The sect of Sylvius propagated a chemical theory of disease. In addition to the Galenical notion of the humours, they supposed the existence of certain chemical operations, among the rest of fermentation, as at one time causing disease, at another aiding the efforts of nature to throw it off. Their practice was founded on the principles of Galen, though they adopted many remedies not indicated by him, but recommended by experience.

In the midst of this confusion of theories, Sydenham arose. He saw that the true mode of investigation was to begin by following nature. As an example of the changes which he introduced into medical practice, we may contrast his treatment of small-pox with that of the physicians of the old schools. By the disciples of Galen and Sylvius, small-pox was supposed to be a disease of the fluids, and the eruption was supposed to arise from the efforts made by nature to throw off the morbid matter. The duty of the physician was, therefore, to aid the efforts of nature towards accomplishing this object, which they did by administering heating remedies, and covering the patient with blankets. Sydenham on the contrary, kept the patient cool, gave laxative medicines and cooling drinks, and in violent inflammatory cases even used the lancet. His doctrine of fevers and his plan of treating them were equally opposed to those prevalent in his day, and remarkably judicious It is surprising that a mind so free from prejudice and error should have at the same time overlooked the contagious nature of small-pox.

Sydenham has also left an excellent treatise descriptive of the plague. His information on the subject was drawn from his experience during the great plague in London in 1665. His practice was unusually successful he trusted almost entirely to blood-letting.

Himself a martyr to the gout, it is fortunate that he has left to us a record of his experience in that disease. His description of it is the most perfect and elegant that we are in possession of, and should be read by every student of medicine. The works of Sydenham are not voluminous, but they are all valuable. He is the father of the school of medicine of the present day; and from his time one of the eras in the science has been dated. Experience and observation are now our guide; hypothetical speculations exercise but little influence upon our practice, and we guide nature only by following her. Boerhaave has pronounced an eloquent and high eulogium on Sydenham in the following words: "Unum eximium habeo Thomam Sydenham, Angliæ lumen, artis Phoebum; cujus ego nomen sine honorifica præfatione memorare erubescerem ; quem quoties contemplor, occurrit animo vera Hippocratici viri species, de cujus erga Rempublicam Medicam meritis nunquam ita magnifice dicam, quin ejus id sit superatura dignitus."

His works appeared in the following order,--On Epidemic diseases, 1675; on the Luis Venereæ, 1680; on Confluent Small-pox, and Hysteria, 1682; on the Putrid Fever of Confluent Small-pox, in the same year; on the Gout and Dropsy, in 1683; a treatise on Fever, 1686; and a treatise on the Practice of Medicine, which was left in manuscript, and was published in 1693. These have been frequently printed, and translated into other languages.

Hon. Robert Boyle.

BORN A. D. 1627.-died A. D. 1691.

THIS distinguished philosopher and admirable man, was the youngest son of the celebrated earl of Cork, and was born at Lismore on the 25th of February, 1627. Genealogists have traced the name of the family to a period anterior to the conquest, and in Doomsday book it is mentioned in conjunction with the estate of Pixley court, near Ledbury, in Herefordshire. The wealth acquired by his father in public employments enabled him to render in return many important benefits to his country, and his family, which consisted of seven sons and eight daughters, largely partook of the esteem and honour he thereby obtained. It has been remarked as a somewhat curious fact, that the subject of this memoir was the only one of the earl's children who did not obtain a title. But the care with which he was brought up, and the abilities he derived from nature, made ample amends for his want of factitious dignity, and while he was the only one of the family left untitled, he is the only one whom posterity has universally consented to regard with reverence. His mother died when he was but three years old, but his father fearing the effects of his being injudiciously nursed at home, had placed him under the care of a woman in the country, whom he directed to pursue the same plan with his son as she did with her own children. His directions being attended to, he had the satisfaction to see their good effects in the rustic health and vigour which characterized the youth of our philosopher, and the subsequent sacrifice of which to a less rational mode of treatment he had so much reason to deplore. On his reaching his seventh year it was deemed expedient to place him under the care of a tutor, and the person selected for the purpose of initiating him in the knowledge of Latin and French, was one of his father's chaplains, a native of France, and a man who appears to have been well-qualified for the task with which he was charged. But when little more than eight years old, his young pupil was removed to Eton, where, under the care of Mr Harrison, the then master of the school, he gave the most evident indications of those valuable endowments which were afterwards to be so usefully exerted in the cause of truth. His attention to study was unremitted, and the advancement of his mind was not inferior to the industry with which he laboured to improve it. The same sensibility to moral and religious impressions,-the same judicious and resolute attention to the most profitable modes of mental discipline, for which he was remarkable in after life, formed even at this early period part of his character. In the course of his residence at Eton, he met with several accidents which put his life in imminent danger. His preservation in these dangers he attributed solely to the merciful intervention of Providence; and when he found that the indulgence he had given himself in reading romances to wile away the languor of sickness, had weakened his aptitude for reflection, he resolved on commencing the study of mathematics.

