1336 
Now the question was whether perhaps below, or in the neigh- 
bourhood of the concentration of 1,75°/,, there would not be one, 
in which the phagocytosis was increased. Therefore the experiment 
was repeated also with weaker concentrations. 
TABLE &% 
Effect of CO, on phagocytosis. 
Boiled out NaCl-sol. 
containing Phagocytosis 
no CO, ax 100 = 27.99, 
17.5 Vol. percent CO, 0 
ie a mead Fog X 100 = 26.7% 
tie. AN or X 100 = 31.9% 
0.35 , aaa tap X 100 = 30 0 
0.175 , ait aan X 100 = 27.6% 
From this series of experiments it appears, just as from the 
preceding table, that in the NaCl-solution containing 17.5 °/, CO, 
the phagocytosis is O, in that containing 3.5°/, about the same as 
if there had been no CO, in it. At 1.75 vol. pere. the phagocytosis 
has risen 14.2°/, and at 0.35 vol. pere. CO,, 7°/,. At 3.5 vol. perc. 
the promotive action is therefore compensated by the noxious effect 
peculiar to CO, 
Consequently this series of experiments plainly demonstrates that 
in weak concentrations carbonic acid increases the phagocytosis, and 
that in higher concentrations it has a paralyzing effect. 
We shall adduce no more experiments in this short article. Let 
the statement suffice that the result was repeatedly and invariably 
confirmed. 
It should, however, be pointed out that the amount of CO,, re- 
quired to effect an increase (or also a paralysis) will have to be 
greater when the phagocytes are surrounded by serum, than in our 
experiments where the medium was a NaCl-solution containing only 
24 vol. pere. of serum. On another occasion we shall, for a different 
