The way for his appearance as an extra-academical lecturer on midwifery was made clear at the end of 1837 by the death of Dr. Macintosh, a successful teacher of that subject. He had been in negotiation, without success, with this Dr. Macintosh for the taking over of the part or whole of his lectures, and found it easy to step at once into his place at his death. He was firmly determined to succeed ultimately to the University Chair of Midwifery. On one occasion he pointed out to some friends the then holder of the Chair, Professor Hamilton, thus:--"Do you see that old gentleman? Well, that's my gown!" The good luck which had been his during his boyhood did not desert him when he began his course of lectures; for not only did he speedily attain a reputation for teaching, science, and practical skill, wonderful for one so young, but he had not two years to wait after thus establishing himself before the chair of his ambition fell vacant owing to the resignation in 1839 of Professor Hamilton, who died soon afterwards at the age of seventy-two. It was a bold step for so young a man--for Simpson was only twenty-eight--to apply for the professorship. He was, however, not without his precedent. The second Monro obtained the Anatomy Chair at twenty-five, Alison filled that of Physic at thirty, and Thomas Hope and Alexander Christison were Professors of Chemistry and Medical Jurisprudence respectively each at the age of twenty-four. But this subject was one which was popularly thought to require a man of experience and especially a married man. Simpson had devoted his energies but partially to midwifery for only four or five years, and except for his short hospital appointment and recent experience as a lecturer on the subject had in the eyes of many no greater claim to the post than any other general practitioner, except in the fact that he had obtained a wide reputation in the science of the subject by his contribution to its literature and his researches. This last was the point on which he himself most relied; for his age he had done more scientifically than any of his opponents. Those who had watched his career knew that he possessed in addition to zeal and ability, brilliant teaching and practical powers. The objection of his youth was less easily got over than that of his unmarried state. With characteristic promptness, as soon as he had determined to apply for the Chair and found that as a bachelor his chances would be small, he disappeared for a time from Edinburgh, and returned triumphantly with Miss Jessie Grindlay, of Liverpool, as his wife. It was a bold stroke which delighted his supporters, discomfited his opponents, who saw therein the removal of a barrier to his success and a weapon from their hands, and astonished the worthy town councillors in whose gift the appointment lay.