Digestion, so long as it is healthy, is an obvious example.

Digestion is the process by which food rendered soluble, and capable of being absorbed for use in carrying on the various vital processes.

The simplicity of his mental state, his complete freedom from responsibility, assure us that his digestion of the raw flesh and the tough roots must have been perfection, and the sleep in those furred skins a dreamless one.

Next to respiration, digestion is the chief function in the economy of life, as, without the nutritious fluid digested from the aliment, there would be nothing to supply the immense and constantly recurring waste of the system, caused by the activity with which the arteries at all periods, but especially during infancy and youth, are building up the frame and developing the body.

The digestion of heavy meals is a tax upon vital powers at any time of life, but particularly so as age advances; and for him who has passed his first half-century, over-feeding is fraught with great danger.

If digestion were a thing to be trifled with, I might sup upon lobster, and the matter of life of the crustacean would undergo the same wonderful metamorphosis into humanity.

Obviously, then, if the use of tobacco interferes with the normal action of the saliva, and if the digestion of starch ends in the stomach, here is the strong point in the argument of the opponents of tobacco.