Page:Cyclopaedia, Chambers - Supplement, Volume 1.djvu/773

 GAD

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GABIREA, in the materia medica, a name given by fome of the old writers to fuch myrrh as was remark- ably fatty. GAD, in mining, an inftrument ufed to dig out the ore. It is a fmall punch of iron with a long handle of wood. One of the miners holds this in his hand, directing the point to a proper place, while the others ftriking it with a large fledge hammer drive it into the vein.

The working by this inftrument is thence called gadirrg, Ray's Engl, words, p. 118.

Gad-£«, in natural hiftory, the common name for a Winged infect, called alfo the dun fly or ox fly; a creature very trou- blefome to cows, horfes, &e. This creature examined by the microfcope has feveral peculiarities worthy obfervation. It has, like the gnat, a long probofcis, with a fharp dart, or two darts, fheathed within it ; the ufe of thefe darts is to penetrate the flefh of animals for the fucking their blood, whereas the probofcis can only ferve to fuck the dews from flowers, rjfc

The eggs of this fly are laid in the waters, and there produce a very remarkable fort of maggot. It is a brown one of. a long flatted figure, with a penal of hiie downy hairs at its tail, which it rereads into a circular form on the furface of the. water, while its head is funk down in fearch of food. When the creature would defcend toward the bottom, thefe hairs are made to approach one another in an oval form, and in this (late they inclofe a bubble of air, by means of which it is able to rife again ; and if this bubble by any acci- dent efcapes, the creature immediately fqueezes out of its own body another to fupply its place. The friout of this maggot has three divifions, whence are thruft out three little pointed bodies like ferpents tongues. Thefe maggots are very common on the furface of ditch water, and the motion of their inteftines is very lingular and obfervable. Bain's Mi- crofcope, p. 206;

GADING, among miners. See Gap.

UADUS, in ichthyology, the name of a genus of the mala- copterigious, or foft fined fifhes, the.charaaers of which are thefe. The bronchioftege membrane on each fide contains feven bones of a fomewhat cylindrie form ; the back in fome fpecies has three fins, and in others only two ; the head in molt fpecies is compreiled, but in fome it is depreffed. Of thofe which have three fins on the back, the following fpecies are enumerated by Artedi.

1. Of thofe which have no cirri there are thefe. i. The gadus with three back fins, with a white body, with no cirri at the mouth, and with the upper jaw longeft. This is our common whiting. 2. The beardlefs gadus with three back fins, with the lateral line ftrait, and the lower jaw longeft. This is the fifli we call the raw pollock, or colefifh. 3. The beardlefs gadus with three fins on the back,- with the lower jaw longeft, and with the lateral lines crooked. This is the whiting pollock.

2. Of the gad! with three back fins, and with cirri of beards, there are the following fpecies. r. The variegated bearded gadus with an even tail, and the upper jaw longeft. This is the cod fiih. 2. The white bodied forked tail'd gadus, with a bearded mouth, and three back fins. This is our had- dock. 3. The bearded gadus with three back fins, with thirty rays in the firft pinna ani. This is our pouting, or whiting pout. The fide lines in this fiftl are black, and'very crooked. 4. The fmall two inch gadus, with beards at the mouth, and with three back fins, and the anus in the middle of the body. This is the mollo of the Venetians ; in Corn- wall we call it the poor, or the power.

3. Of thofe gad! which have only two fins on the back, the fol- lowing are the fpecies. 1. The gadus with two back fins, and with the lower jaw longeft. This is the fifh we call the hake. The head of this fifh is broad, the body oblong, and fomewhat cylindrie. 2. The bearded gadus with two back fins, and the upper jaw the longer. This is the fifh we call the ling. Its body is very long, androundifh; its head flat and depreffed ; its mouth very wide, and its tail rounded at the end. 3. The bearded gadus with two back fins, and both jaws even. This is the mujlela fiuviat'dis of authors, the eelpout of the Englifh. The head is of a deprefs'd figure, the body long and rounded, varioully coloured, and lubricous to the touch ; the tail nearly oval, and the linea lateralis ftrait.

