1396 
The correspondence is satisfactory as far as the temperature of 
reduced oxygen. We shall return to this question in the following 
paper abaut the viscosity of helium, in which we shall further deal 
with the change of the nucleus volume 5 witb the temperature, 
as it follows from our experiments. 
Physics. — “Investigation of the viscosity of gases at low tempera- 
tures. I. Helium”. By Prof. Kammruincu Onnes and Sopavs 
WeBer. Communication N°. 1845 from the physical Labora- 
tory at Leiden by Prof. H. KaMERLINGH ONNES. 
§ 1. Results. With the same apparatus as was used for the 
investigation of the viscosity of hydrogen '), a series of measure- 
2,15 
1,90 
1,65 
1,40 
Sopnus WEBER: Comm N°. 134a. 
1) H. KAMERLINGH ONNES, C. DorsMAN and 
