bound by a voluntary resignation of all their rights to a single person, or to a few, it can never be supposed that the resignation is obligatory on their posterity, because it is manifestly contrary to the good of the whole that it shall be so. From this first principle he deduces all his political maxims, and he never afterwards wavered or varied in his opinions on the subject. Though, however, he approved of a republic in the abstract, yet considering the habits and prejudices of the people of Great Britain, he laid it down as a principle that their present form of government was best suited to them. animosity. Indeed, his necessarian principles coincided with his temper in producing a kind of apathy to the rancour and abuse of antagonists. In his intellectual frame were combined quickness, activity, acuteness, and the inventive faculty which is the characteristic of genius. These qualities were less suited to the laborious investigations of what is termed erudition, than the argumentative deductions of metaphysics, and the experimental researches of natural philosophy. Assiduous study had, however, given him a familiarity with the learned languages sufficient, in general, to render the sense of authors clear to him, and he aimed at nothing more. In his own language, he was contented with facility and perspicuity of expression, in which he remarkably excelled." In summing up the character of Dr. Priestley, as a whole, we cannot do better than quote the words of Mr. Kirwan, which have been adopted by almost all the doctor's biographers:"He was a man of perfect simplicity To this account of Mr. Kirwan, we of character, laying open his whole may add some particulars from Dr. mind and purposes on all occasions, Thomson's Biographical Memoir. He and always pursuing avowed ends by was an early riser, and always lighted direct means, and by those only. In his own fire before any one else was integrity and true disinterestedness, awake; and it was then that he comand in the performance of every social posed almost all his works. His powers duty, no one could surpass him. His of conversation were very great, and temper was easy and cheerful, his his manners in every respect extremely affections were kind, his dispositions agreeable; these were, however, perfriendly. Such was the gentleness and fectly simple and unaffected; and he sweetness of his manner in social inter- continued all his life as ignorant of the course, that some who had entertained world as a child. Of vanity, he is said the strongest prejudices against him, on to have possessed a more than usual account of his opinions, were converted share; but was rather, perhaps, defiinto friends on personal acquaintance. cient in pride. He allowed himself Of the warm and lasting attachment of but little recreation; for his favourite his more intimate friends, a most amusement was playing on the flute, honourable proof was given, which he an instrument on which he performed did not live to be made acquainted tolerably well; and he generally rewith. It being understood, in England, commended music as a relief to the that he was likely to suffer a loss of studious. It was his constant practice, £200 in his annual income, about forty another of his biographers says, to persons joined in making up a sum of employ himself in various pursuits at £450, which it was intended to be the same time; whereby he avoided the continued annually during life. No languor consequent upon protracted man who engaged so much in con- attention to a single object, and came troversy, and suffered so much from to each, in turn, as fresh as if he had malignity, was ever more void of ill- spent an interval of entire relaxation. will towards his opponents. If he were This effort he pleaded as an apology to an eager controversialist, it was be- those who apprehended that the great cause he was much in earnest on all diversity of his studies would prevent subjects in which he engaged, and not him from exerting all the force of his because he had any personalities to mind upon any one of them; and, in gratify. If, now and then, he betrayed fact, he proceeded to such a length, in a little contempt for adversaries whom every pursuit that interested him, as he thought equally arrogant and in- fully to justify, in his own case, the capable, he never used the language of rule which he followed. We shall conclude our memoir with a sketch of the merits of its subject, by the late eminent Professor Playfair; an authority so valuable should not be omitted, especially as it has not before been adduced by any of the biographers of Priestley. "On the whole," says Mr. Playfair, "from Dr. Priestley's conversation, and from his writings, one is not much disposed to consider him as a person of first-rate abilities. The activity, rather than the force, of his genius, is the object of admiration. He is indefatigable in making experiments, and he compensates, by the number of them, for the unskilfulness with which they are often contrived. Though little skilled in mathematics, he has written on optics with tolerable success; and though but moderately versed