CHAPTER V. 



PNEUMONIA. 



LOBAR OR CROUPOUS PNEUMONIA. 



DiPivOCoccus PNEUMONIA (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 diplococ- 

 cus, pathogenic for man and the lower 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 inflammatory 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 dis- 

 eases, and the various micro-organisms associated with it 

 must be separately considered in connection 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 accepted to be the cause of the disease, and about 

 whose specificity very few doubts can now be raised, is the 

 Diplococcus pneumoniae, or pneumococcus 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 Weichsel- 



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

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

 J Communication to the Societe anatom. de Paris, Nov. 30, 1883. 

 "Deutsche med. Wochenschrift," 1885, 31. 



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