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.