in chemistry, he has done very considerable service to that science. If we view him as a critic, a metaphy sician, and a divine, we must confine ourselves to a more scanty praise. In his controversy with Dr. Reid, though he has said many things that are true, he has shewn himself wholly inca pable of understanding the principal point in debate; and when he has affirmed that the vague and unsatisfactory speculations of Hartley have thrown as much light on the nature of man, as the reasonings of Sir Isaac Newton did on the nature of body, he can hardly be allowed to understand in what true philosophy consists. As to his theology, it is enough to say that he denies the immateriality of the soul, though he contends for its immortality, and ranges himself on the side of Christianity. These inconsistencies and absurdities will, perhaps, deprive him of the name of a philosopher, but he will still merit the name of a useful and diligent experimenter." EDWARD WARING. EDWARD WARING, descended from an ancient family at Milton, in the county of Salop, was born in the year 1734. He received his education at Shrewsbury free-school, and at Magdalen College, Cambridge, where he soon became one of the most distinguished mathematical students. He took his bachelor's degree in 1737, and went through his examination, on the occasion, in such a manner as to be considered a perfect prodigy. In 1759, he was elected Lucasian professor; but the appointment of so young a man to a situation which had been filled by Newton, Saunderson, and Barrow, gave great offence to the senior members of the university. This induced Waring to circulate the first chapter of his Miscellanea Analytica, in vindication of his scientific character, and the consequence was a controversy of some duration. It was commenced by Dr. Powell, master of St. John's, who attacked Waring's production in a pamphlet, which was ably answered by Mr. Wilson (afterwards Sir John Wilson, a judge of the Common Pleas,) in behalf of the subject of our memoir. Dr. Powell replied in 1760; and, in the same year, the degree of M. A. was conferred upon Mr. Waring by royal mandate. In 1762, appeared the whole of his Miscellanea Analytica, published in quarto, from the university press, with a dedication to the Duke of Newcastle. This work extended his reputation over all Europe he was elected, without solicitation, member of the societies of Bologna and Gottingen, and received various marks of esteem from the most eminent mathematicians, both at home and abroad. It was written upon the abstrusest parts of algebra, but the author's own words will give the best idea of the nature of this work :-" I have myself wrote," he says, "on most subjects in pure mathematics, and in these books inserted nearly all the inventions of the moderns with which I was acquainted. In my prefaces I have given a history of the inventions of the different writers, and ascribed them to their respective authors, and likewise some account of my own. To every one of these sciences I have been able to make some additions; and, in the whole, if I am not mistaken in enumerating them, somewhere between three and four hundred new propositions of one kind or other, considerably more than has been given by any English writer; and in novelty and difficulty not inferior; I wish I could subjoin, in utility. Many more might have been added, but I never could hear of any reader in England, out of Cambridge, who took the pains to read and understand what I have written. But I must congratulate myself that D'Alembert, Euler, and Le Grange, three of the greatest men in pure mathematics of this or any other age, have since published and demonstrated some of the propositions contained in my Meditationes Algebraicæ or Miscellanea Analytica, the only book of mine they could have seen at that time; and D'Alembert and Le Grange mention it as a book full of interesting and excellent discoveries in algebra. Some other mathematicians have inserted some of them in their publications. The reader will excuse my saying so much, there being some particular reasons which influenced me." These "particular reasons" had, no doubt, relation to the attack which had been made on his scientific capabilities, and are, therefore, a sufficient apology for the egotistical vein in which he vindicates his pretensions to mathematical skill. Mathematics, however, were not the sole object of the attention of Mr. Waring, who appears to have been intended for the medical profession. After having pursued the study of physic for some time, he took his degree of M. D. in 1767; and, subsequently, attended the lectures and hospitals in London, but it does not appear that he ever enjoyed extensive practice as a physician. For this, other reasons have been given besides his fondness for scientific pursuits, which supplied him with an inexhaustible fund of amusement and occupation. These are, his possession of a very handsome patrimonial fortune, and an embarrassment of manner before strangers, which operated much against his success in a profession, one of the chief requisites of which consists in an engaging