than a differential thermometer, fuch as has been described before, having one ball only painted black; for when this inftrument is expofed to the light, the black ball, by absorbing more light is thereby heated more than the oppofite ball, and of course depreffes the fluid in the graduated item. This effect is proportionate to the intensity of the light to which the inftrument is expofed. The various application or ufes of this photometer are mentioned in the twentieth chapter, where it is shown, that with it may be measured the intenfities of light in every poffible cafe; i. e. the enquirer may be enabled to determine the quantities of light of different seasons, of different luminaries, of the different times of the day; alfo the tranfparency of diapha-. nous bodies, the reflecting powers of different fubftances, &c. Towards the end of the fame chapter, Mr. L. shows how the fenfibility of his photometer may be increased to fuch a degree as perhaps to be affected even by the feeble light of the moon. The important experiments relative to the conducting power of air, meaning its power of conducting heat, in different ftates of rarefaction; and likewife the conducting powers of other gafes, are defcribed in the twenty-first chapter, which is the laft of the work. Thofe experiments were performed by fixing the photometer within the glass receiver of the air pump, and applying a hot body to it under different states of rarefaction. The conducting power of air was found to diminish with its rarefaction; but, when the fucceffive denfities of the air were in geometrical progreffion, the decreafing conducting powers did not form a progreffion quite regular. Mr. L. endeavours, with much ingenuity, to trace the nature of this decrease of conducting power; but, with refpect to those particulars, we must refer our readers to the work itself. "Whatever", Mr. L. fays, "has the property of dilating the air, has likewife a tendency to deprefs its power of abftracting heat. The various elaftic vapours, in mixing with the atmospheric fluid communicate their peculiar expanfive force, and feem by that union to occafion a proportional diminution of its conducting quar lity. The influence of humidity is vifible, but the more volatile substances have a marked effect." P. 281. And, in p. 483, he says, "The permanent gafes differ as much from common air, perhaps, by their difpofition to conduct heat, as by their denfity or other pro Hh BRIT. CRIT. VOL. XXV. APRIL, 1805. perties. perties. The azotic and the oxygenous, indeed, feem to poffefs it nearly in the fame degree. But carbonic gas abstracts the heat from a vitreous furface about an eighth part flower, and from a surface of metal one-fourth flower, than common air. By progreffive rarefaction, that property is alfo reduced on a fimilar scale. Hydrogenous gas, however, is the most diftinguifhed by its affection for heat, which it conducts with unufual energy." Thus we have endeavoured to give our readers fome idea of the contents of a work, which highly deferves the attention of the philofophical world. Rich in new and useful facts, as well as in proper remarks, and judicious obfervations; it furnishes abundant matter for philofophical inveftigation, and opens new paths into the labyrinth of natural energies and operations. We are by no means fatisfied with all its hypothetical part; and it might be wifhed that the whole were digefled into a more methodical order, with a fimplification of the calculations, and other ufeful improvements. But we truft that, in a future edition, Mr. L. will endeavour to render this work as perfect as the nature of the fubject may admit. BRITISH CATALOGUE. POETRY. ART. 14. The Pleafures of Compofition, a Poem, in two Parts. Part I. 8vo. 60 pp. 29. 6d. Hatchard. 1804. This unfinished Poem is attributed to a gentleman, whofe writings have more than once received the public approbation, Mr. Eyles Irwin. A cultivated taste, and an ardent zeal, for the polite arts, appear in the prefent compofition; which, as a poem, is chiefly defective from a degree of obfcurity, fuch as a further attention to the ftyle and expreffion might perhaps remove. The following lines, for inftance, though good in cadence, are extremely enigmatical : "By moderns held a monumental art, A nation's tribute to her CHATHAM's fhrine: Hence Hence thro' the abbey's venerable ailes, And poets find new advocates for verfe". P. 11. In the beginning of this paffage, the poet means, that the ancient patriot had a statue fo early, that Cæfar fell before the figure of his rival Pompey, but that moderns wait for pofthumous honour of this kind, as in the cafe of Lord Chatham. This is the general idea; but it is by no means fufficiently developed; and what is intended by the concluding line, we have not been able even to conjecture. This is only one paffage out of feveral, to which a fimilar objection might be made. See particularly 1. 236, in which a whole hiftory is alluded to, without the least direction to the reader, except the note. Compofition is invoked in the beginning as a perfon; we then find that the includes Sculpture, both of ftatues and medals, Architecture, Painting, Mufic, and Poetry. Yet all of these are alfo feparately perfonified; and Sculpture, we fee in the paffage juft cited, is once an orb with fetting rays. The fubject of the Poem is, in fact, rather the history and merits of compofition than the pleafures of it: unlefs the author means (which we rather fufpe&t) the pleasure which the compofitions of one man give to others, and this his title by no means expreffes. He is fometimes incorrect in his accents; as folácer, ver. 333, and óbdurate, ver. 456. The Poem contains only 458 lines; the reft of the book confifts of notes. Should the author proceed in his plan, it will be neceffary for him to revife this first part with much care; taking the advice of competent judges on the fubject. The plan wants improving, in feveral inftances, as well as the expreffion. We fincerely wifh, for the fake of the author, to see it laboured into a more perfect form. ART. 15. The Sorrows of Seduction; with other Poems. 