IROQUOIS 



185 



ITCH-MITE 



when red-hot. I. group of minerals includes 

 magnetite, hematite, limonite, gcethite.chaly- 

 bite, pyrites, marcasite, mispickel, and vivia- 

 nite : usually hard and heavy, and often 

 magnetic. /. pyrites = FeSa= Bisulphide of 

 iron: a common ore of iron. 7. wood, name 

 given to many different trees having hard 

 timber, and especially to Inga-xylocarpa : a 

 tree of Guiana, with small leaves, white 

 flowers, and very heavy durable timber. 

 Passive 7, not acted on by acids. Telluric 

 7, native iron containing tellurium. 



Iroquois. A N. American race. 



Irradiation, (ir-ra-di-a'shun). [L. irradio, I 

 shine forth.] The irregular extension of the 

 image of any object, by means of which it 

 seems increased in size. 



Irregular animals : Burmeister's term for 

 Infusoria. 



Isabnormals, ( i-sab-nor'malz ). [Gk. isos, 

 equal; ab, from; Normal, q.v.] Deviations 

 from mean temperature. 



Isamic acid, (i'sa-mik). [Isatin and Ammonia, 

 .v.]=Ci6Hi3N3O4 ; a crystalline substance 

 obtained by the action of ammonia on isatin. 



Isamide, (I'sa-mid). [Isatin and Ammonia, 

 ?.v.]=Amasatin, q.v. 



Isatane, (!'sa-tan). [Isatin, q. v.]=CszB.2Q^4P6 

 =Hydrated indigotin. 



Isathyd, (i'sa-tld). [Isatin Jiydrogeniaed.]= 

 Indyl hydrate=C 16 Hi2N 2 O4: a grey crystal- 

 line substance obtained from isatin. 



Isatic acid, (i-sa'tik). [Isatis, 2 .u.]=:HoInO2 

 =CgH 7 N0 3 =Hydrated isatin. 



Isatin, (i'sa-tin). [Isatis, g.v.] = C 8 H 5 N0 2 : 

 oxidised blue indigo: a blue dye; also ob- 

 tained from isatis. 



Isatis, (i-sa'tis). [The Greek name.lrrWoad: 

 a tall herb with yellow flower, belonging to 

 Brassicacege, from which the blue dye isatin 

 is obtained. 



Ischium, (is'ki-um). [Ischion, the Greek 

 word.] The lower portion of the thigh bone 

 socket: forming the lowest part of the os 

 innominatum bone. 



Ischyodus, (is-kl'o-dus), [Gk. iscliys, strength; 

 odous, tooth.] A fish, several fossil species 

 of which are known. 



Ischypterus, ( is-kip'ter-us ). [Gk. ischys, 

 strength; pteron, fin.] Fossil remains of fish 

 found in New Red Sandstone of America, the 

 fins of which were large and strong. 



Isethionic acid, (I-se-thl'on-ik). [Gk. isos, 

 equal; Ethionic, g.v.]=C2H 6 S04=Hydrated 

 ethionic acid. 



Isinglass, (I'zin-glas). [Hausenblase, the Ger- 

 man name.] = Fish-glue: a white translu- 

 cent gelatinous substance made from Indian 

 fishes, and the swim-bladder of sturgeon. 

 v. Gelatin. 



Island of Keil. A triangular prominence in 

 brain. 



Isis, (1'sis). [Classical.] No. 42 of the Minor 

 Planets. 



Iso, (l-so). [Gk. isos, equal.] A prefix, im- 

 plying equality. 



Isochimenal lines, (I-so-kI'me-nal). [Gk. isos, 

 equal; cheimon, winter.] Lines of equal 

 winter temperature. 



Isochromatic, (T-so-kro-mat'ik). [Gk. isos, 

 equal; Chromatic, q.v.] Of the same colour. 



Isochronic, ( i-sok'ron-ik ). [Gk. isos. equal; 

 chronos, time.] Occurring at regular inter- 

 vals of time. 



Isochronous, (T-sok'ro-nus). [Gk. isos, equal: 

 chronos, time.] = Isochronic, q.v. I. pendu- 

 lums, vibrating regularly together. 



Isochinal, ( i-so-kli'nal ). [Gk. isos, equal; 

 klinein, to bend.] Having the same inclina- 

 tion or dip. v. Dip. 



Isocryme, (i's6-krlm). [Gk. isos, equal; Tcry- 

 mos, cold.] Cold water Jine = 68 F. mean 

 temperature: the cold limit of coral making 

 polyps. 



Isocyanuric acid, (I-so-sI-a-nu'rik). [Iso and 

 Cyanuric, o;.i7.]=Fulminuric acid, q.v. 



Isoetis, (i-so-e'tis). [Gk. isos, equal; etos, 

 year.] An aquatic stemless plant, belonging 

 to Lycopodiaceee. 



Isogonic lines, (i-s5-gon'ik). [Gk. isos, equal ; 

 yonia, angle. ] Lines passing through all the 

 places at which the magnetic declination is 

 the same. 



Isomerism, (I-som'er-izm). [Gk. isos, equal; 

 meros, part.] Compounds identical in com- 

 position, but different in properties. 



Isomorphism, ( i-so-morf 'izm ). f Gk. isos, 

 equal; morphe , form. ] The crystallization of 

 different substances in the same form : gene- 

 rally, resemblance in form. 



Isonandra, (i-so-nan'dra). [Gk. isos, equal; 

 aner, man. ] A plant belonging to Sapotacese : 

 named from the character of the stamens. 

 7. putta: Gutta-percha tree. 



Isopoda, (i-sop'o-da). [Gk. isos, equal; pous, 

 foot. ]= Wood-lice: crustacean animals, form- 

 ing a sub-division of Edriophthalmata. 



Isoprene, (i'so-prenJ^CgHg: a volatile hydro- 

 carbon , obtained from India-rubber. 



Isopropyl. v. Propyl, 



Isopyre, (I'so-pir). [Gk. isos, equal; pyr, fire.] 

 A mineral: chiefly silicate of iron, calcium, 

 and aluminum. 



Isosceles, (i-sos'se-lez). [Gk. isos, equal; akelos, 

 leg.] 7. triangle : one having 

 two sides equal. 



Isoseismal, (i-so-sTs'mal). [Gk. 

 isos, equal ; seismos, earth- 

 quake.] Lines of equal dis- 

 turbance, v. Seismology. 



Isotartaric. v. Tartaric. 



Isotheral lines, (i-soth'e-ral). 

 [Gk. isos, equal ; thews, sum- isosceles, 

 mer.] Lines of equal summer tempera- 

 ture. 



Isothermal lines, (i-so-ther'mal). [Gk. isos, 

 equal; thermos, heat.] Lines of equal annual 

 average temperature. 



Isotropic, (i-so-trop'ik). [ Gk. isos, equal; 

 trope, turning.]=Amorphous, q.v. 



Isthmus, (ist'mus). [The Latin word.] 7. of 

 Fauces: space between arches of the palate. 



Itaconic acid, (!-ta-kon'ik). [Aconitic, q.v.} 

 A crystalline acid substance, obtained from 

 aconitic acid=C5HgO4. 



Italian May = Spiraea hypericifolia. 



Itch-mite : a microscopical animal, belonging 

 to Acaridse. 