address. His Meditationes Algebraicæ, to which he alludes in the quotation we have made from his writings, were published in 1770, at which time he resided at St. Ives, in Huntingdonshire. In 1772, appeared his Proprietates Algebraicarum Curvarum; and, subsequently, his Meditationes Analytica, which were in the press during the years 1773, 1774, 1775, and 1776. In the latter year, he married, and went to reside on his own estate at Paisley, about eight miles from Shrewsbury, where he continued to prosecute, with unabated diligence, his mathematical inquiries. A variety of papers, which he had communicated to the Transactions of the Royal Society, procured him, in 1784, the Copleian medal; and, in 1794, he evinced the attention he had paid to studies of a more popular and familiar nature, by printing, though, it seems, he never published, An Essay on the Principles of Human Knowledge. From Paisley, Dr. Waring occasionally proceeded to London, on a visit to the board of longitude, of which he was a member, but seldom remained long in the metropolis. He died in consequence of a violent cold, caught whilst he was superintending the repairing of his house, in August, 1798. The private character of Dr. Waring was highly respectable; it was marked by inflexible integrity, as well as great modesty. In his manner he was exceedingly simple and plain, yet he was almost looked up to with reverence by those who knew, from his writings, the superiority of his understanding. As a mathematician, he was undoubtedly one of the most eminent of his day; and is, according to his own account, the discoverer of nearly four hundred propositions in the analytics. This, says his biographer, may appear as a vainglorious boast, especially as the greater part of these discoveries, from their abstruse nature, are likely to sink into oblivion; but he was, in a manner, compelled to make it, by the insolence of Lalande, the celebrated French astronomer, who, in his life of Condorcet, asserts, that, in 1764, there was no first-rate analyst in England. Waring replied to this assertion in a letter to Dr. Masklelyne; in which, after mentioning the inventions and writings of several English mathematicians, of whom two were living in 1764, he gives a full and impartial detail of his own discoveries, many of which were published prior to that year. To use his own words, however, few thought it worth while to read even half of his works; a neglect ascribed, by his biographer, to a perplexity both in the style and manner of his calculations. The reader, it is said, is stopped at every instant, first to make out the author's meaning, and then to fill up some chasm in the demonstration. He must invent anew every invention; for after the enunciation of the theorem or problem, and the mention of a few leading steps, little farther assistance is afforded. His papers which he communicated to the Philosophical Transactions have the same fault, though most of them afford very strong proofs of the powers of his mind, both in abstract science and the application of it to philosophy. They are under the following titles:-Mathematical Problems; New Properties in Conics; Two Theorems in Mathematics; Problems concerning Interpolations; A General Resolution of Algebraical Equations; On Infinite Series; On Finding the Values of Algebraical Quantities by converging Serieses, and demonstrating and extending Propositions given by Pappus and others; On Centripetal Forces; On some Properties of the Sum of the Division of Numbers; On the Method of Corresponding Values; On the Revolution of Attractive Powers; and a second paper On Infinite Serieses. THOMAS HENRY. THOMAS HENRY, descended from a respectable family in the county of Antrim, was born on the 26th of October, 1734, at Wrexham, in North Wales, where his father kept a boarding-school. He was educated at the grammarschool of Wrexham, and was to have been sent to Oxford, to study for the church; but, as the time drew near, says his biographer, his parents, who had a numerous family, and were far from being in affluent circumstances, shrunk from the prospect of expenses that were unavoidable, and the uncertainty of eventual success. He was, in consequence, articled to Mr. Jones, an apothecary of his native town, but served the latter part of his apprenticeship under a member of the same profession at Knutsford, in Cheshire. its expiration, he became assistant to a practitioner at Oxford, where he had the opportunity of attending a course of lectures on anatomy, in which the celebrated John Hunter, then a young man, was employed as demonstrator. 1759, he commenced practice on his own account at Knutsford; and, shortly after, married. At the end of five years, he removed to Manchester, where he continued, for nearly half a century, to be employed in medical attendance, for the most part on the more opulent in habitants of the town and neighbourhood. In It is, however, in his character of a chemical philosopher, that we have principally to consider the subject of our memoir. For chemistry, he had manifested a decided taste during his apprenticeship; and had no sooner made himself sufficiently master of what was ascertained in that department of knowledge, than he felt an ambition to extend its boundaries. 