XII GiOUN UTE Ne rs 
EINTHOVEN (W.) presents a paper of Dr. S. DE Boer: “On artificial 
and spontaneous changes of rhythm in the bled frog’s heart”. 552. 
— On the observation and representation of thin threads. 705. 
ELECTRIC ORGAN (An inquiry into the distribution of potassium compounds 
in the) of the Thorn-back (Raja clavata). 842. 
ELECTROLYTES (On Spray-electricity of solutions of). 658. 
ELECTROMOTIVE BEHAVIOUR (The) of aluminium. II. 966. 
— of magnesium. [. 975. 
ELLIPTIC PENCILS (Explanation of some interference curves of uniaxial and 
biaxial crystals by superposition of). 1223. 
ENDOCRINE organs (On the character of morphological modifications in 
consequence of affections of the). 1328. 
EPsTEIN (P. S.). On the principles of the theory of quanta. 1193. 
EQUATION OF STATE (On the) for arbitrary temperatures and volumes. 
Analogy with PLANCK's formula. II. 887. 
EQUILIBRIA (In-, mono- and divariant). XXI. 1151. 
EQUILIBRIUMS in the system Na,O-Al, Os-H,O. The aluminates of sodium. 129. 
— (On the validity of the law of partition for the) between a mixed- 
crystal phase and a coexisting liquid. I. 679. 
— (On the possibility of statistical) of the universe. 866. 
ERUPTIVE-ROCKS (On the alkalirocks of the Serra do Gericino to the northwest 
of Rio de Janeiro and the resemblance between the) of Brazil and 
those of South-Africa. 1241. 
EXHAUSTION (On smelling during complete) (resp. adaptation) for a given 
odour. 1442. : 
EXTINCTION-measurements (Photographic absorption- and). Contributions to 
the study of liquid crystals. V. Extinction-measurements. 807. 
— by a blackened photographic plate as function of wavelength, quantity 
of silver, and size of the grains. 848. 
EXTRA-PAUSE (On the artificial) of the ventricle of the frog’s heart. 542. 
EYE-MUSCLES (On the effect of tonic labyrinthine and cervical reflexes 
upon the). 509. 
EyYKMAN (C.) presents a paper of Prof. J. J. van LOGHEM: “Identity of 
the blood-digestive and gelatine-liquefying bacterial actions.” 115. 
FELDBRUGGE (J.) and F. Rorrs. On the development of attention from 
the 8th until and including the 12 year of life. 1371. 
FrBriLLATION (On) of the heart. I. 319. IL. On the relation between fibrilla- 
tion of the heart and “Gehäufte” extra-systoles. 329. III. Ventricular 
fibrillation and “Gehäufte” extrasystoles of the ventricle excited by the 
“Erregung’ consequent on an artificial auricular systole. 533. 
FIELD OF CIRCLES (Two representations of the) on point-space. 1323. 
