Conversation so far:
When did William Cullen go to the University of Edinburgh?
In 1755 William Cullen become Professor of Chemistry and Medicine at the University of Edinburgh.
Why did William Cullen go to the University of Edinburgh?
William Cullen was enticed by Lord Kames to become Professor of Chemistry and Medicine at the University of Edinburgh.
How long did William Cullen teach at the University of Edinburgh?
William Cullen was appointed sole professor of the practice of physic, and he continued at the University of Edinburgh until a few months before his death.
Why did William Cullen leave the University of Edinburgh?
Did William Cullen do anything of note other than teaching while at the University of Edinburgh?
On the death of Charles Alston in 1760, William Cullen at the request of the students undertook to finish his course of lectures on materia medica.
What chair did William Cullen accept at the University of Edinburgh?
On the death of Robert Whytt, the professor of the institutes of medicine, William Cullen accepted the chair, at the same time resigning that of chemistry.
Were there interesting developments in William Cullen's personal life during his time as a professor at the University of Edinburgh?
In 1783 William Cullen, together with his sons was a co-founder of the Royal Society of Edinburgh.

Question: How many children did he have?
Self-contained rewrite: How many children did William Cullen have?