concifely; and that the lateft difcoveries and improvements, which had either escaped the notice of the original author, or have been made fince his time, are carefully colleaed and fupplied by the editor, who appears to have made a very extenfive acquaintance with the chemical publications of the Continent. Of the advantages or inconveniencies of M. Wiegleb's method, every reader muft judge for himfelf; and probably there will be different opinions on that fubject, according to the particular views of different perfons in confulting the work. We only wifh, where fuch various objects are joined together in one chapter, that fome intimation had been given, in the runningtitle, or on the margin, of the introduction of every new one: when a reader is turning over the book, he does not need to be reminded, on the top of every page, that it is a General Syftem of Chemistry, but he will wish to know what part of that system he is in; and this is a fatisfaction which he cannot readily obtain, where the many different objects, which compofe one chapter, are no otherwife feparated, or diftinguifhed, than the different paragraphs which relate to one object.—This is a common fault, in most publications. With refpet to the theory, Dr. Hopfon has very properly omitted M. Wiegleb's, and fubftituted a much better of his own. Our philofophical readers will recollect that this gentleman published, in 1781, an Essay on Fire*, advancing a doctrine which is now, we believe, pretty generally acquiefced in, that fire confifts of two diftinct principles, light and heat; and that phlogiston likewife confifts of the fame two principles fixed in bodies. In the prefent work, this theory is offered to the public, to ufe his own expreffion, in a fyftematic garb; and if we think fome parts of this garb to be made of inferior materials, not likely to be fo durable, yet the whole appears to be of good workmanship, and to fit well. In the chapter on Heat, he has inferted a differtation on Specific Heat, drawn up, at his request, by M. Gadolin, Profeffor of Chemistry at Abo in Finland, with a large table of the capacities of different bodies for fpecific heat, as determined by M. Gadolin himself, and all the other writers who have treated on that subject. The doctrine of the generation of acids by the abforption of air, is claimed by Dr. Hopfon as his own: and, indeed, from the circumftances which he mentions, we make no doubt but that it may have occurred to him long before the publication of a like doctrine by M. Lavoifier. Some of Dr. Prieftley's early .experiments very naturally lead to that idea; and it feems to have been those experiments that first fuggefted it to M. Lavcifier himfelf, as well as to Dr. Hopfon. * See Rev. vol. lxvi. p. 238. According According to the theory now before us, acids confift of at united with certain bafes; which bafes generally exift alfo in the compofition of inflammable bodies, but are not inflammable themfelves. Thus the fubftance, which, with phlogifton, forms fulphur, with air, forms vitriolic acid; the fubftance, which, with phlogifton, forms phofphorus, with air, forms phosphoric acid; the mephitis, which, with phlogifton, forms nitrous gas, with air, forms nitrous acid; the fubftance, which, with phlogifton, forms regulus of artenic, with air, forms arfenical acid. In like manner, water is conceived to be compofed of air united, not to the whole fubftance of inflammable gas (for it is inconceivable how water, which is abfolutely incombuftible, fhould have fo combuflible a body in its compofition), but to one of its principles; a principle, which forms inflammable gas with phlogiton, and water with air. To this principle the Dr. has given the name of hydrophlogium, to exprefs the two fubfances formed by it in the different circumftances of combination. He accounts, very fatisfactorily, for the heat which accompanies the production of water from the two elaftic fluids, from the phlogifton of the inflammable gas being liberated, and decompofed into its principles, heat and light. This theory is certainly ingenious, and far more plaufible than that of M. Lavoifier; nor fhould we hefitate to adopt it, if Dr. Prieftley's late experiments did not perfuade us to refrain, for the prefent, from adopting any theory refpecting the compofition of water. But while we applaud Dr. Hopfon's ingenuity, we feel fome concern at feeing it mifemployed in framing another new nomenclator; a work from which its author will derive no credit, unless it be confidered as the exercise of a fchool-boy. Can he imagine that his new fyftem of names will be attended with any utility fufficient to counterbalance the ferious evils of fucn a change? What mighty advantages are likely to accrue (to the English manufacturer especially, for whom the work is, in a great measure, profeffedly calculated) from having the vernacular names for inftance, of the eightand-twenty acids, and of the