Subsequently, Crull settled in England although he may have been a
public school student there before he matriculated at Leiden. He received his M.D. from
King's College in the
University of Cambridge on 7 August 1681 as a result of a
royal mandate from
Charles II on 7 August 1681. In the same year, he was elected a
fellow of the
Royal Society on 23 November and admitted on 30 November. He was later admitted a licentiate of the
Royal College of Physicians on 22 December 1692. Crull's life remains rather ambiguous, as some accounts speculate that he subsisted mainly by doing translations and compilations for booksellers while seeming to have met with little success in his profession since there are a number of omissions of his name on the annual list of the Fellows of the Royal Society which, according to the author (Gordon Goodwin) of the Crull entry in the 1917
D.N.B., suggest an inability to pay. Other accounts imply the likelihood that Crull may have been a dilettante and eccentric who had the means to follow his interests and who may not have paid his fees to the
Royal Society with regularity since he may not have attached a great significance to being listed yearly. Where he practised medicine could have been in London or its environs for he settled in London but resided outside of the city because of "country" being appended to his name on the lists. Crull entreated Sir
Hans Sloane's vote at the coming election of a navy physician and was known to be in contact with Sir
Isaac Newton and other prominent academics. ==Works==