1905.] 



Chi Spontaneous and other Phagocytosis. 



217 



Three different sera were here subjected to experiment — 



1. The pooled unheated serum derived from eight normal men ; 



2. The same serum after it had been exposed to a temperature of 60° C. 

 for 10 minutes ; and 



3. Serum from a patient who had been subjected to therapeutic 

 inoculations of tubercle vaccine. This serum, like the last, had been exposed 

 to a temperature of 60° C. for 10 minutes. 



It will be seen that, as in Curve 1, where no serum was employed, the 

 highest phagocytic counts were with each serum obtained where the 

 concentration of the sodium chloride was least. 



In the case of Trace 3 (obtained with the heated normal serum) the 

 phagocytosis must be interpreted throughout as purely spontaneous 

 phagocytosis. 



In Trace 1 and Trace 2 it must, in the case where low concentrations of 

 NaCl are in question, be interpreted as spontaneous phagocytosis supple- 

 mented — to an extent corresponding with the differences between the counts 

 in these traces and those in Trace 3 — by phagocytosis dependent upon the 

 chemical action of the serum. Lastly, in these two first traces the phago- 

 cytosis registered where high concentrations of NaCl were employed must be 

 entirely dependent upon the chemical action of the serum. 



In Curve 3 we show the effect of making progressive dilutions of one and 

 the same normal unheated serum with, in the one case a - 6 per cent. NaCl 

 solution, and in the other case a 1'3 per cent. NaCl solution, using, as in the 

 experiments above, in each case one and the same suspension of tubercle bacilli 

 and one and the same washed blood cream.* 



It will be seen that while in the lower trace the phagocytic count sank 

 away in an almost regular manner to zero as the opsonins of the serum 

 were more and more diluted, in the upper trace the phagocytic count increased 

 as the serum was diluted by a less concentrated salt solution. 



We do not see room to doubt that in the case of the lower trace spontaneous 

 phagocytosis was completely suppressed, and that such phagocytosis as was 

 obtained was due exclusively to the action of the opsonins, and that in the 

 case of the upper trace the phagocytosis obtained in the outset was due to 

 spontaneous phagocytosis supplemented by the action of the opsonins, while 

 the increased phagocytosis in the latter part of the trace was entirely due to 

 spontaneous phagocytosis. 



* By this procedure there were obtained in the first case phagocytic mixtures whose 

 salt content diminished from 0-8 to 0"7 NaCl, and in the second case phagocytic mixtures 

 in -which the salt content increased from 92 to 1 per cent. 



