CONTENTS. IX 



Hoi^LEMAN (a. f.). On the nitration of ortlio- and metadibromobenzene. 678. 



— presents a paper of Dr. J. J. Blanksma: ''The introduction of halogen atoms 

 into the benzene core in the reduction of aromatic nitro- compounds." 680. 



— and r. H. van der L.\an. The brominafioii of toluene. 512. 



u o L M E s (llesearches on the orbit of the periodic comet) and on the perfurljations 



of its elliptic motion. 642. 

 HONDSUUG (Some observations on the geological structure and origin of the). 06. 



— (The geographical and geological signihcation of the), and the examination cf 

 the erratics in the Northern Diluvium of Holland. 427. 



HOOGEWERFF (s.) presents a paper of ¥. 11. Evdman Jh.: "On colorimetry and 

 a colorimetric method for determining the dissociation constant of acids." 166. 



II u B R E c H T (a. a. TV.) presents a paper of Prof. Eugex Fiscuf.r: "On the primordial 

 cranium of Tarsius spectrum." 397. 



— presents a paper of Prof. H. Sthaul: "The uterus o( Eriuaceus europaeus L. 

 after parturition." 812. 



HULSHOPF POL (d. J.). Bolk's centra in the cerebellum of the mammalia. 2'J8. 

 H u Y G E N s' sympathie clocks and related phenomena in connection with the principal 



and the compound oscillations presenting themselves when two pendulums are 



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

 HYDRAZOBENZENE (Ou Diphenj Ihydrazine), and Benzylaniline, and on the mi.--cibili(y 



of the last two with Azobenzene, Stilbeue and Dibenzyl in tlie solid aggregate 



condition. 466. 

 HYDROCARBON (On the simplest) with two conjugated systems of double bonds 1,3,5 



bexatriene. 565. 

 HYDROCYANIC ACID (On the action of) ou ketones. 141. 

 HYDROGEN (The purifying of gases by cooling combined with compression, especially 



the preparing of pure). 82. 

 HYDROGEN CYANiDE-yieldiiig-plant (Thalictrum aquilegifolium, a). 337. 

 ICE (On the motion of a metal wire through a lump of). 653. 

 INTEGRAL of KuMMER (A definite). 350. 

 INTENSITIES of toues (On the ability of distinguishing). 421. 

 IODINE (Contribution to the knowledge of the isomorphous substitution of the elements 



fluorine, chlorine, bromine and) in organic molecules. 614. 

 ISOMORPHOUS SUBSTITUTION (Contribution to the knowledge of the) of the elements 



fluorine, chlorine, bromine and iodine, in organic molecules. 614. 

 ISOTHERMALS (Improvement in the transference of pressure by compressed gas especially 



for the determinatiou of). 76. 

 I T A L L I E (l. van). Thalictrum aquilegifolium, a hydrogen cyanide-yielding plant. 337. 



— On catalases ot the blood. 623. 



— On the diflerentiation of fluids of the body, containing proteid. 628. 

 jaeger (f. m.). On some derivatives of Phenylcarbamic acid. 127. 



— On Diphenylhydrazine, Hydrazobenzene and Benzylaniline, and on the miscibility 

 of the last two with Azobenzene, Stilbene and Dibenzyl in the solid aggregate 

 condition. 466. 



