at the same time bringing into consideration a great number of facts, more or less known, and a variety of observations which had been made in different parts of the world. By the term fire, the subject of his dissertation, Boerhaave evidently intends to denote the same substance which in modern times is denominated caloric; that is, the cause of heat, and of its phenomena. This fire, however, he divides into two kinds; the pure or elementary, and the vulgar or culinary fire; but as the only difference between these is, according to his own statement, a variation of the circumstances in which they appear, it will be attended with no inconvenience, and some advantage, to treat the subject at present only in its elementary signification. As the result of his enquiries, he infers, 1st. that fire appears to be the general instrument of all the motion in the universe; the universal cause of all the changes in nature. Of this he gives several instances in the effects of fire upon solids and fluids. All natural motion, he observes, is performed either by a separating of parts from each other, or by a rarefying of them, neither of which is done without fire. He remarks the impossibility of separating fire entirely from any body in nature, asserts that the most rarefied air contains a portion of it; and that, if it could be entirely deprived of this portion, it would become solid, perfectly at rest, and incapable of change. He stiles fire (or caloric) the only active and proper instrument of chemistry, without which the chemist would be absolutely incapable of performing or producing any thing. 2. That elementary fire is equally diffused in all places. The proofs he adduces in support of this, though ingeniously applied, appear to be only decisive as far as they shew that no body has yet been found, or can be conceived, totally destitute of caloric, and that amidst all the changes which are perpetually occurring, and the inequalities observable throughout nature, there is a constant tendency in fire to obtain and preserve an equilibrium amongst the various bodies which contain it. 3. That elementary fire is always latent, until set at liberty by some variation of circumstance; and that it then discovers itself by one or more of these effects, rarefaction, light, colour, heat, and burning. 4. That fire only becomes apparent by being collected, or gathered nearer together; "so that there is no exciting, producing, or making of fire, or even putting it in motion; but the whole of what we do is to collect what was before dispersed, and bring it into a narrower compass." From the whole he deduces the 5th or general inference, that fire, or caloric, " is a body sui generis, not creatable, or producible de nove, by any natural or artificial means;" that "its quantity is fixed and invariable ;" and that "the utmost we can do with it, and which has led us to think it producible, is" that, from a state of insensibility, we can "render sensible; where, before, there was no sign of it, it may be made manifest. But this is only effected by determining and collecting it; by bringing it out of a larger space into a less; and driving or directing it upon this body or that," &c. Having inferred the materiality of beat, our author proceeds to investigate its properties, which he lays down in the following mauner. As corporeal, it is composed of particles, which are extended, impenetrable, moveable, figurable, &c.; these corpuscles or molecules are the minutes t and subtilest of bodies; the most solid and indivisible; the most polished and smooth; the most simple and immutable; and move with greater velocity than any other body we are acquainted with. In the prosecution of his enquiry, our author proceeds to notice the different modes of collecting fire, both elementary and vulgar, such as attrition, burning glasses, the putrefaction of vegetables, chemical admixture, contiguity of air, pulverizing, moistening and mixing certain solid bodies, &c.; the different kinds of pabulam, or food of fire, in other words combustible bodies, all the variety of which he reduces radically to two, oil and sulphur; the different effects of fire, according to its different circumstances, degrees, and directions, &c. &c.; never failing, as he goes along, to seize and apply fresh arguments as they present themselves, in support of his favourite notion of the materiality of heat. Notwithstanding, however, the general excellence of Boerhaave's treatise, the attentive reader will discover some examples of inconsistency, and even of paralogisin; some conclusions too hastily drawn, and a few, perhaps, even contradicted by the premises themselves. But these occur rarely, and if it be added that some of his reasonings are nullified by subsequent discoveries, the great improvements that have been made in chemical philosophy since he lived, will suggest an ample apology for his stopping short of infallibility and perfection. It deserves to