Complex sentence: From 1857 to 1869 he was professor of chemistry and geology in South Carolina College, and he was then appointed professor of geology and natural history in the University of California, a post which he held until his death.
Split into simpler sentences: From 1857 to 1869 he was professor of chemistry and geology in South Carolina College. He was appointed professor of geology and natural history at the University, a post which he held until his death.