native city, and studied mathematics, philosophy, and medicine. He then visited the principal medical schools of the continent, particularly those of Paris, where he cultivated his favourite study of botany, under the celebrated Bernard Jussieu. In 1749, he returned to Scotland, and, in the commencement of the following year, took his degree of M.D. at the University of Glasgow, and commenced practice at Edinburgh. After a highly successful professional career of about ten years, he was, in 1761, on the death of Dr. Alston, appointed professor of botany and materia medica, king's botanist for Scotland, and superintendent of the royal garden. The indefatigable zeal and attention, however, with which he pursued his duties as a lecturer, impairing his health, he, in 1768, resigned his office, as teacher of materia medica, and was nominated, by a new commission from the king, regius professor of medicine and botany. At the same time, his other appointments were confirmed to him for life; an honour strongly indicative of his merit, as they had never been given to others but as a temporary grant. He had, in the year last mentioned, been elected physician to the Royal Infirmary; and, in addition to the distinctions he thus received at home, was honoured by the insertion of his name, as a member of several celebrated foreign societies, besides having been elected a fellow of the Royal Society in London. He was held also in high estimation by Linnæus, who placed him among the first class of botanists, and called, after his name, the beautiful shrub Hopea. On Linnæus, indeed, he seems to have had a claim of gratitude as well as esteem; for, according to Dr. Pulteney, “ the adoption of the doctrines of Linnæus by those learned professors, Drs. Hope and Martyn, was the era of the establishment of the Linnæan system in Britain." His death took place on the 10th of November, 1786; "at a time," says Dr. Duncan," when he was holding the distinguished office of president of the Royal College, and might be justly considered at the very head of his profession in Edinburgh."

Scotland is much indebted to Dr. Hope for the improvements he made in

her botanical resources, and for the establishment of a new botanical garden at Edinburgh, where, a short time after its cultivation, were to be seen "the rarest plants of every country, on a spot, which, but a few years before, was considered as little better than a barren waste, hardly producing even a pile of useful grass." He also prevailed upon government, through the medium of the Duke of Portland, to institute a permanent fund for its support; and "indeed," continues the authority just quoted, "to Dr. Hope, who was the first mover in everything respecting that garden, his country in particular, and science in general, are indebted for all the advantages resulting from that establishment." As a proof of his zeal for the diffusion of his favourite science, it may be stated that he prolonged the course of lectures to an equal length with any other at the university; and, at his own expense, gave away an annual gold medal.

He is said to have left, incomplete, an extensive botanical work, to which he had devoted many years; but, his only original compositions in print, are, two articles in the Philosophical Transactions, one on the Rheum palmatum, and the other on the Ferula assafoetida. These illustrate his anxiety to render botany subservient to the arts more immediately useful in life, but particularly to medicine; and, by the former publication, he succeeded, in conjunction with Sir Alexander Dick, in introducing the practical cultivation of rhubarb in Britain. In this, he was so far successful, as entirely to supersede the necessity of sending abroad for that medicine; he was not able to accomplish as much in the assafœtida plant; but he proved that, by proper cultivation, it was capable of being brought nearly to the state of perfection at which it arrives in its native soil.

The character of Dr. Hope was marked by considerable warmth of temper, generosity, liberality, and an enthusiastic earnestness in the pursuit of science, and the encouragement of merit. About ten years after his commencing practice, he married Miss Stevenson, a physician's daughter, at Edinburgh, by whom he had four sons and one daughter.

VOL. III.

JAMES HUTTON, the son of a merchant in Edinburgh, was born in that city on the 3rd of June, 1726. He lost his father when very young, and was sent by his mother to the high school, and, afterwards, to the University of Edinburgh, of which he was entered a student in 1740. His taste for chemistry was first awakened by an observation of Mr. Stevenson, professor of logic, who happened to mention, as an illustration of some particular doctrine, the fact that gold is dissolved in aqua regia; and that two acids, which can each of them singly dissolve any of the baser metals, must unite their strength before they can attack the most precious. Young Hutton immediately sought for such books as might give him further instruction respecting this phenomena; one of which was Harris's Lexicon Technicum, a work which at once fixed his predilection for the science of chemistry.

