Parallel - Digestion and Appetite

First, Shake-Speare:

Macbeth (As the banquet is about to begin):

"Now, good digestion wait on appetite
And health on both!"
  Macbeth 3.4.37-8

Bacon:  "For the preservation of health the stomach should be in good appetite; because the appetite promotes digestion".
   History of Life and Death

Comment:  That good digestion depends on appetite seems a questionable notion - surely appetite is as likely to depend on good digestion. but once again we find Shake-Speare dragging in a Bacon theory on some matter of natural science.