KONINKLIJKE AKADEMIE VAN WETENSCHAPPEN 
TE AMSTERDAM. 
PROCEEDINGS 
VOLUME XXIII 
Ne 
President: Prof. H. A. LORENTZ. 
Secretary: Prof. L. BOLK. 
(Translated from: “Verslag van de gewone vergaderingen der Wis- en 
Natuurkundige Afdeeling,” Vols. XXVIII and XXIX). 
CONTENTS. 
A. SMITS and G. J. DE GRUYTER: “The Electromotive Behaviour of Aluminium”. II. (Communicated 
by Prof. P. ZEEMAN), p. 966. 
A. SMITS, L. v. D. LANDE, and P. BOUMAN: “The Existence of Hydrates in Aqueous Solutions”. 
(Communicated by Prof. P. ZEEMAN), p. 969. 
A. SMITS and R. PH. BECK: “The Electromotive Behaviour of Magnesium”. I. (Communicated by 
Prof. P. ZEEMAN), p. 975. 
A. SMITS and J. SPUYMAN: “A Thermo-electrical Differential Method for the Determination of 
Transition Points of Metals at Comparatively Low Temperatures”. (Communicated by Prof. P. 
ZEEMAN), p. 977. 
BALTH. VAN DER POL JR.: “Discontinuities in the Magnetisation”. II. (Communicated by Prof. H. A. 
LORENTZ), p. 980. (With one plate). 
P. EHRENFEST: “Note on the paramagnetism of solids”, p. 989. 
Miss J. E. VAN VEEN: “The identity of the genera Poloniella and Kloedenella” (Communicated by 
Prof. J. W. MOLL), p. 993. (With one plate). 
G. A. F. MOLENGRAAFF: “On Manganese Nodules in Mesozoic Deep-sea deposits of Dutch Timor” 
with a preliminary communication on “Fossils of Cretaceous Age in those Deposits” by 
Dr. L. F. DE BEAUFORT, p. 997. (With two plates). Thy 
Eug. DUBOIS: “The Proto-Australian Fossil Man of Wadjak, Java”, p. 1013. (With one wake. 
H. A. KRAMERS: “On the application of EINSTEIN’s theory of gravitation to a stationary field of 
gravitation”. (Communicated by Prof. H. A, LORENTZ), p. 1052. 
NIL RATAN DHAR: “Catalysis. Part XII. Some induced reactions and their mechanism”. (Communi- 
cated by Prof. ERNST COHEN), p. 1074. 
Proceedings Royal Acad. Amsterdam. Vol. XXIII. 
