Much argument has been expended on the relative digestibility and usefulness of tea and coffee, but about all that can be said definitely in regard to the matter is, that many persons who can drink tea with impunity are made nervous and are kept awake by a similar quantity of coffee, whereas there are others who find that coffee aids their digestion while tea interferes with it, and that it affects them in every way more agreeably than tea; and still a third class cannot take either tea or coffee without producing indigestion, insomnia, and nervousness. Speaking generally, coffee is believed in the United States to be more digestible and useful than tea, but in other parts of the world, especially in England, China, and India, tea is regarded as more beneficial than coffee. In equal weight, tea contains more than twice as much caffeine or, as it is also called, theine. In this country, however, it is customary to use about 50 per cent more of coffee than of tea to the same quantity of water.

Coffee is said to irritate the mucous membrane of the stomach less than tea when drunk in very large quantities.

It has a more decided stimulant action than tea upon both the force and frequency of the pulse.