238 INFECTION AND IMMUNITY 



The Made of Action of Bacterial Poisons. Close study of the 

 toxic products of various microorganisms has shown that many of 

 the bacterial poisons possess a more or less definite selective action 

 upon special tissues and organs. Thus, certain soluble toxins of the 

 tetanus bacillus and Bacillus botulinus attack specifically the nervous 

 system. Again, certain poisons elaborated by the staphylococci, the 

 tetanus bacillus, the streptococci, and other germs, the so-called 

 1 ' hemolysins, ' ' attack primarily the red blood corpuscles. Other 

 poisons again act on the white blood corpuscles ; in short, the char- 

 acteristic affinity of specific bacterial poisons for certain organs is 

 a widely recognized fact. 



In explanation of this behavior, much aid has been given by the 

 researches of Meyer, 4 Overton, 5 Ehrlich, 6 and others upon the causes 

 for the analogous selective behavior of various narcotics and alka- 

 loids. It seems probable, from the researches of these men, that 

 the selective action of poisons depends upon the ability, chemical 

 or physical or both, of the poisons to enter into combination with 

 the specifically affected cells. From the nature of the combinations 

 formed, it seems not unlikely that the physical factors, such as 

 solubility in the cell plasma, may also play an important part. 



Observations of a more purely bacteriological nature have tended 

 to bear out these conclusions. Wassermann and Takaki, 7 for in- 

 stance, have shown that tetanus toxin, which specifically attacks 

 the nervous system, may be removed from solution by the addition 

 of brain substance. Removal of the brain tissue by centrifugation 

 leaves the solution free from toxin. In the same way it has been 

 shown that hemolytic poisons can be removed from solutions by 

 contact with red blood cells, but only when the red blood cells 

 of susceptible species are employed. 



Similar observations have been made in the case of leukocidin, 

 a bacterial poison acting upon the white blood cells specifically. 8 



That bacterial poisons injected into susceptible animals rapidly 

 disappear from the circulation is a fact which bears out the view 

 that a combination between affected tissue and toxin must take 



* Meyer, Arch. f. exper. Pathol., 1899, 1901. 



* Overton, "Studien iib. d. Narkose," Jena, 1901. 



9 Ehrlich, ' ' Sauerstoffs-Bediirfniss des Organismus," Berlin, 1885. 

 7 Wassermann und Takaki, Berl. klin. Woch., 1898. 

 9 Sachs, Hof meister 's Beitrage, 11, 1902. ' 



