CHAPTER XVI 



PNEUMONIA 



LOBAR OR CROUPOUS PNEUMONIA 



DiPLOcoccus Pneumoniae (Weichselbaum) 



General Characteristics. — A minute, spheric, slightly elongate or lancet- 

 shaped, non-motile, non-flagellate, non-sporogenous, aerobic and optionally- 

 anaerobic, non-chromogenic, non-liquefying diplococcus, pathogenic for man and 

 he low er animals, staining by ordinary methods and by Gram's method. 



"Pneumonia," while generally understood to refer to the lobar 

 form of the disease particularly designated as croupous pneumonia, 

 is a vague term, comprehending a number of quite dissimilar in- 

 flammatory conditions of the lung. This being true, no single 

 micro-organism can be "specific" for all. Indeed, pneumonia 

 must be conceived of as a group of diseases, and the various micro- 

 organisms associated with it must be separately considered in con- 

 nection with the particular varieties of the disease in which they 

 occur. 



The micro-organism, that can be demonstrated in at least 75 per 

 cent, of cases of lobar pneumonia, which is almost universally ac- 

 cepted to be the cause of the disease, and about whose specificity 

 very few doubts can now be raised, is the Diplococcus pneumoniae 

 or pneumo coccus, of Frankel and Weichselbaum. 



Priority of discovery of the pneumococcus seems to be in favor 

 of Sternberg,* who as early as 1880 described an apparently identical 

 organism which he secured from his own saliva. Pasteur f seems to 

 have cultivated the same micro-organism, also from saliva, in the 

 same year. The researches of the observers whose names are now 

 attached to the organism were not completed until five years later. 

 It is to Telamon,! Frankel,§ and particularly to Weichselbaum, || 

 however, that we are indebted for the discovery of the relation which 

 the organism bears to pneumonia. 



Distribution. — The pneumococcus is one of a group of widely dis- 

 seminated organisms of the respiratory tract. It is characterized 

 by certain peculiarities of morphology, certain metabolic peculiari- 

 ties, a definite pathogenesis, and a distinct agglutinative reaction 



* "National Board of Health Bulletin," 1881, vol. 11. 



t " Compte-rendus Acad, des Sciences," 1881, xcii, p. 159. 



t "Compte-rendus de la Soci6t6d' anatom. de Paris," Nov. 30, 1883. 



§ "Deutsche med. Wochenschrift," 1885, 31. 



II " Wiener med. Jahrbuch," 1886, p. 483. 



444 



