VIII CONTENTS 



GILLIS (j.) and A. Smits. On milk-sugar. I. 520. II. 573. 



GLUCOSE (Experimental researches on the permeability of the kidneys to). 668. 



GRAVITATION (On Einstein's theory of). [II. 2. IV. 20. 



— (Some experiments on) The ratio of mass to weight for crystals and radioactiye 

 substances. 542. 



— (Further remarks on the solutions of the tield-equations of Einstein's theory 

 of). 13U9. 



GRAVITATION FIELD (On the energy of the) in Einstein's theory. 1238. 

 GttAViTATiON-THEORV of EiNSTEiN (On the mass af a material system according to 



the). 1076. 

 G R o L L (j. T E M M I N c k). The Influence of Neutral Salts on the action of Urease. 559. 

 HAALMEYER (b. P.). Elementary Surfaces of the third order. 101. 2nd Communication. 



304. 3rd Communication. 736. 4th Communication. 1246. 

 HAAS (w. J. de). On the dillraction-phenomenon caused by a great number of 



irregularly distributed apertures or opaque particles. 1278. 

 HAG A (h.) presents a paper of Miss H. J. Folmer: "A new electrometer; specially 



arranged for radio-active investigations". Part II. 684. 



— presents a paper of Miss H. J. Folmer and A. H. Blaauw: "Researches 

 into the radio-activity of the lake of Kockanje". 714. 



HAMBURGER (h. J.) and R. 15RINKMAN. Experimental researches on the permeability 

 of the kidneys to glucose. 668. 



— and E. Brouwer. On the ellect of H,_>02 on the peristalsis of the isolated 

 intestine. 861. 



HAMBURGER (l.). Ou the light emissiou of gases and mixtures of gases by electric 

 discharges. 1043. 



— and G. Holst. On a method of determining spectral intensities by means ot 

 photography. 1021. 



— and W. Keinders. Ultramicroscopic investigation of very thin metaltilms obtained 

 by evaporation in high vacuum. II. 1135. 



HEAD of vertebrates (Short history of the). 1005. 



HEART (Are contractility and conductivity two separate properties of the skeleton 



muscles and the). 554. 

 HEREDITY of headform in man (Mendelian segregation in the). 435. 865. 

 HERWERDEN (Miss M. A. V A n). On the nature and the significance of volutin in 



yeast-cells. 70. 

 HESCHL convolution (On the vfiriability of the number, of giant pyramidal cells 



in the) in man. 788. 

 HEÜX (j. w. le). On the nature of the constituent of Intestine-Extracts, whicti exerts 



a stimulating influence upon the Gastro-Intestinal movements. 805. 

 hofstede (h. w.) and J. Böeseken. Observations about hydration under the 



influence of colloidal Catalysers and how to account for this process. 424. 

 holleman (a. f.) presents a paper of Dr. E. H. Büchner: "The boiling point 



line of the system : hexane-nitrobenzene'', 322. 



— presents a paper of Dr. A. H. W. Aten : "Ou the passivity of Chromium". I. 

 812. [[. 1119. 



