CORROSIVE, IRRITANT, AND VESICANT 343 



alcohol and sulphuric acid ; and the red-brown colour they 

 produce in neutral solution when treated with ferric chloride 

 a colour which changes on boiling to a brown precipitate 

 of basic acetate of iron. 



Vinegar (acetum) is diluted acetic acid, sometimes con- 

 taining traces of colouring matter, mucilage, alcohol, ethers, 

 sulphuric acid, and calcium sulphate. Besides being got 

 from the destructive distillation of wood, it is also obtained 

 from the oxidation of impure alcohols, by exposing them to 

 the air at a temperature of about 80 Fahr., and in contact 

 with a ferment. In this way vinegars are manufactured in 

 this country from malt, grain, cider, or solutions of sugar or 

 spirit ; in France, by exposing the poorer wines in half-filled 

 casks ; and in Germany, by what is termed the quick vinegar 

 process, from weak spirit mixed with about 1- 1000th part 

 of yeast, or beetroot juice, and allowed slowly to trickle at 

 a temperature of from 75 to 80 Fahr. over a large surface 

 of wood shavings previously soaked in vinegar. There is 

 shortly formed on the surface of the shavings a gelatinous 

 mould the mycoderma aceti which favours attraction of 

 oxygen from the air, supplies it to the alcohol, and hastens 

 its conversion into acetic acid. 



ACTIONS AND USES. Acetic acid is corrosive, irritant, and 

 vesicant. It is seldom used internally. Diluted, usually in 

 the form of vinegar, it is employed externally as a stimulant 

 and refrigerant, and in pharmacy as a solvent. 



Toxic EFFECTS. An ounce of acetic acid destroyed a 

 medium-sized dog in an hour, with symptoms of uneasiness, 

 abdominal pain, vomiting, and collapse ; a quarter of an 

 ounce was fatal in five to nine hours ; four or five ounces 

 of vinegar in ten to fifteen hours (Christison). Horses take 

 six to twelve ounces of vinegar, and cattle three or four 

 pounds, without apparent injury (Hertwig). A goat weigh- 

 ing 44 Ibs. got five ounces, and died in twenty-six hours, 

 the lesions consisting of hypersemia and oedema of the lungs, 

 and inflammation of the mucous lining of the digestive tract, 

 the kidneys, and liver (Frohner). 



Antidotes. Magnesia, soap and water, lime water, chalk 

 and water. 



EXTERNAL USES. Rubbed into the skin, acetic acid 



