Autograph Letter Signed, to Doctor Lettsom, Physician, discussing the effect of medicated lime water and “the medicines you prescribed” on a patient, the effects of the change in the weather, further treatments, new symptoms and much else. 1 page 9 x 7½ inches, a few heavy stains, light dust soiling, otherwise good, with the address leaf. Knayton near Thirsk, 20 June 1783. Charles Bisset M.D., physician and military engineer, served on board Admiral Vernon’s fleet in the 1740’s. From 1746-38 he served in France as a siege engineer, and in 1751 published his Theory and Construction of Fortifications. His medical publications included a Treatise on Scurvy (1755). Some of his correspondence with Dr. John Coakley Lettsom (1744-1815) was published in Pettigrew’s Memoirs and Correspondence of Dr.Lettsom.