manufacturing machinery. The width of the sails, and the distances from each other, must be so regulated as that the wind may strike the sails sufficiently at the same time, so as not to make the angle of the line of the sails with the wind too great. The sails must be made full, so as to form a concave surface to the wind. The machinery for a floating tide, or current mill of great power, is formed similar to that above described, only allowing the lower sails to represent the floats of this, and the water to flow towards the point on which they act. These floats may be of wrought iron, or other materials, and will in general be broader than deep; though, as in the wind-mill, they must form a concave surface to the current, which, if running only one way, the concave side of the float must be so fixed; but, as in the case of tides where the stream Blows both ways, it is made to turn on a pivot in the centre of the frame, above and below. The eats should always be made as deep as the current will admit of, for in this, as in the wind-niill, power is gained without losing time. The drumwheels, chains, and axles and wheels, are the same as for the wind-mill, but as water is a steadier power than wind, the springs are not required for this. The machinery for cattle-mills is on the same principle as for the wind and floating mills, being a connection of planks united by joints, and having at their ends wheels travelling in a channel of the framing round two drum-wheels, to the axle of which is fixed the manufacturing machi nery. The drum may, if preferred, be placed lower than at the head of the horses, so as to cause the cattle to act in part by their gravity, as upon an inclined plane. The cattle drawing from a fixed point, and pulling round the drum-wheels with the machinery by the power of their feet, enables them to work constantly in a straight line, by which means they travel much faster, with greater ease, and performing more work, than by being constrained to tra vel round a circle. The Patentce observes at the con clusion of his specification as follows: "It may be necessary for me to observe that there is a similarity in appearance be tween my plan of working mills by a fall of water, and a method published many years ago by Dr. Desaguhers. Had the doctor's method proved useful for mo derate or small falls, or perfcct for great falls of water, any other plan might have been unnecessary, but the machinery is defective. The friction and obstructions operate too much against the power gained; and though, in very extensive falls, the disadvantages are less in propor tion, they are too great to be of general utility." PROCEEDINGS OF LEARNED SOCIETIES. ROYAL SOCIETY OF LONDON. WE are now to pursue the facts laid before this learned body by Mr. DAVY, Jespecting the metals of the earths, on which he made a variety of experiments, in Lopes of gaining the same distinct evidences of the decomposition of the common carths, as those auorded by the electro-chemical processes on the alkalies, and the alkaline earths. When iron-wire, ignited to whiteness by the power of 1000 double plates, is nega rely electrified and fused in contact with either silex, alumine, or lucine, slightly moistened and placed in hydrogen gas, the iron becomes brittle and whiter, and affords, by solution in acids, an earth of the same kind as that which has been emploved in the experiment. Mr. D. passed potassium in vapour through each of these carthe, heated to whiteness in a flatula tube, and the results were re markable. When silex was employed in the proportion of ten grains to four of potassiom, no gas was evolved, the po tassium was entirely destroyed, and glass, with an excess of alkali, was formed in the lower part of the tube: when this glass was powdered, it exhibited dark specks, having a dull metallic character not unlike the protoxide of iron. When the mixture was thrown into water, there was only a very slight effervescence; but, on the addition of muriatic acid to the water, globules of gas were slowly libe rated, and the effect continued for nearly an hour, so that there is reason to infer that the silcx had been either entirely or partially deoxygenated, and was showiỷ reproduced by the action of the water, assisted by the slight attraction of the acid for the earth. Potassium, in acting upon alumine and glucine, produced more hydrogen than could be ascribed to the moisture quantities of acid and of basis in a neu tral salt. Hence he concludes that barytes contains the least oxygen of all the earths, and silex the largest quantity. According to the most accurate analyses, barytes may be conceived to contain 90-5 of metal per cent.; strontites 86; lime 73.5; magnesia 66: and we are told that the same proportions would follow from Mr. Dalton's theory, viz. that the proportion of oxygen is the same in all protoxides, and that the quantity of acid is the same in all neutral salts; in other words, that every neutral salt is composed of one particle of metal, one of oxygen, and one of acid. M. Berzelius states, that in making an analysis of cast iron, he found that it contained the metal of silex; and that this metal in being oxidated took up nearly half its weight of oxygen. "If," says the professor," the composition of ammonia be calculated upon according to the principle above stated, it ought to consist of fifty-three parts of metallic matter, and forty-seven of oxygen, which agrees very nearly with the quantity of