442 BIOLOGY OF PNEUMOCOCCUS 



IMMUNE SUBSTANCES IN SPUTUM 



Lord and Nye (1921) 831 " 3 observed that purulent sputum col- 

 lected during life and the pulmonary exudate obtained at necropsy 

 from the later stages of lobar pneumonia commonly eroded the 

 surface of Loeffler's blood serum and, in a separate communication, 

 Nye 1021 reported that washed cellular suspensions of pneumonic 

 lungs, previously preserved with chloroform and toluene, contained 

 a proteolytic ferment, derived chiefly from the leucocytes of the 

 exudate. Eddy (1928) 348 found that filtrates from sputum ob- 

 tained after crisis from patients with lobar pneumonia conferred a 

 certain degree of protection on mice, with sometimes only a delay 

 in the time of death. The effect was never produced by filtrates of 

 sputum obtained before crisis or from fatal cases, nor was the fil- 

 trate active with organisms other than those of the type infecting 

 the patient. The sputum of two patients displayed proteolytic ac- 

 tion, but Eddy was unable to demonstrate bacteriophage in any of 

 the specimens of sputum. The observation recalls that of Dick 

 (1912), 314 who by noting the optical rotation of mixtures of serum 

 from pneumonia patients taken at the time of crisis found that a 

 decrease in optical rotation occurred at that time and not before 

 or after the critical period. Dick ascribed the phenomenon to pro- 

 teolytic activity of the serum. 



ANTAGONISTIC SUBSTANCES IN PNEUMOCOCCAL EXUDATES 



Proceeding from the conception that increased acidity in pneu- 

 mococcal cultures might find an analogy in the pneumonic lung, 

 Lord (1919), 826 upon testing the hydrogen ion concentration of 

 morbid exudates, found higher acidity in three of four cases than 

 that in the press juice of the unaffected lung. Lord suggested that 

 increase in acidity in the diseased pulmonary tissue might favor 

 enzymatic action as well as inhibit pneumococcal growth. 



In further studies on pneumonic exudates, Lord with Nye 

 (1921 ), 8301 demonstrated the presence of a proteolytic enzyme. 

 The enzyme remained active after eighteen months' preservation 



