William Hunter joined the College of Physicians in 1755, and the Medical Society about the same time. His “History of an Aneurism of the Aorta,” appears in the first volume published by that Society, in 1757. In regard to aneurisms he had made many original observations, such as to place the subject in a totally new aspect. Several papers he contributed to this Society bear directly on problems of interest in midwifery and the diseases of women. It was in 1762 that the first edition of the “Medical Commentaries” appeared, in which Monro secundus was severely attacked for having claimed as his own discoveries which William Hunter had, years before, promulgated at his lectures. It is to be regretted that in regard to these very matters, as well as others, disputes afterwards arose between William Hunter and his brother John, who it appears had made at least some of these discoveries, while engaged as assistant to his brother. In respect of a number of these, the elder brother gave credit to his junior both when lecturing and in his publications; in regard to others, the elder gave no credit at all when John conceived himself entitled to much, or all, of the praise of originality. Both brothers were strikingly sensitive as to their claims to originality, and William Hunter on several occasions seems to have regarded a new demonstration as his property because made in his dissecting-room, though not by himself. Yet we find it recorded that in the winter 1762-3, when the brothers had separated, William Hunter would frequently say in his lectures: “In this I am only my brother’s interpreter”—“I am simply the demonstrator of this discovery; it was my brother’s.” We must recur to this subject later, merely mentioning now, that John Hunter acted as his brother’s assistant and dissected for him from 1748, and that from 1755 to 1760 a certain portion of the lectures was delivered by him; in 1760 they separated. There is no question that in general education, in manners, in delivery, in all that makes the successful lecturer and the attractive practitioner, William Hunter greatly excelled his brother. Dr. Baillie has said of him, “No one ever possessed more enthusiasm for his art, more persevering industry, more acuteness of investigation, more perspicuity of expression, or indeed, a greater share of natural eloquence. He excelled very much any lecturer whom I have ever heard in the clearness of his arrangements, the aptness of his illustrations, and the elegance of his diction.” If it were not for the tenacity with which he pursued controversial topics, and his unfortunate disagreement with his brother, there would be nothing to mar the pleasurable nature of the picture of William Hunter. The way in which he himself viewed this side of his character may be gathered from the following extract from the Supplement to his Medical Commentaries, published in 1777.