be remarked, in taking leave of this eminent writer, that a passage al-, ready quoted, and another which follows, appear to contain the germ of that doctrine, which was afterwards so beautifully expanded by Dr. Black, under the denomination of latent heat. "Though fire," says he, "be the great cause of fluidity and motion, yet is it frequently found in such small quantity, that instead of fusing bodies, or keeping them in a state of fusion, it becomes enclosed and fixed therein, so as to remain, as it were, imprisoned, till some external cause come to its assistance, and open the cells which before detained it." In what respects Dr. Black's idea differed from this may be seen stated in the articles CAPACITY, CALORIC, and LATENT HEAT. See also PHLOGIS TON. Since the time of Boerhaave, other writers have appeared on the same side of the question. The French chemists who succeeded Macquer have almost generally declared themselves in favour of the materiality of heat: we may instance, particularly, Berthollet, Lavoisier, Guyton de Morveau, and Fourcroy, to whom we are indebted for the introduction of the term caloric, as well as for the formation of the nomenclature itself. To quote these, and other French authors, largely our limits would not admit; and it is the less necessary as most of their writings are easily accessible to those who make chemistry the object of their pursuit. One extract, however, we may venture to transcribe from Fourcroy, because, though it does not reveal for the first time any great discovery, it notices a fact of some consequence in the argument, and which we have not presented before. From the phenomena which he has described, it follows, he says, "that caloric has different attractions, or various degrees of affinity for different bodies." And this attraction, he adds, " varying for each body, is a direct proof of the exist ence of caloric, and a refutation of the doctrine which makes it to consist only in a modification of bodies." Chem. Philos. Professor Pictet, Scheele, and others, have shewn that caloric is radiated, refracted, and reflected, in the same manner as the rays of light, and therefore that if the one be a substance, so must the other likewise. In our own country many writers have recently appeared, who have thrown much light on this intricate subject. Dr. Herschell discovered that there are rays emitted from the sun which produce heat, but have not the power of illuminating; and that, on the contrary, from the same source proceed also rays of light which do not produce heat. The last fact was indeed known long ago by Dr. Hooke and Mr. Scheele; but Dr. Herschell demonstrated it with more precision: and the first has been confirmed by sir Henry Englefeld, who repeated the doctor's experiments with a different apparatus, but with the same results. This division of the solar rays into calorific and luminous, established as it is upon such undoubted premises, Dr. Thomson considers as nearly putting an end to the dispute by demostrating the existence of caloric as a peculiar substance; at least it is put ting it upon the same footing in this respect as light, the materiality of which is not disputed by many who argue on the other side with regard to heat. Chemistry, I. 299. Mr. Tilloch, the editor of the Philosophical Magazine, has inserted in that useful work two very ingenious papers on the subject of caloric; in the first of which he advances several objections against the distinction between sensible and latent heat (see CALORIC in this work, § V.); and in the second, with which alone we are concerned at present, he attempts to prove that "the matter of heat, like other substances, possesses not only volume, but gravity." He brings forward many examples, most of which are well known, to shew that in a great number of cases, mixtures of different kinds, of aeriform and fluid bodies among themselves, with each other, and with solids, are reduced or increased in volume, without parting with or receiving any thing except heat; and therefore he concludes that heat is matter. Again; with respect to its gravity, he thinks the experiments and facts commonly adduced to prove that it is devoid of weight are by no means conclusive; indeed, he conceives that many of them are inexplicable without allowing it to possess weight, though we are not at present in possession of means to ascertain that weight exactly. For ourselves, we must confess that ideas of this kind have frequently been excited in our own minds on the contemplation of various chemical phenomena; and we are not without hopes that some future at tempt to determine the weight of heat will be so far successful as to set that part of the question entirely at rest. Nothing that has yet been done, without excepting count Rumford's careful experiments, ought, in our estimation, to be looked upon as decisive, especially on the negative side of the enquiry. Mr. Tilloch is of opinion that the methods hitherto