1 G N 



EOi OGT, from i$ia, an idea, a 

 discourse. The doctrine of ideas. 



IDES, Lat, pi. of irfws. Eiirht days of 

 each month in the Roman calendar, the 

 first day of which fell on the 13th of Janu- 

 ary, February, April, June, August, Sep- 

 tember, November, and December ; and 

 n the 15th of March, May, July, and 

 "ctober 



IDIOLEC'TRIC, electric perse, from i$to; , 

 and ttexTgizs;. 



IDIOPATH'IC, from fiivs, peculiar, and 

 <rett)o;, affection. An epithet applied to 

 diseases which are primary, and not con- 

 secutive upon any other disease. The 

 term is opposed to symptomatic and sym- 

 pathetic. 



IDIOSYN'CRACY, from idio; , peculiar, fvv, 

 with, and xfenris, a temperament. A 

 peculiarity of constitution, in which a 

 person is affected by certain agents, which 

 produce no effect on the generality of 

 persons. 



ID'IOT. In law, one born without un- 

 derstanding, or who has lost it by dis- 

 ease, so as to have no lucid intervals ; the 

 lunatic is one who has lucid intervals. 



IDIO'TICON. A dictionary of words in 

 one dialect, or of one tract of a country. 



I'DOCRASE, a mineral. The vesuvian of 

 Werner, found in lava, and formerly mis- 

 taken for the hyacinth. Named from 

 idta, form, and xeetrn, mixture, in allu- 

 sion to its occurring both in a massive and 

 crystallised form. Its primitive form is 

 a four-sided prism, with square bases. 



I.E., a contraction of id est, that is to 

 Bay. 



IG'SEOUS ROCKS. Rocks produced by 

 the action of fire ; igneus, fiery. 



IGNES'CENT, Lat. ignescens. Giving out 

 sparks of fire when struck with steel, &c. 

 Plint is an ignescent mineral. 



IG'NIS FAT'CCS, a meteor of light which 

 appears in the night over marshy grounds, 

 occasioned by the liberation and ascent of 

 phosphuretted hydrogen gas. It is popu- 

 larly known as Wtll-o'-thc- Wisp, and Jack- 

 o'- Lantern. 



IGNI'TIO.V, from ignis, fire. A body 

 heated to redness is said to be in a state 

 of ignition. Gold, silver, copper, iron, and 

 platinum maybe ignited without melting ; 

 but lead, tin, bismuth, zinc, and antimony 

 molt before they become ignited. 



IGNO'BLE. Those birds of prey which 

 cannot Be easily employed in falconry arc 

 termed ignobles : they are much more nu- 

 merous than the nobles. The Eagles, Gos- 

 hawks, Sparrowhawks, and Kites are 

 'yitoblfs ; the Common Falcon and Ger- 

 falcon are nobles. 



IOXORA'MVS. In law, a Latin word sig- 

 nifying we do not knmr, and used by the 

 fraud jury, as the term of indorsation, 



! IMA 



when they ignore, or throw out a bill of 

 indictment for want of sufficient evidence. 



IGCAN'IDA, a family of Saurians, pos- 

 sessing the general form, long tail, and 

 free and unequal toes of the Lacertians ; 

 their eye, ear, &c. are all similar, but their 

 tongue is fleshy, thick, and non-exten- 

 sible, and only emarginated at the tip. 

 They are divided into two sections, the 

 Agamians and the Iguanians proper. In 

 the first, there are no palatine teeth ; 

 in the second, there are teeth in the 

 palate. 



IGUAN'ODON, an extinct fossil, herbivo- 

 rous reptile, of great size (70 feet or so in 

 length), discovered in the strata of the 

 Tilgate Forest, by Dr. Mantell, and thus 

 named from iguana, and ooou? , a tooth, on 

 account of the resemblance of its teeth to 

 those of the iguana. 



IL'EUJC, Lat. from e/Aew, to turn about. 

 The last portion of the small intestines, 

 thus named from its convolutions. 



I'LEX. the holly. A genus of evergreen 

 shrubby trees. Tetrandria Tetragynia. 

 There are fourteen species enumerated by 

 Don, of which the I. aquifolium is the 

 British type. Ten or eleven varieties of 

 this species are, however, established. 



IL'IA. In anatomy, the small intestines ; 

 also that part of the abdomen in which 

 they are inclosed. 



IL'IAC, an epithet for parts connected 

 with, or situated near, the ilia. The iliac 

 region is that part of the abdomen between 

 the ribs and the loins. 



IL'IAC PASSION, a disease consisting of 

 severe griping pains and vomiting, accom- 

 panied by spasm of the muscles of the 

 abdomen. Thus named from the ileum 

 being regarded as its seat. 



ILLA'TIVE CONVERSION. In logic, that 

 in which the truth of the converse follows 

 from the truth of the given proposition. 



ILLU'MISATI. 1 Among early Chris- 

 tians, persons who had received baptism. 

 2. Certain associations of men in mo- 

 dern Europe, who combined to overthrow 

 the existing religious institutions, and to 

 substitute for them the law of reason. 



3. Graduates are styled illuminati of 



their particular universities. 



ILLU'MINATING. The art of illustrating 

 and adorning books and manuscripts with 

 miniature painting. This was anciently 

 a profession, practised by illuminators: 

 the writers of the books first finished 

 their part, and the illuminators filled up 

 the blanks left with appropriate illumina- 

 tums, often with great skill and taste, and 

 always with excellent colours. 



IM'AGE, Lat. imago. 1. In optics, the 

 fisuri 1 of any object made by rays of ligbs 

 proceeding from the several points of it 



2. In rhetoric, a lively description of 



anything in discourse. 3. In rwifwn, 



