DISINFECTANTS. ANTISEPTICS 209 



are destroyed only after 30 hours (Arloing, Roux). Tubercle 

 bacilli are killed by direct sunlight in a few hours and by diffuse 

 daylight in a few days (R. Koch). The contagion of rinderpest is 

 affected in the same manner (Theiler). Direct sunlight exerts a 

 powerful disinfectant action upon coli bacilli and the organisms 

 of swine plague, hog cholera, swine erysipelas and fowl cholera, 

 while diffuse daylight also possesses disinfectant properties but 

 in less degree (Neumark, Dissertation, 1907). Perhaps this 

 explains the milder course and less frequent occurrence of some 

 of the infectious diseases in the summer (contagious pneimionia). 

 From the foregoing it follows that the admission of light into dark 

 stables and the airing of blankets essentially assist disinfection. 



Other mechanical methods include: whitewashing or painting 

 (lime, calcium chloride, tar, varnish, paint, lacquer), which 

 covers and fixes the bacteria and prevents their increase; scouring, 

 cleansing, washing, sweeping, wiping, rubbing (rubbing the car- 

 pet with bread), exclusion of air (closing a room before disinfec- 

 tion) and above all washing with soap. The latter is sufficient 

 in many cases, especially for infectious material that is readily 

 destroyed. 



3. DISINFECTION OF WOUNDS 



The Most Important Antiseptics for Wounds. — ^The general 

 statements already made (p. 170) are to be considered in connec- 

 tion with the choice and judgment of the individual antiseptics 

 employed in the treatment of woimds. In the first place, atten- 

 tion is to be given to the different disinfectant values of the individ- 

 ual antiseptics and to the resistance of the microorganisms con- 

 cerned in wound infection to these agents. As already mentioned 

 on page 175, the resistance of these organisms lies about midway 

 between that of the anthrax and black leg spores, which are diffi- 

 cult to kill, and that of the easily destroyed anthrax and swine 

 eiysipelas bacUli. The staphylococci and streptococci especially 

 cannot be destroyed by the milder dismfectants, but require the 

 more powerful antiseptics (corrosive sublimate, creolin, lysol, 

 tannoform, carbolic acid, tincture of iodine, aluminum acetate, 

 silver nitrate). Other points to be considered are the degree of 

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