ad opted to settle the point are totally unit for the purpose: they appear to him no more rational than it would be “for the inhabitants of the ocean to attempt to weigh water by employing a balance suspended in the medium that surrounds them, and putting into one shell a substance that to them should seem wet, and into the other a sub stance which they might call dry." After noticing the advantages, in determining the specific gravi ties of bodies, of weighing them both in the air and in water, and comparing their results; he asks, with reference to heated bodies, "why has the increase of absolute weight not been hitherto observed? I take the reason," he answers, "to be this: they attempted to determine it in the air; overlooking this plain fact, namely, that air may be considered as bearing the same relation to heat that water does to gold, or rather to a substance many times heavier, if such could be found; that is the air, though a rarer substance than the solid bodies weighed in it, is a denser one than heat; and they have been demanding that a substance specifically lighter than air should descend in it." P. M. vol. IX. Without taking upon ourselves to answer for the perfect accuracy of Mr. T.'s representations and reasonings in all cases, the paper contains so much that is worthy of attention in this enquiry, that we cannot but recommend it to the perusal of our readers. Another correspondent, in the same work, vol. XII. has made some remarks to shew that the hy pothesis which makes all heat to be generated by motion is utterly inconsistent with many of its phenomena, and especially with the fact discovered by count Rumford, and confirmed thus far by later experiments; that heat is conveyed, especial ly by fluids, with much greater difficulty downwards than upwards. He allows however the dif ficulty of explaining count Rumford's experiment with the brass cylinder, consistently with the doc trine of materiality, and contends that a single instance of inability to account for a fact ought not to overturn any doctrine that is otherwise well established; but Mr. Tilloch remarks, in a note, that the count, with all the care and precaution he employed, did not succeed in insulating from the contact of caloric the bodies subjected to friction. "Was not the apparatus," he asks," wholly immersed in a bath of caloric-the atmosphere?" P. 321. In the fifth volume of the Manchester Memoirs, Dr. W. Henry has a paper, entitled " A Review of some Experiments which have been supposed to disprove the Materiality of Heat." This paper was written soon after the publication of count Rumford's Enquiry concerning the Source of Heat evolved by Friction, and of Mr. Davy's interesting Essays in Dr. Beddoes's Contributions; and the remarks it contained were intended principal ly to apply to the arguments advanced by these two able philosophers, and to the facts which served as bases to their reasoning. The materia lity of caloric, Dr. Henry contends, may be maintained without admitting that we have made any steps towards determining its quantity in bodies. Avoiding all metaphysical reasoning on the nature of matter, and assuming the generally received definition of matter as sufficiently characterizing it, he examines how far this general character applies to the individual-caloric. "Caloric," he argues, "occupies space, or is extended, because it enlarges the dimensions of other bodies; and, for the same reason, it is impenetrable, since if it could exist at the same time in the same place with other bodies, their volume would never be enlarged by the addition of heat. Of form, or figure, as only a mode of extension, it is unneces sary to prove that caloric is possessed; and, indeed, there is perhaps only one general quality of matter that will not be allowed it, viz. attraction. That caloric is influenced by the attraction of grat vitation, or by cohesive attraction, has never yet been proved; yet the various experiments of Buffon, Whitehurst, Fordyce, Pictet, &c. cannot be alleged as proofs that it is actually devoid of this property; since they only decide, that the small quantities which can be artificially collected are not to be set in the balance against the grosser which has lately been termed chemical affinity, may, I think, after a full survey of phenomena, be fairly predicated of caloric; and if its possession of this quality be rendered probable, we shall thence derive a powerful argument in favour of its materiality." kinds of matter. One kind of attraction, that To those who contend that heat is generated by motion, he replies that, if the phenomena of heat can be shewn to take place where matter is not present; that is, we suppose, any thing which is allowed to be matter by the advocates of the immaterial hypothesis; we shall derive from the fact a conclusive argument against that hypothesis. Such a fact, he remarks, is afforded by an experiment of count Rumford himself, in which heat was