CHAPTER XVI. 



DIPHTHERIA. 



There is no better example of the valuable contributions of 

 bacteriology to scientific medicine than that afforded in the case 

 of diphtheria. Not only has research suppHed, as in the case of 

 tubercle, a means of distinguishing true diphtheria from condi- 

 tions which resemble it, but the study of the toxins of the 

 bacillus has explained the manner by which the pathological 

 changes and characteristic symptoms of the disease are brought 

 about, and has led to the discovery of the most efficient means 

 of treatment, namely, the anti-diphtheritic serum. 



Historical. — As in the case of many other diseases, various organisms 

 which have no causal relation to tlie disease were formerly described in the 

 false membrane. The first account of the bacillus now known to be the cause 

 of diphtheria was given by Klebs in 1883, who described its characters in the 

 false membrane, but made no cultivations. It was first cultivated by Loflfler 

 from a number of cases of diphtheria, his observations being published in 1 884, 

 and to him we owe the first account of its characters in cultures and of some 

 of its pathogenic effects on animals. The organism is for these reasons known 

 as the Klebs-Lbffler bacillus, or simply as Lofifler's bacillus. By experimental 

 inoculation with the cultures obtained, Loffier was able to produce false mem- 

 brane on damaged mucous surfaces, but he hesitated to conclude definitely 

 that this organism was the cause of the disease, for he did not find it in all the 

 cases of diphtheria examined, he was not able to produce paralytic phenomena 

 in animals by its injection, and, further, he obtained the same organism from the 

 throat of a healthy child. This organism became the subject of much inquiry, 

 but its relationship to the disease may be said to have been definitely estab- 

 lished by the brilliant researches of Roux and Yersin, who made an extensive 

 study of its character and life history, and showed that the most important 

 features of the disease could be produced by means of the separate toxins of the 

 organism. Their experiments'were published in i888-go. Further light has 

 been thrown on the subject by the work of Sidney Martin, who has found that 

 there can be separated from the organs in cases of diphtheria substances which 

 act as nerve poisons, and also produce other phenomena met with in 

 diphtheria. 



General Facts. — Without giving a description of the patho- 

 logical changes in diphtheria, it will be well to mention the 



356 



