On the afternoon of an autumnal day in the last quarter of the eighteenth century, two gentlemen, who had considerably passed the prime of life, and looked like confirmed, but highly-respectable bachelors, as indeed they were, might have been observed to leave the vicinity of the South Bridge of Edinburgh at a leisurely pace. They had just succeeded in negotiating the hire of a room, where, with several of their literary friends, they proposed to hold a convivial meeting once during every week of the winter that was coming on. In pretty light spirits, from having proved themselves men of the world by bringing this important matter to a satisfactory conclusion, they were—it might be—discussing and denouncing the ridiculous prejudice, as they believed it to be, which prevented their countrymen making use of snails as an ordinary article of food, and vowing that they would, ere long set an example in this respect which should have the effect of divesting the public mind of such an absurd delusion; though it must be confessed, that when they did attempt to execute this bold intention they suddenly discovered that their appetites had taken an unceremonious flight. Each of these personages was distinguished by amiability of character, and utter unconsciousness of the guile and wickedness that prevailed around him. Their studies and pursuits were somewhat similar; and though frequently taking opposite views of debated questions, they were ever bosom friends. But in dress and manner they presented a striking contrast. One wore on his slender but active person garments plain to affectation, and might have easily passed for a member of the Society of Friends but for his cocked hat. He conversed with force and animation, always displaying much original information; but the accents that came from his lips, which parted while listening, were undiluted Scotch; and his bearing was so remarkably simple, that it was necessary to mark the thin, intellectual face, the high, thoughtful forehead, and the keen, penetrating eye, before being aware that he had “stuff” in him, or was more than an ordinary citizen. The other was of a different stamp. He wore a sort of academic dress; but it had received such careful and harmonious additions, as proved that he was by no means indifferent to external decorations and the propriety of costume. His aspect was comely and prepossessing; his manner was correct and graceful; he was evidently a person of elegant tastes and no inconsiderable refinement; and he used a musical voice to speak good English, with a punctilious accuracy of expression not often heard so far north at that time.

The former—the plain, unvarnished Scot—was Dr. Hutton, the ingenious philosopher, who thought out and published the “Theory of the Earth” that goes by his name, having previously shown his public spirit, and rendered essential services to the agriculture of his native country, by bringing, at much exertion to himself, an improved system of husbandry from the rich and fruitful shire of Norfolk, and introducing it into the district where he possessed a small estate. His companion, whose countenance looked that of a being inwardly satisfied with himself and all who came around him, was Dr. Black, the eminent Professor of Chemistry in the northern capital; he whose experiments tended to open up that path of scientific discovery which others have since so successfully pursued.

Joseph Black, than whom few men have ever lived and died more truly respected by his daily associates, was a native of France. He was born in the year 1728, on the banks of the Garonne, hard by the place where that river visits the city of Bordeaux. There his father, who belonged to Belfast, had settled as a wine-merchant, and married the daughter of an individual engaged in the same trade. But with all these temptations and advantages in one of the largest and most opulent of French towns to embark the boy in the commercial pursuits which formed the business of his nearest relatives, young Black was very early destined to a medical career. Arrangements were made with that view; and at the age of twelve the future chemist left his home and native soil, to be fittingly educated at the grammar-school of the flourishing Irish sea-port town from which his worthy sire had emigrated to the fair land of vines. For several years he pursued his preparatory studies in Belfast; and his maternal grandfather being, though resident in Bordeaux, connected by birth and some territorial possession with Scotland, Black was, most likely from that cause, transported in his eighteenth year to Glasgow, and entered as a student at the University. He was immediately introduced to, and patronized by, the Professor of Natural Philosophy, with whose son he formed a juvenile intimacy, which was cemented by the similarity of their tastes.

About the date of Black’s arrival at this college, it happened that the celebrated Cullen—he who influenced the career of Dr. Hunter—made his first public appearance at that seat of learning, in the capacity of Lecturer on Chemistry; his reputation speedily crept abroad, and the attendance at his class became large. The clever and acute French student was brought under the notice of Cullen, who, being frank and generous to his pupils, almost to a fault, made himself perfectly accessible at all hours, and treated them with much respect. He immediately perceived the bent of Black’s genius; and not only recommended, but strongly urged, him to apply himself with determination to cultivate the science of chemistry, and gave him every assistance in doing so. Cullen was not, perhaps, a first-rate chemist himself, but he had an admirable method of imparting instruction; and his gifted pupil’s preference for the study became so apparent, that he was ere long employed to assist his friend and teacher in the experiments of the classroom; and, when thus occupied, exhibited so much address and dexterity as contributed in no small degree to the success and fame of the lectures.

