human
If you breathe the right air you're all right; and if you breathe the wrong air you're all wrong, and there's the whole science of medicine in a nutshell; believe me, my dear, because I know; mine's the teaching of actual experience. So long as I'm well in a place I stay there; I know the air's right; but so soon as I begin to feel a little out of sorts I know the air has ceased to be right, I go away at once; the consequence is that there are very few people who move about as much as I do.