74 



evaporation failed to show any reaction. Control animals inoculated 

 with the crushed material before filtration always had successful 

 vaccinations. The object of the crushing was to liberate the organ- 

 isms from epithelial cells or other tissues which might retain them. 



Smallpox virus from three fatal cases failed after crushing to 

 pass into the nitrate, as determined by the inoculation of monkeys. 



Filterable bacteria.- -Von Esmarch" sought to determine whether 

 there are such things as ultramicroscopic organisms among the 

 saprophytes. , 



We readily believe that the virus of a filterable infectious disease 

 is made of very small organisms, possibly ultramicroscopic, and that 

 if these organisms could be made to multiply the resulting mass 

 would have an appreciable size. If there are ultramicroscopic sapro- 

 phytes he thought that all conditions were in the highest degree 

 favorable for their multiplication, and that on the ordinary labora- 

 tory media they ought to find their most suitable conditions of 

 growth and give an appreciable evidence of their existence. 



He used 40 different kinds of fluids, including sewage, rich vege- 

 table infusions, decomposing urine, emulsions of sputum, cavaders, 

 and feces. The clear nitrates from these suspensions were planted 

 on all the laboratory media and these plants kept under different 

 conditions showed no growth. 



During the first week's observations of the original filtrate no 

 growth was noted; but after ten days this fluid showed a turbidity 

 which was due to a very fine motile organism (Spirillum parvum) , 

 which grew as vibrios and spirilla, which were recognized only 

 by the greatest magnification. It passed the Berkefeld, Chamber- 

 land F, Reischel, and Pukall filters and appeared in the first 200-300 

 cc. of filtrates. No other bacteria were found in the filtrates. Its 

 size is about the same as that of the influenza bacillus, being 1 to 3 

 micra in length and 0.1 to 0.3 mi era in width. 



Von Esmarch grew bacteria through filters which hold them back 

 in ordinary filtration work. He used Berkefeld, Kitasato, and 

 Maassen filters. 



These filters were filled with plain bouillon and were placed in a 

 vessel containing bouillon inoculated with an organism, and the whole 

 was kept at 37°, or room temperature. 



Typhoid grew through the Kitasato filter at 37° in twenty-four 

 hours, and at room temperature in two days. 



Cholera went through a Maassen filter at 37° in two days, but a 

 control kept at room temperature did not grow through after thir- 

 teen days. 

 A small Berkefeld filter allowed Bacillus prodigiosus to pass in 



o Centbl. fur bakt, bd. 32, 1902, p. 561. 



