Tea and Coffee, common articles of diet, are slightly sedative to the nervous system generally. They lower the pulse, and, by diminishing congestion of the brain, tend to clear and tranquilize the action of the mind. This activity of thought is endangered by the cerebral congestion which exists early in the morning, on account of recent sleep,--and again towards the evening, from the full meal of the middle of the day. It is thus at these times that they are found so useful, and are so universally adopted. They are, in fact, almost indispensable to the daily existence of civilized man, with whom a continual energy of mind is a necessary of life. Infusions of these substances, or of materials similar to them in medicinal nature, are adopted as a daily beverage by all civilized nations. By diminishing congestion of the brain, Tea and Coffee have not only the effect of clearing the mind, but in large quantities they induce wakefulness. This is particularly the case with Coffee. It is not clear that Tea, as commonly drunk, is ever unwholesome. Green Tea is a more powerful sedative, and resembles Coffee. Coffee has a more potent influence over the mind and nervous system than is possessed by Tea, and is apt to disagree with many persons. Like Opium, but in a far less degree, Coffee tends to confine the bowels. By diminishing the congestion of the brain which is produced by Opium, strong Coffee is of use in cases of poisoning by the latter substance. Tea and Coffee are sometimes said to be mental exhilarants; but they only become so indirectly, by removing congestion, which is a cause of stupidity. Both Tea and Coffee contain the alkaloid Theine; but it is probable that their Neurotic action is not so much owing to this, as to a volatile oil, which exists in both in some quantity. ORD. II. SPECIAL SEDATIVES. (Antimonials. Ipecacuanha. Digitalis.) These are medicines which, like the last, depress nervous force, yet they do not exert their influence on the nervous system as a whole, but only on certain parts of it. So far they resemble Special Stimulants; but their effect is of a directly opposite nature. They have also no direct influence on any part of the brain.