[2] He was born in Yorkshire, the son of George Motherby and his wife Anne Hotham; Robert Motherby was a younger brother, and his elder sister Anne married the London bookseller George Robinson (1736–1801).
He gained an MD degree at King's College, Aberdeen in 1767.
[1] Motherby then practised as a physician at Königsberg, in the Kingdom of Prussia.
[1] Through Robert, he came to be on good terms there with Johann Georg Hamann;[3] and vaccinated one of his sons.
A study of the first edition concluded that the most cited authorities were William Lewis (when his translation from Caspar Neumann is included), John Ray, and Herman Boerhaave; followed by Hippocrates and Galen.