COB
COB
3. With alcohol, upon the fpirit of fal armoniac, the white of
<eggs, the ferum of the blood, &c.
+. With acid and alkali, growing folid together, as in the tar
tarum vitriolatum.
5. With fixed alkali, as in milk, And, 6. With acid falts, as
in milk, ferum, and whites of eggs. Booh. Chcm. P. 2.
p. 338. .
CuAGULUM ahoninofum, alum curb a form of medicine, prefcribed long lines by Riverius, and now taken into the London difpenfatory. It is ordered to be made by putting whites of eggs into a pewter or earthen vefFel, and (taring them about with a large lump of alum till they arc coagulated Pemaerion's Lond Difp. p. 379.
COAL (Cycl.) — The common pit coal contains a large quantity of fal armoniac. The mouths of our fubterrancau fires in the coal countries all afford it, and it is even found in brick- kilns, where nothing but coal is burnt with the clay. It may appear Arrange indeed to fome, that this black fubftance fhould yield fo white and fine a fait; but chemifts know, that a.l vo- latile falts whatever may be freed from their fcetor and intenfe colour, by tranfmuting them into a fal armoniac, by the me- diation of an acid, as thefpirit of fait, vitriol, or alum 5 after fublimation with which, they become white, fweet, and pure. The reafon of this change is, that tho' the falts always carry over fome of the foetid oil with them in a ftate of volatility, vet being thus in a manner fixed, the fcetid oil muft by force of fire rife firft, leaving the fubfequent fal armoniac without fmell : tho' it is ftill a doubt, whether the fait be the better or the worfe for this labour. Phil. Tranf. N° 130.
CoA L-balts. In the country of Liege, they ufe a kind of balls made of coal and clay, for firing. 1'hefe balls are made with i of clay, without fand or gravel, and \ of W-duft, well mixed, and formed either into round balls, or into bricks. This <W-duft being the refufe of the mine, makes this fort of firing cheap. See Phil. Tranf. N° 460. Sett. 3.
CoAL-ffiifftf. Wilfully fetting W-mines on fire, is by ftatute felony without benefit of clergy. 10 Geo. II. c. 32. §. 6.
Co a i-fprit. Coals diftilled in a retort not only afford a phlegm, and black oil, but a fpir'it, which is apt to force the lute and break the glafles, and will catch fire at the flame of a candle. We are told that bladders may be filled with this fpirit, which may be kept a confutable time. If the bladder be pierced with a pin, and fqueezed near the flame of a candle, the fpirit will take fire, and afford an amufmg fpectacle. See Phil. - Tranf. N° 452. Sect. 5.
COAMINGS, in fliip -building, are thofe planks, or that frame, which raife up the hatches higher than the reft of the deck, Loon-holes for mufkets to fhootout at, are often made in the coamings-, in order to clear the deck of the enemy when a fhip is boarded.
COANE, among the Greeks, a name given to a pccular fpecics of tutia or tutty, which was always found in a tubular form It had its name from ««»», a word ufed to exprefs a fort of cylindric tube, into which the melted brafs was re- ceived from the furnace, and in which it was differed to cool. In cooling, it always depofited a fort of recrement on the fides of the veffel or tube, and this was the tutty called count.
COATS, in a fhip, are pieces of tarred canvas put about the mafls at the partners. They are alfo put about the pumps at the decks, that no water may go down there ; and they are alfo ufed at the rudder's head.
GOATI, in zoology, the BrafiTian name for an animal of the dog or fox kind,' common in many parts of America, and Sometimes kept for curiofity with us, and called the rackoon. See Tab. of Quadrupeds, N° 20. and the article Rac- koon'.
COATING, in chemiftry. See Lorication.
COBALT, cohaltum {Cycl.) — O.balt is a denfe, compact, and ponderous mineral, very bright and mining, and much re- fembling fome of the antimonial ores.
It is fometimes found of a deep, dufky, bluifh black, very heavy and hard, and of a granulated ftructure, looking like a piece of pure iron, when frefh broken. At other times, it is more compact and heavy, of a very even texture, and not granulated, or compofed of any feparatc moleculte, but re- fembling a dufky mafs of melted lead, not an ore. The inner part, when frefh cut or broken, is in fome ores found much more beautiful than in either of thefe ftates, being of a fine bright filvery grey, and of a beautiful and evenly ftriated ftructure j the ftrire all running great lengths, but be- ing all vario.ufly inflected and undulated, and in fome parts broken. Thefe are the more ufual appearances of cobalt in its ore: but befide thefe, it is fubject to an alteration in the bowels of the earth, by means of fubterraneous fires and ful- phur, which reduce it to a body which cannot be fuppofed at firft fight the fame with cobalt, tho' it prove to be exactly the fame fubftance, on a chemical analyfis.
In thefe ftates, inftead of the lead-like appearance of the common kind, it is of a fine florid red colour, tho' fometimes debafed by accidental mixtures to a grey, black, or yellow, either wholly* or in part : and in this ftate it has two fubordi- nate diftinctions, as it appears fometimes in form of a compact .mafs of an uniform texture, and fometimes in a ftriated and beautifully ridged mafs, refembling the fibraria. The three
firft ftates of cohak, are commonly called cobalt ore, withe ' any diftinction ; hut the firft of thefe red kinds is called by the Germans kupffer nicol, and the latter, or ftriated one, the flower of cobalt.
