Dimsdale accompanied his father, the celebrated Quaker physician and inoculator, to Russia in 1768 and like him received a title for his services from the Empress Catherine.
Dimsdale gave an independent support to Pitt’s administration, though he was a silent Member; it was no doubt his Russian experience that led him to vote with opposition on the Oczakov question, 12 Apr. 1791, and his Quaker heritage that inspired his voting in the minorities for peace, 26 Jan., 6 Feb., 27 May 1795, though he was not positively favourable to repeal of the Test Act in Scotland in 1791. He also voted for parliamentary reform on Grey’s motion, 26 May 1797, and for Grey’s censure motion, 25 Mar. 1801. His retirement in 1802 was attributed to his precarious state of health.
On 12 Aug. 1803 the Russian Emperor awarded him the pension of £500 received by his late father for ‘the services ... rendered by the happy inoculation of his Imperial Majesty and his brother the Grand Duke’ and ‘the good faith and attachment for our interests that he has shown during his parliamentary career’.
