In India he received considerable sums for medical attendance on princes, but his health suffered, and he returned to England and entered Christ's College, Cambridge.
An account of these experiments is given in a note in Charles Hutton, George Shaw, and Richard Pearson's Abridgment of the Philosophical Transactions, 1809, i.
He died at Downing College, Cambridge on 10 November 1814, and was buried in a vault designed by William Wilkins under what is now the Paddock.
He covered his walls with small water-colour portraits, six or eight in a frame, done by Silvester Harding, to whom he asked all his university acquaintances to sit.
Harwood also sent a challenge to Sir Isaac Pennington, the regius professor of physic, which the latter disdained to notice; but the messenger, an undergraduate, published the affair in the London papers.
Harwood published the first volume of a System of Comparative Anatomy and Physiology, Cambridge 1796, and some synopses of his courses of lectures.