8 QUATERCENTENARY STUDIES IN PATHOLOGY 



lung punctures with a Pravaz's syringe before, during, and after the 

 crisis, and inoculated the exudate thus obtained into rabbits and mice. 

 He thus was able to demonstrate that, even after the crisis, one could 

 obtain from the lung an exudate containing not only viable, but even 

 virulent, diplococci, killing the animals rapidly by septicaemia. Thus the 

 crisis does not depend on the killing of all the diplococci in the lungs, 

 for they may be found in considerable abundance, yet on culture the 

 number of organisms was shown to be comparatively few. 



Pneumonia was then induced in dogs by intra-tracheal injection of 

 pneumococcus culture, which was allowed to flow down by gravity into 

 the lower pulmonary lobes. Graduated doses were used, and in several 

 cases the most intense pneumonia was set up. The animals were killed 

 at different intervals, the lungs hardened, sections cut, and stained by the 

 Gram-Weigert method. Thus he was able to demonstrate — 



1. That in the cases going rapidly to a lethal issue, the phenomena of 

 phagocytosis by the leucocytes lying in \he alveoli were entirely absent. 



2. That in cases going on to cure, but killed during the course, there 

 was a large exudate of phagocytes in the alveoli, with numerous cocci 

 lying within them. 



By this method he was also able to show that, in non-resistant animals, 

 the diplococcus causes only a very feeble local inflammatory reaction, 

 and little phagocytosis is present ; the leucocytes do not engulf the cocci, 

 which can therefore go on rapidly multiplying, and quickly cause a fatal 

 issue. In resistant animals, the inoculation of pneumococcus causes 

 an inflammatory process of varying intensity, with dense cellular 

 infiltration and a more or less pronounced phagocytosis. In a further 

 series on animals inoculated with a weak pneumonic virus, Tchistovitch 

 showed the close parallelism between the course of the disease and the 

 leucocytosis, and considered the crisis as mostly brought about by 

 phagocytosis, the intoxication ceasing with the taking up of the cocci. 

 The protective bodies occurring in the serum he regarded as adjuvant 

 factors, the hypothetical stimulins stimulating active englobation by the 

 leucocyte, and the agglutinins causing the massing together of the cocci, 

 and thus rendering their rapid ingestion by the phagocytes more easy. 



But it was destined that a severe blow should be inflicted on the 

 pre-eminence of the leucocyte. The first indication of this was the 

 work of Denys and Leclef (27) on the mechanism of streptococcal 



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