322 Biographical Account of [May, 



chemistry as a field still untrodden, was delivering lectures upon 

 that science in the University of Glasgow. These lectures caught 

 the congenial fancy of young Black, who speedily became a zealous 

 chemist, and the favourite pupil and friend of his master. Mr. 

 Black had made ciioice of medicine as the profession to which he 

 proposed to attach himself; and in 1750 or 1751 he went to the 

 University of Edinburgh to finish his medical studies. Here he 

 lived in the house of his cousin German, JVIr. James Russel, Pro- 

 fessor of Natural Philosophy, in whose society he must have passed 

 his time both agreeably and profitably. 



At this period the opinions of the medical professors were divided 

 about the manner in which certain lithontriptic medicines acted in 

 alleviating the excruciating pains of the stone. One of these 

 medicines was lime-water. Tliey all belonged to the class of bodies 

 called caustic, and their efficacy was ascribed to this causticity. 

 Now this causticity was always induced, either directly or indirectly, 

 by the fire. Thus lime-stone in its natural state possesses no caustic 

 properties ; but by exposure to a strong heat it is converted into the 

 caustic substance called quick-lime. The investigation of the nature 

 and cause of this causticity was considered as very important. It 

 drew the particular attention of Mr. Black. Hp investigated the 

 subject with his accustomed precision and coolness; and having 

 ascertained it in a satisfactory manner, made it the subject of his 

 inaugural dissertation in 1754, when the degree of Doctor of 

 Medicine was conferred upon him by the University of Edinburgh. 

 Next year he published his experiments upon magnesia alia, quick- 

 lime, and other alkaline suLstajiceSf in which the whole subject was 

 developed at length. 



Just at this time Dr. CuUen was removed to Edinburgh, and the 

 chemical chair in Glasgow became vacant. Dr. Black's experi- 

 ments on magnesia and quick-lime, which aSbrded by far the finest 

 specimen of chemical investigation hitherto oftered to the public, 

 secured him that chair. Accordingly he was appointed Professor of 

 Anatomy, and Lecturer on Chemistry, in the University of 

 Glasgow. Not considering himself as sufficiently qualified for the 

 anatomical class, he exchanged tasks with the Professor of Medi- 

 cine. While in Glasgow, therefore, his lectures on the institutes 

 of medicine constituted his chief task. He engaged likewise in the 

 practice of medicine ; and from the sweetness of his manners, and 

 the goodness of his heart, soon became a favourite practitioner. 



While in Glasgow, he brought to maturity his speculations con-' 

 cerning heat, which' had occupied his attention from the very com- 

 mencement of his medical studies. They constitute one of the 

 most important additions ever made to science, and furnish the 

 most delightful proofs of the wisdom and beneficence of the Author 

 of nature. 



Dr. Black continued in the University of Glasgow from 1756 to 

 I7f>6. In that year Dr. Cullen, Chemical Professor in Edinburgh, 

 was appointed Professor of Medicine, and thus a vacancy was made 



