348 INFECTION AND IMMUNITY 



in some alcoholics. He, however, carefully selected his cases. As 

 Petersen 29 concludes, non-specific therapy has produced definite re- 

 sults, though the eventual determination of its definite value cannot 

 yet be made. It is in the experimental stage, and according to 

 Petersen 29 concludes, non-specific therapy has produced definite re- 

 sults, though the eventual determination of its definite value cannot 

 yet be made. It is in the experimental stage, and according to 

 Petersen, "its usefulness and ultimate range" cannot yet be fully 

 judged. 



The effects of the injection, as analyzed by Petersen from his 

 own studies and a study of the literature, are as follows: After 

 injection of the more powerful and active substances, there is at 

 first a chill, sweating, and a definite rise of temperature ; there is a 

 leucopasnia followed by leucocytosis, lowering of the blood pressure, 

 and changes in the blood, such as increase in fibrinogen, a rise of 

 enzyme curve and an increase in blood sugar and antibodies. The 

 less active substances produce some temperature, a slight chill and 

 other symptoms mentioned, to a lesser degree. The beneficial effects 

 may perhaps be to some extent explained by the increase of leu- 

 cocytes and of enzymes, and Petersen makes a point of the fact 

 that if the method is to exert beneficial effects, it is probably neces- 

 sary to use it early in the disease. We are not in any position at 

 present either to recommend or further comment upon the method, 

 but it is an important problem for laboratory experimentation and 

 for careful clinical application in the hands of men trained in ex- 

 perimental studies. 



The Problem of Virulence. An extremely obscure chapter in our 

 knowledge of the reaction of animals and man against infection is 

 the one dealing with the questions of varying pathogenicity between 

 different bacterial species and between different races of the same 

 microorganism. We know that certain bacteria may be injected into 

 an animal or human being in considerable quantities, without pro- 

 ducing anything more than the temporary local disturbance follow- 

 ing the subcutaneous administration of any innocuous material. 

 Other bacteria, on the other hand, such as the bacillus of anthrax 

 or the bacillus of chicken cholera, injected in the most minute 

 dosage, may give rise to a rapidly fatal septicemia. Within the 

 same species, furthermore, fluctuations in virulence may take place 



29 Petersen, Jour. A. M. A., 76, January, 1921. 



