Complex sentence: D. Gooptu & Co. was written by Sir William Brook O'Shaughnessy the then professor of chemistry at the Medical College, and it is worthy of note that this firm owned the first dispensary of English drugs in India which was started by a Bengalee doctor.
Split into simpler sentences: D. Gooptu & Co. was written by Sir William Brook O'Shaughnessy the then professor of chemistry at the Medical College. The firm owned the first known dispensary of English drugs in India which was started by a Bengalee doctor.