SEA-SICKNESS, the symptoms experienced by many per sons when subjected to the pitching and rolling motion of a vessel at sea. Identical symptoms are liable to occur in flying, and in some persons even in railway travelling. They generally show themselves, soon after the vessel has begun to roll, by giddiness, nausea and sinking at the stomach, which soon culminate in vomit ing. With the sickness there are great physical prostration, pallor, cold sweats and feeble pulse, accompanied with mental depression and wretchedness. The condition depends upon disturbance of the balancing system contained in the semicircular canals (see EAR, ANATOMY oF) but visual, mental and olfactory impressions con tribute.
No means has yet been discovered which can altogether prevent sea-sickness. Swinging couches or chambers have not proved of practical utility, nevertheless there is less risk of sickness in a large and well-ballasted vessel than in a small one. None of the
medicinal agents proposed is infallible even in the same person on different occasions. Nerve sedatives, e.g., bromide of potassium, acetanilide, bromural or chloral, appear to act usefully in many persons. On the other hand, some authorities have recommended nerve stimulants, such as a small cupful of very strong coffee, to be taken about two hours before sailing. The recumbent position and warmth, especially to the feet, often help ; so soon as they can be taken small amounts of dry biscuit or toast and weak brandy and soda aid recovery. As a rule the individual is well again in 24 hours or less but in lengthened voyages sea-sickness may be so severe that the help of the ship's doctor is necessary. Even the ship's doctor is sometimes subject to sea-sickness.
See R. A. Bennett, "Sea-sickness and Its Treatment," Brit. Med. Jour., 1928, 1,751.