76 OPERATIVE TECHNIQUE. 



which might become inflamed under the action of antiseptics, to 

 hmited cases of necrosis, and to intoxications; but if asepsis can be 

 ensured, it is useless to apply to healthy tissues strong antiseptic 

 solutions. Of the two principles — "antisepsis before and during," 

 *' antisepsis before, asepsis during " — the former is preferable in our 

 practice on account of the chances of the wound, the hands, and the 

 instruments becoming infected during operation. Even in human 

 surgery, where, thanks to better surroundings and to special apparatus, 

 rigorous asepsis can much more readily be obtained, and where the 

 operator can count on highly skilled assistants, antisepsis, nevertheless, 

 has its uses. 



Among the organisms producing surgical infections two species, 

 micrococci and bacilli, stand pre-eminent. Whilst the former are 

 usually quickly killed by heat and the principal antiseptics, the latter 

 resist to a varying degree, depending on whether they have attained 

 the adult rod-like form or exist as spores. The adult bacilli are easily 

 killed, the spores on the other hand are strongly resistent. Certain 

 spores, like those of tetanus and septiccemia, exhibit most extra- 

 ordinary vitality. 



When dry, all microbes resist the action of heat and antiseptics 

 to a higher degree and for a longer time than when moist. The most 

 convenient method of destroying them is exposure to moist heat. 

 Whilst steam at 212° F. kills the majority of pathogenic microbes, 

 the dry temperature required for the same result varies from 290° to 

 330° F. Moisture considerably enhances the destructive action of high 

 temperatures and of antiseptics. Few pathogenic microbes resist 

 steam heat for more than a few minutes. Many die at 175°, 160°, and 

 even 150° F., but the spores of tetanus and of some septic organisms 

 endure higher temperatures than 212° F. without destruction. The 

 following table shows the temperatures at which the organisms of chief 

 surgical interest are destroyed : 



Staphylococcus pyogenes aureus is destroyed in ten minutes by a temperature of 137° F. 

 ,, ,, albus 



„ ,, citreiis 



Streptococcus of erysipelas 



,, strangles 



The bacillus of tetanus 



,, ,, tuberculosis 



,, ,, ^ glanders 



Anthrax spores are destroyed in ten minutes by a temperature of 

 Tetanus spores ,, ,, ,, ,, 



Septicaemia spores „ „ ,, „ 



Tetanus spores are destroyed in fifteen minutes by a temperature of 

 212° F. and in five minutes by a temperature of 240° F. At ordinary 



