To some degree, seasickness is produced or imitated by dietetic errors prior to or after sailing. Genuine seasickness seems to be a disturbance of equilibrium, partly visual but mainly due to actual motion and includes in its symptomatology and pathogeny, a condition of shock and of gastric irritability, sometimes one, sometimes the other being more prominent. The movements of the abdominal viscera, especially the heavy liver and the kidneys - particularly if already preternaturally movable - probably tug upon nerve filaments, since the condition is to some degree relieved by the horizontal posture and by bandaging the abdomen. Essentially the same condition may be caused by the movements of any other vehicle or even a swing or hammock.

Farewell banquets, alcoholic excess and various dietetic errors often produce symptoms which are called seasickness on water but which may be entirely independent of this condition. However, an abstemious diet and a mercurial purge before sailing have some value as prophylactics.

Any narcotic or sedative drug will control seasickness if given in adequate dose, subject to the qualification that mild sedatives have no positively efficient dose and that the more powerful ones are objectionable.

Two radically different methods of treatment exist; sailors advise forced feeding or drinking of sea water, alcoholic beverages etc. The opposite method is to follow the inclinations of the patient and to allow him to abstain from food unless the seasickness lasts so long as to reduce the strength too much under starvation treatment. Lemon juice, raw prunes, oranges, clear tea, iced champagne and various other beverages are recommended to quiet the stomach. Toast, wafers, salt or smoked meats etc., usually excite less disgust than fresh meat, vegetables and desserts but. in true seasickness, the patient vomits until the stomach has squeezed out its contents, when it will usually remain passive till more food is taken.

Whether it is better to try to force the patient to eat or not, is a moot point, and the merits of the individual case must be considered. Most persons are rather benefited by a fast of a few days. The terrible depression is the main factor in seasickness and may require hot saline enemata or rectal alimentation.