14 POISONOUS PEOTEINS 



pecially when properly stained. Even the chro- 

 mogenic bacteria come through as white pow- 

 ders, all the color being removed by the alcohol 

 and ether. The freedom of this cellular mate- 

 rial from extraneous matter is best appreciated 

 from the fact that when one gram of it is in- 

 cinerated there is no trace of chloride in the 

 ash. With chloride of sodium in the culture me- 

 dium and considering the ease with which traces 

 of chloride are detected, this indicates a sur- 

 prising degree of purity in the material. The 

 significance of the absence of chloride will be 

 discussed later. The cellular protein of many 

 pathogenic and nonpathogenic bacteria has been 

 obtained by growth in the tanks. I may say 

 that I have never dared to grow anthrax bacilli 

 in these massive cultures and have contented 

 myself so far as this organism is concerned with 

 the less abundant growths in Eoux flasks. For 

 obtaining abundant growths of the tubercle ba- 

 cillus the tanks are less suitable than glycerine 

 beef-tea cultures. 



CHEMISTRY. It has been generally assumed 

 that bacteria are unicellular plants. This as- 

 sumption rests, so far as I can learn, upon early 

 statements, such as that of Pollender, that an- 

 thrax bacilli are not affected by strong alkali 

 and this has been interpreted as meaning that 



