In 1764, he resigned his professorship, but continued to give clinical lectures at the hospital.

On the expiration of this term he resigned his professorship.

He resigned his professorship in 1787 on account of a prolonged visit to England.

In 1865 he became an associate professor, resigning his professorship 19 years later (1884).

In 1897 he resigned his professorship, and died on 11 June 1899.

Warren resigned his professorship at the end of 1925 and was made emeritus professor.

Early in 1900 he was forced by ill-health to resign his professorship, and died a few months later.

In 1681 he resigned his professorship and founded a scholarship for medical students.

A year later he resigned his professorship to remain director at the observatory.

One fine spring morning at the end of the school term, he had resigned his associate professorship to join the Accord military.