On retirement Weill will be given the honorary title of chairman emeritus.
He was prominent among the founders of Andover Theological Seminary, and was its first professor, occupying the chair of Christian theology from 1808 to 1846, and being professor emeritus until his death in Andover on the 24th of August 1854.
In 1879 he left Chicago and became pastor of the church of the Messiah in New York city, and in 1903 he became pastor emeritus.
He has been involved in what he calls " green research " ever since, and is now senior fellow emeritus at the institute.
In 1883 he left the active service of the London Hospital, and became emeritus professor of surgery at the Hospital's medical school.