He was established there as a physician, as well as in London, his home, his address in 1701 being the Old House, Ludgate Hill.
Sir John Floyer's treatise on cold bathing, entitled The ancient Psychrolousia revived (1702), has appended to it a letter from Baynard "containing an Account of many Eminent Cures done by the Cold Baths in England; together with a Short Discourse of the wonderful Virtues of the Bath Waters on decayed Stomachs, drank Hot from the Pump."
Baynard's popular work entitled Health, a Poem.
The fourth edition appeared in 1731; the fifth, corrected, in 1736; the seventh in 1742; the eighth without date; and the ninth at Manchester in 1758.
Baynard has two papers in the Philosophical Transactions, one of them being on the "Case of a Child who swallowed two Copper Farthings."