344 TARTARIC AND LACTIC ACIDS 



speedily causes redness, and eruption of large blisters 

 resembling those produced by boiling water ; but as a vesi- 

 cant, mustard or cantharides is preferable. As an astringent 

 or caustic it is rarely used. Dissolving albumin, fibrin, and 

 gelatin, it removes warts as well as corns in the human sub- 

 ject, softens scurf, destroys cryptogamic parasites and acari, 

 and hence is sometimes found in prescriptions for mallenders, 

 ringworm, scab, and mange. Along with either hot or cold 

 water, vinegar is used for contusions and strains, and for 

 sponging the skin and checking excessive perspiration in 

 febrile disorders. Once in high repute as an antidote for 

 many poisons, vinegar is now employed only in poisoning 

 by the alkalies and alkaline carbonates. It dissolves the 

 active principles of various drugs, and enters into the 

 composition of aceta,or vinegars of cantharides, ipecacuanha, 

 and squill. Oxymel is made by heating together forty 

 ounces of sugar or honey, and five each of acetic acid and 

 distilled water. 



TARTARIC ACID, H 2 C 4 H 4 6 . 



Acidum tartaricum is prepared from acid potassium tar- 

 trate. The crystals are colourless, monoclinic prisms, longer 

 than those of citric acid, with an acid taste, soluble in less 

 than their own weight of water, and less than three times 

 their weight of alcohol (90 per cent.). Either watery or 

 spirituous solution not too diluted, when stirred with potas- 

 sium acetate, yields a white crystalline precipitate. 



Tartaric acid is devoid of irritant and poisonous properties. 

 Christison gave drachm doses to cats without causing them 

 apparent inconvenience. Like other organic acids, it is 

 burnt within the body, and the resulting carbonates exert 

 their usual alkaline effects. It closely resembles citric acid, 

 and, like it, is used as a cooling antipyretic. Doses, horses 

 and pattle, 3ij- to 3J V - ; dogs, grs. x. to grs. xxx. 



LACTIC ACID, CHg.CHOH.COOH. 



Acidum lacticum produced by the fermentation of lactose, 

 from the action of the lactic acid bacillus, is a colourless, 