On leaving Eton, where he remained but four years, he repaired to his father's residence at Stalbridge in Dorsetshire, and endeavoured,

under another tutor, to recover his knowledge of the classics, which, it is said, he had been allowed to neglect at Eton for other pursuits. In 1638 he was sent, accompanied by one of his brothers, to finish his studies at Geneva. He resided in that city with a Mr Marcombes, a person of considerable learning and ability, and with his assistance, he became acquainted with the principal branches of natural philosophy. So well versed also did he become in French, that he for some time employed that language in preference to English. The most interesting circumstance, however, recorded of this period of his life, is the sensible change which now took place in his religious feelings. Allusion has already been made to the susceptibility of his mind on the subject of providential interferences; but this feeling is not necessarily connected with religious belief, properly so called, and he had not, it appears, till the time of which we are speaking, paid any serious attention to the evidences on which it rests. There were, however, two main principles in his mind, which form, as it were, the natural soil of religion,—a keen apprehension, namely, of what is morally right and excellent, and an equally keen desire to arrive at truth. The former of these rendered him more than commonly alive to every indication of Divine power, the latter at length led him to inquire with profound attention into the modes of its developement. It was on the occasion of an awful thunder-storm, which awoke him one night out of a deep sleep, that he first felt himself called upon to examine the situation in which he stood with respect to the solemn warnings of Christianity. The feelings which then had birth in his mind were farther increased by the visits which he paid to the Carthusian monastery at Grenoble, where he appears to have been assailed by all those conflicting emotions so natural to a youthful mind, in which reason and imagination as yet held disputed sway. While suffering under the distressing sensations produced by this state of feeling, he began a serious examination of the evidences,—a labour for which he was rewarded by a firm and settled conviction of the truth. At the time when he thus anxiously devoted himself to religious inquiry, he was but fourteen, and had we not ample proofs of the advances he had made in other pursuits beyond the attainments usual at that age, we might be disposed to regard his religious progress as nothing more than the effect of youthful enthusiasm. But he had already learnt to reason; his mind was naturally cautious in its operations, and he had by this time acquired a sufficient stock of scientific knowledge to counterbalance the workings of any idle fancy. The method, therefore, which he pursued with regard to religion was the same which he had employed in the acquisition of other truth. "The perplexity," he himself says, "which his doubts had created, obliged him, in order to remove them, to be seriously inquisitive of the truth of the very fundamentals of Christianity; and to hear what both Greeks and Jews, and the chief sects of Christians, could allege for their several opinions, that so, though he believed more than he could comprehend, he might not believe more than he could prove, and not owe the steadfastness of his faith to so poor a cause as the ignorance of what might be objected against it." After a stay of about two years in Geneva, he proceeded to Italy, but while on his return from that country he received intelligence from his father, that owing to a rebellion in Ireland he could barely afford to send him the sum necessary to bring him and his brother to England. Even the order

