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 supplied a means of disting- 

 uishing true diphtheria from conditions 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-diph- 

 theritic serum. 



Historical. 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 Loffler from a number of cases of diphtheria, his 

 observations being published in 1884, and to him we owe the first 

 account of its characters in cultures and some of its pathogenic effects 

 on animals. The organism is for these reasons known as the Klebs- 

 Loffler bacillus, or simply as Loffler's bacillus. By experimental in- 

 oculation with the cultures obtained, Loffler was able' to produce false 

 membrane 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 established by the 

 brilliant researches of Roux and Yersin, which showed that the most 

 important features of the disease could be produced by means of the 

 separated toxins of the organism. Their experiments were published in 

 1888-90. 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 out- 

 standing features which ought to be considered in connection 



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