( 656 ) 
saturation, hysteresis) or, in conformity with Curie ? s law, a stronglyJ 
increased paramagnetism. The susceptibility at the temperature oil 
solid hydrogen should be about twenty times as great as at ordinary 
temperature x ). At this time we were not yet aware of the results? 
published last month by H. du Bois and Honda s ), from which it| 
appears that the inverse proportionality of paramagnetism to the. 
absolute temperature is but one of the possible cases. To get an 
idea of the order of magnitude of the expected phenomena we may 
suppose that the paramagnetic y iron still exists at 14° K. with the 
same Curie constant (product of absolute temperature by susceptibility)J 
In that case a value of about 400 is found for the magnetization! 
of this substance in a field of 20000 Gauss. 
Some time ago Gebhardt 3 ) determined the susceptibility of man¬ 
ganese at ordinary temperature and found K — 322.10 6 (density? 
6.4). The above calculation gives a value 134 for the magnetization 
of this substance in the same circumstances. And as the deflection 
in our apparatus is proportional to the square of the magnetization, 
one would obtain a deflection smaller in the proportion of 18 in the 
case of y iron or 160 in the case of manganese than that which 
was found for iron at the ordinary temperature; as k this was 100 cm. 
the manganese deflection should still be quite easily readable. 
When we now introduced into our apparatus roughly formed 
ellipsoids of Moissan vanadium and Goldschmidt chromium and 
manganese in succession, the awaited change did not appear. In 
every case the deflection at the temperature of solid hydrogen as 
well as at that of hydrogen boiling under atmospheric pressure 
remained the same as it was at ordinary temperature, that is, to a 
few tenths of a millimetre, and these must be ascribed to the 
magnetism of the suspending apparatus. There was therefore no 
ferromagnetism and we were obliged to choose between the following 
two hypotheses for these substances. We were either dealing with 
paramagnetism of a new kind or with diamagnetism, which is also 
) A similar supposition formed the starting point of a research by H. Kamer- 
ungh Onnes and A. Perrier, winch will shortly be published, and is closely 
connected with the present research. This investigation has been taken to hand 
at the same time with the present subject. Using the method of the maximum 
couple and the hydrostatic rise the magnetizations of liquid oxygen at various 
temperatures and of solid oxygen at the temperatures of boiling and solidifying 
y rogen were measured. The increase of the magnetization at low temperatures 
was found to be very great, though not so much as was expected, and a distinct 
deviation from Curie’s law and a characteristic curve were found. 
*) H. do Bois and Honda 1 . cit. 
s ) Gebhardt. Inaug. Dissert. Marburg 1909. 
