Billeder på siden

vessel as for two reasons particularly suited to, but the same matter expanded in a body of vapour the experiment, first, that it might sooner bring filled half a pint. I, therefore, set down the on the boiling with less heat, lest the bladder, ratios according to the dimension expressed in the which was to be put above the phial, should be table: a vapour of water can bear a ratio of eightyburned and dried up by an intenser heat: secondly, fold to a body of water. The bladder filled with that it might receive a less portion of air in that wind in the manner I have mentioned, if no part which was not to be filled with water : since breathing-place be given, but it be removed whole I was aware that the air itself received extension from the fire, immediately decreases from the inthrough fire. I determined, therefore, of making Alation, and subsides and is contracted. The use of but a little air, that that extension might not vapour whilst the bladder swells, being emitted disturb the ratios of the water. The phial was from the hole, had another kind of vapour distinct not straight-necked, without any lip, (for, then, from the common one of water, more thin, clear, the vapour of the water would distil more rapidly, and upright, and not so soon mingling itself with and the dew would glide down that part of the the air. bladder, which was joined to the neck of the phial,) but with the neck at first straightened a little, and

Cautions. then returned as it were with the lip. This vessel I half filled with water, (supposing that this We must not suppose that if there were a greater would hasten the boiling,) and took the weight of consumption of water, a greater bladder could be the water with the phial itself by sand put in the filled in proportion. I tried this and found that scale of a balance. Then I took the bladder, it would not answer, but the inflation that follows which might contain about half a pint, taking upon it does not take place gradually, but altogecare that it should be neither old nor dry, and ther. This I attribute partly to the infiaming of given to resist more from dryness, but new and the bladder, which was made harder and would rather soft. I, then, tried the soundness of the not yield so easily, and was perhaps more porous; bladder by blowing, to be certain that there were (but this might be corrected by a moist heat as no holes in it, and then emptied all the air out of by the balneum Mariæ ;) but still more to this, it as much as possible. I also first of all applied that the vapour being increased through the conoil to the outside of the bladder, and made it take stant succession, inclines to recover itself and the oil by rubbing it in. This I did to make the condenses itself. The vapour, therefore, which bladder closer, and to stop up the pores (if there is received into the bladder is not to be compared might chance to be any) with the oil. I fastened to those which are received into stoves, because the bladder securely about the mouth of the phial, these latter mutually following and urging each the mouth of the phial being received into the other, thicken, but those expand themselves at mouth of the bladder; this was done with a string will from the soft and yielding nature of the bladwaxed a little, that might adhere better and tie der, especially at the beginning, (as I said,) before more closely. But this is made better by clay the copiousness of the vapour brings on its remade out of meal and the white of an egg, and covery. bound with black paper and well dried, as I myself The expansion of the vapour of water is not to have found. At last I placed the phial over burn- be judged entirely from the appearance of the ing coals on a little hearth. The water soon after vapour which flies off into the air ; for that vabegan to boil, and by degrees to inflate every part pour being immediately mixed with the air, borof the bladder, till it seemed as though it would rows by far the greatest dimensions of its mixed break. I immediately removed the glass from body from the air, and does not remain in its own the fire and placed it upon the carpet, lest the size. And so it is amplified to the bulk of the air glass should be broken by the cold, and instantly into which it is received, as a little red wine or I made a little hole at the top of the bladder with any other coloured fluid which imparts a colour to a needle, lest, on the vapour being restored to a great quantity of water. The exact ratios in so water at the ceasing of the heat, should fall back minute a case cannot be obtained without laborious and confound the ratios. But afterward I took and unprofitable research, and are very slightly away the bladder itself with the string, and cleared connected with our present design. It is enough it from the clay, if any had been used, and then that from this experiment it is plain that the ratio weighed the remaining water with the phials of vapour to water is not twofold, nor tenfold, nor again. And I found that about the weight of two fortyfold, nor again a thousandfold, two hundredpennyweights had been consumed. And I saw fold, &c. For the limits, not degrees of natures, that whatever of the body had filled the bladder are the subjects of our investigation. If, therewhen it was full of wind, was made and produced fore, any one, by any accident or slight variation from that which had been lost from the water. in the mode of his experiment, whether from the The matter, therefore, when it was contracted in shape of the glass he makes use of, or the hardthe body of the water, filled as much space as ness or softness of the bladder, or the degree of two pennyweights of the body of water filled : ! heat, does not fall upon the ratio of eightyfold, the

