KCTOPNS TEEN WEISS XIX 
SOLVENTS (On the latent heat of mixing for associating). 174. 
SOMMERFELD (A). Simplified deduction of the field and the forces of an electron, 
moving in any given way. 346. 
SPECTRA (Dispersion bands in the) of 3 Orionis and Nova Persei. 323. 
SPECTROHELIOGRAPHIC results explained by anomalous dispersion. 140. 
SPHAEROPSIDEA (On Sclerotiopsis pityophila (Corda) Oud., A) occurring on the needles 
of Pinus silvestris. 211. 
SPHERICAL SPACES (On non-linear systems of) touching one another. 562. 
STANDARDCLOCK (A new method of interpolation with compensation applied to the 
reduction of the corrections and the rates of the) of the Observatory at Leyden, 
Hohwii 17, determined by the observations with the transitcircle in 1903. 241. 
ST. DENIS (Island of Réunion) (A short account of the determination of the longitude 
of) executed in 1874. 602. 
STEREOISOMERIC g-and @-trithioacet (The intramolecular transformation in the) and 
a-and #-trithiobenzaldehydes. 329. 
STOK (J, P. VAN DER). On a twenty-six-day period in daily means of the barometric 
height. 18. 
SULPHOISOBUTYRIC ACID and some of its derivatives. 275. 
suMATRA (The connection between the primary triangulation of South-Sumatra and that 
of the West-Coast of). 453. 
SURFACE (Contributions of the knowledge of van per Waats’y-). IX. The conditions 
of coexistence of binary mixtures of normal substances according to the law of 
corresponding states. 222. 
SURFACES (Multiple umbilics as singularities of the first order of exception on point- 
general). 336, 
SUYVvER (J. F.). The intramolecular transformation in the stereoisomeric g- and 
B-trithioacet and z- and @-trithiobenzaldehydes. 329. 
SYPKENS (B.). On the nuclear division of Fritillaria imperialis L, 412, 
SYSTEMS (On non-linear) of spherical spaces touching one another. 562. 
— (On linear) of algebraic plane curves. 711. 
TAMMES (TINE). On the influence of nutrition on the fluctuating variability of 
some plants. 398. 
TARSIUS SPECTRUM (On the development of the brain in), 331. 
TEICHNER’s experiments (The influence of admixtures on the critical phenomena 
of simple substances and the explanation of), 474, 
TEMPERATURES (The determination of the conditions of coexistence of vapour and 
liquid phases of mixtures of gases at low). 233, 
— (On the measurement of very low). V. The expansioncoefficient of Jena- and 
Thüringer glass between + 16° and — 182° U, 674, VII. Comparison of the 
platinum thermometer with the hydrogen thermometer, 290. VILI. Comparison of 
the resistance of gold wire with that of platinum wire. 300. 
— (An exact expression for the course of the spinodal curves and of their pluit- 
points for all), in the case of mixtures of normal substances. 646. 
TETRAEDAL COMPLEX (On a special). 572. 
