473 



as set forth in raj description. The properties and animal experiments 

 correspond to those of Rabinowitsch and others. Rabinowitsch believes 

 that the reason why so many investigators could not produce a cul- 

 ture, is that the bacilli occur in the blood principally in a certain 

 period, viz. at the conclusion of the fever-period, immediately before 

 the crisis, so that, as he puts it, it is not the day of the beginning 

 of the disease, but the day of the crisis that is of prime importance. 



I happened to collect blood from the patient on the very day 

 when his disease had reached its acme and his life was feared for. 

 The following day, however, he suddenly took a turn for the better, 

 but in consequence of several complications occurring with the disease, 

 the temperature was not indicative of the time of the critical period. 



Those who have grown these bacilli agree that it is exceedingly 

 difficult to produce cultures. Frequently the rods were demonstrated 

 in the microscopic preparations (e. g. in broth or expression-water), 

 but they could not be developed any farther. Rabinowitsch holds that 

 the blood-serum of the patients inhibits the growth also when diluted. 

 Very weak dilutions would, therefore, further the growth. Even 

 the fluid expressed from the agar he considers to be a dilution. 

 Without touching the agar surface'he first puts the blood in the expres- 

 sion-water and only then, after shaking it well he pours it out over 

 the agar. My success in producing cultures may be owing partly to 

 similar dilutions in my procedure, and partly to the use of hypotonic 

 fluids to put Ihe blood in, and to the lucky circumstance of drawing 

 the blood at the proper moment. 



Plotz and later on Popoff are the only investigators who detected 

 an organism considered by them as the etiological factor of typhus 

 exanthematicus, differing essentially from all other organisms detected, 

 this bacillus typhi-exanthematici being obligate anaerobe. 



Several investigators succeeded in cultivating organisms not only 

 from the blood, but also from the urine and the feces of sufferers 

 from typhus exanthematicus. They were agglutinated by the blood 

 of the patients. Horiuchi e.g. produced from the feces and the urine 

 a paratyphus-like bacillus; Wilson obtained from urine and feces 

 bacilli differing from the Bacillus coli only in that they did not 

 convert lactose; Predtjetschensky managed to grow from urine, 

 sputum, and bronchial mucus the same diplobacilli as from the 

 blood ; Klodnitzky grew from house-bugs, obtained in a typhus 

 ward, a culture of small motile very virulent bacilli, called by him 

 bacillus violentus. Howevei' he refrains from considering them as 

 the agent exciting typhus exanthematicus. Petruschky collected from 

 sputum rodlets which he took to be the cause of the disease; Weil 



31 



Proceedings Royal Acad. Amsterdam. Vol. XX. 



