22 QUATERCENTENARY STUDIES IN PATHOLOGY 



nuclears of pneumonia patients are equally active to those of normal 



blood. 



Total number of cocci in 40 leucocytes of normal blood - - - 540 

 ») It 90 II Pneumonia patient No. i - 700 



ti II 85 It M No. 2 - 720 



In some of the cases it was very remarkable how wonderfully the 

 counts in relative numbers totalled up. In a case of pneumonia in which 

 there were, on the days of estimation, 12,500 leucocytes to normal 8,700, 

 the results were : — 



Cocci in 

 50 leucocytes. 



Normal serum + Normal leucocytes + Pneumococci - - - 473 



•1 + Pneumonia patients' leucocytes 4- Pneumococci - 376 



But the number of polymorphonuclears of normal blood to that of the 

 patient's blood was approximately i : 1*4, and, if one adds two-fifths to 

 the pneumonia patient's count, we have 470, as compared with 473 in the 

 normal man. 



Effect of dilution of the Serum. — Many experiments were performed 



on the effect of diluting the serum of the individual examined by normal 



saline solution (0*85 per cent.). Serum of a normal individual was 



diluted with definite quantities of saline solution. Three parts of the 



normal serum and three parts of each of the diluted specimens were 



added to the leucocytes of a normal individual and an emulsion of cocci. 



The mixtures were incubated at 37° C. for 15 minutes, films made, and 



the total number in 80 leucocytes estimated and an average determined. 



Result :— 



Cocci per 

 leucocyte. 



Normal serum 3 parts 10*9 



Normal serum 2 pts. + Normal saline i pt. - - 107 



Normal serum i pt. + n 2 pts. - - 10*2 



Normal serum J pt.+ m 2 J pts. - - 5*9 



(Normal serum : Normal saline = i : 8) 3 pts. - - 2*0 



( II II =1 : 10) 3 pts. - - 1*9 



The conclusion drawn at first glance from these figures is that the 

 opsonic index is not an index of the amount of opsonin in the serum, 

 seeing that the serum can be diluted to as much as one in three with 



(386) 



