This is the case stated against coffee and tea in its broadest and most emphatic form. The opponents of the use of tea drinking term both tea and coffee “drugs.” What is commonly thought to be the pleasantest property of both tea and coffee, namely, their ability to banish one’s sense of fatigue, is regarded by the critics of the tea and coffee drinking habits as perhaps the most sufficient evidence of their poisonous character. “No one would doubt for a moment,” says one such critic, “the poisonous nature of a drug capable of producing irresistible drowsiness in a person who is not weary, as morphine would, for instance. Vice versa, the power of a drug to produce wakefulness in a person strongly inclined to sleep as the result of fatigue is equal evidence of its poisonous character. The sallow complexion common among women of the higher classes who have reached middle life, the almost universal nervousness among American women, and many common digestive disorders, and the increasing prevalence of nervous or sick headaches, afford to the experienced physician ample evidence of the toxic or poisonous character of tea and coffee.” Tea and coffee contain (in addition to caffeine) tannic acid, and various other volatile poisons, each of which produces characteristic harmful effects. The volatile oils give rise to nervous excitability, and after a time provoke serious nervous disorders. Caffeine is a narcotic, which has been shown to diminish the activity of the peptic glands—and thus seriously to interfere with the normal operation of the organs of digestion. The eminent physiologist, Wolfe, showed by experiments that three grains of caffeine—an amount that might easily be imbibed in an ordinary cup of tea or coffee—very substantially impairs the quality of the gastric juices, lessening their total acidity. Roberts’ experiments showed that tea and coffee interfere with the action of the saliva upon the starch of the food, and at times may even wholly destroy its effect. XI DIET REFORM IN THE FAMILY The reader is now familiar with the new ideas upon the subject of human nutrition. It is obvious, of course, that if these ideas should ever come into general acceptance, there would be enormous changes in the every-day habits of human beings. And we can well imagine that a person might be fully convinced of the soundness of all the arguments which have been advanced in this book, and yet shrink in dismay from the complications incidental to applying them.