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 filtrate, as determined by the inoculation of monkeys. 
Filterable bacteria .—Yon 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 filtrates 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. 
Fon 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 sjnall Berkefeld filter allowed Bacillus prodigiosus to pass in 
o Centbl. fur bakt., bd. 32, 1902, p. 561. 
