ACETIC ACID In the glacial form this acid acts as a corrosive, the dilute acid as an irritant. Cases have been recorded of poisoning by the glacial acid. _Symptoms._--The parts with which the acid has come in contact are softened and rendered yellowish-white in colour. The larynx is commonly affected by the acid, as it is very volatile. _Post-mortem Appearances_ are those of corrosive poisoning with inflammatory action in the upper air-passages. _Fatal Period_ is variable but rapid. _Fatal Dose._--One drachm caused death in a child, but recovery has taken place in an adult after taking six fluid ounces. _Chemical Analysis._--Separate the free acid from organic matter by distillation, if in combination it should be liberated by adding phosphoric acid. With ferric chloride and ammonia to neutralisation a red colour is produced, turned yellow by hydrochloric acid. _Treatment._--Magnesia should be given to neutralise the acid and vomiting produced. The laryngeal symptoms will require treating on general principles; tracheotomy may be necessary. THE ALKALIES POTASH. SODA. AMMONIA Poisoning by the use of the alkalies is very rare. For the sake of convenience, and as the symptoms produced by the caustic preparations of soda and potash, taken in large doses, do not greatly differ, one description will do for both: =Potash= is found in commerce as (1) caustic potash, either solid or in solution; (2) carbonate and bicarbonate; (3) pearl-ash and soap-lees. =Soda= is found as (1) caustic soda; (2) carbonate (washing soda) and bicarbonate; (3) soap-lees, carbonate of soda mixed with caustic alkali. _General Characters._--Like the inorganic acids, the alkalies destroy the animal tissues with which they come in contact. Their action is local, no specific remote effects being produced. They are seldom, if ever, used for the purpose of homicide; the deaths caused by them are in most cases the result of accident or suicide. When injected directly into the veins of animals, the toxic action of potash and soda appears to differ, the former arresting the action of the heart in diastole, whereas the latter, according to Podocaepow and Guttman, does not, even in large doses, affect the heart or temperature--Guttman, moreover, asserting that soda has no influence upon the nerve centres, the peripheral nerves, or the muscles. It is difficult to understand how, with this asserted negative action, soda, like potash, causes death. _Symptoms._--During the act of swallowing, the patient complains of a caustic taste, accompanied with a sensation of burning in the mouth and throat, extending into the stomach. Vomiting may or may not be present; but in severe cases, when it does occur, the vomited matters may be mixed with blood. The surface of the body is cold, and bathed in a cold sweat. Purging is generally present, accompanied with intense pain and straining. The pulse is weak and quick, and the countenance anxious.