104 MANUAL OF BACTERIOLOGY. 



Experiments in sterilization and disinfection as described 

 in Chapter VIII., Part II., may be performed with the bacteria 

 mentioned, which present every variety of resisting power up to 

 the almost incredible resistance of the spores of the hay and 

 potato bacilli. The efficiency of the methods used for steriliz- 

 ing surgical materials, as silk and catgut (Chapter IX., Part II.), 

 should be tested; also, of the methods for disinfecting the hands ; 

 if possible, of the methods for disinfecting rooms, as well. 



After some proficiency has been acquired, various pathogenic 

 bacteria may be studied as the circumstances of the case require. 

 Much judgment has to be used in allowing students to work 

 with pathogenic bacteria. Anthrax, glanders, tetanus, cholera, 

 bubonic plague, Malta fever, and diphtheria all have occurred 

 in laboratory workers through accidental infection, sometimes 

 with fatal results. Everything should be handled with forceps 

 as far as possible, and the forceps sterilized in the iiame before 

 and after using. Particles of cotton fiber should not be allowed 

 to fly off from the plugs. The various rules for the manage- 

 ment of the platinum-wire, hanging-drop slides and sputum 

 bottles, and for the handling of cultures and other infectious 

 materials have already been given (pages 22, 23, 33 and 72 to 

 75). As the risks of infection from neglect of proper caution 

 are obvious enough, it would seem, that it should be super- 

 fluous to warn students of the danger to themselves and others 

 of infecting their hands and surroundings; but some- who work 

 in bacteriological laboratories become careless, just as do those 

 who work with explosives. The most important precaution, 

 perhaps, is observance of the rule that, while working in the 

 laboratory, nothing should be put in the mouth. Cultures 

 should never be left in improper places. Cultures of 

 bacteria should be thoroughly sterihzed before the tubes are 

 cleaned. The writer is in the habit of having tubes and dishes 

 containing pathogenic bacteria placed in the steam sterilizer 

 at 100° C. for an hour on each of three days, and of having the 



