His hospital career

Two glowing testimonials in support of Dr Mackenzie's application for the position of Medical Officer in the Workhouse Infirmary and his own letter of application (Click the individual images to enlarge)

In 1907, he left Burnley to work in London, working in two hospitals, West London Hospital and Mount Vernon. He eventually rented a surgery in Harley Street and ran a department in the London Hospital. 

In 1909, he was elected Fellow of the Royal College of Surgeons and  in 1913, he was appointed a member of the Medical Council. In 1915, he became a Fellow of the Royal Society and also received a knighthood. 

In April 1918, he retired to St. Andrews where he established the St. Andrews Institute for Clinical Research. He left St. Andrews for London in 1924 and died the following year on 26 January 1925.