Imágenes de páginas
[ocr errors]

ftress upon there, and makes a decent apology for any errors that may be found in them.

• It is impoffible' (he says) for a man, who muft employ the greate est part of his time in the duties of a profeffion which allows no vacation, to superintend such experiments as those on which the foregoing estimates have been founded, from the commencement to the terminacion ; and being thus circumstanced, I think it necessary to observe, that some part of every one of these experiments and menfurations was committed to the care and fidelity of my operator. If any unintentional errors on his part should happen to conspire to the encrease of mine, my eftimations may be very incorrect in regard to the proportions; but I have no reason to doubt that the notions of metallic reduction, of the principles of fixable air and dense infiammable air, and of all that does not depend on accurate proportion, will abide the test of future experience.'

We hope the Doctor's operator has been more attentive to his duty than the compoficor, or corrector of the press, whose mistakss are more apparent, and pretty numerous; and have a like apology made for them. Beside those which are noticed in the errata, and which, in general, are of no great consequence, we Thall mention one or two that happen to occur to us at the moment, and which may possibly embarrass an ordinary reader. In page 228 and 29, we are told, that a cubic inch of one (pecies of air weighs 260 grains, and of another less than 2 grains ; that the medium of those two numbers is 23 ; and that if one cubic inch weighs 23 grains, 46 cubic inches will weigh between 80 and 11 grains : these apparent absurdities have arilen merely from the omision of a point of separation between integers and decimals; for 260 and 23, read 2.60 and 2.3, that is 210 and 2id, and the whole becomes clear and confiftent.--— The other inttance we allude to is in p. 181. The Author has shewn in the preceding pages, that as pure air is a constituent part of metallic calces, the transition of metal, by solucion, to the state of salt or calx, can take place only as the menftruum supplies this air ; that in making aqua regia with a mixture of nitrous and marine acids, a part of the nitrous acid is decomposed, nitrous air being emicted, and its pure air united with the marine acid, which, in virtue of this accesion of air, becomes capable of diffolving metals that resist the common spirit of falt. On chis occasion he communicates a very remarkable fact, that when two pounds of manganese are mixed with two or three of ordinary spirit of salt, the elastic fluid that issues in diftillation may be nearly all condensed in a solution of fixed vegetable alcali: and that the solution will then yield a confiderable quantity of nitre as well as sea salt: he finds also that manganese, by mere ignition, yields a great quantity of pure air with phlogiltic air, as nitre does; and from these facts he concludes, that manganese contains nitrous acid, or its principles, in great quantity. . But'


G g 3

(continues he) red lead, and the calces which serve to depbloo gifticate marine acid, or to produce the change expressed by that word, yield also pure and phlogistic air by ignition; and I venture to prognosticate, that nitrous acid will also be found in thefa cases to make aqua regia with marine acid, exclusive of any change producible in the marine acid by its union with empyreal air supplied from the calx.' Now, we apprehend the Doctor meant to say, not that nitrous acid, but that calces of lead would be found to make aqua regia with marine acid, and we can easily conceive how the perverfion of his meaning may bave hap. pened: he might write nitrous acid by mistake, and inadvertently insert the correction these calces in a wrong place; and the prin. ter might retain both, changing these calces (which would have been nonsense in the situation where he found them) into in these cases. Whatever may be in this conjecture, if the Author really means that calces of lead are capable of producing nitrous acid, it is a pity that fo important a bint should be loft to any of his readers.

After the particular facts and inductions, of which we have been endeavouring to give a concise view, the Doctor proceeds to enquiries of a more extensive and abstruse nature, respecting the matter of fire, and the explication of various operations and phenomena in which it is concerned. His primary notions of fire are, That it is subject to laws of attraction, by which it is fixed or disguised in divers substances; and that it produces heat, or acts as fire, only when it is extricated from other kinds of matter :-- that its homogeneal parts repel each other :- that the mutual repulsion of its own parts, and their attraction to other matter, is the cause of the elasticity of aeriform Auids :-that the charges of repellent matter, by which the gravitating particles form elastic Auids, are diftinct atmospheres of fiery matter, in which the densities are reciprocally as the diftances from the central particles, in a duplicate or higher ratio :-that the repulfion of the particles of fire limits the quantity that can be engaged by bodies ;-and that the matter of fire limits the quantities in which aeriform fluids, and oiher bodies containing it, can combine chemically. He conceives light to consist in a rapid projectile motion of ihe fiery fluid, independent of its den fry; and beat to consist in the density of the fluid, independent of progress five motion. We cannot say that we are entirely satisfied with this last notion ; for if heat and light be one and the same fluid, differing only in velocity, some reason ought to be assigned for that immente difference, and for the immense differences also in their permeation of gross bodies.



