20 



similar secretions, with aqueous methylene blue and several 

 others of the ordinary dyes used. There are practically only 

 two stains which are recommended, namely Loffler's me- 

 thylene blue or other alkaline methylene blue solutions and 

 particularly carbol-fuchsin (diluted 10—20 times and stai- 

 ning for 5—10 minutes). Thus it can hardly be stated with 

 absolute certainty that Pfeiffer's bacillus only appeared in the 

 last stage of the pandemic 1889—92 with the great frequency 

 and in the abundance that Pfeiffer demonstrated, but we 

 must content ourselves with supposing it the more probable. 

 In the investigations which were undertaken in the course 

 of the years 1892 — 94 in various places Pfeiffer's discovery 

 was on the whole supported although the bacillus was not 

 always found with such regularity (Weiciiselbaum (2), Ruber, 

 Ciiiari, Pribram (1), Borchardt, E. Neisser, Baumler, Pie- 



LICKE, RlCHTER, VOGES). 



Account of the Occurrence of Pfeiffer's Bacillus. 



In order to appreciate the significance of Pfeiffer's ba- 

 cillus correctly, it is necessary to have a detailed picture of 

 its occurrence at different times, in different neighbourhoods, 

 in various diseases and also in healthy persons, as well as 

 (possibly) outside the human body. The literature on all these 

 conditions is so extensive that it would lead much too far 

 to give an analysis of all the papers extant. In place of 

 this an impression of the occurrence of Pfeiffer's bacillus which 

 one obtains from perusing the accessible literature will first 

 be given, and afterwards the majority of the statements made 

 will be substantiated or at all events illustrated by short sum- 

 maries of a selection of the most enlightening investigations. 



The conception I think one should form of the occurrence 

 of Pfeiffer's bacillus is practically embraced by the following 

 13 points, of which nos. 1 — 7 especially, but not exclusively, 

 refer to the interval between the two pandemics, while nos. 

 8 — 13 deal with the conditions during the last pandemic. 



