From a letter sent by Douce to George Cumberland on 4 February 1826:
I read no book on health -they only hip one. I have lately lost my truly valuable & excellent friend & physician Dr. Fryer who could not save himself & admitted to me, as did Dr. Beddoes & Dr. Willar that physicians were profound ignoramuses.
If you covet a long life, & who does not combined with health?
take moderate exercise
eat & drink moderately
avoid spirituous liquors
clothe yourself warmly in winter
avoid through airs or draughts of wind
avoid heated rooms, & never leave them suddenly to go into cold air
keep your feet warm & head cool
keep the skin clear by ablutions in warm water, unless you are under 40 and then use cold water.
Do all this, or as much of it as you can, & you will live to 100.