246 PASSIVE IMMUNIZATION 



usually within twenty-four to forty-eight hours there is definite 

 improvement, as evidenced by a return to consciousness, disappear- 

 ance of delirium, diminution of the general hypersensibility , etc. 

 The duration of the disease is shortened to eight to twelve days, 

 as contrasted with five weeks or longer, which is the rule in fully 

 one-half of the cases that end in recovery, in the absence of serum 

 treatment. 



In conclusion it would seem that late effects of the malady are 

 only exceptionally observed; mental disorder, paralysis and blind- 

 ness in particular are only rarely seen. 



We may accordingly look with pride and satisfaction upon the 

 antimeningitis work as one of the brightest pages in the history 

 of serology. 



STREPTOCOCCUS INFECTIONS 



Since the days when v. Behring first came forward with the 

 announcement that it is possible with the serum of an animal that 

 has been immunized against the corresponding toxin, not only to 

 protect individuals against diphtheria, but even to cure the disease 

 after this has once developed, attempt after attempt has been made 

 to produce an effective antiserum also against streptococcus infec- 

 tions. But as yet the problem has not been solved. Much work 

 of value has been accomplished, but still more remains to be done. 

 That it is possible to protect animals against a fatal infection with 

 streptococci by means of a corresponding antiserum had been shown 

 by v. Behring himself in 1892, and shortly after a number of French 

 observers attempted to influence the infection in the human being 

 also in a similar manner. 



The most noteworthy of these early attempts is intimately con- 

 nected with the name of Marmoreck. This investigator, believing 

 in the unity of practically all the different types of streptococci 

 which are pathogenic for man, succeeded in increasing the virulence 

 of an angina strain by animal passage to such a degree that 

 0.000000001 c.c. was sufficient to kill a rabbit with acute symptoms. 

 With this strain he immunized horses and sheep and then recom- 

 mended the resulting antiserum, which is thus a monovalent serum, 

 for the treatment of all forms of streptococcus infections occurring 

 in the human being. The results, however, were practically nil. 



