ANTISEPTIC AND ASEPTIC METHODS. 75 



Those, however, introduced by insufficiently cleansed hands, instru- 

 ments, and dressings are not only much more numerous but infinitely 

 more dangerous. Septicaemia, once so common after hospital operations^ 

 was not due, as believed, to the introduction of atmospheric germs, 

 but to organisms carried by dirty instruments, which had either 

 undergone only a semblance of cleansing, or had even passed from the 

 post-mortem room to the operating theatre ! 



The principal source of contamination being recognised, the 

 disinfection of instruments, hands, and dressings received greatly 

 increased attention. Bacteriological researches and some clinical 

 investigations showed that disinfection by chemical agents is not 

 always complete even when concentrated solutions are used. Organic 

 substances, even in thin layers, are not always readily penetrated by 

 liquid antiseptics, and the deeper strata may retain virulent organisms 

 in spite of the prolonged action of such liquids. Chemical disinfectants 

 are therefore reserved for the seat of operation, and the hands ; 

 instruments, ligatures, drainage-tubes, and other materials used for 

 dressing are subjected to the action of boiling water, glycerine^ 

 heated oil, or simply to a high degree of dry heat. The simplest and 

 most practical method is that of boiling in water, with or without 

 the addition of sodium carbonate. Although it does not give absolute 

 security — certain spores resisting even a temperature of 212° F. — 

 it is almost always sufficient. 



In hospital practice Chamberland's autoclave and dry heat stoves 

 are very useful, the former being used for sterilising objects preserved 

 in liquids where temperatures of 120° to 150° C. are required. Although 

 during the last few years Continental surgeons have practised 

 antisepsis in all its details and continued to perfect its technique, 

 English and American surgeons are more and more abandoning the 

 use of chemical bactericides and resorting almost entirely to the 

 observance of rigorous cleanliness ; in a word, they are abandoning 

 antisepsis for asepsis. In veterinary surgery, however, the latter 

 method will probably never obtain the same favour as the former. 

 Strictly speaking, antisepsis and asepsis do not stand in opposition, 

 but rather form mutual complements one of the other, aseptic 

 methods being preventive, antiseptic curative ; their association is 

 often advantageous. Antisepsis is resorted to when the region of 

 operation includes a suppurating wound, a fistula, or an ulcer, or 

 when reunion by first intention has failed. Antiseptics are then 

 employed to disinfect the seat of operation, the hands, the instru- 

 ments, and the dressing materials. The aseptic method, on the 

 other hand, is applicable to operations on infection-free tissues 