observed to pass through a Torricellian vacuum, in which, if heat be not matter, there could be nothing to transport or propagate motion; thus proving that heat can exist independently of other matter, and consequently that it is a distinct and peculiar body. Such are the outlines of the controversy respecting the nature of heat, and such are the principal arguments by which the advocates on each side support their opinions. Those who are desirous of pursuing the enquiry further may consult Dr. Crawford's Experiments and Observations on Animal Heat and the Inflammation of Combustible Bodies; Scheele's Experiments on Air and Fire, with Mr. Kirwan's notes; Leslie on Heat; Thomson's Chemistry, vol. I.; Boerhaave's Chemistry, and Davy's Essays, before referred to; Rumford's Essays, and various papers of his in the Philosophical Transactions; several of Dr. Herschell's Papers in the same work; several volumes of the Philosophical Magazine, and of Nicholson's Journal, to specify which is unnecessary, as those who have sets of those very useful works may easily be directed to those papers which re late to the subject, by consulting their respective indexes. HEAT (Animal). See PHYSIOLOGY. HEAT (Latent). See the end of the article CALORIC, also LATENT HEAT. We may just notice here a difference of conception on this point between two eminent philosophers: Dr. Irvine, of Glasgow, ascribes the disappearance of heat, without increase of temperature, to a change of capacity in bodies; while Dr. Black, the great illustrator of this doctrine, supposes caloric to become latent by a chemi cal combination with bodies. See a letter from the son of Dr. Irvine, in Nicholson's Journal, New Series, VI. 25. HEAT (Propagation of). HEATER. s. (from heat.) An iron made hot, and put into a box-iron to smooth linen. HEATH. s. (erica, Latin.) 1. A shrub of low stature (Miller). 2. A place overgrown with heath (Shakspeare). 3. A place covered with shrubs of whatever kind (Bacon). HEATH, in botany. See ERICA. TION. See PROPAGA HEATH (Pea). Sce OROBUS. nated black game, specially protected by the HEATHEN. s. (heyden, German.) The gentiles; the pagans; the nations unacquainted with the covenant of grace (Addison). 1. HEA'THEN. a. Gentile; pagan (Addison). HEATHENISH. a. (from heathen). Belonging to the gentiles (Hooker). 2. Wild; savage; rapacious; cruel (South). HE ATHENISHLY, ad. After the manner of heathens. HEATHENISM. s. (from heathen.) Gentilism; paganism (Hammond). HE'ATHY. a. (from heath.) Full of heath. To HEAVE. v. a. pret. heaved, anciently hove; part. heaved or hoven. 1. To lift; to raise from the ground (Milton). 2. To carry (Shakspeare). 3. To raise; to lift (Dryden). 4. To cause to swell (Thomson). 5. To force up from the breast (Shakspeare). 6. To exalt; to elevate (Shakspeare). 7. To puff; to elate (Hayward). with pain (Dryden). 2. To labour (After.). tion or effort upward (Dryden). HEAVE OFFERING. s. An offering among the Jews (Numbers). HEAVEN. s. (heopon, Saxon.) 1. The regions above; the expause of the sky. 2. The habitation of God, good angels, and departed (Milton), 3. The supreme power; pure souls the sovereign of heaven (Temple). 4. The pagan gods; the celestials (Shakspeare). 5. Elevation; sublimity (Shakspeare). tronomy, for an orb, or circular region, of the HEAVEN is more particularly used, in asæthereal heaven. The ancient astronomers assumed as many different heavens as they observed different motions therein. These they supposed all to be solid, as thinking they could not otherwise sustain the bodies fixed in them; and spherical, that being the most proper form for motion. Thus we had seven heavens for the seven planets; viz. the heavens of the Moon, Mercury, Venus, the Sun, Mars, Jupiter, and Saturn. The eighth was for the fixed stars, which they particularly called the firmament. Ptolemy adds a ninth heaven, which he called the primum mobile. After him two crystalline heavens were added, by king Alphonsus, &c. to account for some irregularities in the motions of the other heavens: and lastly, an empyrean heaven was drawn over the whole, for the residence of the Deity; which made the number twelve. But others admitted many more heavens, according as their different views and hypotheses required. Eudoxus supposed 23, Calippus 30, Regiomontanus 33, Aristotle 47, and Fracastor no Jess that 70. HEAVEN-BORN. Descended from the celestial regions; native of heaven (Dryden). HEAVEN BRED. Produced or cultivated in heaven (Shakspeare). HEAVEN-BUILT. Built by the agency of gods (Pope). HEAVEN-DIRECTED. 1. Raised toward the sky (Pope). 2. Taught by the powers of heaven (Pope). HEAVENLY. a. (from heaven.) 1. Resembling heaven; supremely excellent (Sid.). 2. Celestial: inhabiting heaven (Dryden). HEAVENLY. ad. 1. In a manner resembling that of heaven. 