For the sake of greater clearness sensory gastric neuroses are best divided into two main groups: (a) Comprising abnormal sensations of a more or less general character; (6) special sensations emanating from the stomach itself, (a) Abnormal Sensations of a General Character.

The need for food makes itself felt through the sensation of hunger, the need for drink through that of thirst. The nervous centre for these sensations appears to be located in the medulla oblongata (R. Ewal2 and Rosenthal). The stomach is the organ into which all substances satisfying hunger and thirst are introduced. The act of satisfying the sensation of hunger with relish is called "appetite." Normally there appears in man a slight feeling of hunger at the usual mealtime. A man relishes the food he takes until at the end of the meal a feeling of satiety appears. The latter may be best characterized by noting the point at which the sensation of hunger has entirely disappeared. On going beyond this point to any extent - i.e., by continuing to introduce further food into the organ - a sensation of weight and tightness around the stomach develops. This can then be hardly considered as a normal process, and is the way the stomach responds to interference with its habitual mode of work.

1 M. Rosenthal: "Magenneurosen und Magenkatarrh." Wien und Leipzig 1886.

2R. Ewald: Cited from C. A. Ewald. l c. p. 380.

The time at which hunger appears is physiologically variable and depends upon the time persons are accustomed to take their meals. On this account there are people who feel hungry only twice a day, as they are in the habit of taking only two meals daily; others again who feel hungry about every three hours, as they are accustomed to take five meals a day, and so on. Although the ingestion of food may sometimes lead to some variations in the time at which hunger is experienced - so that a man who is in the habit of taking a light meal at a certain period during the day, after having partaken of a much heavier meal than customary, will perhaps not feel hungry at his next meal - this is of less consequence than the influence of the time at which the meals are ordinarily taken. Thus every one knows that if he has been accustomed to take his lunch, for instance, at one o'clock, the hungry feeling will appear at one, and if not satisfied within a certain period of time (half an hour to an hour), then very frequently it will disappear to return at the next mealtime.

Pathologically we find that the above-named sensations may exist either in an exaggerated form, or may be greatly diminished or even absent.