consequence is immaterial. For I suppose that | But if the vapour is inflamed in the part verging there are none so ignorant as to imagine that a little obliquely from the mouth of the phial, the pneumatic and volatile vapours, which fly off from inflammation becomes pensile in the air, undulatheavy bodies, lie hid in the pores of the same ing or winding after the appearance of vapour, bodies, and are not of the same matter with the and would doubtless attend it longer if the vapour ponderous body, but are separated from the pon- remained together and did not confound itself derous part, when the water is, as it were, entirely with the air. And the body itself of spirit of wine, consumed, and evaporates into nothing. A live if no remarkable vapour goes before, the fire being coal, if placed in the scale of a balance and left applied to it and kept to it a little while is changed till it becomes a cinder, will be found to be much into the flame, and it expands with so much the lighter. Metals themselves are changed in a won- greater ease and swiftness, as the spirit is more derful degree in weight by the evolutions of their widely diffused and occupies a less altitude. But smoke. The same matter, therefore, is tangible if the spirit of wine is put in the hollow of the and has weight, and is yet pneumatic, and can be palm of the hand, and a lighted candle between divested of weight.

the fingers is placed near the palm of the hand,

(as boys are wont to play with powder of resin,) History,

and the spirit is gently moved forward, and straight "The mode of the process of oil is this. If oil forward, not upward; the body itself burns in the be poured into a common glass phial and placed air, and when burning sometimes descends in a upon the fire, it will boil much more slowly, and right direction, sometimes unfolds a little cloud will require a greater heat than water. And at flying in the air, which nevertheless verges itself first some drops and small grains appear scattered to descent; sometimes when set on fire it cleaves through the body of the oil, ascending with a burning, to the roof or sides, or floor of the room, creaking sound : the bubbles in the mean time do and gradually becomes extinct. not play on the surface, as is the case with water, Vinegar, verjuice, wine, milk, and other simple nor does the body rise whole, and in general no liquors (I speak of vegetable and animal substeam flies off, but a little afterward the whole stances, for of minerals I will treat by themselves) body is inflated and dilated in a remarkable pro- have their modes of expansion, and some remarkportion, as if rising in a twofold degree. Then, able differences attending them, which it would indeed, a very copious and dense steam arises : be out of place here to enumerate : but they are if a fire be applied to the steam, even a good way in those natures which we have remarked in the above the mouth of the phial, the steam forth with processes of water, oil, and spirit of wine; namely, produces a flame, and descends immediately to in the degree of heat; and mode of expansion. the mouth of the phial, and there fixes itself and which is threefold, either in the whole body or in continues burning. But if the oil is heated to a froth, or in rather large bubbles ; for fat bodies, greater degree, the steam burning to the last, out of unripe juice, as generally ascend in greater of the phial, without any flame or ignited body bubbles, of dried sap, as vinegar, in less. A colbeing applied, completely inflames itself, and lection of spirit moreover differs in its site. For takes the expansion of the flame.

in the boiling of wine, the bubbles begin to collect

themselves about the middle, in vinegar about the Caution.

sides : and it is the same in ripe and strong wine,

and again in vapid or stale, when they are infused. See that the mouth of the phial is rather nar- But all liquors, even oil itself, before they begin row, that the phial may confine the fumes, lest by to boil, cast up a few and thin half bubbles about their largely and immediately mixing with the the sides of the vessel. And all liquors boil and air, they lose their inflammable nature.

are consumed quicker in a small than in a great


The method of process of spirit of wine is this :

