PRACTICE OF MEDICINE AND HYGIENE 



diphtheria renders the body uninhabitable for 

 the diphtheria bacillus. 



How was this knowledge gained ? Klebs in his 

 microscopic examination of the false membrane 

 of diphtheria had noticed peculiar rod-shaped 

 bacteria. Many other varieties of bacteria 

 were also present. It remained for Loef- 

 fler to separate these bacilli and grow them ar- 

 tificially in pure culture. Having isolated and 

 cultivated them in the laboratory, the next step 

 was to learn if they would produce diphtheria. 

 He rubbed some of the culture upon the mu- 

 cous membrane of the throats of rabbits, and 

 produced the characteristic false membrane, 

 general and local symptoms of diphtheria, and 

 death in these animals. Further studies 

 showed that certain other bacilli in the throats 

 of healthy persons had the appearance of the 

 diphtheria bacillus; but their nonpathologic 

 character was determined by subsequent ex- 

 periment. It was also found that the real 

 diphtheria bacillus often remained in the throat 

 a long time after the individual had recovered 

 from the disease sometimes weeks and 

 months. Persons were going about unknow- 

 ingly carrying diphtheria among children. 

 Such a case was found in a nurse, whose pres- 



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