DEVELOPMENT OF INFECTIOUS DISEASES. 151 



form us whether or not any test of the phosphate precipi- 

 tate was made. 



Bacterial Products which Favor the Develop- 

 ment OF Infectious Diseases. — Roger has made a 

 very interesting contribution on this subject, aud if his 

 worii be confirmed the question of mixed infection will 

 become more important than it has been supposed to be. 

 Rabbits are not naturally susceptible to the germ of char- 

 bon symptomatique ; indeed, inoculation with pure cultures 

 of the bacillus has no visible effect. But Roger fiuds that 

 if the staphylococcus pyogenes aureus, proteus vulgaris, or 

 bacillus prodigiosus be injected into the animal at the same 

 time with the germ of charbon symptomatique the latter 

 develops and produces the disease. The same result is 

 obtained when a sterilized culture of the bacillus prodigi- 

 osus is employed. He at first supposed that the chemical 

 products of the bacillus prodigiosus so lowered the vitality 

 of the tissues that the pathogenic germ was enabled to 

 establish itself; but he found that the same results were 

 obtained when the two inoculations were made in distant 

 parts of the body. The most marked effects were seen 

 when the sterilized culture was injected into a vein and the 

 charbon bacillus subcutaneously. In these instances the 

 rabbits rapidly developed enormous tumors, and died 

 within twenty-four hours. One drop of the sterilized cul- 

 ture was found to be sufficient, when injected intravenously, 

 to render rabbits susceptible to the pathogenic germ. 



In this connection it may be remarked that from time 

 to time statements have been made which would lead us to 

 infer that there are certain poisonous proteids which in 

 some way yet unknown render the body especially suscep- 

 tible to the invasion of bacteria. Rossbach injected a 

 poisonous albumose from the juice of the papain tree into 

 the bloodvessels of animals and obtained a septicaemia. 

 The blood was found to be filled with non-pathogenic 

 germs which came from the intestines. The results of 

 Rossbach have, however, been questioned by others. 

 Hankin makes the statement that a small dose of snake- 



