Page:Cyclopaedia, Chambers - Supplement, Volume 2.djvu/711

 V EN

{hat by moving parallel to itfclf, is fuppofed to generate an creel: prifm, or cylinder, always equal to the ("olid. The Ve- locity with which an angle flows, is meafured by the Velocity of a point, fuppofed to dc-fcribe the arc of a given circle, which fubtends the angle, and meafures it. See Mac Laur. Flux- ions, B. i. ch. i.

All theft Velocities are meafured at any term of the time of the motion, by the fpaces which would be defcribed in a given time, by tbefe points, lines, or furfaces, with their motions continued uniformly from that term. Mac Laur. ibid. The Velocity with which a quantity flows, at any term of the time, while it is fuppofed to be generated, is called its fluxion. See the article Fluxion,

'VELVET (Cycl.)— Colour of black Velvet. The manner of giving this deep and fine colour to glafs, is this : Take of cryitalline, and pulverine frit, of each twenty pounds, of calx of lead and tin four pounds ; fet all together in a pot in the furnace, well heated; when the glafs is formed and pure, take fteel well calcined and powdered, fcales of iron that fly off from the fmith's anvil, of each an equal quantity ; powder and mix them well ; then put fix ounces of this pow- der to the above defcrijed metal while in fufion ; mix the whole thoroughly together, and let all boil flrongly together, then let it Hand in fufion twelve hours to purify, and after

■ this work it. It will be a moft elegant Velvet black.

There is another way of doing this; which alfo produces a very fair black. It is this : Take an hundred weight of rochetta frit, add to this two pound of tartar, andlix pound 'of manganefe, both in fine powder; mix them well, and put them to the metal while in fufion^ at different times, in feveral parcels ; let it ftand in fufion after this for' four days, and then work it. Neri's Art of Glafs, p. 95,' & fed.

VELUM, in ecclefiaftical writers, the fame with what is' 0- therwife called brandeum. See the article Erandeum.

Velum quadragefimale, a veil, or piece of hangings, antiently: drawn before the altar in Lent, as a token of mourning and forrow. Blount.

VENABULUM, in antiquity, a long kind of fpear ufed in hunting wild bcafts. Hofm. Lex. Uriiv. in voc. "

VENCU, in botany, the Chinefe name for an excellent fruit found in that country, which the Portuguefe call jamboa, and the Dutch pompebimes : It grows on prickly trees, like the limon- tree, only larger. Its flowers are white, exactly the fame in fhape with thofe of the limon, and have an ex- ceeding fvvcet fmell ; a very fragrant water is diftilled from them. The fruit itfelf far exceeds the citron in bulk, being in fize equal to, and fometimes exceeding a man's head. The rind is like that of the golden rennet ; the pulp is of a reddifh colour, and its tafte partakes of fweet and acid, refembling that of grapes not fully ripe. A liquor is prefled from it, as in Europe, from apples, pears, &c. It will keep for a whole year. Hofm. Lex. Univ. in voc.

VENDITOR regis, the king's faltsman, or perfon who ex- pofed to (ale, goods and chattels feized or diftrained to anfwer 'any debt due to the king. This office was granted by king Edward I. to Philip de Lardimer, in the county of York, ha quodipje, -uel certus fuus attornatus, ibit ad ir.andatum viceco~ mitts de loco in locum infra com. presd. fumptibus tuts ad v\endi\ tiones faciendas, fjf capiat de utiaau'aque venditione pro feodo fuo xxxii. Den. but the office was foiled into the king's hands for rhe abufe thereof. Anno 2 Ed. 2. Blount.

VENENUM cocci, a term ufed by many of the antients for the purple tinge, which the kermes berry, as it is ufually called (fee the article Kermes) gave to linnen, or other things. The word Venenum being generally underftood to exprefs poi- fon, it has been fuppofed by many, that the kermes was efteemed poifonous, or that there were two forts of this druo- ; the one a harmlefs medicine, and the other poifonous. But there is no warrant for this in any of the old writers, and the whole feems indeed but a miftakc about the fenfe of the word Venenum, which we find by many pafiages of the b'eft authors, fignified a f tain, as well as a poifon.

The antients called the veftments dy'd fcarlet with the kermes indifferently, by the names 'of flatmnex:, or venenata;. Servius tells us, that in certain facred ceremonies, it was necefiiiry that the prieft fhould be clothed in a fcarlet robe ; and he tiles the word venenata to exprefs it in fome places, ixxifiammeo in others.

VENER, one of the many names by which the chemifts calj Mercury.

VENEREA concha, in natural hiftory, the name of a very large and elegant genus of fhells, more ufually called the porcellanes. Seethe article Porcellana.

VENETA bolus, a fine red earth ufed in painting, and called in the colour-fhops Venetian red.

It is improperly denominated a bole, being a genuine fpecies of red ochre. It is of a fine bright, and not very deep red, approaching, in fome degree, to the colour of minium, or red- lead, and is moderately heavy, and of an even and fmooth texture, yet very friable, and of a dully furface : it adheres firmly to the tongue, is very fmooth, and foft to the touch, eafily crumbles to pieces between the fingers, and very much flains the fkin in handling. It has a flight ailringent tafte, and makes no fermentation with acids.

