URI
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ts weight of alcohol, and apply a gentle heat. A great part of theniass will be dissolved, and tie-re will remain only a number ofsaline substances. Pour the alcohol-solution into a retort, and dis-by the heat of a sand-bath, till the liquid, after boiling someHue, is reduced to the consistence of a thick syrup. The whole of|fij-alcohol j s tI0W - separated, and what remains in the retort crys-tallizes as it cools. These crystals consist of the substance calledUr ea. It was first described by Rouelle llie younger, in 1773,l )nder the name of the saponaceous extract of urine. He men-tioned several of its properties; but very little was known of it tillt'ourcroy and VauqucSin published their experiments on it in1799. These celebrated chemists have named it Urea , which hasbeen generally adopted. Urea, obtained thus, lias (lie form ofc O’stal)i»e pkites crossing each other in different directions. Itscolour is yellowish white, It has a fetid smell, somewhat resem-bling garlic, or arsenic, its taste is strong and acrid ; resemblingthat of ammoniacal salts. It is very viscid and difficult to cut,a,1 d lias a good deal of resemblance to thick honey. When ex-posed to the open air, it very soon attracts moisture, and is con-Vei 'tcd into a thick brown liquid. It is extremely soluble in water ;ai 'd during its evolution a considerable degree of cold is produced.Alcohol dissolves it with facility, but scarcely in so large a propor-tion as water. The alcohol-solution yields crystals much morereadily on evaporation than the solution in water. When nitricac, d isdroptinto a concentrated solution of urea in water, a greatnumber of bright pearl-coloured crystals are deposited, composedurea and nitric acid. No other acid produces this singulareffect. The concentrated solution of urea in water is brown ; blitP becomes yellow, when diluted with a large quantity of water.■The infusion of nutgalls gives it a yellowish brown colour, hutcauses no precipitate. Neither does the infusion of tan produceany precipitate. When heat is applied to urea it very soon melts,swells up, and evaporates with an insupportably fetid colour.
UR EDO, the blasting or blighting of trees or herbs. It is some-times used by physicians for an itching or burning of theskin.
URENA, a genus of the monadelphia polyandria class and or-der of plants. Corolla with five, oblong, obtuse, connated petals,broader than the apex, narrower at the base; fruit a round eclii-nated capsule five-angled, five-ceiled; seeds solitary, roundish,compressed. I here are eight species.
URETHRA, the passage of the urine. See Ana-
tomy.
URGANTZ, or JURGANTZ, a town of Turkomania, 70 milesS. of Lake Aral, and 240 E. of the Caspian Sea . Lon. CO. 25. E.-Eat. 40. 55. N.
URI, the most southern canton of Switzerland , and the fourtli>u rank. It is hounded on the N. by the canton of Switz, and the■ake of Waldstadter See ; E. by the canton of Glarus ; S. by thelate four Italian bailiewicks now in Italy ; and W. by the canton !of Underwalden, and part'of Bern . It is fiO miles long and 22Broad. It con-isls almost every where of high mountains coveredwith eternal snow, and deep valleys, pretty fertile, and very hotin summer. Among the former is St. Gotbard, the highestfountain in Europe .
URIC ACID, an acid discovered by Scheele in the year 1770.Itw as at first called litliic acid. It constitutes one of the com-ponent parts of urinary calculi, and is also found in human(lr ine. That species of calculus, which resembles wood in itscolour and appearance, is almost entirely composed of tills sub-*fiuic e . It lias neither taste nor smell; is insoluble in cold water,bl .'t reddens vegetable blues, especially the tunisol. A great partot Rie acid precipitates again, as the water coois. It combines>eadi|y witi, ,| le a ihalies and earths; hut the compound is decom-posed bv every oilier acid. Muriatic acid lias no action on it;. Ilei tl)er has sulphuric acid while cold ; hut when assisted by heat,i; Recomposes it entirely. When triturated with potass or soda11 iotnis a saponaceous paste ; very soluble in water, when there is, " ^cess of alkali, hut sparingly when the acid is neutralized. The! ate of potass, or of soda is nearly tasteless. The last is found..Jstallized, constituting gouty concretion 5 . Ammonia does notiiio e l "' ic acicl > but'it combines with it, and forms a salt notch ,? Sulllb le than the pure acid, and resembling it in its external‘-"araclers,
V ° L ' 'V.— -no. 214.
