Specialising in obstetrics and gynaecology, he continued his studies and obtained his doctorate MD in 1880, with a gold medal and the Syme Surgical Fellowship on "The Structural Anatomy of the female pelvic floor".

[7] Dr Hart lived in an exceptionally fine Georgian townhouse designed by Robert Adam at 29 Charlotte Square in Edinburgh's First New Town.

In later life he lived at 5 Randolph Cliff on the edge of the Moray Estate in Edinburgh's affluent West End.

A granddaughter was Marian Lines, a writer and actress, and his grandson David Berry-Hart, painter and sculptor.

Regarded by others as a tour de force of dubious utility, he drew on Mendelian principles with singular vigour.