In compliance, however, with the wishes of his friends, he was, in 1743, apprenticed to Mr. George Chalmers, writer to the signet; but, unable to restrain the bent of his mind, he devoted more of his time to making experiments, than to the transcribing of law papers. Mr. Chalmers perceiving this, advised him to select some other profession, and generously freed him from the articles into which he had entered with himself. He, in consequence, selected that of medicine, as most nearly allied to chemistry; and, in 1744, was entered a medical student of the university. In 1747, he went, for improvement, to Paris; and, after a stay there of about two years, returned home by way of the low countries, and took the degree of M. D. at Leyden, in 1749. On coming to London, however, at the end of the year, he altered his views with respect to the pursuit of medicine as a profession, and ultimately came to a resolution to abandon it altogether. This was in consequence partly of the want of an opening at that time for a physician in Edinburgh, and, partly, of a correspondence into which he had

entered with a friend respecting the joint establishment of a manufacture of sal ammoniac from coal-soot. This was some time before it took place; however, on coming to Edinburgh, in the summer of 1750, Dr. Hutton relinquished all idea of practising, and turned his attention to agriculture. He went, for some time, into Norfolk, where he took up his residence in the house of one Dybold, a farmer, who was at once his preceptor and his host The pursuit of rural economy led him to make frequent excursions into various parts of England; and it was in the course of these journies that he first began to study mineralogy, by way of amusing himself on the road. In a letter to Sir John Hall, written in 1753, he says, that he was become very fond of studying the surface of the earth, and was looking with anxious curiosity into every pit, or ditch, or bed of a river, that fell in his way; and that "if he did not always avoid the fate of Thales, his misfortune was certainly not owing to the same cause." The antiquity of husbandry in Flanders, induced him to pay that country a visit in 1754; whence he returned, in the summer of the same year, with an accession of agricultural and mineralogical knowledge. He fixed upon his own farm in Berwickshire as the place of his agricultural operations, and remained there till about the year 1768, with the exception of a few months, occupied by him in an excursion to the north of Scotland. His improvements in tillage were soon conspicuous on his farm; and he has the credit of being one of the first who introduced the new husbandry into a country where it has since made more rapid advances than in almost any other part of Great Britain. The sal ammoniac establishment, to which we have before alluded, appears to have been founded during Dr. Hutton's residence in Berwickshire; but it was not till 1765, that the subject of our memoir became a regular partner in the concern.

Dr. Hutton now took up his resi

dence at Edinburgh; and having let his farm to advantage, began to confine his attention to scientific pursuits. In the course of a variety of experiments, he discovered, for the first time, that mineral alkali is contained in zeolite, a fact which the experiments of M. Klaproth, Dr. Kennedy, and others, have since confirmed. In 1774, he made a mineralogical tour into Wales; and, in 1777, he gave to the world his first publication, under the title of Considerations on the Nature, Quality, and Distinctions of Coal and Culm. This little pamphlet was designed to answer a question, which began to be much agitated, and at length came before the privy-council, whether the small coal of Scotland is the same with that of England, and whether it ought to be carried coastwise, free of all duty. The result was, the exemption from the paymentduty of the small coal of Scotland; which was owing, in a great degree, to the satisfactory information given by Dr. Hutton on the subject, in the above pamphlet.

Dr. Hutton had, from the period of his fixing his residence in Edinburgh, been a member of the Philosophical Society, before which he read several papers, but the only one published was that On Certain Natural Appearances of the Ground on the Hill of Arthur's Seat. It appeared in the second volume of the Transactions of the Royal Society of Edinburgh, shortly after the incorporation of that body with the one above-mentioned, in 1783. It was to the Transactions of this Society also that Dr. Hutton communicated his account of the theory of the earth, a subject upon which he had been engaged nearly thirty years. The distinguishing feature of this theory, which has been so ably illustrated by Professor Playfair, is, the universal agency of heat in consolidating the rocky strata, after the materials of which they were formed had been collected by the subsiding of loose, earthy materials, at the bottom of the sea; and the heat he conceived to be seated in the central parts of the earth. The elevation of the strata from the bottom of the sea to the higher situations, which they have since occupied, he ascribes to the expansive power of heat acting on water or other bodies; and he thus accounts