Cobalt is found in Germany, Saxony, Bohemia and England. Ours is hut a poor kind, but is met with in confiderable plen- ty on Mendip-hills. The German cobalt generally contains a large quantity of bifmuth, and the Bohemian of iilver. The world is obliged to Kunkell, for the hiftory of the feveral arfenics, zaff're and fmalt, which are all the produce of co- halt. See Arsenic, &c.
T\\p-cqbaU is roafted in a reverberatbry furnace, and the flow- ers, which it yields in great abundance, are collected in long wooden funnels, which fupnly t he-place of chimnies, on the infidesof which it fticks in form of loot, and from this foot or flower are made all the feveral forts of arfenic or ratfbane. If 1 his is only rdublimed, or but barely melted in a covered veffel, the fubftance which we call white arfenic or common ratfbane is produced. If a tenth part of fulphur be mixed withthem, and they are fublimed together, the product is our yellow arfenic; and the red arfenic is made by adding to the flowers only one fifth of fulphur, and a little copper flag. When the flowers or foot of cobalt is ail difcharged, the re- maining matter is powdered very fine, and being mixed with three times the weight of common flints in powder, and wetted with water, the whole concretes into a folid mafs, and is what is called zaffer. See Zap fer.
Two parts of this being fuied with three parts of common fait, and one part potafh, the whole becomes a beautiful blue fubftance, 'Called fmalt. See Smalt.
The fprinkling the powder of the calx of flints and cobalt, for the making them into zaffer, giving them a pretty firm coalef- cence, and even the hardnefs of a common ftone, perfons who were unacquainted with the procefs, have taken zaffer for a native mineral. Hilts Hift. of Foil', p. 67.5.
Cobalt is alfo ufed by fome to exprefs that fufFocative vapour or damp in mines, which often proves fatal to the miners. It is common among; the Germans to fay on this occafion, that the cobalt rofe and choaked them .
COBITIS, in zoology, the name of a fmall frefh- water fifh, commonly called in Englifh the loach. It very much refem- bles our common gudgeon, both in figure and colour, but it is much fmaller, about two inches being its ufual length, and three, or a little more, the utmoft that it ever arrives at. Its body is foft and flippery ; its tail flat and broad, and it has either extremely minute fcales, or none at all. It is of a brown colour, fpotted all over with black fpecks, and it has three pair of beards at its upper jaw. It is caught in frefh wa- ters in many parts of the world, and is cftcemed by many a very delicate fifh, efpecially when very young and fmall. Willughby, Hift. Pifc. p. 265.
The generical characters of the cobitis, according to Artedi, are thefe : the head and the body are both of a com- prefled form : the fifh is of the malacopterygious kind : the back and belly fins are placed at the fame diftance from the ro- ftrum or fnout : there are always cirri at the mouth, and the body is always fpotted.
The fpecies of this fifh enumerated by Artedi > arc thefe : 1 . The colitis, with a forked fpine under each eye. 2. The fmooth and fpotted cobitis, with a cylindric body. 3. 1 he bluifh co- bitis, marked with five black lines on each fide, running lon- gitudinally on the body. This is the fifh called mifgum and fifgum at Nuremberg and Ratifbon. It has ten or more cirri at the mouth. Artedi Gen. Pifc.
The word colitis is truly Roman, and ufed by the beft au- thors to exprefs the fame fifh we now call by it ; but its de- rivation is uncertain.
Cobitis aculeata, called alfo cobitis oxyrynchus, a fmall frefh- water fifh of the loach kind, but armed with two prickles on the coverings of each of its gills, by means of which it moves nimbly about among the ftoncs. ifillugcby, Geu.Pifc. p. 265. See Dacolithus.
COBIUS, in ichthyology, a name given by Ariftotlc, iEHan, Appian, and the other Greek writers, to the gobius marinus, or fea gudgeon of authors, diftinguifhed by Artedi by the name of the blackifh variegated gobius, with fourteen rays on the fecond fin of the hack. It is called by the French goule- rot, or boulerot. See Gobius.
Coeius leucoicnts, in ichthyology, a name given by Arifrotle, Athemeus, and fome other of the old Greek writers to the fifh called gobius albus by later authors. It is a genuine fpecies of the gobius, and is diftinguifhed by Artedi by the name of the gobius with the ventral fin blue, and the rays of the anterior back fin rifing above the membrane. This is a fufficient di- ftinction from all the other gobii. bee Goeius.
COBOB, the name of a difh among the Moors. It is made of feveral pieces of mutton wrapt up in the cawl, and afterwards roafted in it; the poorer people, inftead of the meat, ufe the heart, liver, and other parts of the entrails, and make a good difh, though not equal to the former. Philof. Tranf. N" 25 r.
COBRA de !as cabecas, in zoology, the Portuguefe name for an American fpecies of ferpent of the amphifbena kind, whofe bite is very fatal. It lives under ground, and feeds on ants. See the article Ibijara.
Cobra
