312 AUGUSTUS WADS WORTH 



using strong bichloride-alcohol for decolorization, Gram-negative 

 organisms retained the gentian-violet stain and were demonstrable 

 in the sections. 



The difficulties of staining encapsulated pneumococci in sections 

 of diseased tissues are thus purely technical, similar to those met 

 with in all precise histological work, and with due care easily elimi- 

 nated. By using the Gram method of staining a practical differ- 

 ential procedure is available for the accurate determination of pneu- 

 mococci in sections of diseased tissues. This is particularly valuable 

 in the study of pneumonic lesions, where contaminations or secon- 

 dary infections often occur, and cultural examination fails to reveal 

 the true significance of the bacteria isolated, or the relationship 

 of these organisms to the disease processes. 



These methods of studying the encapsulated pneumococcus, 

 uniform in principle, for the most part simple, and adaptable to 

 varying conditions, have been of such value in my studies that I 

 believe they may prove similarly useful to other workers in this field. 



BIBLIOGRAPHY. 



1. BONI. Munch, med. Wchnschr., 1900, 47, p. 1262. 



2. BUERGER. Med. News, 1904, 85, p. 1117; Centralbl. f. Bakt., 1905, orig. 39, pp. 

 216, 335. 



3. FRIEDLANDER. Fortschr. der Med., 1885, 2, p. 757. 



4. GORDON. Brit. Med. Jour., March 19, 1904, p. 659. 



5. GUARNIERI. Atti. d. v. Accad. med. di Roma., 1888, Ser. II, 4, p. 114. 



6. Hiss. Jour. Exp. Med., 1904, 6, p. 335. 



7. HlSS, BORDEN, AND K.NAPP. Ibid., 1905, 7, p. 547. 



8. KOLLE u. WASSERMANN. Handbuch der pathogenen Mikroorg., 1903, Bd. i, 

 p. 422. 



9. MACCONKEY. Lancet, 1898, 2, p. 1262. 



10. MALLORY. Ztschr. f. Hyg., 1895, 20, p. 220. 



11. MUIR AND RITCHIE. Manual of Bacteriology, 1903, p. 106. 



12. PANE. Centralbl. }. Bakt., 1898, 24, p. 289. 



13. RIBBERT. Deutsche med. Wchnschr., 1885, u, p. 136. 



14. Roux, NICOLLE ET REMLINGER. Traite de technique microbiolog., 1902, p. 328. 



15. SMITH. Boston Med. and Surg. Jour., 1902, 147, pp. 659-67. 



16. WELCH. Johns Hopkins Hospital Bull., 1892, 13, p. 128. 



17. WRIGHT. Ztschr. f. Hyg., 1895, 20, p. 220. 