1771, he communicated to the Royal College of Physicians in London, An Improved Method of Preparing Magnesia Alba, which he published two years afterwards, with essays on other subjects, in a volume dedicated to his friend, Dr. Perceval. The calcination of magnesia had, at that time, been practised only in connexion with philosophical inquiries: Mr. Henry was the first to make trial of the pure earth as a medicine; to recommend its general use as such; and to lay open to the In scientific world some of its most important chemical properties, which, as ascertained by him, were considered by Bergman and by Macquer, as worthy of being incorporated into their respective histories of magnesia. On Mr. Henry was elected a fellow of the Royal Society in May, 1775; and, in the following year, he translated Lavoisier's Historical View of the Progress of Pneumatic Chemistry, from the time of Van Helmont downwards, with notes by himself. He subsequently translated a series of memoirs, communicated by the same author to the Paris Academy of Sciences, in which the views of Lavoisier, respecting the antiphlogistic theory, are more fully developed. The results of many of Mr. Henry's experimental pursuits were given to the world chiefly through the publications of his friends, Dr. Priestley and Dr. Perceval. The most important of these were some experiments on fixed air, by which he endeavoured to show, that though fixed air is injurious, when unmixed, to the vegetation of plants, yet that, when mingled in small proportions with common air, it is favourable to their growth and vigour. Dr. Priestley, on having these facts communicated to him, told Mr. Henry that he was anxious to make them public, not only for their general merit, but because, in some respects, they differed from the result of his own experiments. The investigation was afterwards resumed by Mr. Henry, and made the subject of a paper, which Mr. Edgeworth, and his daughter, in their celebrated Treatise on Practical Education, recommend, among other works, for the perusal of young persons, as calculated to gratify in them an enlightened curiosity respecting the causes of natural phenomena. Mr. Henry's next discovery was a method of preserving water at sea, by impregnation with lime, on which subject he addressed the Admiralty, in a pamphlet, describing his manner of separating that earth from the water, and the apparatus by which it was effected. About this time, a philosophical society being established at Manchester, Mr. Henry was, in 1781, appointed one of the secretaries, and he subsequently became president. He contributed a variety of papers to its Transactions, two of which deserve particular notice, as having greatly enhanced his reputation as a chemical philosopher. The first of these contains an account of some experiments on ferments and fermentation, by which a mode of exciting fer mentation in malt liquors, without the aid of yeast, is pointed out; with an attempt to form a new theory of that process. The theoretical speculations which this essay contains have been superseded by subsequent discoveries; but the facts, which it gives, are of considerable importance. It was at that time believed that the infusion of malt, called wort, could only be made to ferment by the addition of yeast, or barm; but Mr. Henry discovered that fermentation might be also produced by an impregnation with carbonic acid gas. By this method he was enabled to obtain, not only good beer, but yeast fit for the making of bread; and, from separate portions of the fermented liquor, he procured also ardent spirit and vinegar. The other essay, or paper, to which we have alluded is entitled, Considerations relative to the Nature of Wool, Silk, and Cotton, as Objects of the Art of Dyeing; on the various preparations and mordants requisite for these different substances, and on the nature and properties of colouring matter. In this elaborate essay, after giving a general view of the history of the art of dyeing, he examines, first, the various theories respecting the facility and permanency with which different substances attract colouring matter; and, secondly, the mode of action of those substances, which, though themselves destitute of colour, are important agents in the processes of dyeing. In 1783, Mr. Henry commenced giving lectures on the general principles of chemistry, together with a course on the arts of bleaching, dyeing, and calico-printing. He continued to follow both his professional and scientific pursuits till within a few years of his death, which took place on the 18th of June, 1816. Mr. Henry's private character was most exemplary, and has, together with an account of his life and discoveries, been made the subject of a most eloquent and elaborate éloge, in the Transactions of the Manchester Philosophical Society. In his practise of a physician he was highly successful; and, both in his medical and scientific character, was considered the most eminent man in Manchester. |