266 CARBOLIC ACID. 



ing the life of contagious disease germs, as well as 

 offensive smells. The smoke from the burning of 

 pitch and tar has long been celebrated for its puri- 

 fying properties. Even the vapour of tar is held to 

 be serviceable in this .way. A minute trace of some 

 of the ingredients of tar dissolved in water is certainly 

 destructive to many of the lower forms of life. Pitch 

 and tar have been used as disinfectants from the 

 earliest times. The material used by the ancient 

 Egyptians for embalming, was obtained from pitch. 

 The active antiseptic agents, it has recently, been 

 shown, are carbolic and cresylic acids, which are now 

 extracted in large quantities and used in a pure state. 

 Of these, the first is the most important. The anti- 

 septic properties of wood smoke and of creosote, are 

 due mainly to the carbolic acid which is present. 



Carbolic Acid. During the prevalence of the Cattle 

 Plague, many experiments were tried with these sub- 

 stances, but of all that were employed, carbolic acid 

 was, there is reason to think, the most efficacious. 

 This substance, which was obtained by Laurent under 

 the name of phenic acid from the oil of coal tar, has 

 of late years been made in large quantities by Messrs. 

 Calvert & Co., of Manchester. 



Carbolic Acid is highly -volatile, and diffuses itself 

 with remarkable rapidity. The vapour is not in any 

 way injurious to linen, metals, or furniture. It is per- 

 fectly harmless, and so far from being disagreeable, the 

 odour is one to which we readily become accustomed, 



