Another class of cases only presents gastralgic pain without any other symptom. Such are frequently patients who have had gastric ulcer before. Others will come to you with intercostal neuralgia on the left side. They have, perhaps, tried all the usual anti-neuralgic remedies, have gone through a course of treatment by electricity, and spent a large amount of time and money, without obtaining permanent relief, until some physician puts them on a strict milk diet and cures them in this way in a short time. Some cases of ulcer of the stomach present the queerest symptoms. For instance: they complain of pain after drinking milk, or even after taking a morphine powder, while they can eat the coarsest food without any harm. Others run along without presenting any symptoms at all, until they, as well as their physicians, are surprised by the perforation of a gastric ulcer. All these abnormal cases, which form about one-fifth of all the cases occurring, are so indistinct that they frequently remain unrecognized throughout their entire course, and baffle the skill of the best diagnosticians. In order to be able to make a sure diagnosis, there must be a localized pain, together with tenderness on pressure from without on the painful spot. A great many persons in good health are tender in the epigastrium, so that you have to be on your guard in this direction, too. From the occurrence of hæmatemesis in an otherwise healthy person you can, with great probability, diagnose ulcer of the stomach. _Differential Diagnosis._ In order to differentiate _between catarrh and ulcer_, it is simply necessary to keep in mind the difference in the character of the pain, the fact that local pressure is more liable to aggravate the pain in ulcer than in catarrh, and the occurrence of hemorrhage in the former. The two conditions, however, frequently occur in the same patient. The differentiation between _ulcer and neurosis_ has already been discussed. The direct connection of the attacks of pain with the introduction of food, and the character of the pain will soon clear up the matter. Should you still be in doubt, a course of treatment, such as an ulcer would demand, will soon clear up the matter. If the case is one of ulcer, it will have been cured or materially benefited, if it was a pure neurosis the patient will if anything feel worse than before. By far the most difficult question to decide in making a diagnosis is whether the case is one of _ulcer or cancer_ of the stomach. Here close attention to several points will usually clear up the diagnosis. Cancer sufferers always have a sallow complexion, a worn, emaciated, cachectic appearance, no matter what or how much they eat. Ulcer patients frequently have a robust, healthy appearance, and are emaciated or run down only after repeated hemorrhages, or when other grave diseases, such as heart disease, chlorosis, tuberculosis, etc., are also present.