The water in urine voided daily amounts to about 1·866lbs. The blood contains no acid except a little muriatic. But in urine we find sulphuric, phosphoric, and uric acids, and sometimes oxalic and nitric acids, and perhaps also some others. The quantity of sulphuric acid may be about forty-eight grains daily, containing nineteen grains of sulphur. The phosphoric acid about thirty-three grains, containing about fourteen grains of phosphorus. The uric acid may amount to fourteen grains. These acids are in combination with potash, or soda, or ammonia, and also with a very little lime and magnesia. The common salt evacuated daily in the urine amounts to about sixty-two grains. The urea, a peculiar substance found only in the urine, amounts perhaps to as much as 420 grains. It would appear from these facts that the kidneys possess the property of converting the sulphur and phosphorus, which are known to exist in the blood, into acids, and likewise of forming other acids and urea. The quantity of water thrown out of the system by the urine and lungs is scarcely equal to the amount of liquid daily consumed along with the food. But there is another organ which has been ascertained to throw out likewise a considerable quantity of moisture, this organ is the skin; and the process is called _perspiration_. From the experiments of Lavoisier and Seguin it appears that the quantity of moisture given out daily by the skin amounts to 54·89 ounces: this added to the quantity evolved from the lungs and the urine considerably exceeds the weight of liquid taken with the food, and leaves no doubt that water as well as carbonic acid must be formed in the lungs during respiration. Such is an imperfect sketch of the present state of that department of physiology which is most intimately connected with Chemistry. It is amply sufficient, short as it is, to satisfy the most careless observer how little progress has hitherto been made in these investigations; and what an extensive field remains yet to be traversed by future observers. THE END. C. WHITING, BEAUFORT HOUSE, STRAND. POPULAR NOVELS, JUST PUBLISHED BY HENRY COLBURN AND RICHARD BENTLEY, NEW BURLINGTON STREET. I. PHILIP AUGUSTUS. By the Author of "De L'Orme," "Darnley," &c. 3 vols. post 8vo. II. JACQUELINE OF HOLLAND. By the Author of "The Heiress of Bruges," "Highways and Byways," &c. In 3 vols. post 8vo. III. COMPANION TO LAWRIE TODD. BOGLE CORBET; OR, THE EMIGRANTS. By the Author of "Lawrie Todd," &c. 3 vols. post 8vo. IV. THE YOUNG DUKE. By the Author of "Vivian Grey." 3 vols. post 8vo. V. MOTHERS AND DAUGHTERS. A TALE OF THE YEAR 1830. 3 vols. post 8vo. "The best novel of the season--a faithful, exact, and spirited picture of the Aristocracy of this country."--SPECTATOR. VI. WEDDED LIFE IN THE UPPER RANKS.