I consider that compounded liquors are not it is excited by much less heat, and brings itself proper to the history of the expansion and union to expand sooner and more than water. It boils of matter through the medium of fire, because up with great bubbles without froth, and even with they disturb and confuse the ratios of simple exthe raising of its whole body, but the vapour, pansion and coition by their separations and mixwhilst it is collected, will on the application of tures. I leave them, therefore, for the proper fire produce fire, at a good distance from the history of the separation and mixture of matter. mouth of the glass, not so bright (but at least as

History compact) as oil, but thin and scant of a blue colour, and almost transparent. But being inflamed, Spirit of wine, put in an experiment with that it is borne to the mouth of the glass, where is a elastic cap, (which I described when speaking of supply of more copious fuel, as it is also with oil. water,) obtains this sort of expansion. I find VOL. II.-72

3 B 2

[ocr errors][ocr errors]

that a weight of six pennyweights, consumed clearly see that air itself is expanded and conand dissolved into vapour, filled and fully inflated tracted from heat and cold in those bodies of wind a great bladder which could contain eight pints; which physicians use for attraction. For, these which bladder was greater by sixteen times than warmed over the fire, and then applied imme that which I used in the case of water, which re- diately to the body, draw the skin, the air conceived only half a pint. But, in the experiment tracting itself and gradually recovering itself. of the water, there was a consumption of the And this it does of itself, although the hemp may weight of only two pennyweights, which is only not have been put on and heated, which is used the third part of six pennyweights. The ratios to produce a more powerful attraction. Moreover, being thus calculated, the expansion of the va- if a cold sponge be applied outside over the blispour of spirit of wine bears a fivefold ratio and ter, the air contracts itself so much the more by more, to the expansion of the vapour of water. virtue of the cold, and the attraction becomes And that very great expansion did not keep the more determined. body, on the removal of the vessel from the fire, I have put a silver saltcellar of the usual bellfrom hastening to recover itself, the bladder forth- tower form, in a bath or goblet filled with water, with becoming red and remarkably contracted. bearing the air depressed with itself to the bottom And, from this experiment, I began to estimate of the vessel. I then put two or three live coals the expansion of the body of flame on probable, in the little hollow space in which the salt is though not indisputable conjecture. For, since the placed when applied to its ordinary use, and raised vapour of spirit of wine is so inflammable, and a flame by blowing. Very soon after, the air, approaches so near the nature of fire, I considered rarefied by the heat, and impatient of its former that the ratios of spirit of wine, compared with orbit, lifted up the bottom of the saltcellar on one fire, agreed with the ratios of the vapour of water side, and ascended in bubbles. Hero describes compared with air. For, we may suppose that an altar so constructed as that, if you laid a hola the ratios of perfect and fixed bodies (as of air caust upon it and set it on fire, suddenly water and fire) are in harmony with those of the ele- would fall to extinguish the fire. This might be ments, or imperfect and moving bodies, (as of accomplished by air being received under the vapours.) And it will follow from this, that fire altar in a hollow space closed up, and with no exceeds air by five degrees, in the rarity or ex- other way of exit, (when the air was extended by pansion of matter. For such is the excess of the fire,) but where it might force out the water their respective vapours, as was before said. For, prepared for this purpose in the channel. There the fire itself may bear the ratio of one and a were lately in this country some Hollanders who half to the proper vapour, not the impure, but the had invented a musical instrument, which, on highly prepared vapour; as I have laid it down, being struck by the rays of the sun, gave out a also that air can have the same ratio to the vapour certain harmony. This was very probably owing of water highly prepared. And these experiments to the extension of the heated air, which could do not disagree materially with what we may fre- produce the motion of the instrument, since it is quently observe. For, if you blow out a lighted certain that air acted upon by the contact of the wax candle, and mark the dimension of the smoky very slightest heat, immediately begets expansion. thread which ascends, (in the lowest part before But, in order to come at a more accurate knowit is dispersed,) and place the candle near the fire, ledge of the expansion of the air let into that and again look at that portion of the fire which first elastic bladder, I took an empty glass, (I mean, reaches it, you will not imagine that it exceeds filled only with air,) and placed upon the bladder, more than double the magnitude of the smoke. the cap of which I before treated. But when the If you mark with accuracy the dimension of gun- phial was placed over the fire, the air extended powder, or, for greater certainty, measure it in a itself more quickly and with less heat than water little box, and again take the dimension of its or spirit of wine, but with not a very ample exflame, after it has been lit, you will readily grant pansion. For it bore this proportion. If the that the flame exceeds the body, as far as it can bladder held less by six ounces than the phial be told at first sight, a thousand degrees. And, itself, the air completely filled and inflated it; it from what has been before laid down, there should did not ascend easily on greater expansion; and be a considerable proportion of fire according to no visible body proceeded out of it, after making the nitre. But this I will explain more perfectly a little hole in the top of the bladder, until it was in my observations upon this history. We very inflated.

