His early career there was spent qualifying himself as a chemist and druggist under Dr Robertson of George Street in Edinburgh.

After his early training as a chemist he was appointed senior apothecary and dispenser to the Royal Infirmary of Edinburgh.

He spent ten years in this post during which time he attended classes at Edinburgh University and the Royal College of Surgeons with a view to gaining medical qualifications.

[2][3] According to the 1905 valuation role Dr Gunn built up a considerable property portfolio including a tenement block and a number of houses,[4] however at the time of his death the family were left without means.

Their daughter, Jean (1887-1975), had to have her fare paid to India so that she could marry her childhood friend Andrew Geddis.