366 BIOLOGY OF PNEUMOCOCCUS 



showed the presence of a specifically precipitable substance in al- 

 most every instance during some stage of the disease. Precipi- 

 tinogen appeared as early as twelve hours after the initial chill 

 and in some cases was demonstrable as late as five weeks follow- 

 ing defervescence. The authors at the time presented data on the 

 chemical nature of the soluble specific substance which showed that 

 the substance which formed in the animal body during pneumo- 

 coccal infection and passed through the kidneys into the urine 

 was the complex carbohydrate which later was identified as the 

 specific capsular polysaccharide. 



A year later, Quigley, 1114 in following the precipitin reaction 

 during the course of lobar pneumonia due to pneumococci of 

 Types I, II, III, and Type (Group) IV, found that when the urine 

 was tested at intervals of two to three days, the reaction gradually 

 increased in intensity during a period of three or four days, per- 

 sisted from two to nineteen days, and then gradually disappeared. 

 There seemed to be no regularity as to the period in the disease 

 when the precipitinogen appeared in the urine, nor as to the 

 length of time it persisted. Furthermore, its presence seemed to be 

 independent of crisis. In the same year Blake 125 reported that, 

 in nineteen carefully studied cases, there was a definite relation 

 between the excretion of soluble pneumococcal antigen in the urine 

 and the development of antibodies in the blood in lobar pneumonia. 

 Precipitins were found only in clinically mild cases with negative 

 blood cultures and with no antigen in the urine ; and these patients 

 recovered. Blake stated that daily estimation of the concentra- 

 tion of soluble antigen excreted in the urine, taken with the num- 

 ber of cocci per cubic centimeter of blood, had great prognostic 

 value in the individual case of lobar pneumonia. 



The type-specificity of the precipitin reaction was verified by 

 Blake (1917), 123 who employed as precipitinogen the peritoneal 

 exudate from mice infected intraperitoneally with pneumococci of 

 Types I, II, and III, and Group IV. The method applied to a large 

 number of strains yielded consistently positive and specific re- 