A. T. R.




arbitrarily applied, so as to form a certain likeness CHAPTER I.

of some individual, it is the work of imagina

tion; which, restrained by no law or necessity Division general of Human Learning into Histo- of nature or of matter, can unite things which in

ry, Poesy, Philosophy, according to the three nature are most discordant, and divide those Faculties of the Mind, Memory, Imagination, which never exist in separation, so as however Reason; showing that the same Division holds this is still confined to such original parts of the also in Matters Theological ; since the Vessel, individuals. For there is no imagination, not namely, Human Intellect, is the same, though the even a dream, of objects which have not in some Matter contained, and the Mode of its Entrance, shape presented themselves to the senses. Again, be different.

if the same sections of objects be joined or

divided according to the real evidence of things, We adopt that division of human learning and as they actually present themselves in nature, which is correlative to the three faculties of the or at least as they are observed to present themintellect. We therefore set down its parts as selves according to the general apprehension of three, History, Poesy, Philosophy :-history has mankind, this is the office of reason; and all such reference to memory, poesy to imagination, phi- adjustment is ascribed to reason. losophy to reason. By poesy in this place, we Whence it clearly appears that from these three mean nothing else but feigned history. History sources there arise the three several streams of hisis, properly, the history of individual facts, the tory, poesy, and philosophy, and that there canimpressions of which are the earliest and most not be other or more branches than these. For under ancient guests of the hunan mind, and as it were the name of philosophy we comprehend all the the primitive matter of the sciences. To deal arts and sciences, and whatever in short can, with these individuals and that matter forms the from the presentment of the several objects of mind's habitual employment, and occasionally, nature, be by the mind collected and arranged its amusement. For all science is the labour into general notions. Nor do we think that there and handicraft of the mind; poetry can only be is occasion, in consideration of the extent of the considered its recreation. In philosophy the subject, for any other division of learning than mind is enslaved to things, in poesy it is let loose that which we have stated above. For though from the bondage of things, and breaks forth the responses of a divine oracle and of the senses illimitably, and creates at will. And any one are different, no doubt, both in the matter and the may easily comprehend that this is so, who shall mode by which it finds access to the mind; yet seek the source of things intellectual even on the the spirit of man which receives both is one and simplest principles, and with the most crass the same, just as different liquors passing through apprehension. For the images of things indivi- differents apertures are received into one and the dual are admitted into the sense and fixed in the same vessel. Wherefore we assert that history memory. They pass into the memory, as it were, itself either consists of sacred history, or of divine whole, in the same manner as they present them- precepts and doctrines, which are, so to speak, selves. These the mind recals and retraces; and, an everyday philosophy. And that part which which is its proper business, puts together and seems to fall without this division, prophecy, is decomposes their parts. Now, individuals seve- itself a species of history, with the prerogative rally have something in common one with another, of deity stamped upon it of making all times and again something diverse and complex. Com- one duration, so that the narrative may antici. position and division takes place either at the pate the fact; thus also the mode of promulwill of the mi itself, or agreeably to what is gating vati tion by vision, or the heavenly found in nature. If it is done at the mere voli. doctrines by parables, partakes of the nature tion of the mind, and such parts of things are of poetry.

new face of things, or second universe. WhereCHAPTER II.