2. By the agency or influence of heaven. HEAVENWARD. ad. (heaven and pean, Saxon.) Toward heaven (Prior). HEAVIER. A stag deprived of his testicles by castration: an operation occasionally performed, in order that a supply may not be wanting for the chase during the time of rutting, in which the stag is perpetually ranging from one hind to another, for three weeks or longer; not allowing himself the comforts of food, sleep, or rest. Towards the termination of this copulative period he becomes lean, languid, and dejected; and withdraws himself from society, to seek repose and food. So debilitated and ill-adapted is he for sport, that the operation of castrating has been occasionally employed to prevent him from thus falling a prey to venereal pleasures and to preserve him for the chase. It is worthy of remark, that if a stag undergo the operation when his horns are shed, they never grow again; on the contrary, if it be performed while the horns are in perfection, they will never be shed at all; and it is equally reniarkable, that on being deprived of only one testicle, the horn will not regenerate on that side, but will continue to grow, and shed on the other side, in which the testicle remains perfect. Heaviers are of great strength, and stand a long time before hounds; for which reason the hunting establishment of his majesty in Windsor forest is never without a regular succession. HEAVILY. ad. (from heavy.) 1. With great ponderousness. 2. Grievously; afflictivey (Collier). 3. Sorrowfully; with grief (Cla. HE'AVINESS. s. (from heavy.) 1. Pon derousness; the quality of being heavy; weight (Wilkins). 2. Dejection of mind; depression of spirit (Shakspeare). 3. Inaptitude to motion or thought (Arbuthnot). 4. Oppression; crush; affliction. 5. Deepness or richness of soil (Arbuthnot). HEAVY. a. (hear13, Saxon.) 1. Weighty; ponderous; tending strongly to the centre (Wilkins). 2. Sorrowful; dejected; depressed (Shakspeare). 3. Grievous; oppressive; afflictive (Swift). 4. Wanting alacrity; wanting briskness of appearance (Prior). 5. Wanting spirit or rapidity of sentiment; unanimated (Swift). 6. Wanting activity; indolent; lazy (Dryden). 7. Drousy; dull; torpid (Luke). 8. Slow; sluggish (Shakspeare). 9. Stupid; foolish (Knolles). 10. Burdensome; troublesome; tedious (Swift). 11. Loaded; incumbered; burdened (Bacon). 12. Not easily di gested (Arbuthnot). 13. Rich in soil; fertile: as heavy lands. 14. Deep; cumbersome: as heavy roads. HEAVY. ad. As an adverb it is only used in composition; heavily (Matthew). HEAVY SPAR, in oryctology. See BA RYTES. HEBDOMAD. s. (hebdomas, Lat.) A week; a space of seven days (Brown). HEBDO'MADAL. HEBDO'MADARY. 4. (from hebdomas, Lat.) Weekly; consisting of seven days (Brown). HEBDOME, a festival observed by the Athenians, on the seventh day of every month, in honour of Apollo. HEBE, in fabulous history, daughter of Jupiter and Juno, and according to some, of Juno only, who conceived her after eating lettuces. As she was fair, and always in the bloom of youth, she was called the goddess of youth, and made by her mother cup-bearer to all the gods. Ganymedes, however, succeeded her as cupbearer, in consequence of her having fallen when she was serving the nectar. She was employed by her mother to prepare her chariot, and to harness her peacocks whenever requisite. When Hercules was raised to the rank of a god, he married Hebe, by whom he had two sons, Alexiares and Anicetus. As Hebe had the power of restoring gods and men to the vigour of youth, she, at the instance of her husband, performed that kind office to Jolas his friend, She is represented as a young virgin crowned with flowers, and arrayed in a variegated garment. In Greece and Rome she was wor shipped under the name Dia and Juventas. To HE BETATE. v. a. (hebeto, Latin.) To dull; to blunt; to stupify (Arbuthnot). HEBETATION. s. (from hebetate.) 1. The act of dulling. 2. The state of being dulled. HE BETUDE. ́s. (hebetudo, Latin.) Dul ness; obtuseness; bluntness (Harvey). HE BRAISM. s. (hebraisme, French; he braismus, Latin.) A Hebrew idiom (Addison). HEBRAIST. s. (hebræus, Latin.) A man skilled in Hebrew. HEBREW, something relating to the Hebrews or Jews; as Hebrew bible. HEBREW CHARACTER. There are two kinds of Hebrew characters: the ancient, called also the square; and the modern, or rabbinical characters. The square Hebrew takes its denomination from the figure of its characters, which stand more square, and have their angles more exact and precise than the other. This character is used in the text of holy Scripture, and their other principal and most important writings. When both this and the rabbinical character are used in the same work, the former is for the text, or the fundamental part; and the latter for the accessory part; as the gloss, notes, commentaries, &c. The best and most beautiful characters of this kind, are those copied from the characters in the Spanish manuscripts; next, those from the Italian manuscripts; then those from the French; and lastly, those of the Germans, whose characters are much the same, with respect to the other genuine