XX G10) Ne CENTS 
THEORY of monatomic gases (Some remarks on the). 737. 
THIN FILMS (On the electric resistance of) of metal. 597. 
THIRD DEGREE terms (On the use of) in the energy of a deformed elastic body. 281. 
TRANSIT-OBSERVATIONS (On a peculiar anomaly occurring in the) with the Leiden 
meridiancircle during the years 1864—1868. 345. 
TRANSMUTATION (Some considerations on complete). I, 856. IL. 1100. 
TRESLING (J.). On the use of Third Degree terms in the energy of a deformed 
elastic body. 281. 
— The equations of the theory of electrons in a gravitation field of Einstein deduced 
from a variation principle. The principial function of the motion of the electrons. 
892, 
TWISTED CUBICS (Pencils of) on a cubic surface. 97. 
TWISTED CURVES (A simply infinite system of hyperelliptical) of order five. 271. 
URANIUM (On the analogy between potassium and) when acting separately in contra- 
distinction to their antagonism when acting simultaneously. 1043. 
UVEN (M. J. VAN). Logarithmic frequency distribution. 533. 
— Skew frequency curves. 670. 
VAPOUR PRESSURES in the system: carbon disulphide-methylalcohol. 1232. 
VARIABILITY of segregation in the hybrid. 805. 
VARIATION PRINCIPLE (The equations of the theory of electrons in a gravitation field 
of Ernstern deduced from a). 892. 
— (The virtual displacements of the electromagnetic and of the gravitational field 
in applications of HAMILTON’s). 968. 
vELOCITY (Direct optical measurement of the) at the axis in the apparatus for F1zEavu’s 
experiment. 125. 
VERSCHAFFELT (J. E.). The viscosity of liquefied gases. VI. 1062. VII. 1073. 
VIII. 1079. 
VERSCHAFFELT (J. E.) and Cu. Nroarse. The viscosity of liquefied gases. IX. 1084. 
VERTEBRATES (On the relation of the anus to the blastopore and on the origin of 
the tail in). 1256. 
VIRTUAL DISPLACEMENTS (The) of the electromagnetic and of the gravitational field in 
applications of HAMILTON's variation principle. 968. 
viscosity (The) of liquetied gases. VI. 1062. VII. 1073. VIII. 1079. IX. 1084. 
VISSER (s. w.). On the diffraction of the light in the formation of halos. 1174. 
VIsUAL FATIGUE (On the nature and progress of). 167. 
VOS VAN STEENWIJK (J. E. DE) and E. F. van DE SANDE BAKHUYZEN. On a 
peculiar anomaly occurring in the transit-observations with the Leiden meri- 
diancirele during the years 1864—1868. 345. 
VOSMAER (G. C. J.) presents a paper of Dr. H. C. Detsman: “On the relation of 
the first three cleavage planes to the principal axes in the embryo of Rana fusca 
Rosel”. 498. 
VRIES (HK. DE). The circles that cut a plane curve perpendicularly. If. 255. 
— presents a paper of Dr. J. Worrr: “On the nodal-curve of an algebraic surface”. 
1115. 
