ICO 3 



ICE'FLANT, the Jfeiembryaiithcinuin c <;/- 

 tallinum, a plant remarkable for the little 

 icy and pellucid vesicles which cover its 

 surface. 



ICH DIEN, Germ, for I serve. The motto 

 of the Prince of AVales. It was first used 

 by John, King of Bohemia, slain at the 

 battle of Cressy, when it was adopted by 

 Edward the Black Prince, as a mark of 

 subjection to his father Edward III. 



ICHNEC'MON. 1. In zoology, the man- 

 goiute of Egypt, an animal larger than our 

 cat, and slender as a marten. It takes its 

 name (i%ittuuMv, from i%vtvat, to follow) 

 from its hunting for the eggs of the croco- 

 dile. It is domesticated and kept for 

 destroying rats and mice. The Euro- 

 peans at Cairo call it Pharaoh's rat ; the 

 natives nenis. See MANGOUSTE. 2. In en- 

 tomology, a genus of hymenopterous 

 insects of the family Pupivora, Cuv., 

 thus named from the circumstance of its 

 preying upon the posterity of the Lepi- 

 doptera under the form of caterpillars, 

 just as the quadruped so named destroys 

 the crocodile, by breaking its eggs. There 

 are 1200 species. 



ICHNOG'RAPHY, from i%vo;, a footstep, 

 and ygaa, to describe. 1. In perspective, 

 the view of anything cut off by a plane, 

 parallel to the horizon just at the base of 



the object. 2. In architecture, the plan 



of a building exhibited by a transverse 



section. 3. The term is sometimes used 



to designate a description of ancient works 

 of art, as statuary, paintings. &c. 



ICHTHYOL'OGY, from /%$W, a fish, and 

 \o-ytf, discourse. That branch of zoology 

 which treats of the structure, classifica- 

 tion, and habitudes of fishes. 



ICHTHYOSAU'RUS, from i^Sy;, a fish, and 

 fetvfot , a lizard, the fish-lizard. An ex- 

 tinct genus of marine-lizard or reptile, 

 approaching to the characters of a fish in 

 its organization. Several species have 

 been ascertained, some of which are of 

 enormous size. 



ICHTHY'OSIS, the fish-skin disease, from 

 i%9vf> a fish. It is characterised by a 

 thickened, hard, rough, and in some cases 

 almost horny texture of the integuments 

 of the body, with some tendency to scali- 

 ness, like the skin of a fish. 



ICON'OCLASTS, image-breakers, from 

 ttxuv, an image, and x^tntrTva, a breaker. 

 A name which Catholics give to those who 

 reject the use of images in their religious 

 worship. 



ICOJJOG'RAPHY, from ttxtav, in image, 

 and j^aipai, to describe. The description 

 of ancient statues, busts, paintings in j 

 fresco, mosaic work, &c. 



ICOSAHE'DRON , from uxxri. twenty, and ! 

 'if*, a basis. A regular solid, consisting . 



18 IDE 



of twenty triangular pyramids, which 

 have their heights and bases equal, and 

 whose vertices therefore meet in the cei- 

 tre of the circumscribing sphere. 



ICOSAN'DRIA, from uxw, twenty, and 

 atvr;j, a man. The twelfth class of plants 

 in Linnaeus's sexual system, consisting of 

 such as have hermaphrodite flowers, fur- 

 nished with twenty or more stamens in- 

 serted into the calyx. Epithet icomndrian. 



IDE. In chemistry, a termination for 

 certain compounds which are not acid ; a 

 oxides, chlorides, bromides, and iodides. 



IDE'A, Lat. for fact, from fitu, to see. 

 In popular language, idea signifies the 

 same thing as conception, apprehension, 

 notion. To have an idea of anything i 

 to conceive it. In philosophical use, it does 

 not signify that act of the mind which 

 we call thought or conception, but some 

 object of thought. Reid. Whatever the 

 mind perceives in itself, or is the imme- 

 diate object of perception, thought, or 

 understanding, that I call an idea Locke. 

 The word /5sa, as used by Pindar, Aris- 

 tophanes, and St. Matthew, represented 

 "the visual abstraction of a distant ob 

 ject, when we see the whole without dis 

 tinguishing its parts." Plato adopted it as 

 a technical term, and as an antithesis to 

 iibtuXct, or sensuous images, and transient 

 and perishable emblems or mental words 

 of ideas. Des Cartes introduced into his- 

 philosophy the fanciful hypothesis of ma- 

 terial ideas, or certain configurations of 

 the brain, which were so many moulds to 

 the influxes of the external world. Mr. 

 Locke adopted the term, but extended its 

 sisnification to whatever is the immediate 

 object of the mind's attention or consci- 

 ousness. Mr. Hume, distinguishing those 

 representations which are accompanied 

 with a sense of a present object from those 

 reproduced by the mind itself, designated 

 the former by impressions, and confined 

 the word idea to the latter. S. I. Cole- 

 ridge. 



IDE'AI. An imaginary model of perfec- 

 tion, considering ideas as images or forms 

 in the mind. Thus we speak of the ideal 

 of beauty, the ideal of virtue, &c. 



IDE'ALISM. That system or theory that 

 makes everything to consist in idwis, and 

 denies the existence of material bodies. 

 Walsh. Materialism is a circumference 

 without a centre; idealism is a centre 

 without a circumference. Guesses at 

 Truth. 



IDEN'TITY, PERSONAL. The sameness of 

 the conscious subject, /, throughout all 

 the various states of which it is the sub- 

 ject. 



I DEOGRAPH'IC CHARACTERS, from /Sj . one 

 7 -txtta, 1 write. In philology. <r^-v. 

 which express figures or notions. 



