1331 
Company “Oxygenium” at Schiedam had been prepared by fractio- 
nated distillation of liquid air. Tt still contains about 1°/, of oxygen, 
further gases of the helium group, and a bit of oil-products due to 
the pumps. At any rate it seemed desirable to carry out experi- 
ments with hydrogen likewise. 
Il. Lifect of hydrogen phagocytosis. 
These experiments were carried out lke those with nitrogen. 
Here too compressed gas was used which had been purified in the 
usual way. The results, however, were different from what we had 
expected, the phagocytosis was found to have decreased instead of 
increased. 
The phagocytosis was compared in fluids of which the NaCl- 
solution had not been treated, and which contained therefore compa- 
ratively much oxygen, with the phagocytosis in fluids of which the 
NaCl-solution had lost the greater part of its oxygen by being treated 
with H. 
TABLE-V: 
Effect of hydrogen on phagocytosis. 
Degree of phagocytosis. 
The fluid is not It is treated with 
treated | hydrogen 
24.5 A 14.7 0/0 
ZEI 5 ; 14.9"; 
10 5, OE 5 
219 EE 
The average of the first column comes to 21.5°/,, that of the 
second to 17.1°/,. There can be no doubt, therefore, but the hydrogen 
has impaired the phagocytosis. 
The most obvious explanation was, that some noxious impurity 
had not been removed altogether. Therefore we used in the follo- 
wing experiments hydrogen which we had prepared ourselves from 
chemically pure zine, which had been provided with a thin layer 
of copper by means of a copper-sulphate-solution of 5°/,. 
Now the results were entirely different ; ¢variably the phagocytosis 
wus promoted by the treatment with hydrogen. 
88 
Proceedings Royal Acad. Amslerdam. Vol. XVII. 
