I C T
'Ibflils of vegetable origin*. Bat they have plainly alt of them been the bony coverings of different parts of the mouths of certain fifh of the cattilagineous, and perhaps other kinds, whofe principal food being fhell-fifh, thefe bony palates were neceflary to the eating them. Many of the lebthyperia are found indeed plainly worn and rounded by life* They are fometimes found in their foflile ftafce in congeries joined one to another, as they originally {food- in the mouth of the fifh, but this is more rare ; the great quantities that 'arc found being either in angle pieces or joints as they may be called, or in fragments of lUch. They are all of the fame fubftance with the bufonitze, and are of very various figures according to the different (pedes of fifh, or different part of the mouth they have belonged to, the fame fifh very probably having furniihed from the middle and the fides of its mouth very differently lhaped lebthyperia. The molt ufual figure of thefe bodies is that of half the fhell of the pod of a lupine, or other leguminous plant, accord- ing to the feveral fpecies, and this has ufually its inner part filled up with the matter of the ftratum, in which it is de- pofited. The principal differences of their figure are thefe; The moft common are thofe refembling the half lupine pod ; next to thefe, are thofe which more referable that of the field pea ; and there are fome found, which refemble that of a kidney-bean, or a part of fuch a pod. Some of them are very broad and fhort, others as remarkably long and (lender ; fome are very gibbofe on the back, others are plainly arched ; and the feveral kinds are at times found more or lefs flat. Some of them are crooked at one end ; others are wreathed or twitted, as it were ; fome approach to a triangular, and others to a rhomboidal form ; fome are roundifh and flatted, and others are remarkably prominent in the middle - y and many of them refemble in fome degree the bufonita?. They are found of various fizes from the tenth of an inch to two inches in length, and an inch in breadth ; and are fome- times of a perfectly fmooth even and poliihed furface; butmore frequently they are finely filiated or finuated, and fometimes they are wholly covered with tubercles. Their colour is not lefs various, than their fhape. They are moll frequently either black, or of dark and blackilh chefnut colour j but they are fometimes found greenifh, bluifh, yellowifh, or whitiih ; and fometimes, tho' rarely, they are fpotted with different colours. Hill's Hid. of t'off. p. 645. They are found lodged and bedded in the ftrata of flone, in Germany, Italy, and France, and in the iflands of the Ar- chipelago, and in Syria among the fpines of the echini ; but they are no where fo frequent as in England, there be- ing with us very few quarries of ftone which do not afford more or lefs of them. See Tab. of Foffils, Clafs 8.
ICHTHYS, r*0w? 3 a famous acroftic of the Erythraean fibyl, mentioned by Eufebi us and St. Auftin ; the firfl words of every verfe of which make up \%a&% p^iroc S;b vt&s e^t^, Jefus Cbrijlus, Dei filius, fervator. The initial letters of which compofe the word Icbthys, lx$v<;. See Hoff?n. Lex. in voc.
ICICA, in the materia medica, a name given by fome to the gum elemi. Pifo, p. 59.
ICICARIBA, in botany, a name ufed by fome authors for the tree which affords us the gum elemi, ufed in medicine. Pifo, P- 59-
ICOCA, in botany, the name of a genus of plants, defcribed byPlumier; fmce called by Linnseus, Chryfobalanus. Plu- mierGen. 3. Seethe articleCHRYSOBALANUs.
ICON, 'Vikw, in rhetoric, the fame with image. See the article Image, Cycl.
ICOSANDRIA, in botany, a clafs of plants with hermaphro- dite flowers, and a large number of (lamina or male parts in each. The word is derived from the Greek \w?^ twenty, and emif, male. See Tab. 1. of Botany, Clafs r. It fhould therefore ftrictly fignify a flower with twenty fta- mina, but it is only underftood in an indefinite fenfe, and made to exprefs fuch plants as have any 'large number, or more than twelve (lamina in each flower, and thofe growhio- to the inner fide of the cup of the flower, not to the recep- tacle of the future feeds. Of this clafs are the torch thiftle, the myrtle, the florax, the almond, &c.
ICTERIAS Lapis, in natural hiftory, a name given by the an- tients to a flone, famous for the cure of the jaundice. Pliny defenbes four fpecies of this ftone. The firfl of a oreyifli yel- low-; the fecond of a paler colour, and more pellucid ; the third ufually found in flat pieces, of a greenifh colour with
■ dufky veins ; and the fourth with black veins in the fame greenifh colours. The third was alfo diftinguiftied from all the others, by its remarkable lightnefs. Thefe defcriptions are fo fhort, that we cannot determine from them which of the (tones of thofe known at prefent, were intended by them.
ICTERUS, the jaundice-bird* in zoology, a name bV which feveral of the old authors have called the Galbula, a bird of the turdus kind, very beautifully coloured all over with a gold yellow, but with black wings. Aldrovand. de Avib. See the article Galbui.a.
ICTIAR, in the Eaftcrn military orders, an ofKcer who has gone through all the degrees of pofts in his refpective body ; and has a right to be a member of the divan. Po- sack's Egypt, p. 166.
