Page:Cyclopaedia, Chambers - Supplement, Volume 1.djvu/802

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The other method is by making a coat or two of gold fize, and letting it dry ; they wet it when the gold is to be laid on, and cover it with the leaf gold, wetting it again when the gold is on, and add frefh where there are any blemifhes. When all is thoroughly dry, this is burnifhed with a dog's tooth, or other fmooth fubftance. This is the ■fhort method of gilding now praftifed. See the article Gold Jtze. GILLS of fifhes, (Cycl.) the parts which ferve to their taking and throwing out again proper quantities of water, impregnated with its due and natural portion of air. The bronchia:, or gills of fifli, therefore, are the organs which in them cor- refpond to the lungs in quadrupeds and birds, as alfo of frogs, ferpents, and lizards, creatures too much confounded with fifli by the old authors ; all fifhes therefore have thefe bran- cbitE, except the cetaceous and the petromyzum. The gills in all fifh are eight in number, four being placed on each fide the throat. The loweft gill is always mucrrfmaller than either of the others ; the other three on each fide are gradually larger to the top one, which is in all fifh the largeft. Every one of thefe gills is compofed of a bony fubftance formed into a femtcircle, in moft kinds, or bent into the fhape of a bow. On the convex fide of which there is formed a fort of plume, or the refemblance of a leaf. Each leaf (to ufe that word) is compofed of a double row of bony lamella;, formed like fo many fickles, and each of thefe lamellae is fixed to the convex part of the bow, by means of the membrane with which that bow is covered. Thefe lamellae 1 have one part convex, and the other concave. The convex fide is covered with numerous hairs in all parts, and thefe are longeft near the bafe, and fliorteft toward the apex. They are lefs hairy on the concave fide ; the hairs there being fhorter, and continued only to the middle of the lamella?, not running all the way along it. Thefe hairs are all the way connected to the gill by a very tender mem- branous fubftance, which covers the lamellae, but they are each fiflgle at the bafe. Jrtedi, Ichthyolog. The concave part of every lamina is applied to the convex part of the next oppofite lamina, and the lamina; are all connected one with another, by means of a membrane which arifes at their bafe, and is continued up half their length ; at this part the membrane becomes ftronger and forms a fort of cord. The reft of the lamina is free and terminates in an extremely fine and flexile point. Every om of thefe laminae is inverted with a fine and thin membrane, and each ferves to receive the ramifications of the vcflels which are brought into the branchia. The infide of every bow or bony femicircle which makes one gill, gives place to one artery, one vein, and one nerve. The conforma- tion of this hollow part of each gill is different in diffe- rent fifli; in fome it contains a number of fmooth tuber- cles, which are fhort and fcarce ftand out beyond the fur- face : this is the cafe in the gills of the cyprinus, &c. In fome it is in this manner befet with very rough tubercles as in the cotti ; in fome others thefe tubercles are rough, and refemble teeth, as in the falmons, &c In fome alfo this furface, inftead of tubercles, is befet with a fort of long hairs rcfembling rays as in the clupeae ; and finally in fome this part is befet with real, but fhort prickles, as in theefoces, The ufe of the gills in fifh feems to be to receive the blood which is protruded from the heart into the aorta 3 and derive it to the utmoft parts of the lamina, from whence it is returned by veins which diftribute it to every part of the body and to ferve for the office of refpiration. The motion of the gills of fiih is no way fo beautifully ken as in the viewing thofe of a fmall eel with a microfcope. Two rows of thefe are always bended roundifh one againft the other, while their ends play againft one another, touch- ing and going back again very regularly and fucceflively and imitating the opening and (hutting of a pair of bellows, in a regular fucceffion ; and in the generality of fifh, one pair does this, while another pair only continues advanced, fo as to clofe with their bafe, and this is done alternately by one and another pair all the time that the obfervation is con- tinued. Philof. Tranf. N°. 222.

apertures of the Gills. See Branchiarum foramina.

Leaf of the Gills. See Folium Brancbiarum.

GILT head, Aurata, in zoology, the name of a broad and flat fea fifli, not unlike the bream in fhape, and by fome called the fea bream, a name too loofely ufed and fome- times applied alfo to the fparus, cantharus, and other flat fifhes. It fometimes grows to eight or ten pound weight. its fcales are moderately large, its back is of a blackifh green, and its fides of a dufky brown, with a faint cart of yellow. At the upper angle of the coverings of the gills it has ufu- ally a black fpot, and under that often a purple one be- tween its eyes. It has a fine gold coloured, arched or lunated mark, the convex or gibbofe part of which is toward the mouth, the points toward the eyes.