square Hebrew characters, that the Gothic, or Dutch characters, are with respect to the Roman. Several authors contend that the square character is not the real ancient Hebrew character, written from the beginning of the language to the time of the Babylonish captivity; but that it is the Assyrian, or Chaldee character, which the Jews assumed, and accustomed themselves to, during the captivity, and retained afterwards. They say, that the Jews, during their captivity, had quite disused their ancient character; so that Ezra found it necessary to have the sacred books transcribed into the Chaldean square character. These authors add, that what we call the Samaritan character is the genuine ancient Hebrew. HEBREW CHARACTER (Modern or rabbinical), is a good neat character, formed of the square Hebrew, by rounding it, and retrenching most of the angles or corners of the letters, to make it the more easy and flowing. The letters used by the Germans are very different from the rabbinical character used every where else, though all formed alike from the square character; but the German in a more slovenly manner than the rest. The rabbins frequently make use either of their own, or the square Hebrew character, to write the modern languages in. There are even books in the vulgar tongues printed in Hebrew characters; instances whereof are seen in the French king's library. HEBREW LANGUAGE, that spoken by the Hebrews, and wherein almost all the books of the Old Testament is written. This appears to be the most ancient of all the languages in the world, at least we know of none older; and some learned men are of opinion, that this is the language in which God spoke to Adam in Paradise. Dr. Sharpe adopts the opinion that the Hebrew was the original language; not indeed that the Hebrew is the unvaried language of our first parents, but that it was the general language of men at the dispersion; and however it might have been improved and altered from the first speech of our first parents, it was the original of all the languages, or almost all the languages, or rather dialects, that have since arisen in the world. The books of the Old Testament are the only pieces to be found, in all antiquity, written in pure Hebrew; and the language of many of these is extremely sublime: it appears perfectly regular, and particularly so in its conjugations. Indeed, properly speaking, it has but one conjugation; but this is varied in each seven or eight different ways, which has the effect of so inany different conjugations, and affords a great variety of expressions to represent by a single word the different modifications of a verb, and many ideas which in the modern and in many of the ancient and learned languages cannot be expressed without a periphrasis. The primitive words, which are called roots, have seldom more than three letters or two syllables. In this language there are twenty-two letters, only five of which are usually reckoned vowels, which are the same with ours, viz. a, e, i, o, u; but then each vowel is divided into two, a long and a short, the sound of the former being somewhat grave and long, and that of the latter short and acute: it must however be remarked, that the two last vowels have sounds that differ in other respects besides quantity and a greater or less elevation. To these ten or twelve vowels may be added others, called semi-vowels, which serve to connect the consonants, and to make the easier transitions from one to another. The number of accents in this language are indeed prodigious: of these there are near forty, the use of some of which, notwithstanding all the inquiries of the learned, are not yet perfectly known. We know, in general, that they serve to distinguish the sentences like the points called coinnias, semicolons, &c. in our language; to determine the quantity of the syllables; and to mark the tone with which they are to be spoken or sung. It is no wonder then that there are more accents in the Hebrew than in other languages, since they perform the office of three different things, which in other languages are called by different names. As we have no Hebrew but what is contained in the Scripture, that language to us wants a great many words; not only because in those primitive times the languages were not so copious as at present; but also on this account, that the inspired writers had no occasion to mention many of the terms that might be in the language. The Chaldee, Syriae, Ethiopie, &c. languages, are by some held to be only dialects of the Hebrew; as the French, Italian, Spanish, &c. are dialects of the Latin. It has been supposed by many very learned men, that the Hebrew characters or letters were often used hieroglyphically, and that each had its several distinct sense understood as a hieroglyphic. Neumann took infinite pains to find out the secret meaning of these letters: but the enquiry is too trifling to be pursued here. HEBREW (Rabbinical or Modern), is, the |