Mr. Cooper was appointed Professor of Comparative Anatomy at the Royal College of Surgeons in 1813, being the first appointment after Sir Everard Home retired. He lectured during only two seasons, in 1814 and 1815. Not being deeply read in his subject, he resolved to see what industry could do, and restricted himself to three or four hours’ sleep, that he might gain additional time for the dissection of animals. He also employed several assistants to dissect for him, and the result was that his specimens came by coach-loads to each lecture. Mr. Clift remarks of one lecture, “This was an overpowering discourse, and highly perfumed, the preparations being chiefly recent and half-dried and varnished.” His lectures were very successful, though he would have preferred lecturing on surgery, which was allotted to Abernethy. In the year last mentioned he resigned the professorship and also moved to New Street, W., hoping thereby to diminish the fatigue occasioned by the numerous visits which he had to pay westward. In the following May he signalised his skill by his celebrated operation of tying the aorta or principal artery of the body, for aneurism, in a case in which life was in the extremest peril. The ease with which he prepared for the operation and the masterly skill and success with which he completed it—without the aid of chloroform, be it remembered—excited admiration throughout the profession, who could best judge of the difficulties which had to be overcome. The patient died of incurable disease, but the success of the operation was undoubted. After having for some years attended Lord Liverpool, Mr. Cooper was in 1820 called in to George IV., who afterwards insisted on his performing a small operation upon him, although he then held no court appointment. He was very reluctant, fearing erysipelas, and only at length yielded to command. His success in this was followed by the conferment of a baronetcy, which was hailed with acclamation by all his friends both professional and public. In 1822 Sir Astley first became an Examiner at the College of Surgeons. In this capacity he was very conscientious and considerate, never asking catch-questions, or making abstract inquiries, but invariably dwelling upon practical matters, and putting his questions in simple and straightforward language. In the same year appeared perhaps his most important work, that on Dislocations and Fractures of the Joints, and as was his fixed principle, he published it at a price just sufficient to cover the cost of the letterpress and engravings.