KONINKLIJKE AKADEMIE VAN WET ZNSCHAPPEN 
TE AMSTERDAM. 
PROCEEDINGS 
VOLUME XVIII 
N°, 6. 
President: Prof. H. A. LORENTZ. 
Secretary: Prof. P. ZEEMAN. 
(Translated from: Verslag van de gewone vergadering der Wis- en 
Natuurkundige Afdeeling, DI, XXIII and XXIV). 
CONTENTS, 
F. M. JAEGER and VAN KLOOSTER: “Investigations in the Field of Silicate-Chemistry. IV. Some 
data on the Meta- and Ortho-Silicates of the bivalent Metals: Beryllium, Magnesium, Calcium, 
Strontium, Barium, Zinc, Cadmium and Manganese", p. 896. 
F. ZERNIKE: “An interpolation-formula for resistance-thermometry at low temperatures.’ (Communi- 
cated by Prof. H. HAGA), p. 914. 
L. H. SIERTSEMA: “The magnetic rotation of the plane of polarisation in titane tetrachloride.” II. 
(Communicated by Prof. H. A. LORENTZ), p. 925. 
E. VAN EVERDINGEN: “The propagation of sound in the atmosphere”, (Communicated by Dr. 
J. P. VAN DER STOK), p. 933. (With 2 pl. and one table). 
ERNST COHEN: “The Metastability of the Elements and Chemical compounds in consequence of 
Enantiotropy or Monotropy and its bearing on Chemistry, Physics, and Technics” I. p. 961. 
H. A. VERMEULEN: “On the vagus and hypoglossus area of Phocaena communis.” (Communicated 
by Prof. L. BOLK), p. 965. 
P. E. VERKADE: “Glutaconic acid.” (Communicated by Prof. J. BOESEKEN). p. 981. 
A. SMITS, G. MEYER, and R. PH. BECK: “On Black Phosphorus” I. (Communicated by Prof. J.D. VAN 
DER WAALS), p. 992. 
C. H. SLUITER: “The composition of the hydrochlorides obtained from formaldoxime.” (Communi- 
cated by Prof. A..F. HOLLEMAN), p. 1007. 
W. DE SITTER: “On the orbital planes of Jupiter's Satellites, as derived from measurements made at 
Berlin”, p. 1012. 
F. A. H. SCHREINEMAKERS: “In-, mono- and divariant equilibria” IV, p. 1018 and V. p. 1026. 
J. E. VERSCHAFFELT: “The viscosity of liquefied gases”. III. The aperiodic rotational motion of a 
sphere in a viscous liquid”. (Communicated by Prof. H. KAMERLINGH ONNES), p. 1038. 
58 
Proceedings Royal Acad. Amsterdam. Vol. XVIII. 
