INDEX 



827 



Hyaloplasm, 128 

 Hydathodes, 163 

 Hydrsemia, 337 

 Hydration, nature of, 229 



of ions, 178, 236 



of saccharose, 230 



of solutes, 113, 230 



absorption spectra of, 231 



in relation to dilution, 237 

 Hydrochloric acid in stomach, secretion of, 



359 



Hydrodiffusion, 157 

 Hydrogen as food for bacteria, 19 



electrode, 36, 190, 191 



ion concentration in relation to enzymes, 



313 



- of blood, 192, 194, 202 

 optimal of, for heart, 678 



exponent, 184 



ions, concentration of, 183 



excitation of respiratory centre by, 

 630, 631 



increase of, in tryptic digestion, 314 



measurement of concentration of, 187 



relation of, to muscle process, 447, 

 448, 454 



peroxide produced by chlorophyll, 565, 



566 



Hydrol, 233 



Hydrolysis of cane-sugar by acid, 312 

 by enzyme, 312, 314 



of esters, hydrogen ions determined by, 



194 

 Hydrolytic dissociation, 196, 238 



of dyes, 162 



and proteins, 198 



prevention of, 238 



oxidative-reducing reactions, 586 

 Hydrone, 235 



Hydronol, 235 



Hydrophile and hydrophobe colloids, 78 



Hydrosol and hydrogel, 78 



Hydrotropism, 241 



Hyoscine, optical activity of, 728 



Hypertrophy of active organs, 288 



Hypnosis, 506 



Hypodynamic heart, 211 



Hypophosphite as reducing system, 587 



Hypotonic urine, 337 



Hysteresis in colloidal systems, 4 



I 



i, van't HofFs factor, 169 

 Ice, colour of, 234 

 in steam, presence of, 234 

 Ideal illumination, 595 

 Ileo-colic sphincter, 369 

 Illumination, ideal, 595 



Imbibition and adsorption of water. 101 



and osmosis in cells, 115 



and osmotic pressure, 162 



by emulsoids, 96, 99, 116 



nature of, 101 



temperature coefficient of, 42 

 Immediate spinal induction, 490 

 Immunisation, 729, 730, 731, 732 

 Immunity of electric fish, 660 

 Imperative of energetics, 28 

 Impermeability of cells to acid and alkali, 



121 



to crystalloids, 116, 119, 159 

 Importance of basal sciences', ix 



of small concentrations (Hopkins), 20 

 Independent variable, 36 



Indicator for muscle, 440 

 Indicators and table, 188, 189 



precautions in use of, 188, 190, 238 



theory of, 188, 238 



use of, in coloured solutions, 188 

 Induction currents, 381 



period in action of light, 555, 556 

 Inertia of galvanometers, 638 



of photographic plate, 556 



Inflation of lungs, impulses in vagus pro- 

 duced by, 387 



Influence of tissues on one another, 25 

 Infra-red absorption of haemoglobin, 625 

 Inhibition always of similar nature, 419 



an active process, 414, 425, 491 



as adjusting reflexes, 498 



electrical change in, 406 



in conditioned reflexes, 505 



in nerve centres, 409^ 



is complete, 410 



meaning of, 401 



more than block, 425, 491 



necessity of, in nerve centres, 409, 489 



of decerebrate tone, 541 



of dilator tone, 697 



of inhibition, 399, 415, 416, 506 



of inhibitory neurone, 416, 506 



of pancreatic secretion by vagus, 349 



of spinal reflexes in frog, 410 



of tonic reflex, 409 



of vaso-constrictor centre, 411, 412 



of vaso-dilator centre, 416 



of vasomotor centres, 411 



prominence of, in cortical reactions, 480, 



481 



seat of, in nerve centres, 497 



theories of, 418 



wave of, in ureter, 652 

 Inhibitory nerves to glands, 349, 408 

 Inogen theory, 272, 443 

 Instability of colloidal state, 75 

 Instinct, 482 



Intelligence, 202, 482 

 Intensity factor of energy, 28 

 Interaction of reflexes, 500 