compounds which they refpectively form with the different alkaline falts, earths, and metals, all turned into Greek? And why fhould Dr. Hopfon the chemift call the vegetable fixed alkali by the Greek name podium, when Dr. Hopion the phyfician must call it kali? If he was to write fpedium in a prefcription, the apothecary might be juftified in giving either the white afhes of zinc, which rife in the furnaces where brafs is made, or the black afhes of ivory; for his Greek, his Latin, and even English dictionaries will inform him, that the word fpodium fignifies afhes, and that one or other of thofe fubftances is meant by it. But we forbear to enter into particulars, obferving only, that if writers writers continue to indulge them felves in the licentiousness of changing and confounding the names of things at their pleasure, accommodating them to their own tafte or particular fyftems, they will foon turn chemiftry into a tower of Babel; and, inftead of facilitating the attainment of this most useful science to beginners, they will become unintelligible to one another. ART. VI. An Effay on Senfibility: a Poem. In Six Parts. 8vo. Pp. 190. 45. fewed. Nicol. 1789. WE E learn from the author's preface, p. v. that the question he undertakes to difcufs is, Whether fenfibility or the want of it, is, upon the whole, moft productive of comfort and happiness in the courfe of life.' He divides his fubject into fix parts. A first part is employed in confidering the different pleafures of fenfibility; a fecond, in contemplating its pains refult ing from thofe general evils, whether natural, or moral, to which mankind are expofed; a third, in furveying the different fpecies of difguft produced by the view of private characters; and a fourth, in enumerating the pangs which accompany the dearer and domeftic relations; a fifth confiders the nature and effects of apathy; a fixth examines into the causes, and points out the remedies, of the pains of fenfibility, and concludes with establishing, in its favour, the balance of happiness.' Interefting as every inquiry into the fources of our happiness muft be, it cannot be expected that we should follow the author's arguments through the whole of this long poem. In fact, were we inclined to do fo, he has prevented us by extending his refearches to an unneceflary length. This is particularly obfervable in the fecond part, when, in enumerating the evils arifing from fenfibility, he mentions, among others, the fufferings from difeafe, and bodily pain. But thefe are not the confequence of fenfibility, according to the ufual acceptation of the word, but the unavoidable confequence of our being poffeffed of fenfes. The question then comes to a very speedy iffue. Is it better to have or to want the fenfe of feeling or touch? Shall we forego the daily benefits of enjoying our fenfes, from the fear of having them, at fome future time, changed into evils? Similar objections might be urged again ft the whole catalogue of natural evils, as tending to prove fenfibility hurtful: the obvious queftion being, not whether our fenfibility, or rather fenfations, would be here painful; it would be abfurd to fuppofe otherwife but whether thefe natural evils can be fet in oppofition to the correfponding natural benefits; and confequently whether our fenfibilities or fenfations would not be more frequently pleafing, than difagreeable. Whether we ought to reject the advantages of the air which furrounds us, because it may REY. NOV. 1789. E e fome fometimes be stirred into a tempeft? or refuse the use of water, because it may drown us? of fire, because we may be burnt? But waving objections, which might eafily be multiplied, it is with pleasure that we give the author's fentiments on the felly of exceffive, or as it might be termed, morbid sensibility. The falfe opinion self-love has begot, Is to maturity by reading brought. Who would not feel the fentimental pow'r? And giving fcope to his capacious foul, O'erlooks the parts, while he furveys the whole.'- Those, too, of others must attention share '— How oft the word that ftruck us to the heart, As envy's poniard, or as fatire's dart, Was but a fhaft, which, free and debonair, Yet from fuch fancied wounds the bofom bleeds, Till fettled rancour intercourfe confound, How oft an air, a tone, a glance, offend, Is oft exceflive, fickle, and undue. Sudden it fprings, and, like Nilean flies, Which taint the air, and wound the fprings of life.' Of the author's fkill in drawing characters, the following extracts will afford no unpleasant proof. Behold Mercator, who, on fhirtless back, He fet up fhop; by ounces and by pounds, A bankruptcy reftor'd him to repose, And from a bankruptcy he richer rofe. At last, his tow'ring wishes to compleat, He candidate commenc'd, and bought a feat, Well! now Mercator fcarce can count his fields; Long did Notario drive the clofe-cut quill; He hopes, perhaps, at laft to mount the bench!"- Much |
