Vv. 
PYOGENIC BACTERIA. 
Tuer demonstration made by Ogston, Rosenbach, Passet, and 
others that micrococci are constantly present in the pus of acute 
abscesses, led to the inference that there can be no pus formation in 
the absence of microdrganisms of this class. But it is now well 
established, by the experiments of Grawitz, De Bary, Steinhaus, 
Scheurlen, Kaufmann, and others, that this inference was a mis- 
taken one, and that certain chemical substances introduced beneath 
the skin give rise to pus formation quite independently of bacteria. 
Among the substances tested which have given a positive result are 
nitrate of silver, oil of turpentine, strong liquor ammonia, cada- 
verin, etc. The demonstration has also been made by numerous in- 
vestigators that cultures of pus cocci, when sterilized by heat, still 
give rise to pus formation when injected subcutaneously. This was 
first established by Pasteur in 1878, who found that sterilized cul- 
tures of his “microbe générateur du pus” induced suppuration as 
well as cultures containing the living microbe. This fact has since 
been confirmed, as regards the pus staphylococci and various bacilli, 
by a number of bacteriologists. Wyssokowitsch produced abscesses 
containing sterile pus by injecting subcutaneously agar cultures of 
the anthrax bacillus sterilized by heat. Buchner obtained similar 
results in a series of forty experiments from the injection of steril- 
ized cultures of Friedlander’s bacillus (‘‘ pneumococcus ”), and has 
shown that the pus-forming property belongs to the bacterial cells 
and not to a soluble chemical substance produced by them. When 
cultures were filtered by means of a Chamberlain filter the clear 
fluid which passed through the porous porcelain was without effect, 
while the dead bacteria retained by the filter produced aseptic pus 
infiltration in the subcutaneous tissues within forty-eight hours 
after having been injected. Subsequent experiments gave similar 
results with seventeen different species tested, including Staphylo- 
coccus pyogenes aureus, Staphylococcus cereus flavus, Sarcina auran- 
tiaca, Bacillus prodigiosus, Bacillus Fitzianus, Bacillus subtilis, 
Bacillus coli communis, Bacillus acidi lactici, etc. From the experi- 