on

for the present appearances. He supposes the earth to have undergone many revolutions at very distant intervals of time, and to be subjected to a law which produces a general and sudden convulsion, as a stage in certain cycles of changes, which at all other times are slowly, yet incessantly advancing. This theory, as Dr. Playfair observes, rests, as to its evidence, partly on its conformity to analogy, and partly the explanation which it affords of certain phenomena in the natural history of the earth. The degree of this evidence will be considered differently by different minds; Dr. Hutton, certainly thought that the conclusion to which he had come, founded upon the fact of the liquefaction of mineral substances by heat, (which he considered completely established) was indisputable. No other proof, in his opinion, seemed necessary; nor did he appear to think that the direct testimony of experiment, could it have been obtained, would have added much to the credibility of the results deduced from this part of his system. "For my part," says his biographer and illustrator, "I will acknowledge, that the matter appears to me in a light somewhat different; and though the arguments of Dr. Hutton are sufficient to produce a very strong conviction, it is a conviction that would be strengthened by an agreement with the results even of such experiments as it is within our reach to make. It seems to me, that it is with this principle in geology, much as it is with the parallax of the earth's orbit in astronomy; the discovery of which, though not necessary to prove the truth of the Copernican system, would be a most pleasing and beautiful addition to the evidence

by which it is supported. So, in the Huttonian geology, though the effects ascribed to compression are fairly deducible from the phenomena of the mineral kingdom itself, compared with certain analogies which science has established; yet the testimony of direct experiment would make the evidence complete, and would leave nothing that credulity itself could possibly desiderate."

The Huttonian theory, however, was received with indifference by the scientific world, probably on account of the many unsatisfactory geological theo

ries that had before appeared. Mr. Playfair, however, confesses that other reasons contributed to prevent the Huttonian theory from making a due impression: it was proposed too briefly, and with too little detail of facts, for a system which involved so much that was new, and opposite to the opinions generally received. Dr. Hutton's succeeding works were, On the Theory of Rain; Physical Dissertations; Dissertations on different Subjects of Natural Philosophy; An Investigation of the Principles of Knowledge, and the Progress of Reason from Sense to Science and Philosophy, in three quarto volumes; and, in 1795, his Theory of the Earth, in two volumes, was published in consequence of an attack which had been made upon his doctrines by Mr. Kirwan. He left behind him a third volume, which is still in manuscript, together with a volume of Elements of Agriculture. These works formed his

latest occupations, and were nearly ready for the press a short time before his death, which took place on the 26th of March, 1797.

Dr. Hutton was simple in his manners, but extremely animated and forcible in conversation; and, whether serious or gay, full of ingenious and original information. His general character was highly amiable, and no man was more esteemed by his friends. In person, he was slender, but active, with a thin countenance, high forehead, and a keen penetrating eye; but full of gentleness and benignity. With respect to his intellectual capacities, "none,' says his biographer, "was more skilful in marking the gradations of Nature, as she passes from one extreme to another; more diligent in observing the continuity of her proceedings; or more sagacious in tracing her footsteps, even where they were most lightly impressed.

THIS eminent naturalist was born at Downing, in Flintshire, in 1726. He received his school education at Wrexham and at Fulham, whence he was sent to the University of Oxford, with a view of studying jurisprudence. A decided bent, however, towards natural history prevented him from following the law as a profession. He imbibed his taste for the former science as early as his twelfth year, from a perusal of Willoughby's Ornithology; and for mineralogy, by making a tour into Cornwall, in 1746, in company with Dr. Borlase. In 1754, he was elected a fellow of the Society of Antiquaries; and, in the following year, an account which he sent to Linnæus, of a concha anomia, procured his enrolment as a member of the Royal Society of Upsal. In 1761, he published his British Zoology, in one hundred and thirty-two coloured plates, for the benefit of the Welch Charity Schools. He republished it some years afterwards; added a volume relative to reptiles and fishes; and another, containing the vermes, testaceous, and crustaceous animals.