fore natural history of either the liberty of nature

or its errors into bonds. Now, if it be unpleasing A partition of History into Natural and Civil, Ec- to any one that the arts should be called the

clesiastical, Literary, and Particular, included bonds of nature, since they are rather to be conin Civil History. A division of Natural Histo- sidered its deliverers and champions, since they ry into the History of Generations, Præter-gene- make nature, in some instances, mistress of her rations, and Arts ; according to the three states object, by reducing obstacles into her order. We of Nature, namely, Nature in course, varying, regard little such delicacies and elegancies of and constrained.

language. We only mean to signify this, that

nature, by means of arts, is placed by compulsion History is either natural or civil. In natural under a necessity of doing that which without history we recount the events and doings of arts would not have been done, whether that be nature; in civil, of men. Things divine no denominated force and bonds, or assistance, and doubt have a conspicuous share in both, but consummating skill. We shall therefore divide chiefly in human, so as to constitute a branch of natural history into the history of generations, their own in history, which we are accustomed to the history of preter-generations, and the history call sacred or ecclesiastical. We shall therefore of arts, which we are accustomed to call mechaniassign that branch to the province of civil histo- cal and experimental history. And we willingly ry: and we shall first speak of natural history. place the history of arts among the species of There is extant no natural history of things natural history, because there has obtained a now individual. Not that we would lay down the inveterate mode of speaking and notion, as if art false position that history ought to be engrossed were something different from nature, so that with describing individuals, which are limited in things artificial ought to be discriminated from time and place. For in that view it is proper things natural, as if wholly and generically difthere should be none; since, however, there is a ferent; whence arises this evil, that most writers general resemblance of natural objects, so that of natural history think they have accomplished if you know one you know all, it were super- their task if they have achieved a history of anifluous and interminable to speak of individuals. mals, plants, or minerals, omitting the experiThus, if in any case that indistinguishable general ments of mechanics, which are of by far the resemblance be wanting, natural history admits greatest consequence to philosophy; and there individuals those, that is, of which there is not a has insinuated itself into mens' minds a still number or family. For a history of the sun, the subtler error, namely, this, that art is conceived to moon, the earth, and the like, which are unique be a sort of addition to nature, the proper effect in their species, is most properly written, and no of which is to perfect what nature has begun, or less of those which conspicuously vary from to correct her where she has deviated; but by no their species and are monstrous; since the de- means to work radical changes in her, and shake scription and the knowledge of the species neither her at the roots, which has been a source of great sufficiently nor competently supplies the want of despondency in the attempts of men. Whereas, it. Wherefore natural history does not exclude on the contrary, that ought to be sunk deep that these two classes of individuals, but is in by far things artificial do not differ from natural in form the largest part of it, as we have already stated, or essence but in efficients only; that in reality employed about species. But we attempt a par- man has no power over nature, except that of tition of natural history, derived from the ten- motion, namely, to apply or to remove natural dency and condition of nature herself, which is bodies; but nature performs all the rest within found placed in three several states, and subject herself. Wherefore, when there is granted a as it were, to three modes of government. For proper application or removal of natural bodies, nature is either free, spontaneously diffusing and men and art can do all; when not granted, nodeveloping itself in its wonted course, that is, thing. Again, provided that due admission and when nature depends upon itself, in no way removal takes place in order to some effect, it obstructed and subdued, as in the heavens, ani- matters not whether it be done by man or by art, mals, plants, and all the natural productions; or, or by nature without man. Nor is the one more again, it is evidently torn down and precipitated potent than the other; so, if any one by sprinkling from its proper state by the pravity and erratic water create the apparition of a rainbow upon a tendency of obdurate and resisting matter, or by wall, he does not find nature less obedient than violence of obstacles, as is the case in the care when the same takes place in the air on humid of monsters and unnatural productions; or, final- clouds. Again, when gold is found pure in ly, it is coerced by the art and industry of man, veins, where nature has performed exactly the fashioned, altered, and as it were made anew, as same office to herself, as if pure gold was er. in things artificial. For in things artificial nature tracted by means of the smelting pot and ministry seems, as it were, new made, and there is seen a l of man. Sometimes, too, a ministry of this kind

« ForrigeFortsæt »