Black was still engaged in medical studies, and in order to complete them under advantageous circumstances he repaired, in 1751, to Edinburgh, where he stayed in the house of a cousin, who held one of the professorships. Having, during three sessions, attended all the requisite classes, he duly took the degree of Doctor of Medicine. On that occasion he chose for his theme a chemical topic—the acid arising from food and magnesia alba. Next year he, “still achieving, still pursuing,” communicated his further ideas on the subject to a scientific society, in a paper which was then read by him, and afterward published in the second volume of “Essays, Physical and Literary,” and gave an account of a most important chemical discovery. This was the existence of an aËrial fluid, which he called fixed air, the presence of which gives mildness, as its absence gives causticity, to alkalies and calcareous earths.

In 1756, on Cullen’s removal to Edinburgh, Black was appointed Professor of Chemistry and Anatomy at Glasgow in his stead; but not relishing, nor feeling particularly qualified for, the anatomical part of the business, he requested and obtained the assent of the heads of the university to an exchange, which he effected with the Professor of Medicine. While in this position he matured and made public his theory of latent heat, and explained to a society in Glasgow his experiments on the subject, in the clearest and most satisfactory manner; and this proved a principal leading step to the discoveries of Laplace, Lavoisier, and others: though they niggardly and enviously abstained in their dissertations from giving him that credit in the matter to which he was so justly entitled. In 1764 he had as one of his pupils the celebrated Watt; and it proved most fortunate for the interests of science and for the fame of both, that these great men were thus brought together.

Dr. Black was, in 1766, recalled to Edinburgh to fill the professorial chair of Chemistry, which was rendered vacant by the appointment of his old friend and adviser, Cullen, to that of Medicine. During the remainder of his career he was regarded as one of the chief ornaments of the university, as well as a most distinguished member of the literary circle which then adorned the Scottish metropolis, where his private character was highly esteemed. He continued his researches with perseverance and success; and his lectures were so remarkable for ease and elegance of style, novelty of information, and originality of reasoning, that few students ever left college without having attended a course or two. His devotion to the duties of his professorship was so complete, that it interfered materially with the spread of his fame, as others were thus allowed to pass him in that very path of discovery which his genius had illumined and opened up. A paper which he furnished, on the “Effects of boiling upon water in disposing it to freeze more readily,” was published in the “Philosophical Transactions” for 1774; and an “Analysis of the water of some hot springs in Iceland,” appeared in the Scottish “Philosophical Transactions for 1791.” In due time he became a member of the societies of London and of the city where he resided, and, moreover, had the distinction of being selected as one of the eight Foreign Associates of the Academy of Sciences at Paris. His lectures on the “Elements of Chemistry,” delivered in the University of Edinburgh, were, as late as 1803, published in two volumes, by Professor Robison.

While thus achieving scientific triumphs, the pecuniary affairs of Dr. Black had flourished better than even the most inquisitive of his neighbors had supposed; and the manner in which he disposed of his money by his will was peculiar and characteristic. When he felt the approaches of age, and found it necessary to employ an assistant, about his sixtieth year he had a list drawn up of persons who had a claim on his bounty, and whom he wished to inherit his treasure; and he destined it in such proportions as seemed consistent with the extent of care and solicitude to which they were entitled at his hand.

His health had long been in a delicate state, insomuch that he was under the hard necessity of refraining from writing an account of his brilliant discoveries, as the exertion of doing so for any continuous period invariably brought on a spitting of blood; and he felt himself in no condition to encounter the criticism or engage in the controversy likely to follow such a publication. Moreover, he is said to have been apprehensive of a long sickness, which for many reasons he anxiously wished to avoid. This fate was averted by the sudden nature of the summons he received to another world. On the 26th of November, 1799, while he was seated at table partaking of such abstemious fare as he had lately restricted himself to, the messenger of death was upon him, and struck the fatal blow. His servitor went into the room according to custom, but observing the cup of the venerable philosopher in his hand, as if about to be raised to his lips, and naturally supposing him to be in deep thought, he noiselessly withdrew. Entering soon after, he perceived his master still in the same posture, but on going up to the chair, was beyond measure surprised to find that the lamp of life had gently expired.