The death of his wife, to whom he had been married about eight years, induced him, in 1765, to visit the continent, where he became known to the most distinguished scientific foreigners of the day. In 1767, he was elected a fellow of the Royal Society; and, in 1770, the University of Oxford presented him with the degree of LL.D. In the previous year he had published his Indian Zoology; and, about the same time, he made a journey into Scotland, an account of which he published in 1771. His description of a country, at that time but partially known to England, was read with interest and avidity, and induced the author to visit the Hebrides, in 1772, of which islands he gave a most entertaining and valuable account. He now became an habitual tourist; and, after visiting the northern counties of England, made several excursions in his native country, the result of which he gave to the public in 1778, in one quarto volume, with plates, entitled A Tour in Wales; followed, in 1781, by A Journey to Snowdon.

He also published, in two volumes, quarto, his History of Quadrupeds, of which a synopsis had previously appeared; and, in the Philosophical Transactions of the same year, was inserted his History and Natural History of the Turkey. In 1785, came out, in two volumes, quarto, his Arctic Zoology, containing quadrupeds and birds, with a copious introduction prefixed, which has been considered the most interesting and original of all his writings. His London, however, is, perhaps, his most popular work, and has been preferred to all other publications of the class, both for its style and matter. In 1793, he printed his autobiography, in which he announced his intention of resigning authorship; but his habits were too strong for his resolution. He employed his time in writing an account of the History of the Parishes of Whiteford and Holywell, in which he gives a garrulous but vivacious account of many particulars of his family history. It appeared in 1796, and was succeeded by a View of Hindostan, in 1798, in which year our author died, at the age of seventy-two. He had married a second wife in 1776, the sister of Sir Roger Mostyn, and left families by both marriages.

Mr. Pennant, who was a member of several foreign societies, was gentle

manlike and agreeable in his manners, a cheerful companion, and warm friend. His light, rapid, and vivacious style, render him one of our most amusing topographical writers; though, for want of sufficient care, he is frequently incorrect. He is chiefly distinguished as a natural historian; in which character he is considered as very respectable authority, and has the merit of being clear and judicious in his principles of arrangement, and concise, energetic, and, for the most part, exact in his descriptions.

The following anecdote has been told of him:-Among other peculiarities, he had a great antipathy to a wig, which however, he could suppress, until reason yielded to wine. Dining once at Chester, with an officer who wore a wig, Mr. Pennant became half seas over; when another friend, that was in company, carefully placed himself between Pennant and the wig, to prevent mischief. At length, however, after much patience, and many a wistful look, Pennant started up, seized the wig, and threw it on the fire. Down stairs ran Pennant, and the officer, with his sword, after him, through all the streets of Chester; but Pennant, from his superior knowledge of topography, escaped. This was, whimsically enough, called Pennant's Tour through Chester.

THIS eminent chemist was born of British parents, at Bordeaux, in 1728. He was intended for the medical profession, and received his education at the grammar-school of Belfast and the University of Glasgow, which latter he entered in 1746. Here he became one of the favourite pupils of the celebrated Cullen, whose excellent method of instruction in chemistry, though not a first-rate chemist himself, gave Black a decided preference for that science. He assisted his master in several of his experiments; and on taking his degree of M. D., at Edinburgh, in 1754, he chose a chemical topic. It was a treatise entitled De humore acido a cibris orto et Magnesia Alba; and, in the next year, he communicated his further

ideas on the subject, in a paper, read before a society in Edinburgh, containing Experiments on Maguesia Alba, Quick Lime, and some other Alkaline Substances. In this paper, which was published in the second volume of The Essays, Physical and Literary, 1756, he gave an account of one of the most important discoveries in chemistry, and which is generally considered as the source of much that has immortalized the name of Cavendish, Priestley, and others, memorable for their acquisitions in the knowledge of aërial bodies. This was no other than the existence of an aërial fluid, which he denominated fixed air, the presence of which gave mildness, and its absence causticity, to alkalies and calcareous earths.