The eves are large, the mouth moderately wide, and the tongue pointed. It has fix or eight teeth in each jaw with ranges of tubercles behind them, and thefe are covered by thick lips. Its back is ridged and fharp, and its fins have fome of their anterior rays prickly, the others foft. It is

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common in the markets of Rome, Venice, csV, and caught in great plenty in the fummer months in different parts of the Mediterranean ; in winter it is more fcarce, but more valued. Rondelet. de Pifc. Lib. 5. Cap. 2. p. 115. Bella/:, de Pifc. p. 118. GIN. See the article Geneva.

Gin, in mechanics. See Crabb. ,

GINGER (Cycl.) — The two forts of ginger, the one of which is cultivated in great plenty in the warm parts of the Weft- Indies, and the root of which is what we ufe in the kitchen ; the other a wild plant in fome parts of the Eaft Indies, and whofe root is called xerwnbetb, and ufed in medicine, are both kept in the gardens of the curious with us. They are progagated by parting the roots, the beft feafon for doing which is early in fpring before they begin to flioot. Every large part of the root may then be divided into feve- ral flips with two or three eyes to each, all which will fuc- ceed : thefe are to be planted feparately in pots of a light rich earth, and plunged into a hot bed of tanners bark, where they muft be frequently watered, and in hot weather muft often have the glafles raifed with a brick to give them air. They will encreafe greatly at the root, and fometimes flower with us, but they muft be kept in die hot bed all the fummer, and in winter be removed into the back ftove. Miter's Gard. Djft.

GINGIBRACHIUM, a name given by fome medicinal au- thors to the fcurvey, when it affects the arms and other ex- tremities.

GINGIPEDIUM, a name given by fome authors to the (curvy when it afreclrs the feet.

GINETTA, or Genetta, the name of a fmall animal of the weafel kind, of a mixed colour, between yellowiih and blackhh, and ornamented with feveral black fpots in diffe- rent parts of the body. It is naturally a very tame and in- offenfive creature. It is ufually found about rivers feed- ing on what it finds about their banks. It is found in fome parts of Spain, and at Conftantinople, and in fome other parts of the Turkifli dominions. It runs loofe about the houfes like a cat, its tail is variegated with circles of darker and paler colours, and its ikin is of a fomewhat per- fumed fmell. Ray's Syn. Quad. p. iox.

GINGRA, in antiquity, a kind of dance ufed at funerals, Pttifc Lex. Ant. in voc.

GINGRINA, in antiquity, a name given to a fmall kind of flute fit for beginners.

GIOAR, in the materia medica of the antient Arabians, % word applied to feveral different fubftances, and fometimes ufed as the diftin£f. names of them ; fometimes only as an epi- thet to them. It is generally ufed by Avifenna as a name fdr arfenic, fometimes for antimony ; and in Serapio, we often find it Handing for any of the mineral poifons. The original meaning of the word is no more than what the Greeks exprefied by the word wn«., fubftance, but it be- came applied to feveral things moft eminent in their way, as to arfenic the moft fatal of poifons ; to antimony, iup- pofed at that time the moft valuable of medicines ; and to pearls, as the moft valuable of gems.

GIOMELU, a body of the fpahis, or horfe in the fervice of the Grand Signior. Pocock's Egypt, p. 166.

GIR, a name by which fome of the chemical writers have called quick-lime.

GIRANDOLE, a large kind of branched candleftick. See Branch and Jesse.

GlRDING-£z>r, at fea. The feamen fay a fhip is girt, or hath a girding-gtrt, when her cable is fo tight or {trained, that upon the running of the tide, fhe cannot go over it with her ftern part, but will lie acrofs the tides.

GIRDLE, among jewellers, the line which encomnafles the ftone, parallel to the horizon j or, which determines the greateft horizontal expanfion of the ftones. "Jeffries on Diamonds.

GIRGILIM, in the materia medica, a name given by fome authors to the fefamum, or oily purging grain.

GIRGITES, a name ufed by fome chemical writers for a fort of white ftones found in rivers, of which they make a pecu- liarly ftrong lime. The ftones are of the fparry kiiid worn into roundnefs by the motion of the water, and they have their name Girgites, from the word Gir, ufed by the che- mirts for lime.

GIRMER, a word ufed by fome of the chemical writers, to fignify tartar.

GIRROCK, the common Englifh name of the fifh called the lacertus, a larger fpecies of gar fifh, caught in the Mediter- ranean and Englifli feas. IVilloughbfs Hift. Pifc. p. 232. See Lacertus.

GIRT, in meafuring timber, is ufed for the circumference of a tree. See Csggefball's Sliding-.^/?, Cycl. Some call the fourth part of the circumference the girt, and fuppofe the fquare of this equal to the area of the fe&i- on of the tree. Treat. Pra£t. Geom. p. 150. See Timber, Cycl. and Suppl.

GISARMS, or Guisarmes, in our old writers, an h albert

or hand ax ; it comes from the latin bis anna, becaufe it

wounds on both fides. Shene.—Kjl armorum genus longo

4. tnanubria