance. For the works of nature are carried on in much smaller portions, and in more delicate and varied positions than those of fire, as we now employ it. But man will then appear to have really augmented his power, when the works of nature can be imitated in specie, perfected in power, and varied in quantity; to which should be added the acceleration in point of time. Rust, for instance, is

Moreover, since nature supplies cold so sparingly, we must act like the apothecaries, who, when they cannot obtain any simple ingredient, take a succedaneum, or quid pro quo, as they term it, such as aloes for xylobalsamum, cassia for cinnamon. In the same manner we should look diligently about us, to ascertain whether there may be any substitutes for cold, that is to say, in what other manner condensation can be effected, which is the peculiar operation of cold. Such condensations appear hitherto to be of four kinds only. 1. By simple compression, which is of little avail towards permanent condensation, on account of the elasticity of substances, but may still however be of some assistance. 2. By the contraction of the coarser, after the escape or departure of the finer parts of a given body; as is exemplified in induration by fire, and the repeated heating and extinguishing of metals, and the like. 3. By the cohesion of the most solid homogeneous parts of a given body, which were previously separated, and mixed with others less solid, as in the return of sublimated mercury to its simple state, in which it occupies much less space than it did in powder, and the same may be observed of the cleansing of all metals from their dross. 4. By harmony or the application of substances which condense by some latent power. These harmonies are as yet but rarely observed, at which we cannot be surprised, since there is little to hope other trees.

*It may often be observed on the leaves of the lime aud

respond in their conformation; others, on the contrary, correspond in the former and differ in the latter. Thus the chymists have well observed, that in their trial of first principles, sulphur and mercury, as it were, pervade the universe; their reasoning about salt, however, is absurd, and merely introduced to comprise earthy, dry, fixed bodies. In the other two, indeed, one of the most universal species of natural harmony manifests itself. Thus there is a correspondence between sulphur, oil, greasy exhalations, flame, and, perhaps, the substance of the stars. On the other hand, there is a like correspondence between mercury, water, aqueous vapour, air, and, perhaps, pure intersidereal ether. Yet do these two quaternions, or great natural tribes (each within its own limits) differ immensely in quantity and density of substance, whilst they generally agree in conformation, as is manifest in many instances. On the other hand, the metals agree in such quantity and density, (especially when compared with vegetables, &c.,) but differ in many respects in conformation. Animals and vegetables, in like manner, vary in their almost infinite modes of conformation, but range within very limited degrees of quantity and density of substance.

since these latter are more apparent, they may throw great light, when well observed and diligently examined, upon those which are more latent.

The more eternal harmony and aversion, or friendship and enmity, (for superstition and folly have rendered the terms of sympathy and antipathy almost disgusting,) have been either falsely assigned, or mixed with fable, or most rarely discovered from neglect. For if one were to allege that there is an enmity between the vine and the cabbage, because they will not come up well when sown together, there is a sufficient reason for it in the succulent and absorbent nature of each plant, so that the one defrauds the other. Again, if one were to say that there is a harmony and friendship between the corn and the cornflower, or the wild poppy, because the latter seldom grow anywhere but in cultivated soils, he ought rather to say there is an enmity between them, for the poppy and the corn-flower are produced and created by those juices which the corn has left and rejected, so that the sowing of the corn prepares the ground for their production. And there are a vast number of similar false assertions. As for fables, they must be totally exThe next most general correspondence is that terminated. There remains then but a scanty between individual bodies and those which sup- supply of such species of harmony as has borne ply them by way of menstruum or support. In- the test of experiment, such as that between the quiry, therefore, must be made as to the climate, magnet and iron, gold and quicksilver, and the soil, and depth at which each metal is generated, like. In chymical experiments on metals, howand the same of gems, whether produced in ever, there are some others worthy of notice, but rocks or mines; also as to the soil in which par- the greatest abundance (where the whole are so ticular trees, shrubs, and herbs mostly grow and, few in numbers) is discovered in certain medias it were, delight; and as to the best species of cines, which, from their occult and specific qualimanure, whether dung, chalk, sea-sand, or ashes, ties, (as they are termed,) affect particular limbs, &c., and their different propriety and advantage humours, diseases, or constitutions. Nor should according to the variety of soils. So also the we omit the harmony between the motion and grafting and setting of trees and plants (as re- phenomena of the moon, and their effects on gards the readiness of grafting one particular lower bodies, which may be brought together by species on another) depends very much upon an accurate and honest selection from the experiharmony, and it would be amusing to try an ex-ments of agriculture, navigation, and medicine, periment I have lately heard of, in grafting forest trees, (garden trees alone having hitherto been adopted,) by which means the leaves and fruit are enlarged, and the trees produce more shade. The specific food of animals again should be observed, as well as that which cannot be used. Thus the carnivorous cannot be fed on herbs, for which reason the order of Feuilletans, the experiment having been made, has nearly vanished; human nature being incapable of supporting their regimen, although the human will has more power over the bodily frame than that of other animals. The different kinds of putrefaction from which animals are generated should be noted.

The harmony of principal bodies with those subordinate to them (such indeed may be deemed those we have alluded to above) are sufficiently manifest, to which may be added those that exist between different bodies and their objects, and,

or of other sciences. By as much as these general instances, however, of more latent harmony are rare, with so much the more diligence are they to be inquired after, through tradition and faithful and honest reports, but without rashness and credulity, with an anxious and, as it were, hesitating degree of reliance. There remains one species of harmony which, though simple in its mode of action, is yet most valuable in its use, and must by no means be omitted, but rather diligently investigated. It is the ready or difficult coition or union of bodies in composition or simple juxta position. For some bodies readily and willingly mix and are incorporated, others tardily and perversely; thus powders mix best with water, chalk and ashes with oils, and the like. Nor are these instances of readiness and aversion to mixture to be alone collected, but others also of the collocation, distribution, and digestion of the parts when