4. Thebearded gadus with two back fins, and with a furrow at the firft back fin. This is the kind named by the peo- ple of Cornwall the whiffle fifti. Artedi Gen. Fife. 15. GADWALL, inzoology, the name of a fpecies of duck which frequents freih waters, and is called, in fome parts of Eng- land, she gray. It is called anas Jlrtpera by authors. It is ol the fizc of the widgeon, or fomething larger; its body is of a longifh fhape, and its rump black; its back is brown,

OUPPL, Vol.. I.

but the edges of the feathers are edged with white ; the fronil of the head, and upper part of the throat, are white, fpotted with fmall brown fpecks ; the head is of a blueifh black, the throat of a greyifh white, and toward the breaft fome- what redifh ; the upper part of the breaft, and the fhoulders are beautifully variegated with brown, white, and black ; the breaft is white, arid the belly brownifh, with fmall tranfverfe ftreaks of black ; the beak is blackifh and yellow, and the legs are whitifh. The female is different from the male in many refpects, particularly it wants the blacknefs of the rump; but both the male and female are diftinguiihed at fight from the other fpecies, by having marks of three different colours one above another on their, wings ; thefe are white, •black, and a redifh brown. ictf/s.Ornitholog. p. 287.

G/EEL/EUM, earth oil, in natural hiftory, a name given by fome of the old writers to the petroleum, or as we ufually ■ call it, oil of Petre. See Petroleum.

GAFET, in the materia medica of the Arabians, a name given by Avifenna and others to the farcocolla of the Greeks. So the word is tranflated; but it is to be obferved, that the far- cocolla of the Greeks expreffes two very different things ; the one a gum, now known among us by that name ; the other a plant, called alfo argemone, and agrimonia, for they have fometimes called the one of thefe plants, and fometimes the other by that name. The agrimony feems however to have been generally meant by this name, and this is the gafet 'of the Arabians, for they call the other or right farcocolla, both the gum, and the tree which produces it, arizarut.

GM'OL'D-land, or GAFUL-land, terra fenfualis, in our old writers, land liable to taxes, and rented, or letten for rent. Sax. Diet.

GAGATES, jet, in natural hiftory, the name of a foifile fub- ftance, the characters of which are thefe. It is a folid, drv, opake, inflammable body, found in large detached maffes 'of a fine and regular ftrudture, having a grain like that of wood, fpliting more eafily horizontally than in any other direction, ■very light, and moderately hard, not fufible, but readily in- flammable, and burning a long time with a fine greenifh white flame.

This is a fubftance about which there have been many er- rors, and which has been very little underftood even in our own kingdom, where the fineft in the world is produced, haying been ufually confounded with a thing greatly in- ferior to it in. value, the common cannel coal, fo that many believe that there is no other jet than that fubftance ; and of the few who fuppofe them different, none feem to have had any clear idea of their diftinguiihing characters, but they are eafily known afunder when thefe are properly con- fidered.

Jet is always found in detach'd manes lodged in other ftrata ; cannel coal conftitutes of itfelf whole ftrata. Jet has the grain of wood, and fplits horizontally much more eafily than in any other direction ; cannel coal has no peculiar grain, and fplits with equal eafe any way. Jet is but moderately hard, cannel coal not lefs fo than many ftones, and jet when fet on fire flames a long time; cannel coal but a little while. Jet is found in Italy, Germany, and the Eaft Indies, but no Where fo plentifully as in England ; it is very common in Yorkfhire, and other of the northern counties, and is found in many of our clay pits about London. Hill's Hilt, of' Faff p. 413.

Jet, in medicine, is highly praifed by the antients, but the modern practice has never enquired whether juftly or not. Diofcotides tells us, that it is an excellent emollient and difcutient ; he recommends a fumigation of it for difeafes of the womb, and fays that water, in which burnt jet has been quenched, is a cordial. Aetius orders it to be extin- guifhed in wine for the fame purpofe. Hill's Hift. Mat. Med. P- 170.

GAGATRONICA, a word ufed by the writers of the middle ages, as the name of a diftinct ftone, but feeming only a falfe fpelling of the Word garatronium. See Garatro- niuivi.

GAGNOLA, in ichthyology, a name given by the Spaniards to a fpecies of the acus, or fyngnathus of Artedi. The par- ticular fpecies meant by it, is that called by Artedi, the hex- agonal bodied fyngnathus with the pinnated tail ; others call it the acus Ariftotelis, or acus fecunda, and the French the trompette; we call it fometimes the needle fifh, fometimes the trumpet fifh, and fometimes the tobaccopipe fifh.

GAHALA, in botany, a name given by fome writers to the colocafia.

GAIDEROPSARUS, in ichthyography, a name given by fome to a fifti of the truttaceous kind caught in the Mediter- ranean, and more ufually called ca/larias. Bellonius de Pifc. See Callarias.

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