Thomas Dimsdale

Thomas Dimsdale was a banker, doctor and pioneer of smallpox inoculation. Thomas was born on 29 May 1712 in Theydon Garnon, Essex. He was the son of John Dimsdale, a surgeon, and his wife Susan. Dimsdale received early medical training from his father, before training further at St Thomas’s Hospital, London. He began to practice medicine in Hertford in 1734.

By about 1761 Thomas Dimsdale had entered into the private banking partnership of Dimsdale, Archer & Byde in Cornhill, London. In 1774 he was one of two partners who broke away and reformed the partnership as Staples, Baron Dimsdale, Son & Co.

Dimsdale himself retired from the bank around 1776, but his sons succeeded him, and the bank remained a Dimsdale family enterprise for generations until eventually, in 1891, it merged with Prescott, Cave, Buxton, Loder & Co to form what became Prescott’s Bank.

Dimsdale had a particular interest in the prevention of smallpox by inoculation (variolation), infection via the skin, which usually produced a mild but protective effect. He published The present method of inoculating for the smallpox in 1767 which went into five editions by 1769. In 1768, perhaps due to his prominence in London society, he was invited to St Petersburg to variolate the Empress Catherine the Great of Russia. In 1769, Dimsdale variolated the Empress, her son Grand Duke Paul and over 140 members of the Court. The results were a success. Catherine rewarded Dimsdale with £10,000, a pension of £500 per annum, and £2000 expenses. She also created him a Baron of the Empire. Dimsdale's son, who accompanied him, was also rewarded. In case the results had produced adverse effects, the Empress had arranged for a relay of fast horses to be available to speed the Dimsdales out of the country. During the long preparatory period before the variolations he wrote Tracts on inoculation written and published at St Petersburg in the year 1768.

Dimsdale was also a Member of Parliament from 1780 till 1790, when he was replaced by his son. In 1739 Thomas Dimsdale married Mary Brassey, daughter of the Hertford MP and banker Nathaniel Brassey. They had no children. She died in 1744. In 1746 he married Anne Iles, a relative of his first wife. They had 9 children. Anne died in 1779. Soon afterwards, he married Elizabeth Dimsdale of Bishop’s Stortford. They had no children.

Thomas Dimsdale died on 30 December 1800. He was buried in the Quakers' burial ground at Bishop's Stortford.