965 
curve. (The observations for xenon, however, extend only to t = 0.7). 
The cause of this correspondence can well be explained on the as- 
sumption *) that the contracting influence of the simpler molecule 
and the diverging influence of the comparatively high critical tem- 
perature (-+ 16°.6 C) have, at least in part, cancelled each other. 
Physics. — Muaynetic researches, VII. On paramagnetism at low 
temperatures (continued). By H. KAMERLINGH ONNES and 
E. Oosrernuis. Communication N°. 132e from the Physical 
Laboratory at Leiden. Communicated by Prof. H. KAMERLINGH 
ONNES. 
(Communicated in the meeting of December 28, 1912). 
§ 9. Crystallized manganese sulphate. The salt was procured from 
Merck as puriss. pro analysi. The results were *): 
TABLE QVIT: 
Crystallized manganese sulphate MnSO,.4H,O. (1). 
| 
| 
T | z.10s | 47106 | Limits of H Bath 
| 
| 
E | 
288°.7 K. 66.3. 19140  10000—17000 | Air. 
169.6 | 1G es 18910 8000 — 17000 | Liquid ethylene. 
rs Oona ee cre Ee | | 
70.5 | 270 | 19030 | 6000—16000 Liquid nitrogen. | 
64.9 e292 18950 | | 
| 
20.1 | 914 18370 | 
18 | 1021 18170 | 4000—16000 | Liquid hydrogen. | 
14.4 1233 17760 | | 
| 
| | 
Down to and at nitrogen temperatures, this substance follows 
pretty much the law of Curie. 
1) See N°. 34 of Enc. Math. Wiss. V. 10. Suppl. N°. 23. 
2) Prof. Werss has kindly informed us that in the determination of standards 
of susceptibility in Zürich, for this substance z% = 66.77.106 at 14° 2 CG. was 
found. 
65 
Proceedings Royal Acad. Amsterdam. Vol. XV. 
