STERILIZATION AND DISINFECTION. 113 



surgeon which cannot well be rendered incandescent, 

 exposed to dry heat at 150 C., steamed, or intermittently 

 heated without injury. For these objects disinfection 

 must be practised. Ever since Sir Joseph lyister intro- 

 duced antisepsis, or disinfection, into surgery there has 

 been a struggle for the supremacy of this or that highly- 

 recommended germicidal substance, with two results 

 viz. that a great number of feeble germicides have been 

 discovered, and that belief in the efficacy of all germi- 

 cides has been somewhat shaken; hence the origin of the 

 successful aseptic surgery of the present day, which 

 strives to prevent the entrance of germs into, rather than 

 their destruction after admission to, the wound. 



For a complete discussion of the subject of antiseptics 

 in relation to surgery the reader must be referred to the 

 large text-books of surgery, where much space is thus 

 occupied. A short list of useful germicides of which 

 the respective values are given, and a brief discussion 

 of some of the more important measures, can alone find 

 space in these pages. The antiseptic value of some of 

 the principal substances used may be expressed as fol- 

 lows, the figures indicating the strength of the solution 

 necessary to prevent the development of bacteria : 



Pyoktanin (methyl violet) . i : 2,000,000 i : 5000. 



Formalin i : 25,000 i : 5000. 



Bichlorid of mercury . . . i : 14,3. 



Hydrogen peroxid i : 20,000. 



Formalin . i : 20,000. 



Nitrate of silver 

 Creolin . 



Chromic acid 



Thymol 



Salicylic acid 



Potassium bichromate . 



Trikresol 



Zinc chlorid 



Potassium permanganate 



Nitrate of lead 



Izal . . . 



: 12,500. 



: 5000 to i : 200 (does not kill 



anthrax). 

 15000. 

 : 1340. 

 : looo. 

 1909. 



: 1000 i : 500. 

 1526. 



: 285 ; not prompt in action. 

 -.277. 

 : 200. 



