_Symptoms._--Burning pain in mouth, throat, and gullet, strong acid, metallic or alkaline taste; retching and vomiting, the discharged matters containing shreds of mucus, blood, and the lining membrane of the passages. Inside of mouth corroded. There are also dysphagia, thirst, dyspnoea, small and frequent pulse, anxious expression, shock. Death may result from shock, destruction of the parts--_e.g._, perforation of stomach or duodenum, suffocation; or some weeks subsequently death may be due to cicatricial contraction of the gullet, stomach, or pylorus.
_Post-Mortem Appearances._--Those of corrosion, with corrugation from strong contraction of muscular fibres, and followed by inflammation and its consequences. The mouth, gullet, and stomach, and in some cases the intestines, may be white, yellow, or brown, shrivelled and corroded. The corrosions may be small, or may extend over a very large surface. Sometimes considerable portions of the lining membrane of the gullet or stomach may be discharged by vomiting or by stool. Beyond the corroded parts the textures are acutely inflamed. The stomach is filled with a yellow, brown, or black gelatinous liquid or black blood, and may in rare cases be perforated.
2. =Irritants.=--These are substances which inflame parts to which they are applied. The class includes mineral, animal, and vegetable substances, and contains a larger number of poisons than all the other classes together. Irritants may be divided into two groups: (1) Those which destroy life by the irritation they set up in the parts to which they are applied; (2) those which add to local irritation peculiar or specific remote effects. The first group includes the principal vegetable irritants, some alkaline salts, some metallic poisons, etc.; and the second comprises the metallic irritants, the metalloids (phosphorus and iodine), and one animal substance, cantharides.
_Symptoms._--Burning pain and constriction in throat and gullet, pain and tenderness of stomach and bowels, intense thirst, nausea, vomiting, purging and tenesmus, with bloody stools, dysuria, cold skin, and feeble and irregular pulse. The vomit consists at first of the food, then it becomes bile-stained, and later dark coffee-grounds in appearance, due to extravasation of blood from the over-distended vessels in the gastric mucous membrane. Death may occur from shock, convulsions, collapse, exhaustion, or from starvation on account of chronic inflammation of the gastro-intestinal mucous membrane.