X CONTENT S. 



JAEGER (f. m.). Contributions to the knowledge of the isomorplious subslitutiou of 

 the elements fluorine, chlorine, bromine and iodine in organic molecules. ()14. 



— A simple geometrical deduction of the relations existing between known and 

 unknown quantities, mentioned in the method of Voigt for determining the 

 conductibility of heat in crystals. 793. 



— and J. J. Bi.ANKSMA. On the six isomeric tribromoxylenes. 153. 



,1 o N K E R (h. g.). Some observations on the geological structure and origin of the 



Hoodsrug. 96. 

 JU1-IÜS (w. H.). Measurement of the heat produced by the integral radiation of 



the corona and of the solar disk. 503. 

 A. new method for determining the rate of decrease of the radiating power 



from the center toward the limb of the solar disk. 668. 

 jupiter's satellites (On the orbital planes of). 767. 

 KAMERLINGH ONNES (h.). Improvement to the open mercury manometer of 



reduced height with transference of pressure by means of compressed gas. 75. 

 Improvement in the transference of pressure by compressed gas especially for 



the determination of isotherm als. 76. 



— Methods and apparatus used in the cryogenic laboratory. VH. A modified 

 cryostat. 77. VIII. Cryostat with liquid oxygen for temperatures below — 21(|oC. 

 79. IX. The purifying of gases by cooling combined with compression, especially 

 the preparing of pure hydrogen. 82. 



presents a paper of Dr. J. E. Verschaffelt : "Contributions to the knowledge 



of van der Waals' ifi-surface. X. On the possibility of predicting the properties 

 of mixtures from those of the components". 743. 



— presents a paper of Dr. J. E. Verschaffelt : "Appendix to the communications 

 published in the meetings of June 28, September 27, 1902 and October 31, 

 1903". 752. 



KAPTEYN (J. c). On the parallax of the nebulae. 601. 



presents a paiier of Dr. W. de Sitter: "On the orbital planes of Jupiter's 



satellites". 767. 

 KAPTEYN (av.). a definite integral of K.UMMEK. 350. 



— The quotient of two successive Bessel functions. I. 547. II- 640. 

 ketones (On the action of hydrocyanic acid on). 141. 

 KLUYVER (J. c). A local probability problem. 341. 



kohnstamm (ph.) — Some remarks on Dr. — last papers (on the osmotic ])ressure). 49. 



KORTE WEG (d. J.) presents a paper of Dr. W. A. Versluys: "On the number of 

 common tangents of a curve and a surface". 176. 



Huygens' sympathie clocks and related phenomena in connection with the 



principal and the compound oscillations presenting themselves when two pendu- 

 lums are suspended to a mechanism with one degree of freedom. 436. 



K u M M E R (A definite integral of). 350. 



laan (f. h. van dek) and A. E. Holleman. The bomination of toluene. 512. 



LAAR (J. J. V A n). On the shape of the plaifpoint curves for mixtures of normal 

 substances. 2nd communication. 33, 



