He was never known to relax in any object which he had once undertaken. During the whole term of these five years he was never seen by anyone on any occasion to be ruffled in temper. Whatever he determined on he did. He had little faith in any peculiar aptitude being implanted by nature for any given pursuits. His favourite maxim was, that whatever one man had done another might do; that the original difference between human intellects was much less than it was generally supposed to be; that strenuous and persevering attention would accomplish almost anything; and at this season, in the confidence of youth and consciousness of his own powers, he considered nothing that had been compassed by others beyond his reach to achieve; nor was there anything which he thought worthy to be attempted which he was not resolved to master.
In 1792 he entered the medical profession, learning anatomy from Hunter in London.
In 1793 he became a pupil at St. Bartholomew’s Hospital, and on May 30 he had a paper read to the Royal Society on the ‘Structure of the Crystalline Lens,’ which he thought to be muscular. Hunter claimed the discovery as his, and was only prevented by death from giving the Croonian lecture at the Royal Society in proof of his right. Sir E. Home, in the Croonian lecture the following year, stated that neither Young nor Hunter was right.
In 1794 (æt. 21) he was elected a Fellow of the Royal Society.
About this time the Duke of Richmond, at Bath, thus wrote to Dr. Brocklesby:
Bath, May 5, 1794.
I need not write much about myself, as your nephew, who dined with us yesterday, will give you a good account of my health. I have, however, still returns of head-ache, and my legs continue very weak. But I must tell you how much pleased we all are with Mr. Young. I really never saw a young man more pleasing and engaging. He seems to have already acquired much knowledge in most branches and to be studious of obtaining more; it comes out without affectation on all subjects he talks upon. He is very cheerful and easy without assuming anything, and even on the peculiarity of his dress and Quakerism he talked so reasonably that one cannot wish him to alter himself in any one particular. In short, I end as I began, by assuring you that the Duchess and I are quite charmed with him, and shall be happy to renew our acquaintance with him when we return to London.
Later in the autumn the Duke, who was Master-General of the Ordnance, offered to make him his private secretary.
In a letter to his mother Young says:
I have very lately refused the pressing offer of a situation which would have been the most favourable and flattering introduction to political life that a young man in my circumstances could desire. I might have lived at a duke’s table, with a salary of 200l. a year, as his secretary, and with hopes of a more lucrative appointment in a short time. I should have been in an agreeable family, have had time enough for study, a library, a laboratory, and philosophical apparatus at my service; and I was not ashamed to allege my regard for our society as a principal reason for my not accepting the proposal.
In the winter of 1794-5 he went to Edinburgh to study medicine. He learnt Spanish, German, music in theory and by playing the flute, dancing; and he went as much as he could into society and to the play.