transmitted for this purpose never reached him, and he was obliged to the kindness of his tutor, Mr Marcombes, for support during the two years he was necessitated to remain in Geneva after the receipt of his father's letter. Anxious at the end of that period to make their way home, the young men had no other means of doing so than by obtaining some jewelry on Mr Marcombes' credit, and selling it at the different stages of their journey. On their arrival in England they found that the earl had been dead nearly a year, and though the subject of our memoir received as his inheritance the estate at Stalbridge, and others of great value in Ireland, he was obliged, for want of money, to reside four months in the house of his sister, Lady Raneleigh. His affairs being at length settled, through the powerful interest of his friends, he took up his abode at Stalbridge; and thus placed in the enjoyment of wealth and tranquillity, resumed his literary occupations with redoubled ardour. With most of the celebrated men of the day he was on terms of close intimacy, and his general correspondence affords convincing evidence of the strong interest he took in the progress of every species of scientific investigation. In those times of trouble and contention he preserved a spirit of unchanging charity and benevolence. Though not wanting in zeal for the promotion of his principles, he never allowed it to warp the mild and generous sentiments of Christian brotherhood, and he declared with equal wisdom and goodness, that for his part, he could never observe in any church-government such transcendant excellency, as could oblige him either to bolt heaven against, or open Newgate for, all those who believed they might be saved under another. About this period he produced his essay on 'Mistaken Modesty;' 'the Free discourse against Customary Swearing;' and his Seraphic Love; each of which contains striking indications of his amiable feeling and correct judgment. Nearly the same date may also be assigned for his union with the Invisible or Philosophical college as it was termed, and which formed the germ of the Royal society. But his philosophical studies did not prevent his faithful adherence to the resolution he had formed to examine the ground works of religion, and in 1652 he wrote an essay on the Scriptures. This was a work of labour and inquiry. He prepared himself for the task by not only weighing the opinions of critics and commentators, but by the careful study of the original languages. "Reflecting," says he, "often on David's generosity, who could not offer, as a sacrifice to the Lord, that which cost him nothing, I esteem no labour lavished that illustrates or endears to me that divine book; and think it no treacherous sign that God loves a man, when he inclines his heart to love the Scriptures, where the truths are so precious and important, that the purchase must, at least, deserve the price. And I confess to be none of those lazy persons who seem to expect to obtain from God a knowledge of the wonders of his book upon as easy terms as Adam did a wife, by sleeping soundly."

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Finding it necessary to visit Ireland in the year 1654, he employed the few months he spent there in the study of anatomy, having for his tutor and companion in the pursuit, Dr William Petty, a man of great skill and erudition. On his return to England, he fixed his residence at Oxford, in order to enjoy a more frequent intercourse with his learned associates than he could while at Stalbridge. The meetings of the Invisible college were now regularly held at the several lodgings

of the members, and the conferences which took place among them led the way for that experimental study of natural philosophy to which science has been ever since so largely indebted. Boyle himself was ever among the most active and persevering of the inquirers, and one of the earliest results of his labours was the invention of the air-pump, which at once changed the whole aspect of pneumatical science. The first instrument of this kind that had ever been produced, was invented by a counsellor of Magdeburg, named Otto Guericke, and an account of which was given in the Technica Curiosa, a work published by Schottus, the professor of mathematics in the university of Wirtemberg. From this publication our philosopher simply learnt that the instrument had been invented by Guericke, and that he had now been long employed in making experiments respecting the air, and the relative weights of bodies weighed in that and other fluids: but he eagerly caught at the idea, and produced an instrument, which, though second to that of the Magdeburg counsellor, was sufficiently different to secure him a considerable share of credit as an inventor. The experiments which he made with his air-pump were productive of important improvements, and tended to prove in the most striking manner all those laws explanatory of atmospheric phenomena which had been first investigated by Toricelli, Pascal, Huygens, and some other philosophers on the continent. But even at this period, when his mind might have so easily allowed itself to be engrossed by the pursuits which were daily procuring him some additional praise, he continued to attend with unremitted ardour to the examination of Scripture. This led him to cultivate the acquaintance of the most eminent divines of the age, and so great was the reputation he enjoyed among the best supporters of the church, that after the restoration he was earnestly solicited by the lord-chancellor Clarendon and others, to receive holy orders and devote himself to the ecclesiastical profession. He was only prevented from taking this step by the consideration, that what he wrote in favour of religion as a layman, would have more force with many persons than it would if coming from him as one of the clergy. His reputation and fortune, however, enabled him to effect much good, and in a great variety of ways, for which the government found means to reward him, without raising him to a bishoprick. In 1662 he received a grant of forfeited impropriations in Ireland, and on the re-establishment of the corporation for the propagation of the gospel in New England, he was appointed governor of the society. From both these marks of public favour he drew fresh motives for benevolent exertion. With the income he derived from the Irish lands he maintained industrious clergymen in the several parishes, and improved the condition of the poor. In his capacity of governor to the society above named, he contributed greatly by his individual attention to its interests to promote the prime objects of its institution. The same circumstance also is apparent at this period of his life which we have remarked before, and which, indeed, characterized the whole course of this excellent man's career. Religion and philosophy walked with him side by side, giving to each other mutual support, and to their votary himself continual increase of strength and wisdom. While labouring in the most profitable manner to propagate the gospel, he at the same time shone as one of the first of European philosophers, and in his situation in the council of the newly established