URIM and TIIUMMIM, among the ancient Hebrews, a cer-tain oracular manner of consulting God , which was done bv thehigh priest dressed in his robes, and having on his pectoral orbreast-plate. Various have been the sentiments of commentatorsconcerning the urim and thummim. Josephus , and several others,maintain, that it meant the precious stones set in the high-priest’sbreast plate, which by extraordinary lustre made known the willof God to those who consulted him. Spencer believes that theurim and thumniim were two little golden figures shut up in thepectoral as in a purse, which gave responses with an articulate voice.In short, there are as many opinions concerning the urim and tlium-mim as there are particular authors that wrote about them. Thesafest opinion, according to Broughton, seems to be, that thewords urim and thumniim, signify some divine virtue and powerannexed to the breast plate of the high priest, by which an oracu-lous answer was obtained from God when he was consulted by thehigh priest; and that this was called urim and thumniim, to ex-press tile clearness and perfection which these oracular answers al-ways carried with them ; for urim signifies “ high,” and thumniim“ perfection these answers not being imperfect and ambiguous,like the heathen oracles, but clear and evident. The use made ofthe urim and thumniim was to consult God in difficult cases re-lating to the whole state of Israel ; and sometimes in cases relatingto the king, the sanhedrim, the general of the army, or some othergreat personage.
URINE, a serous and saline fluid, separated from the-blood,and carried by the enmlgent arteries to the kidneys, from whenceit descends to the bladder by the ureters, and is from time to timeemitted thence by the canal of the urethra. See Anatomy. Byanalysis urine lias been found to contain the following substances:1. YVater. 2. Phosphoric acid. 3. Phosphate of lime. 4. Plios-:pliate of magnesia. 5. Carbonic acid. 6. Carbonate of lime. 7.Uric acid. 8. llosacic acid. 9. Benzoic acid. 10. Gelatine andalbumen. 11. Urea. 12. Resin. 13. Muriate of soda. 14.Phosphate of soda. 15. Phosphate of ammonia. 16. Muriate ofammonia. 17. Sulphur. These are the only subsiances whichare constantly found in healthy urine ; but it contains also occa-sionally other substances.
URN was a kind of vase, of a roundish form, hut biggest in themiddle, like the common pitchers, now seldom used hut in theway of ornament over chimney-pieces, in buffets, Sec. The greatuse of urns among the ancients, was to preserve the ashes of thedead after they were burnt; for which reason they were calledcineraria, and urine cineraris, and were placed sometimes underthe tomb-stone whereon the epitaph was cut; and sometimes invaults in their own houses. Urns were also used at their sacrificesto put liquid things in.
URSA, ill astronomy, the name of two constellations in thenorthern hemisphere. See Astronomy.
URSINUS, Zacharias, an eminent Protestant divine, born atBreslaw, in 1534. In 1558, he became president of the academyof Breslaw, whicli place he filled with honour; hut turning Cal-vinist, lie went to Zurich , and was soon after made prolessor ofdivinity at Heidelberg . He next went to Nieustadt, on the in-vitation of Pr. Casimir to fill the same office there. He died in1585.
UHSULINES, in churcli-hisfory, an order of nuns, foundedoriginally by St. Angela of Brescia , in 1537; and so called fromSt. Ursula, to whom they were dedicated.
URSUS, the Bear ; a genus of mammalia of the order ferae.Six fore-teeth in the upper jaw, alternately hollow in the inside,and six in the under jaw, the two lateral ones being lohated ; tuskssolitary, conical; eyes furnished with a nictitating membrane;nose prominent. There are ten species.
U. Americanus, the American Bear , is black; the throatand cheeks a rusty brown. This species is spread through thewhole of America , except Chili and Patagonia. They are alsofound in Kamtschatka . They reject animal-food, even thoughpressed by hunger, eating nothing hut vegetables. They are re-markably fond of potatoes and maize. Dr. Gmelin says, how-ever, that (hey also feed on fish. The head is more lengthenedthan that of the European hear; the ears are longer; the hair ismore smooth and glossy, blacker and softer; the whole body ismuch smaller; the nose is longer and more pointed, and of a yel-lowish or rusty brown colour.
10 C
U. Arctos,