Page:Cyclopaedia, Chambers - Volume 1.djvu/342

 C H A

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C H A

extraordinary Tcnfion, or Swelling, they occafion Pain.

Of this Kind are Butter, and many Oils, f§c. See Emol- lient. '

The Word comes from the Greek %***», Ifften.

CHALAZA, among Naturalitts, the Tr&ddle of an Egg, or that flat, dented Part at each End ; fo call'd, as being antiently fuppos'd to be the Sperm of the Cock. See

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Its Ufe, according to Harvey, is to be as it were the Poles of this Microcofm, and the Connections of all the Membranes twifted and knit together ; whereby the Li- quors are not only conferv'd, each in its Place, but alio in its due Pofition to the reft.

Mr. Dcrham adds, that they alfo ferve to keep one and the fame Part of the Yolk uppermoft, let the Egg be turn'd which way it will ; which is done by the following Mechanifm : The Chalaza are fpecifically heavier than the Whites wherein they fwim 5 and being brae'd to the Mem- brane of the Yolk, a little out of the Axis, caufe one fide of the Yolk to be heavier than the other. The Yolk be- ing thus by the Chalazce made buoyant, and kept fwim- ming in the midft of two Whites, is by its own heavy fide kept with the fame Side always upper molt : which upper- molt fide he imagines to be that whereon the Cicatricula, lies. See Cicatricula.

CHALCANTHUM. See Calcanthum.

CHALCEDONY, or CALCEDONY, a precious Stone of a blueiih or yellowifli Colour, rank'd among the Kinds of Agate. 'Tis fuppos'd to be the white Agate of the An- tients 5 tho we fometimes find Pieces of it blackifti. See Agate.

It is very fit for the Graver 5 and much us'd, either to engrave Arms, &c. upon, as being harder and preferable to Cryftal, if good 5 or to paint them on the backfide. In fome Parts, Vafcs, Cups, Religious Beads, &c. are made thereof. The cleareft and belt is that with a pale caft of blue.

Selon fays, 'tis fo common among the 'Turks, that it ferves them for threfhing their Corn : but he miftakes. Hence,

Chalceeonius is a Term us'd by the Jewellers, for a Defect found in fome precious Stones ; when, in turning them, they find white Spots, or Stains, like thofe of the Chalcedony : This Defeft is frequent in Grenates and Ru- lies. The Lapidaries remedy it by hollowing the Bottom of the Stone. See Grenate, and Ruby.

CHALCID1C, CHALDICUS, CHALCIDICUM, or, as Fcjlus calls it CHALCEDONIUM, in the an tient Ar- chitecture, a large magnificent Hall belonging to a Tribu- nal, or Court of Juftice.

In Vitruvius, it is us'd for the Auditory of a Bafthca : In other of the antient Writers, for a Hall, or Apartment, where the Heathens imagin'd their Gods to eat.

Feftus fays, it took its Name from the City Chalets ; but does not give the Reafon. (Philander will have it to be the Court, or Tribunal, where Affairs of Money and Coinage were regulated 3 from ka^k^, Srafs, and JVxff, r /i/Jlice. Others fay, the Money was ftruck in it 5 and de- rive the Word from KctKK&t, and oiK&- y Houfe.

CHALCIT1S, fometimes call'd Colcothar, is a kind of Mineral ; or, as fome call it, a "Vitriol 5 reddifli, like Copper 5 friable, not very hard, and having yellow Alining Veins within. See Colcothar.

It has the Tafte of a Vitriol, melts alone in a Crucible, and diflblves very eafily in watry Liquors. There are two other Minerals, call'd Mijt, and Sory, very much like the Chalcitis. In effeft, the Antients confounded them toge- ther $ and not only the Mifi and Sory, but alfo the Me- la-nteria ; or rather, they imagin'd a fucceffive Tranfmu- tation of the four Minerals, which began with Chalcitis, became/l^/?, then Melanteria, and laftly Sory, where itfix'd.

The Moderns make thefe four dHtinct Matters $ tho the chief Difference between them, is fuppos'd to lie in the different Tenuity or Groflhefs of their Subftance.

Some fay, the Mifi is form'd on the Chalcitis, as Verdc- greafc on Copper, being properly its Ruft ; and that Chal- citis is form'd in the fame manner on the Sory.

This is certain, they are all found in Copper Mines : But the modern Druggifts know little of any of them but Cbalcitis.

This is brought from Germany : It is very Cauftic and Kfcharotic. Its chief ufe is in the Compofition of Venice- Treacle ; in Heu of it are frequently fubflituted Calcan- thum rubefy 'd, or Copperas, or Catamites.

CHALCOGRAPHY, the Art of Engraving on Copper and Bra fs. See Engraving.

CHALDEE, or CALDEE Language, that Jpoke by the Chald£avs, or People of Cbaldea. See Language.

The Chaldee is a Dialect of the Hebrew. See Hebrew.

Chaloee Paraphrafe, in the Rabbinical Style, is call'd tfar^wn. SccTargum.

There are three Chaldee Paraphrafes in Walton s Poly-

glot 5 viz. that ofOnkelos, that of Jonathan Son of Uziel and that of Jerttfalcm. See Paraphrase, and Polyglot!

