that the mortality for the total 495 cases is 10- 5 per cent.* The 

 serum is given intravenously in doses of 90-100 c.c, repeated 

 every eight hours until there is a satisfactory fall of temperature 

 and improvement of symptoms. Cole states that the average 

 amount of serum required per case is from 200 to 300 c.c, but 

 in severe cases, treated late in the disease, larger amounts are 

 needed, even up to 1,000 c.c. 



South African Types. 



In South Africa, Lister has attempted a serological classifica- 

 tion of strains of pneumococci obtained from cases of pneumonia 

 amongst native miners. During the period 1913-17f he collected 

 148 strains and found that these were divisible into 12 groups. 

 His Group C (American I) contained 32 cases (21-6 per cent.); 

 Group B (American II) contained 24 (16-2 per cent.); and 

 Group E (American III) contained only 2 cases. The rest, 

 apparently, would all be relegated by the Americans to the 

 " scrap-heap," Type IV, including Lister's Group A, which was 

 the most important of the twelve, as it contained 46 cases 

 {31 per cent.). 



Lister vaccinated miners with cultures of his three most 

 important groups and found that protection was conferred against 

 pneumonia attributable to members of these groups. 



Multiplicity of Agglutinins. 



From the above brief outline it would appear that antigenic 

 differences amongst pneumococci are extremely numerous, that 

 the search for such differences is far from being completed, and 

 that there is no definite prospect of arriving at a stage of finality. 



It should be mentioned, however, that some investigators 

 have found evidence of serological relationship amongst strains 

 more usually regarded as antigenically distinct. Miriam Olm- 

 stead,J for example, found that members of " Type IV " were 

 not quite so heterogeneous amongst themselves as was originally 

 supposed. By means of agglutinating rabbit sera, she succeeded 

 in classifying 94 "Type IV" strains into 12 serological groups. 

 Mildred Clough has stated§ that, amongst the pneumococci 

 isolated from pneumonias and other cases in the Johns Hopkins 

 Hospital during 1915-18, nine strains agglutinated with sera 

 of all three types (I, II, and III) in fairly high dilution (1 : 8 to 

 1 : 64 or higher), while normal horse serum caused no agglutina- 

 tion. In confirmation of these results, she found that the three 

 type sera also stimulated active phagocytosis of all the strains, 

 though there was no phagocytosis with normal horse serum 

 controls; and the nine strains elaborated in the bodies of 



• Cecil and Blake have also used this serum successfully on monkeys 

 experimentally infected with doses of Type I pneumococci which were 

 fatal to the controls (Journ. Exper. Med.. XXX 1 1 p. I. 1920} 



t Publ ic at i on* of the South African Institute for Medical Research 

 No. 10. November, 1917. 



% Jottrn. Immunol., II. p. 425. 1917. 



§ Journ. Exper. Med., XXX, p. 123. 1919 



