VI CONTENTS, 
Crystallography. I’, M. Jarcer: “On Benzylphtalimide and Benzylphtal-iso-imide”. 77. 
— F. M. Jarcer: “On the preservation of the crystallographical symmetry in the 
substitution of position isomeric derivatives of the benzene series’. 191. 
cuBic surfaces of a pencil (The congruence of the conics situated on the). 264. 
curve (On an expression for the class of an algebraic plane) with higher singu- 
larities. 42. 
— (On an expression for the genus of an algebraic plane) with higher singularities. 107. 
— (On the curves of a pencil touching an algebraic plane) with higher singu- 
larities. 112. 
— (The relation between the radius of curvature of a twisted) in a point P of the 
curve and the radius of curvature in P of the section of its developable with 
its osculating plane in point P. 277. 
curves (On Px-) of mixtures of acetone and ethylether and of carbontetrachlo- 
ride and acetone at 0°C, 162. 
— (On nets of algebraic plane). 631. 
— (An exact expression for the course of the spinodal) and of their plaitpoints 
for all temperatures, in the case of mixtures of normal substances. 646. 
— (On linear systems of algebraic plane). 711. 
a 
DALFSEN (B. M. VAN), On the function 7 for multiple mixtures. 94, 
DEDUCTION (Simplified) of the field and the forces of an electron, moving in any given 
way. 346. 
DEKHUIJZEN (M. €). On the osmotic pressure of the blood and urine of fishes. 537. 
DENSITIES (Application of the Baroscope to the determination of the) of gases and 
vapors. 770. 
DEVENTER (cH. M. VAN). On the melting of floating ice. 459. 
DICHLORONITROBENZENES (On position-isomeric). 668. 
DILUTE SOLUTION (Kinetic derivation of van ’t Hoff’s law for the osmotic pressure 
in a). 729. , 
DILUVIAL 1CE MOTION over the Netherlands (On the direction and the starting point 
of the). 40. 
DISPERSION (Spectroheliographic results explained by anomalous). 140. 
DISPERSION BANDS in absorption spectra. 134. 
— in the spectra of d Orionis and Nova Persei. 323. 
prro (J w.). The viscosity of the system hydrazine and water. 329. 
DORMAAR (J. M. M.). The inversion of carvon and eucarvon in carvacrol and its 
velocity. 63. 
bDUBOIS (EUG.). On the direction and the starting point of the diluvial ice motion 
over the Netherlands. 40. 
— (Some considerations on the conclusions arrived at in the communication made 
by Prof.), entitled: “Some facts leading to trace out the motion and the origin 
of the underground water of our sea-provinces”’. 45. 
— On the origin of the fresh-water in the subsoil of a few shallow polders. 53, 
— Gn an equivalent of the Cromer Forest-Bed in the Netherlands. 214, 
en a 
