DIPLOCOCCUS PNEUMONIA 365 



by Neufeld, l Wadsworth, 2 Hiss, 3 and others, the organism for such tests 

 being brought into solution either with bile or with concentrated salt 

 solution. Such sera also contain powerful opsonic substances, or, as 

 Neufeld and Rimpau 4 prefer to call them, " bacteriotropins. " It seems 

 most likely that such phagocytosis-aiding substances are most power- 

 fully concerned in protection and cure. Clough 5 has reported an 

 increase of opsonins at the time of crisis, and Dochez 6 has shown that 

 protective substances may appear in the serum at or soon after the 

 time of crisis. The outcome of a case according to Cole depends 

 very largely on the virulence of the organism and on the ability of the 

 body first to limit the local infection and to prevent the invasion of the 

 blood with the organisms. In this process, of course, the protective 

 and opsonic bacteriotropic substances would play a most important part. 



The history of attempts to produce sera for passive immunization 

 in man is extensive. Washburn, 7 Mennes, 8 Pane 9 and many others 

 in the past have succeeded in protecting animals with such sera, but 

 with irregular results. The rational beginning based on the recognition 

 of different pneumococcus types was made by Neufeld and Haendel in 

 Germany, and carried to a considerable degree of success by Cole and 

 his associates at the Rockefeller Hospital in New York. By the immun- 

 ization of horses with the various types of pneumococci mentioned 

 above, considerable success has attended the use of sera produced 

 with Typfc I, and less success but great promise, that of sera produced 

 with Type II. The injection of considerable quantities of the homolog- 

 ous sera intravenously at least aids in sterilizing the blood stream, and 

 upon this the eventual outcome of many cases may depend. 



Since these methods which at present seem to promise the establish- 

 ment of a definite specific serum therapy in this serious disease depend 

 upon a rapid identification of the type with which the patient is infected, 

 it becomes a part of the work of the bacteriologist to control the methods 

 which have been developed for such determinations. The methods in 

 use at the present writing depend mainly upon the agglutination of the 

 strains in homologous sera. 



1 Neujeld, Zeit. f. Hyg., 1902, xi. 2 Wadsworth, loc. cit. 



3 Hiss, Jour. Exp. Med., vii, 1905. 



4 Neufeld and Rimpau, Deut. med. Woch., 1904. 

 6 Clough, Johns Hopkins Hosp. Bull., Oct., 1913. 



6 Dochez, Jour. Exp. Med., 1913. 



7 Washburn, Brit, Med. Jour., 1897. 8 Mennes, Zeit. f. HVK-, 1897. 

 9 Pane, Rif. med., 1897. 



