URIC ACID URINE. 



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aually, from Switzerland to Italy. The road over 

 the Simplon is now generally preferred. Uri fur- 

 nishes 602 men to the army of the confederacy. Its 

 quota of money is 3012 Swiss francs. 



URIC ACID. See Urine. 



URIM AND THUMMIM (light and perfection) ; 

 a kind of ornament belonging to the habit of the 

 Jewish high-priest, by means of which he gave ora- 

 cular answers to the people. What they were, and 

 the mode in which the divine will was communi- 

 cated to the high-priest by means of them, is dis- 

 puted among the critics. 



URINE is an excrementitious fluid, designed for 

 ejecting from the system substances which, by their 

 accumulation within the body, would prove fatal to 

 health and life. It is secreted by the kidneys, 

 whose sole office it appears to be to separate from 

 the blood the superfluous matters that are not re- 

 quired for nutrition, or which have already formed 

 part of the body, and been removed by absorption. 

 The substances, which, in particular pass off by this 

 way, are nitrogen and various saline and earthy 

 compounds. In its natural state, it is transparent, 

 of a yellow colour, a peculiar smell, and saline taste. 

 Its quantity, and, in some measure, its quality, de- 

 pend on the seasons and the peculiar constitution of 

 the individual, and are likewise modified by disease. 

 It k observed, that perspiration carries off more or 

 less of the fluid which would else have passed off 

 by urine ; so that the profusion of the former is at- 

 tended with the diminution of the latter. The spe- 

 cific gravity of the most concentrated urine is 1-030. 

 It gives a red tint to litmus paper a circumstance 

 which indicates the presence of a free acid, or of a 

 supersalt. Though at first quite transparent, an 

 insoluble matter is deposited on standing ; so that 

 urine voided at night is found to have a light cloud 

 floating in it by the following morning. This sub- 

 stance consists in part of mucus, and partly super- 

 urate of ammonia, which is much more soluble in 

 warm than in cold water. Urine is prone to spon- 

 taneous decomposition. When kept for two or 

 three days, it acquires a strong smell ; and as the 

 putrefaction proceeds, the disagreeable odour in- 

 creases, until at length it becomes exceedingly of- 

 fensive. As soon as these changes commence, the 

 urine ceases to have an acid reaction, and the earthy 

 phosphates are deposited. In a short time, a free 

 alkali makes its appearance, and a large quantity of 

 carbonate of ammonia is gradually generated. Simi- 

 lar changes may be produced in recent urine, by 

 continued boiling. In both cases the phenomena 

 are owing to the decomposition of urea. This 

 principle is procured by evaporating fresh urine to 

 the consistence of a sirup, and then gradually add- 

 ing to it pure concentrated nitric acid, till the whole 

 becomes a dark-coloured crystallized mass, which is 

 to be repeatedly washed with ice-cold water.andthen 

 dried by pressure between folds of bibulous paper. 

 To the nitrate of urea thus procured, a pretty 

 strong solution of carbonate of potash or soda is 

 added, until the acid is neutralized ; and the solution 

 is afterwards concentrated by evaporation, and set 

 aside, in order that the nitre may separate in crys- 

 tals. The residual liquor, on evaporation and reso- 

 lution in alcohol, deposits transparent and colour- 

 less crystals of urea. It leaves a sensation of cold- 

 ness on the tongue, like nitre, and its smell is faint 

 and peculiar, but not urinous ; specific gravity 

 1-35 ; it fuses at 248 Fahr., and, at a rather higher 

 temperature, is resolved into carbonate of ammonia 

 and cyanic acid : water dissolves, at 60, more than 



its own weight of urea, and boiling water takes up 

 an unlimited quantity. The numerous researches 

 made concerning urine have given the following as 

 its component parts: 1. water; 2. urea; 3. phos- 

 phoric acid ; 4, 5, 6, 7. phosphates of lime, magne- 

 sia, soda, and ammonia; 8, 9, 10, 11. lithic, rosa- 

 cic, benzoic, and carbonic acid ; 12, carbonate ot 

 lime ; 13, 14. muriates of soda and ammonia ; 15. 

 gelatin; 16. albumen; 17. resin; 18. sulphur. 

 According to Berzelius, healthy urine is composed 

 of water 933, urea, 30-10, sulphate of potash, 3-71, 

 sulphate of soda 3-16, phosphate of soda 2-94, mu- 

 riate of soda 4-45, phosphate of ammonia 1-65, 

 muriate of ammonia 1-50, free acetic acid, with 

 lactate of ammonia, animal matter soluble in 

 alcohol, and urea, 17'14, earthy phosphates with 

 with a trace of fluate of lime 1-0, uric acid 1, mu- 

 cus 0-32, silex 0-3, in 1000-0. The uric add is a 

 constant ingredient in urine : when pure, it has the 

 following properties : it is sometimes in the state 

 of a white impalpable powder, sometimes in small 

 four-sided prisms, having considerable lustre. It is 

 very tasteless, very white, light, and insoluble both 

 in water and alcohol. In concentrated sulphuric 

 acid, it speedily assumes the form of a jelly, and 

 with the aid of a little heat, a complete solution is 

 obtained. In nitric acid, even though dilute, it dis- 

 solves with effervescence ; and when the solution is 

 evaporated to dryness, it assumes a fine pink colour, 

 which becomes much deeper when water is added, 

 so as to have a near resemblance to carmine. In this 

 state it stains wood, the skin, &c., of a beautiful 

 red colour. The watery solution of this matter 

 loses its red colour in a few hours and it cannot af- 

 terwards be restored. Uric acid combines with the 

 different bases, and forms a genus of salts called 

 urates. The only ones of importance are the urates 

 of ammonia, potash and soda. Urate of ammonia is 

 soluble, to a considerable extent, in boiling, but 

 more sparingly in cold water. The urates of soda and 

 potash, if neutral, are of very feeble solubility; but 

 an excess of either alkali takes up a large quantity of 

 the acid. When uric acid is heated in a retort, car- 

 bonate and hydrocyanate of ammonia are generated, 

 and a volatile acid sublimes, called pyro-uric acid, 

 which is believed to be identical with cyanate acid. 

 Such is a general view of the composition of human 

 urine in its healthy state. But this fluid is subject 

 to a great variety of morbid conditions, which arise 

 from the deficiency or excess of certain principles 

 which it ought to contain, or from the presence or 

 others wholly foreign to its composition. Of those 

 substances which, though naturally wanting, are 

 sometimes contained in the urine, the most remark- 

 able is sugar, which is secreted by the kidneys, in 

 diabetes. Diabetic urine has a sweet taste, and yields 

 a syrup by evaporation, is almost always of a pale 

 straw colour, and in general, has a greater specific 

 gravity than ordinary urine. The sugar when pro- 

 perly purified, appears identical, both in properties 

 and composition, with vegetable sugar, approaching 

 nearer to the sugar of grapes than that of the sugar 

 cane. The acidifying process which is constantly 

 going forward in the kidneys, as evinced by the for- 

 mation of sulphuric, phosphoric and uric acids, 

 sometimes proceeds to a morbid extent, in conse- 

 quence of which, two acids, the oxalic and nitric, 

 are generated ; neither of which exists in healthy 

 urine. The former, by uniting with lime, gives 

 rise to one of the worst kinds of urinary concre- 

 tions ; and the latter appears to lead to the forma- 

 tion of purpurate of ammonia, by reacting on uric 