I D E
ICTIS,- in zoology, a name originally Greek, by which fome authors call the ferret. See tiie article V ivkkra.
1DJEM Radix, in botany, a name ufed by Coiumua and fome other authors for the large narrow-leav'd kind of ruicus ur butcher's broom ; called by others Bijlingua. See the ar- ticle Rvscus.
IDEA (Cycl.) — The term Idea has, by Mr. Locke, been ex-* tended to every thing we know or have any notion of, any- thing about which the mind is employed in thinking. But this extenfive ufe of the term Idea is thought improper by a very ingenious and acute writer % who obferves that we may be faid to have fome knowledge or notion of our own minds, of fpirits and active beings, whereof in a ilrict fenfe we have not Ideas. In like manner, we know and have a notion of relations between things or Ideas, which relations are diftinct from the Ideas or things related, mafmuch as the latter may be perceived by us, without our perceiving the former. The fame author elfewhere obferves b , that by mind, jpirit, jbuL or felf, he does not denote any one of his Ideas, but a thinu- entirely diftinct from them j wherein they exilt, or which it the fame thing, whereby they arc perceived ; for the exiftence of an Idea conhils, as he fays, in being perceived. He alio obferves c the word thing or being, is the moil general name of all, and comprehends under it two kinds entirely diftinct and heterogeneous ; having nothing common but the name, to wit, fpirits and Ideas. And in another part of "his trea- tifej he exprefsly affirms d , there can be no Idea formed of a foul or (pint.— [» Berkley Princip. of Human Knowledge, 2d edit. feet. 89, p. 112. b Ibid. fe£t. 2. p. 36. c Ibid* feci. 89. p. in. d Ibid. feet. 27. p. 57. See alfo feet. 142. p. 160.J
Another author, has alfo blamed Mr. Locke, for confound- ing Ideas and notions. He obferves, that by Idea, according to the common and moft ufual fignification of the word is meant, the image, picture, or repreientation in the mind of a fenfible appearance, or of an object which hath before been perceived by fenfe. To which fenfible appearance therefore the Idea neccfiarily refers, for whatever is m it, or upon any account can be afcribed to it : And it ferves, or is made ufe of in its Head, for the mind to contemplate or employ itfelf about in thinking, at fuch time when the object it repre-
fents is not immediately perceived, as in the act of fenfe.
Vid. pag. 105, U 106. of a book intitled Two Differtations concerning Senfe and the Imagination, with an Efiay on Confcioufhefs, Lond. 1728. 8°.
This author farther afferts in oppofition to Mr. Locke that the perception of an Idea is not an ac~t of underftandino-. He urges, that an Idea by Mr. Locke's own account of \t° is an object or fomething perceived, and about which the mind is employed in thinking. Wherefore if perception (fuppofe) which is an operation or act of the mind, ihould itfelf be confidered as an Idea, (and under this very title Mr. Locke treats of perception) then one Idea would be the object of an- other Idea, and fo there would be an Idea of an Idea, or an object of an object; and one Idea would perceive another Idea, which there is no making any tolerable fenfe of. And indeed in explaining or declaring the operation of any fa- culty, to give it the fame name and appellation, with the object itfelf about which it is employed, and which there is a neceffity of conlidering in order to Vet forth the particular quality and nature of the operation, and the precife manner of its concerning and having to do with the object, feems very inconfiftent with fuch a purpofe or defign. This author has been very elaborate in proving and inforcing the diftinction between notions and Ideas. In another trea- tife, he obferves that Mr. Locke in his efTay on Human Un- derftanding, takes no notice of rational notions, and thereby has not only given a partial and imperfect account of his iubject, but made an unjuft and unfair reprefentation of it. — Vid. an eflay concerning rational notions, printed at London, 1723.
That fome confufion may have arifen from givino- the fame name to thefe heterogeneous things, cannot be queftioned. However Mr. Locke is in this refpect no more guilty than ■ Malebranche and the Cartefians, who ufe the term Idea in the fame extenfive (cn^c with him, and from whom indeed he feems to have taken it. But then the Cartefians feem to have been more follicitous to diftinguifh between the Ideas of the imagination, and thofe of the intellect, underftanding, or tie I'efprk pur, as they fometimes exprefs themfelves, and have thereby guarded againft the inconveniencies arifmg from the too general fignification of the term Idea. See the ar- ticle Notion.
The origin of our Ideas and notions is a perplexed queflion, and not at all cleared up by the labours of metaphyficians. As to Ideas of fenfe, fome philofophers have pretended that bodies acting or prelung upon our nerves, or putting the ani- mal fpirits in motion produce fenfations : But as the motion communicated to the nerves or fpirits has nothing in common either with the thing or body moving, or with the Idea ex- cited in the mind, and that we do not conceive the leaft re- lation between the motion of the nerve or fpirits and the production of an Idea, to fay that the motion of, or im-, preflion upon the nerves or animal fpirits, is the caufe of Ideas) is explaining nothing at all. . The
