_Symptoms._—The chief symptoms occasioned by the foregoing poisons are, an acrid, burning taste, with a sensation of excoriation and burning extending along the mouth and throat, to the stomach. There soon ensue exquisite pain in the epigastrium, and tenderness on pressure. Frequently there is cough, hoarseness, dyspnœa, as well as vomiting of altered mucus mixed with blood and detached portions of the mucous membrane. The tongue, mouth, and fauces become swollen, soft, and flabby, and deglutition is difficult. The surface of the body gets cold and moist, the pulse small and feeble, and there is great pain over the abdomen, with diarrhœa. Death took place, in the case of a boy, in three hours from the time of swallowing a strong solution of carbonate of potash. Ammonia, by its effect on the air passages, has proved fatal in four minutes. When recovery from the immediate effects of the poison has taken place, death has subsequently ensued from stricture of the œsophagus, producing starvation. By the proper use of bougies, &c., life may occasionally be prolonged for many months, or even for years. In some instances, however, it is almost impossible to effect dilatation, owing to the whole of the gullet becoming thickened and contracted, so that the opening into the stomach will hardly admit a crow-quill. The pylorus may also be contracted in like manner. _Post-mortem Appearances._—The mucous membrane of the mouth and gullet is softened and inflamed, and portions of it detached. The coats of the stomach and intestines are inflamed, stained of a dark color, and sometimes ulcerated. When death has resulted from ammonia, signs of inflammation are usually found in the larynx and bronchial tubes. The other caustic alkalies may also destroy life by producing inflammation of the glottis, which consequently may be found thus occluded after death. _Treatment._—The object must be to neutralize the poison, which may be effected by a weak acid. Vinegar and water is perhaps the best antidote, and that most readily procurable; its administration may be followed up by freely allowing acidulated demulcent drinks, orange juice, &c. The use of oil has been recommended, on the principle that it converts the alkali into a soap. But that its efficacy is doubtful has been in some measure shown by the death of two young children from swallowing a mixture of ammonia and oil. In one of these cases nearly two ounces of linimentum ammoniæ (made of one part of liquor ammonia to two of olive oil) were poured down an infant’s throat by a child five years old. Were, however, the oil given in much greater abundance, the result would probably be different. At all events, its administration should not be neglected.