Årr. VIL An Esay on the Life, Character, and Writings, of Dr.

Samuel Johnson. By Joseph Towers, LL.D. 8vo. zs. 60,

Dilly. 1786. TN this Effay, we have a sober and candid Revietu of Dr. JohnI fon's literary and personal character. The judicious Author allows all his excellencies to their full extent; but he is not blind to his imperfections. He communicates, indeed, to the Public, little that is new; bue he adverts, with itrict attention, to whatever has been advanced by the various biographers, and the numerous relators of anecdotes concerning this great and fingudar man,- this noble Heteroclite, as fome one hach, not unapuly, Ayled him.

After a series of just criticisms on Dr. Johnson's writings, throughout, interspersed with occasional remarks on his genius, principles, prejudices, &c. our Author, in the conclusion of his Essay, thus briefly sketches, to use his own expredion, the principal features of the Doctor's character :

He possessed extraordinary powers of understanding, which were much cultivated by study, and fill more by mcditation and reflection. His memory was remarkably retentive, his imagination une commonly vigorous, and his judgment keen and penetrating. He had a strong sense of the importance of religion ; his piery was fincere, and sometimes ardent; and his zeal for the interests of virtue was often manifested in his conversation and in his writings. The Same energy, which was displayed in his literary productions, was exhibited also in his conversation, which was various, striking, and instructive; and, perhaps, no man ever equalled him for nervous and pointed repartees.

• The great originality which sometimes appeared in his conceptions, and the perspicuity and force with which he delivered them, greatly enhanced the value of his conversation ; and the remarks that he delivered received additional weight from the strength of his voice, and the solemnity of his manner. He was conscious of his own fue periority; and when in company with literary men, or with those with whom there was any poflibility of rivalship or competicion, this consciousness was too apparent. With inferiors, and those who readily admitted all bis claims, he was often mild and gentle: but to others, such was often the arrogance of his manners, that the en. durance of it required no ordinary degree of patience. He was very dextrous at argumentation ; and, when his reasonings were not solid, chey were at least artful and plausible. His retorts were so powerful, that his friends and acquaintance were generally cautious of entering the lifts againft him; and the ready acquiescence of those with whom he associated, in his opinions and assertions, probably rendered him more dogmatic than he might otherwise have been. Wich those, however, whom he loved, and with whom he was familiar, he was fometimes cheerful and sprightly, and sometimes indulged himself in fallies of wit and pleasantry. He spent much of his time, elpe. cially in his latter years, in conversation : and seems to bave had such

G g 4


an averfion to being left without company, as was somewhat extra. ordina:y in a man possessed of such intellectual powers, and whose understanding had been so highly cultivated.

• He sometimes discovered much impetuosity and irritability of temper, and was too ready to take offence at others; but when conceflions were made, he was easily appeased. For those from whom he had recei ed kindness in the earlier part of his life, he seemed ever to retain a particular regard, and manifested much gratitude towards thole by whom he had at any time been benefited. He was soon offended with pertners, or ignorance ; but he sometimes seemed to be conscious of having answered the questions of others with too much roughness; and was then desirous to discover more gentleness of temper, and to communicate information with more suavity of manners. When not under the influence of personal pique, of pride, pr of religious or political prejudices, he seems to have had great ardour of benevolence; and, on some occasions, he gave very signal proofs of generosity and humanity.