Chaldee Paraphraji. See Pentateuch.

CHALDRON, CHALDER, or CHAWDREN of Coals, a dry Englijh Mcafure, confifting of 56 Bufhels heap'd up, according to the fealed Buihel kept at Guild- hall, London. See Measure.

The Chaldron fhould weigh 2000 Pounds. On Ship. board, z 1 Chaldrons of Coals are allow'd to the Score. See Coals.

CHALICE, or Cup. See Calix.

CHALK, a white Subftance ufually reckon 'd as a Stone- but Dr. Slare thinks, without Reafon ; fince, when exa- min'd by the Hydroftatical Ballance, it is found to want much of the Weight and Confidence of a real Stone : fo that he thinks it more juftly rank'd among the Soles than Stones. See Bole.

This he obferves to be the Cafe, not only in Chalk, but various other Bodies, taken for granted to be Stones 5 ibme whereof are nearer Earth than Stones ; others nothing but Earth, Sulphur, Metal, &c. See Stone, Earth, &c.

Chalk is of two forts ; the hard, dry, ftrong Chalk, us'd for making of Lime : See Lime. The other a foft, unc- tuous Chalk, us'd to manure Lands 5 as eafily diflolving with Rain and Froft : It is beft for cold, four Lands, ana promotes the yielding of Corn ; it fwee tens Grafs fo as to caufe Cattel to fatten fpeedily, and Cows to give thick Milk. See Manure, and Soil.

Chalk is us'd in Medicine, as an Aftringent, an Abfbr- bent, and a Sweetner ; and is celebrated for curing the Heartburn, beyond any thing whatfoever.

CHALLENGE, a Cartel, Defiance, or Invitation to Duel, or other Combat. See Cartel, Duel, and Combat.

Challenge, in Law, is an Exception taken either a- gainfl 'Perils, or Things : Againft Perfons ; as in an Affize, to the Jurors, when any one, or more of them are excepted againft, in Cafe of Felony, by the Prifoner at the Bar.

Againft Things, as a Declaration. Sec Declaration.

Challenge to tl?e Jurors, is either made to the Array, or to the Tolls : To the Array, as when the whole Number is excepted againft, as partially empanell'd. To the Poll, as when Particulars are excepted againft, as not indifferent.

Challenge to the Jurors, is alfo divided into Challenge Principal, and Challenge per Caufe 5 i. e. upon Caufe or Reafon alledg'd.

Challenge 'Principal, otherwife called Challenge 'Peremp- tory, is what the Law allows without Caufe alledg'd, or further Examination ; as a Prifoner at the Bar, arraign'd on Felony, may peremptorily challenge twenty, one after another, alledging no Caufe but his own Diilike 5 and thty ihall be fet afidc, and new ones chofen in their room. In Cafe of High-Trcafon, no Challenge Peremptory was for- merly allow'd j but by Stat. 7. Gill. HI. liberty is given peremptorily to challenge 35.

Yet there feems to be a Difference between Challenge Principal and Challenge Peremptory 5 the latter being on- ly in Matters Criminal, and without any Caufe alledg'd ; the former moftly in Civil Cafes, and with affigning fome fuch Caufe, as being found true, the Law allows 5 v.g. if either Party alledges, that one of the Jurors is the Son, Brother, Coufin, or Tenant of the other, the Exception is good. Alfo in the Plea of the Death of a Man, or in any Aclion Real or Perfonal, where the Debt or Damages amount to 40 Shillings 5 It is a good Challenge to a Juror, that he cannot difpend 40 Shillings per Anmim of Freehold.

Challenge upon Reafon or Caufe, is when the Party does alledge fome fuch Exception as is fufficicnt upon acknow- ledgment of the Truth of it ; v. g. If the Son of the Juror have marry 'd the Daughter of the other Party.

The Word Challenge was antiently latin'd Calumnia.

Challenge is alfo a Hunting Term : for when Hounds at firft finding the Scent of their Game, prefently open, and cry, the Huntfmen fay, they Challenge.

CHALYBEAT, in Medicine, fomething that partakes of the Nature of Steel, or Iron-, or that is impregnated with Particles of thofe Metals. See Iron j fee alio Mars, and Steel.

Chalyheats a6l chiefly as Abforbents, and Deobftruents. Iron, M. Lemery obferves, is a Mixture of an oily Sub- ftance with a metallic Matter ; but the Oil is the Pre- dominant in the Mixture : and between the Parts mix'd are large Pores. Hence, Iron becomes eafily diflolvable ; and its Oil eafily difengages it felf : But when once decom- pounded, i. e. when once the Oil is feparated from the pure, ferruginous, or metallic Parr, no Diflolvent has any Effecl: on that Caput Mortuum. Hence appears the Ab- furdity.of that common Practice, of calcining Iron to fuch a degree, as to convert it into what the Chymifts call a Cro- cus, or Saffron. This Operation mull of neceflity take away all, or moft of the oily Subftance, and have left no- thing but the indiflbluble Caput Mortuum. Which Oil here feparated, fhould properly have been feparated by the

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