PART II. 



BACTERIA PATHOGENIC TO MAN INDIVIDUALLY 

 CONSIDERED. 



CHAPTER XVII. 



THE BACILLUS AND THE BACTERIOLOGY OF DIPHTHERIA. 



Historical Notes. The specific contagious disease which we now call 

 diphtheria can be traced back under various names to almost the Homeric 

 period of Grecian history. The Greeks believed that it had been com- 

 municated to their country from Egypt. The description of the pharyn- 

 geal and laryngeal manifestations of this disease left by Aretseus leaves 

 no doubt that it was of diphtheria that he wrote. From time to time 

 during the following centuries we hear of epidemics both in Italy and 

 in other portions of the civilized world which indicate that the disease 

 never absolutely ceased. The disease early crossed to America, and 

 in the New England States we get clear accounts of its ravages. 



In 1765 Home, a Scotchman, tried to show that "croup" and pharyn- 

 geal diphtheria were different diseases, and this subject remained 

 under controversy until it was settled, through bacteriological examina- 

 tions, that while most cases were undoubtedly diphtheria, a few were 

 not. 



In 1771 Bard, an American, supported the opposite theory from Home, 

 considering the process the same wherever located. His observations 

 .upon diphtheria were very important and accurate. 



In 1821 Bretonneau published his first essay on diphtheria in Paris 

 and gave to the disease its present name. His observations were so 

 extensive and so correct that little advance in knowledge took place 

 until the causal relations of the diphtheria bacilli and their associated 

 micro-organisms to the disease began to be recognized. Since then 

 the combined clinical, bacteriological, and pathological studies have 

 sufficed to make diphtheria one of the best understood of diseases. 



The Diphtheria!. Bacillus. 



Discovery. In the year 1883, bacilli which were very peculiar and 

 striking in appearance were shown by Klebs to be of constant occur- 

 rence in the pseudomembranes from the throats of those dying of true 



