Taken in moderation, it acts partly as a sedative, partly as a stimulant, arresting the destruction of tissue, and seeming to invigorate the whole nervous system.

The water in it, even if impure, is made wholesome by boiling, and the milk and sugar give a certain amount of real nourishment.
Nervous headaches are often cured by it, and it has, like coffee, been used as an antidote in opium-poisoning.
Pass beyond the point of moderation, and it becomes an irritant, precisely in the same way that an overdose of morphine will, instead of putting to sleep, for just so much longer time prevent any sleep at all.

The woman who can not eat, and who braces her nerves with a cup of green tea,--the most powerful form of the herb,--is doing a deeper wrong than she may be able to believe.

The immediate effect is delightful.

Lightness, exhilaration, and sense of energy are all there; but the re-action comes surely, and only a stronger dose next time accomplishes the end desired.
Nervous headaches, hysteria in its thousand forms, palpitations, and the long train of nervous symptoms, own inordinate tea and coffee drinking as their parent.