Background
He was born at Simprin, Berwickshire, on 20 July 1797.
He was born at Simprin, Berwickshire, on 20 July 1797.
Johnston was educated first at Kelso, then at Berwick grammar school, and finally at the University of Edinburgh. He was apprenticed to John Abercrombie, and in 1817, qualifying as a member of the Royal College of Surgeons of Edinburgh, he went to London. Also in 1819 he graduated Doctor of Medicine
Johnston was one of the founders of the Berwickshire Naturalists" Club and became its first president His books include The Flora of Berwick-upon-Tweed, History of British Zoophytes, and History of British Sponges and Lithophytes. When he was still young, his family moved to Ilderton in Northumberland.
In 1818 Johnston began practice at Berwick-on-Tweed, where he remained.
Catharine illustrated many of his publications. of Edinburgh, and in 1824 became Fellow of the Royal College of Surgeons.E. He was thrice mayor of Berwick, and became Doctor of Laws of Aberdeen. He retired from practice in 1853, and died at Berwick on 30 July 1855.
He was one of the founders of the Ray Society and of the Berwickshire Naturalists" Club.