12mo. 3s. 6d. Longman and Co. 1805. This little volume, which, as the author fays, paffed from himfelf immediately to his publifhers, without any examination on the part of a friend, exhibits great elegance of taste, and warmth of feeling. The first Poem, on Seduction, though unfortunately the fubject is trite, is well managed, and has many pathetic and beautiful paffages. We have only room for a specimen of the author's lighter effufions. 66 EARLY SPRING. With timid air, and cautious foot, Young Spring, With Flora fair and Zephyr on the wing, In bending attitude with lift'ning ear, She darts her glance along the mofs-brown vale, Fearful left Winter hoar, with aspect drear, Should rude affail her with his withering gale. Hhz Oft Oft as the hears him murmur in the dell', Young Genius, thus by fearful breaft betrayed, ART. 16. The Minfttel; or, the Progress of Genius. With fome other Poems. By James Beattie, LL. D. A new Edition. To which are prefixed, Memoirs of the Life of the Author. By Alex. Chalmers, Ejg. 12mo. 168 pp. 45. Mawman. 1805. This little volume, in its poetical part, offers only the ufual collection of Dr. Beattie's compofitions; and very excellent reasons are offered (in p. xiii.) against bringing forward to public notice, those poems which the author's own judgment had determined him to fupprefs. The Life of Dr. Beattie, the only novelty in the book, as being the production of the biographer of the British Effayifts, will defervedly attract attention. The foundness of Mr. Chalmers's opinions, which we have always admired, appears confpicuously in the following paffage, which is alfo very happily expreffed. It is occafioned by the defence which Dr. Beattie thought it necessary to make for his own warmth, in fome part of the Effay on Truth. "The mode of treating the writings of infidels, like every other fpecies of controversy, muft partake of the varieties of human temper, and temper is frequently obferved to take a freer range in the clofet than in fociety. I am willing to allow, therefore, that the author of the Effay on Truth" is warm when compared to fome who have written against Hume and the fceptical philofophers. Dr. Campbell has been praised for his urbanity to Hume, and for carrying on a ref pectful correfpondence with a man whofe pernicious opinions he thought it his duty to expofe and confute. Dr. Campbell was beyond all doubt fincere, but he was not indignant. The question, therefore, may to fome appear of difficult folution, in what manner the profeffed enemy of Chriftianity is to be treated? This has been frequently propofed, but it has not been fatisfactorily anfwered. All will acknowledge that there are certain rules of good manners, the breach of which no controverfy can juftify; but the mere admiffion of this will probably be thought infufficient. There are men likewife who think that we ought to argue for the evidences of religion and the foundations of human happinefs, with as much coolness as if the conteft related to the niceties of grammar, or the dates of hiftory; but neither will this be admitted as a confiftent principle. In all difputes, the warmth, the zeal, the exertions, muft rife in proportion to the value of the object contended for; and if the exuberance of the affections be ever pardonable, it must furely be in the cafe of a man who endeavours to rescue from fophiftry and perverfion doctrines of eternal importance; and who fees, or thinks he fees, the religion, morals, and * See Brit, Crit, vol. xxiii. p. 548. happine happiness of mankind, at ftake. Such was certainly the cafe of our author, and fuch was his opinion. He fays in the abovementioned poftfcript, "when doctrines are published fubverfive of morality and religion, doctrines of which I perceive and have it in my power to expofe the abfurdity, my duty to the public forbids me to be filent ; efpecially when I fee that, by the influence of fashion, folly, or more criminal causes, thefe doctrines fpread wider and wider every day, diffufing ignorance, mifery, and licentioufnefs, wherever they prevail." In this view of his duty, a writer who betrays no warmth, no animated fympathy with his fubject, who is courtly in expreffing indig. nation, and fhy in expofing danger, myft have either been dragged into the contest against his will, or must be indifferent to the iffue, The truth is, Mr. Beattie had many opportunities of obferving the mifchief occafioned by Mr. Hume's writings among his countrymen". P. 19. Every good man will rejoice, when the pen of fo very able an advocate for truth is employed to add dignity and value to a new publi cation. ART. 17. The Bettyad, a Poem, defcriptive of the Progrefs of the Young Rofcius in London, by S. M. Woodward, Author of Eccentric Excurfions through England and Wales, &c. 8vo. 17 PP. Allen. 1805. A very good-natured attempt to celebrate the fuccefs of this juvenile performer, in fuch verfes as the following: "What founds confus'd falute my ears? Oh! bleh maheart,-old Levi cries, John Bull cries, what's the matter ?" The laft ftanza is fo well meant, that we cannot refrain from in ferting it, "Thus ends the Mufe her frolic play, Or on pale Envy's tablets write A line, his well-earn'd praife to blight, |