XVI CON TENS 
HUMOR AQUEUS FLUID (The interchange between blood-plasm on one hand 
and) and cerebro-spinal fluid on the other hand, studied from their 
sugar-percentages and in connection with the problem of combined 
sugar. 1343. 
HyYACINTHUS ORIENTALIS (On the influence of circumstances of culture on 
the habitus and partial sterility of the pollengrains of). 1289. 
HyprRaTEs (The existence of) in aqueous solutions. 969. 
HypROCHLORIC ACID (The influence of different substances on the decom- 
position of monoses by an alkali and on the inversion of cane sugar by). 149. 
HYDROGEN (The rectilinear diameter of). 1175. 
HYDROGEN VAPOUR CRYOSTAT (Improved form of a) for temperatures between 
al Cand <= 253° CISS; 
Hydrology. Euc. Dusois: “On the motion of ground water in frost and 
thawing weather.” 1321. 
HIJMANS VAN DEN BERGH (A. A.) v. BERGH (A. A. HIJMANS VAN DEN). 
HypoTHEsis of A. F6ppL (Motion relativated by means of a). 1412. 
HysTEREsSIS (On the theory of) according to VOLTERRA. 663. 
IHLE (J. E. W.) and G. J. vAN Oorpr. On the larval development of 
oxyuris equi (Schrank). 603. 
IMPERMEABILITY (A direct proof of the) of the bloodcorpuscles of man and 
of the rabbit to glucose. 1256. 
INDEX CEPHALICUS (On the) and the absolute dimensions of the head of 
the population of Holland. 103. 
INTEGRALGLEICHUNG (Die) der elliptischen Thetanullfunktion. 2e Note: 
Allgemeine Lösung. 817. 
INTENSITY (Measurements on the) of spectrum lines by the aid of the echelon. 790. 
INTERFERENCE CURVES (Explanation of some) of uniaxial and biaxial crystals 
by superposition of elliptic pencils. 1223. 
INTERRUPTER (The mechanism of the automatic current). 869. 
INVOLUTION of rays (An) defined by a congruence of REYE and an involutory 
homology. 466. 
ISOAMYLHYDROCUPREIN (eukupin) and isoctyl hydrocuprein (vuzin). (On the 
pharmacological action of). 481. 
JAEGER (F. M.). On some condensation-products of aromatic aldehydes 
and amines. 74. 
— and G. BERGER. The photochemical decomposition of potassium- 
cobaltioxalate and its catalysis by neutral salts. 84. 
— and J. H. pr Boer. Colloidal sulphurcompounds of ruthenium. 95. 
— Two isomeric chloro-tetracetyl-d-fructoses. 342. 
— On the crystalforms of some substituted amides of para-toluenesulphonic 
acid. 347. 