• He was naturally melancholy, and his views of human life ap. pear to have been habituaily gloomy, This appears in his Raselas, and in many passages of his writings. It was also a striking part of the character of Dr. Johnson, that with powers of mind that did ho. nour to human nature, he had weaknesses and prejudices that seemed suited only to the lowest of the species. His piety was strongly tinc, 'tured with superstition and we are astonished to find the author of the Rambler expressing serious concern, because he had put milk into his tea on a Good Friday. His custom of praying for the dead, though unsupported by reason or by scripture, was a less irrational superfti. tion. Indeed, one of the great features of Johnson's character, was a degree of bigotry, both in politics and in religion, which is now feldom to be met with in persons of a cultivated understanding. Few other men could have been found, in the present age, whose political bigotry would have led them to style the celebrated John HAMEDEN " the zealot of rebellion;" and the religious bigotry of the man, who, when at Edinburgh, would not go to hear Dr. Robertson preach, because he would not be present at a Presbyterian assembly, is not easily to be paralleled in this age, and in this country. His habitual incredulity with respect to facts, of which there was no reafonable ground for doubt, as itated by Mrs. Piozzi, and which was remarked by Hogarth, was also a singular trait in his character; and especially when contrasted with his fuperftitious 'credulity on other occasions. To the close of life, he was not only occupied in forming schemes of religious reformation, but even to a very late period of it, he seems to have been solicitous to apply himself to ftudy with renewed diligence and vigour. It is remarkable, that, in his fixtyfourth year, he attempted to learn the Low Dutch language ; and, in his fixty-seventh year, he made a resolution to apply himself * vigorously to study, particularly of the Greek and Italian tongues."

The failes and the foibles of JOHNSON, whatever they were, are now descended with him to the grave; but his virtues should be the object of our imitation. His works, with all their defects, are a moft valuable and important accellion to the literature of England. His political writings will probab!y be little read, on any other account


chan for the dignity and energy of his style ; but his Dictionary, his moral effays, and his productions in polite literature, will convey useful instruction, and elegant entertainment, as long as the language in which they are written thall be underitood; and give him a jurt claim to a distinguished rank among the best and ableit writers that England has produced.'

We shall conclude this article with another, but more brief, sketch of Dr. Johnson's character, firuck out, currente calamo, a few years before his death, by a celebrated northern writer, in a familiar letter to a literary friend: .

"Ichink not highly of his learning, but very highly of his understanding; as a critic he is to be read with caution: his Itrong sense often directs him righr; he is then great; but his prejudices often mill-ad his judgment : in his te'mper he is bene. volent, in his life charitable to an extreme; in his writings he is four, contemptuous, and malignant: with these faults, if he had not great virtues, he would be insufferable; with these virtues, it he had no: great faults, he would be highly respectable : nay, with all his faulis he must be respected." ART. VIII. A Diljertation on the Antiquity of the Earth, read at the • Royal Society, 12th of May, 1785. By the Rev. James Douglas, · F. A. S. 4to. 105. 61. Boards. Nicol. 1785. . THOUGH we firmly believe that this work was presented

to the Public with a fincere intention of rendering science a material service, yer we are sorry to find that so ftrenuous and warm an advocate for the promotion and advancement of natural knowledge, as the Author seems to be, mould have deviated from the true method of philosophizing, by admitting hypothetical arguments to influence his reasoning, instead of guiding his inquiries by the unerring principles of demonstrative evidence ; and we are the more surprised that he should fall into this error, since he ac. knowledges the superior excellence of the latter in philosophical subjects. Having the passions and prejudices of mankind ta combat, which mathematical certainty can alone effi ctuaily Suppress, we must content ourselves only with making converes of those who have minds sufficiently expansive to listen to bypo. thetical arguments, without the Mackles of Euclid, and the va. nity of displaying their own learning and pedantry. Much may be said in favour of that restriction which the human mind would be subject to, when, on the flight of imagination, it may be in. duced to foar to the dangerous regions of conjecture; but were we only to admit mathematical argument into our inquiries, men would be restrained from their ardour of conception, and becoming languid in their pursuits alter knowledge, they would fink into a lasting supineness.' Pref. p. v.

We should insult the judgment of our readers were we to offer any remarks upon a pallage lo inconsistent with the present crue mode of pursuing philosophical inquiries,


« AnteriorContinuar »