COP 



and which is known in medicine by the 

 title of balsam of'copaivu. See BALSA*. 



COI'AI,. This substance, which deserves 

 particular attention from its importance 

 as a varnish, and which, at first sight, 

 seems to belong 1 to a distinct class from 

 tin- resins, is obtained from the rims co- 

 pallinum, a tree which is a native of 

 North America ; but the best sort of co- 

 pal is said to conie from Spanish America, 

 and to be tin- produce of difleivnt trees. 

 Copal isa beautiful white resinous sub- 

 stance, with a slight tint of browji. It is 

 sometimes opaqii", mid sometimes almost 

 perfectly transparent. When heated it 

 i,i. -Its like other n-sins; but it differs 

 from them in not being- soluble in alcohol, 

 nor in oil of turpentine without peculiar 

 management. Neither does it dissolve 

 in the fixed oils with the same east- us 

 the other resins. It ivsembles gum animc 

 a little in appearance, but. is easily dis- 

 tinguished by the solubility of this last 

 in alcohol, and by its being brittle be- 

 tween the teeth, whereas auime softens 

 in the mouth. The specific gravity of 

 copal varies from 1.045 to 1.139. Mr. 

 Hatchet found it soluble in alkalies and 

 nitric, acid with the usual phenomena, so 

 that in this respect it agrees with the 

 other resins. 



When copal is dissolved in any volatile 

 liquid, and spread thin upon wood, metal, 

 paper, Ike. so that the volatile menstruum 

 may evaporate, the copal remains per- 

 fectly transparent, and forms one of the 

 most beautiful and perfect varnishes that 

 can well be conceived. The varnish thus 

 formed is called copal varnish, from the 

 chief ingredient in it. Copal varnish 

 used by the English japanncrs is made 

 as follows. Four parts by weight of co- 

 pal in powder are put into a glass ma- 

 trass and melted. The liquid is kept 

 boiling till the fumes, condensed upon 

 the point of a tube thrust into the ma- 

 trass, drop to the bottom of the liquid 

 without occasioning any hissing noise, as 

 water does. This is a proof that all the 

 water is dissipated, and the copal has 

 been long enough melted. One part, of 

 hoiling hot linseed oil (previously boiled 

 in a retort without any litharge) is now 

 poured into it, and well mixed. The 

 matrass is then taken off the fire, and 

 the liquid, while still hot, is mixed with 

 about itsown weight of oil of turpentine. 

 rhe varnish thus made is transparent, 

 hut it lias a tint of yellow, which the ja- 

 panners endeavour to conceal, by giving 

 the white ground on which they apply 

 it a shade of blue. It is with this varnish 

 VOL IV. 



COP 



that the dial plates of clocks are covered 

 after having been painted white. 



Mr. Sheldrake has lately favoured the 

 public with another and easier method of 

 dissolving copal. This method is as fol- 

 Provide a strong vessel made of 

 tin or other metal ; it should be shaped 

 like a wine bottle, and capable of hold- 

 ing two quarts ; it will be convenient to 

 have a handle strongly rivetted to the 

 neck ; the neck should be long, and have 

 a cork fitted to the mouth, but a notch, 

 or small hole should be made in the 

 cork, that, when the spirit is expanded 

 by heat, a small portion may force its 

 way through the hole, and thus prevent 

 the vessel from bursting. Dissolve half 

 an ounce of camphor in a quart of spirit 

 of turpentine, and put it into the vessel ; 

 take a piece of copal the size of a large 

 walnut, reduce it to a coarse powder or 

 very small pieces, put them into the tin 

 bottle, fasten the cork down with a wire, 

 and set it, as quick as possible, upon a 

 fire so brisk as to make the spirit boil al- 

 most immediately ; then keep it boiling 

 very gently for about an hour, when so 

 much of the copal will be dissolved 

 will make a very good varnish ; or, if the 

 operation has been properly begun, but 

 enough of copal has not been dissolved, 

 it may be again put on the fire, and by 

 boiling it slowly for a longer time, it 

 may be at last brought to the consistence 

 desired. 



COPARCENARY, an estate held in 

 coparcenary, is where lands of inheri- 

 tance descend from the ancestor to two 

 or more persons. It arises either by 

 common law, or particular custom. By 

 common law, as where a person seized 

 in fee-simple, or fee-tail, dies, and his next 

 heirs are two or more females, his daugh- 

 ters, sisters, aunts, cousins, or their re- 

 presentatives, in this case they shall all 

 inherit. And these co-heirs are then 

 called coparceners, or, for brevity sake, 

 parceners. Parceners, by particular cus- 

 tom, are where lands descend, as in 

 gavel-kind, to all the males in equal 

 degree, as sons, brothers, uncles, or other 

 kindred; and in either of these cases, all 

 the parceners put together make but 

 one heir, and have but one estate among 

 them. 



COPEKXir AN rystem, or Hypothesis, 

 that system r.f the world, wherein the 

 Sun is supposed at rest in the centre, 

 and the planets, with the Earth, to move 

 in ellipses round him. The Sun and stars 

 are here supposed at rest, and that diur- 

 nal motion which they appear to have, 

 G 