V ; E R

It is dug in Carinthia, and fent from Venice into all parts 0/ the world, being an excellent colour, and' very cheap ;our colour-men, however, find too many ways of adulterating it Hill's fflk of Foffils, p. 59 : ? "

VENISON, Cycl. — The old huntfmeh have determined, that every beafr of the foreft, that is food for man, hVemfon. ' I n many parts of the world,- the bears are as regularly hunted, zi ■ the hare and buck, &c. t are with us, and. there are called Ve- nifin 1 but with us, atprefent, the word Venifon feems limit- ed to the flefn of the hart, the hind, the buck, the doe, and the other creatures of that kind.

Some have extended the fignifkation of the word to the beaffs of the forefrs, which were chafed as game, and afforded the diverfion of hunting, whether their flefh were eaten or not ; thus, in fome places, the wolf and the fox are reckoned a- rnong the Fcntjon beafts. See the article Forest.

VENOSA arteria. Seethe article Arteria wnoja.

VENOSE Luaf Venofum folium, among botanifts. See the" article Leaf,'

VENTININA, a term ufed by Paracelfus and his followers, to exprefs' the art of divining, or knowing by the winds and their couffes, the good or ill effects of feafons.

VENTRICULTJS fucCenikriatus, in medicine, a name glvert by fome to the duodenum, .when very large. Medic. Efl", Edinb. abridg. Vol. %. p. 34.

VENUS {Cycl.)— A fmaller ftar having been obferved by Mi** Short near Vemts 7 which had the fame phafis as that planet, has given fome fufpicion of its having a fateHite. See Phil. Trnnf. N°. 459. fe&. 23. where it is faid, that M. Caffini, hi his Elemens d'Aftronomiei mentions a like obfervation.

VER-pucfro??, iii natural hiftory, a name given to a kind of in- fects which are fond of eating the puceron, and deftroy them m vaft numbers. See the article Puceron. They are thus called, as the ant-eater is, formica ko, from their deftroying great numbers of them. Thefe Ver-piccrom are a fort of worms produced from 'the eggs of flies, and are of two principal kinds; the one having legs, the other none.

Vv hen we obferve the vaft number of young produced by eve- ry puccron, and the quick progrefs they make in (.heir multi- plication, we are apt to wonder, that every plant and tree in the worH is not covered with them ; but on the contrary, when we obferve the devastation thefe devourers make among them, we are apt to wonder how any of them efcape at' all, "to perpetuate the fpecies. Thefe worms indeed feem created for no other purpose but to deftroy them ; and this they do in fo violent a manner as is fcarce to be conceived. As the flies of many kinds lay their eggs on meat and other fubftances, which they know will afford food for the young ones, when hatched from them : fo the parents of thefe worms lay their eggs on the branches and leaves of trees loaded with pucerbns, on which they know' they will feed. The worms produced from them are devourers from the very inftant they 'are hatched, and find themfclves placed in the nfidft of prey, be- ing every Wi\y furr'ounded by a nation of creatures which are their proper food, and Which are furnifhed with no weapons, either offenfive or defenfave, and which never fo much as at- tempt to fly from them, but feem wholly ignorant of their danger, till feized upon by the devourers. Reaumur's HifU of Infects, Vol. 6. p. in.

Thefe worms are very large iri proportion to the pucerons, the difference not being lefs than that between the lion and the fmalleft quadruped; Their figure is varied at pleafure ; but feems, in its moft natural ftate, to be much larger at the po- fterior part than at the anterior ; the pofterior part alfo ufually remains fixed, while the other is twifted about various ways ; but the creature can, at its pleafure, fhbrten the body, by drawing in the feveral rings, and then it appears of an oval figure.

Thefe worms are of different colours, and different fpecies; thofe which are found on the elder are green, with a white ray down the back ; thofe on the floe and goofe berry-tree are whitifh, variegated with yellow undulations. Other fpecies are of a pale yellow, others of a fomewbat deeper yellow^ with two Streaks running down their backs of a bright chef- nut colour, between which there is one black one. Some have reckoned thefe feveral fpecies among the caterpillars, but very improperly, as they have no one character of this kindj but every way refemble the worms or maggots, produced from the eggs of the common flies, Thefe creatures have at their head a dart of a brown colour and hard fubftance, orna- mented with two fmalier points at the bafe, fo that it repre- fents, in lome degree, a flower-de-luce : this is the weapon with which they deftroy the pucerons, and' this they either draw back within the head, or thruft out at pleafure. The mouth of the creature is placed under this dart, but is not ea- fily difcovered, the creature ufually keeping it very clofely {hut; there are times however, when the creature is feen bend- ing its head down feveral times towards its belly ; and if the anterior and under part be then examined, the place of the mouth will be diftinguiflied by means of a yeliowifti liquor which it throws out of it.

All thefe worms have two ftigmata or apertures for the receiv- ing air at the hinder part of the body. Thefe are very di- ' ■ ftinflly