Simpson’s untiring activity could not content itself, however, with strictly professional subjects. Before the end of his first session of professional lectures, he began to work at a memoir which received the title of “Antiquarian Notices of Leprosy and Leper-Houses in Scotland and England.” In it he makes nearly five hundred references to out-of-the-way authorities, and in the appendix is a list and notices of one hundred and nineteen leper-houses which he had traced in Britain. The memoir is a mine of valuable antiquarian information. By the end of 1842 his pecuniary position was assured beyond all doubt, although his benevolence would have made this difficult had not his skill become so famed. His success when little over thirty years of age was marvellous; the hotels were filled with his patients, and his practice was said to be worth many thousands of pounds a year to these establishments. His house had to be enlarged to receive some who insisted on remaining in the closest proximity to the great doctor. But in the whirl of practice one fault became prominent. Methodical and exhaustive in his literary researches, and possessed of a powerful memory, he could not be persuaded to make systematic notes of his appointments, and seemed to be incapable of so planning out his time as to spend it to the greatest advantage for his patients. He not unfrequently forgot a definite appointment, and was sometimes overpersuaded by pushing people or by professional friends to attend to cases out of their proper turn. That he ever consciously did any one an injustice either for pay or without it is quite untrue. But he was blamed as if he had. He was indeed only too careless about money, and frequently too regardless of his own interest to demand a proper fee. His receipts were stuffed at once into his pockets, which were emptied at night, he knowing nothing of their contents before. Sometimes a fee was received in a letter, and neither taken out nor acknowledged. Once he received £10 thus, when a much larger fee might have been expected, and several notes of expostulation followed on his neglect to acknowledge its receipt. One stormy night Simpson was much disturbed in sleep by the rattling of a window. He got up, felt in his pocket for a bit of paper, and lighted on the £10 note, which was devoted to the tightening of the window-frame. On Mrs. Simpson discovering the nature of the bit of paper in the morning, he merely replied, “Oh, it’s _that_ £10.” A sample of ridiculous expostulations is the case where repeated letters asked Dr. Simpson’s opinion whether three leeches should not be applied to a hip-joint, instead of two, which the family medical man recommended.