CONTENTS. XXI 



R O M B u R G H (p. VAN). Oil Ociuiene. 700. 



— Additive compounds of s. trinitrobenzene. 702. 



ROOTS (On the penetration into mercury of tlie) of freely floating germinating seeds, 182. 

 R o o z E B o o M (h. w. b A k h u t s). See Bakhuis Eoozeboom (H. VV.). 

 KUTTEN (jan). Description of an apparatus for regulaling the pressure when 

 distilling under reduced pressure. 665. 



R IJ N B E R K (G. V A n). On the fact of sensible skin-areas dying away in a centripetal 

 direction. 346. 



— and C. Winkler. Structure and function of the trunk-dermatoina. IV. 3i7. 



— Something concerning the growth of the lateral areas of the trunkdermatomata 

 on the caudal portion of the upper extremity. 392. 



SAND E BAKHUYZEN (e. f. VAN D e). Investigations of the errors of the tables of 

 the moon of Hansen-Newcomb for the years 1895—1902. 370. S^ci paper. 412. 422. 



— presents a paper of C. Sanders : "Contributions to the determination of geogra- 

 phical positions on the West-coast of Africa." 11. 426. 



SANDERS (c). Contributions to the determination of geographical positions on the 



West-coast of Africa. II. 426. 

 SCHOUTE (P. H.) presents a paper of Dr. W. A. Versluys : "The singularities of 



the focal curve of a curve in space." 17. 



— Centric decomposition of polytopes. 366. 



— Plücker's numbers of a curve in 8^, 501. 



— presents a paper of Dr. W. A. Versluys : "The singularities of the focal curve 

 of a plane general curve touching the line at infinity (t times and passing s times 

 through each of the imaginary circle points at infinity." 621. 



— presents a paper of Dr. W. A. Versluys : "On the position of the three points 

 which a twisted curve has in common with its osculating plane." 622. 



— Eegular projections of regular polytopes. 783. 



SCHUH (pre d.). An equation of reality for real and imaginary plane curves wich 

 higher singularities. 764. 



sclerotinia (On a) hitherto unknown and injurious to the cultivation of tobacco 

 (Sclerotinia Nicotianae Oud. et Koning). 48. Postcript. 85. 



sea-provinces (Facts leading to trace out the motion and the origin of the under- 

 ground water in our). 73S. 



seeds (On the penetration into mercury of the roots of freely floating germinating). J 82. 



series derived from the series 2 ' . 305. 



7)1 



siboga-espedition (On some of the results of the). 846. 



siERTSEMA (l. h.). Investigation of a source of errors in measurements of mag- 

 netic rotations of the plane of polarisation in absorbing solutions. 760. 

 silver (A determination of the electrochemical equivalent of). 441. 

 SKEW curve (On complexes of rays in relation to a rational). 12. 

 SKIN-AREAS (On the fact of sensible) dying away in a centripetal direction. 346. 

 SLEEP (The cause of). 86. 



