Macadam was born in Northbank, near Glasgow, Scotland. He studied chemistry at the Andersonian University and the University of Edinburgh, later switching to medicine at Glasgow. In 1855, he went to Melbourne, where he became the first lecturer to teach at the University of Melbourne School of Medicine. On March 3, 1862, he started lectures on chemistry.
Macadam died in 1865 after a ship-board accident. His grave is in Melbourne General Cemetery.
