7 20 



Hop resins, ii. 119; action of, on 



yeasts, ii. 246, 247 

 tannins, effect of, on yeasts, ii. 

 246 



Hop-leaf aphides, ii. 63 



Hops as a culture medium, ii. 314 



Hordeum distichum nudum, i. 189 



Hormiscium cerevisise, ii. 275 



Hormodendron cladosporioides, i. 218, 

 375, 376, 378, 379 



Horny matter, solution of, by fungi, 

 ii. 64 



Horse-dung, nitrogen liberated by, 

 i. 308 



House-fly disease, ii. 167 



Household cheese, bacteria in, i. 320 



Hunger-torpidity, i. 52 



Hydration, i. 291 



Hydrochloric acid, ii. 35, 160, 170, 

 *176, 467, 527, 531 ; action of, on 

 micro-organisms, ii. 244; onproteo- 

 lysis, ii. 552 ; effect on enzymes, 

 ii. 352 



Hydrocollidine, i. 343 



Hydrocyanic acid, ii. 364, 510, 520, 

 526, 557 ; action of, on enzymes, 

 ii. 469 ; on yeasts, ii. 457 



Hydrofluoric acid, ii. 520 ; action of, 

 on micro-organisms, ii. 244 ; as 

 an antiseptic, i. 110 



Hydrogen, ii. 488, 494, 501, 507, 559 ; 

 effect of, on bacteria, i. 185 



Hydrogen peroxide, ii. 398, 487 ; 

 as an antiseptic, i. 110 ; for control 

 of water filter, i. Ill ; produced 

 in sterile urine exposed to sunshine, 

 i. 78 



Hydrogenase, ii. 488, 558 



Hydrokinone, action of, on yeasts, 

 ii. 247 



Hydro lysing enzyme of yeast, ii. 172 ; 

 processes, i. 250-252; action on 

 vital activity of yeast, i. 250 ; pre- 

 vention of inversion, i. 277 



Hydrolysis of glycogen, ii. 172 



Hydrotropism, ii. 16 



Hydroxyl, ii. 486 



Hydroxylamine hydrochloride, ii. 470 

 Hypha, ii. 3 

 Hyposulphites, ii. 48 

 Hypoxanthin, ii. 162, 163 



ICE, bacteria in, i. 213 



Ilex aquifolium, ii. 279, 280 



Illumination and respiration quotient, 

 ii. 78 ; clarification of beer by 

 light, ii. 186 ; influence of light on 

 vegetation, ii. 55 



Immunity, i. 305, 306 



Indian meal, detection of arsenic in* 



ii. 51 



Indican, i. 155 



Indicators for nutrient media, i. 130 

 Indiglucin, i. 155 

 Indigo bath, i. 157 

 'blue, i. 155 

 brown, i. 156 

 carmine, ii. 559 

 fermentation, i. 155 ; enzyme of, 



i. 156 



maladies, i. 157 

 red, i. 156 

 rubin, i. 157 

 white, i. 155 



Indigo-sulphuric acid, i. 185 

 Indigofera, i. 155 

 Indole, i. 291, 292 

 nitroso-, i. 291 

 reaction, i. 291 

 Infection threads, i. 348; coloured 



in sections, i. 348, 349 

 Infusions, ropy, i. 283 

 Infusoria, i. 2 

 Infusum foliorum digitalis, ropy, i. 



283 



senega, gelatinised, i. 283 

 Inosic acid, ii. 164 

 Inositol, ii. 206 

 Insects as carriers of yeasts, ii. 436, 



437 

 Intercalary gemmation, ii. 24 ; growth, 



ii. 6 



Intestinal formation of toxic nitrites 

 by Bact. coli commune, i. 308 ; 

 gases, i. 196 ; putrefaction, i. 291, 

 298 



Intramolecular respiration, ii. 78, 83 

 Inulase, ii. 206, 406 ; species of 



Aspergillacese secreting, ii. 365 

 Inulin, ii. 282, 293, 365, 514 ; action 

 of Mucor Rouxii on, ii. 89 ; deriva- 

 tion of alcohol from, by /3-Amylo- 

 myces, ii. 91 



Invert sugar, ii. 368, 435 ; content of 

 molasses in, i. 277 ; decomposition 

 of, i. 26 ; influence on the crystalli- 

 sation of cane sugar, i. 275 

 Invertase, ii. 351, 362, 363, 406, 431, 

 453, 457, 471, 473, 511, 516-522, 

 528, 536 ; produced by Aspergillus 

 niger, ii. 362 ; by Bacillus fluores- 

 cens liquefaciens, B. megateriurn, 

 i. 277; B. subtilis, i. 274; red 

 Kiel bacillus, i. 277 ; Bacterium 

 gelatinosum betse, i. 277 ; Chlamy- 

 domucor oryzse, ii. 93 ; by Leu- 

 conostpc mesenteroides, i. 274 ; 

 by Monilia Candida, ii. 445 ; by 



