6 BIOLOGY OF PNEUMOCOCCUS 



in September, 1881, in the fibrinous exudate and in hardened sec- 

 tions of lung and pleural tissue, stained by the Weigert-Koch 

 method, from eight cases of acute pneumonia and in the fluid with- 

 drawn from living pneumonia patients by lung puncture, he had 

 observed spherical and ellipsoidal cocci, occurring mostly in pairs, 

 and sometimes in longer chains made up of diplococci. 



In 1882, Giinther, 579 at a meeting of the Verein fiir tnnere Medi- 

 zin in Berlin, had reported that the microscopic examination of 

 stained preparations of purulent, bloody matter from lung punc- 

 ture showed numerous diplococci. He gave a demonstration of his 

 preparation and exhibited a drawing which caused Fraenkel to re- 

 mark that the cocci seemed to be surrounded by an unstained rim. 

 Giinther replied that the rim was really a hull. Early in the same 

 year, Colomiatti, 271 who was familiar only with the work of Klebs, 

 reported finding Monas pulmonale in a growth on the heart valve 

 and in the subarachnoid fluid in a case of croupous pneumonia 

 complicated with endocarditis and meningitis. 



In 1883,* Friedlander 4878 announced that he had found the same 

 micrococci in the alveolar exudate in all but a few of fifty cases 

 of pneumonia. Stained by the method of his colleague, Gram, 

 these cocci took an intense color, which was not extracted by treat- 

 ment with alcohol, and exhibited a well-defined capsule. The cap- 

 sule, which a short time before had been observed by Giinther, 

 could be clearly demonstrated by fixing the preparations with 

 acetic or mineral acids and staining with gentian violet, fuchsin, 

 Bismarck brown, or methylene blue. The capsular substance was 

 insoluble in alcohol, ether, or chloroform, and was best shown by 

 preliminary staining with aniline gentian violet, a short exposure 

 to alcohol, and counterstaining with eosin. The contour was 

 brought out by osmic acid but there was no blackening of the cap- 

 sule or cell. Friedlander observed that the capsules were most char- 

 acteristic at the highest stage of the cells' development, and con- 



* A greater part of this work was done with the collaboration of Frobenius, 

 who, because he did not remain until the completion of the study, declined the 

 inclusion of his name in the authorship of the paper ! 