hydrogen and ammonia produced from the amalgam." The earths and metallic oxides were formerly supposed to belong to the same class of bodies, and the earths as calces which they had not found the means of combi ning with phlogiston. Lavoisier insisted on this analogy: still, however, the alka lies, earths, and oxides, have been generally considered as separate natural orders: but, if these be placed in distinct classes, the common metals must be ar ranged under many different divisions, there being as strong grounds for distinct classification in the one case as in the other; and the more the subject is enquired into, the more distinct will the general relations of all metallic substances appear. The alkalies and alkaline earths combine with prussic acid, and form compounds of different degrees of solubility: the case is analogous with solutions of galls: these are precipitated by almost all neutro-saline solutions; and they form compounds more or less soluble in water, more or less coloured, and differently coloured, with all salitable bases. The case is similar in the combina tions of the alkalies and earths with oils, to form soaps; and of the earthy soaps, some are equally insoluble with the me tallic soaps. The oxide of tin, and other oxides abounding in oxygen, approach very near in their general characters to zircon, silex, and alumine; and, in habits of amalgamation, and of alloy, how near The results of the action of the potassium were pyrophoric substances of a dark grey colour, which burnt, throwing off brilliant sparks, and leaving behind alkali and earth, and which hissed violently when thrown upon water, decomposing it with great violence. Mixtures of the earths with potassium, intensely ignited in contact with iron filings, gave distinct results. Whether silex, alumine, or glucine, was used, there was always a fused mass in the centre of the crucible, and this mass had perfect metallic characters; it was in all cases much whiter and harder than iron. In the instance in which silex was used, it broke under the hammer, and exhibited a crystalline texture. The alloys from alumine and glucine were imperfectly malleable. Each afforded, by solution in acids, &c. oxide of iron, alkali, and notable quantities of the earth employed in the experiment. Mr. Davy adds, "Though I could not procure decided evidences of the production of an amalgam from the metals of the common earths, yet I succeeded perfectly by the same method of operating, in making amalgams of the alkaline earths. By passing potassium through lime and magnesia, and then introducing mercury, I obtained solid amalgams, which consisted of potassium, the metal of the earth employed, and mercury. The amalgam from magnesia, was easily deprived of its potassium by the action of water. It then appeared as a solid white metallic mass, which, by exposure to the air, became covered with a dry white powder, and which, when acted upon by weak muriatic acid, gave off hydrogen gas in considerable quantities, and produced a solution of magnesia." Hle conceives that the power of chemical attraction and electrical action may be different exhibitions of the same property of matter, and that oxygen and inflammable bodies are in relations of attraction, which correspond to the function of being negative and positive respectively; and, if this be so, it would follow that the attractions of acids for sulitiable bases would be inversely as the quantity of oxygen that they contain; and, supposing the power of attractions to be measured by the quantity of Lasis which an acid dissolves, it would be easy to infer the quantities of oxygen and metallic matter from the do oxide of irou. do the metals of the alkalies approach to "Should it be established by future researches that hydrogen is a protoxide of ammonium, ammonia a deutoxide, and nitrogen a tritoxide of the same me tal, the theory of chemistry would attain a happy simplicity, and the existing arrangements would harmonize with all the new facts. The class of pure inflammable bases, would be metals capable of alloying with each other, and of combining with protoxides. Some of these bases would be known only in combina tion, those of sulphur, phosphorus, and of the boracic, fluoric, and muriatic acids; but the relations of their compounds would lead to the suspicion of their being metallic. The salitiable bases might be considered either as protoxides, deutox ides, or tritoxides." The tenour of the antiphlogistic doctrines points to such an order, but Mr. Davy suggests another hydrogen be theory: "If," says he, " considered as the principle which gives inflammability, and as the cause of me Re-tallization, then our list of simple substances will include oxygen, hydrogen, and unknown bases only: metals and inflammable solids will be compounds of these bases with hydrogen: the earths, the fixed alkalies, metallic oxides, and the common acids, will be compounds of the same bases with water." The arguments in favour of this theory are as follow: searches on this subject do not appear unworthy of pursuit, and they may possibly tend to improve some of our most important manufactures, and give new instruments to the useful arts." In a theoretical view, Mr. Davy observes, that hydrogen is the body which combines with the largest proportion of oxygen, and yet it forms with it a neutral compound. This, on the hypothesis of electrical energy, would shew that it must be much more highly positive than any other substance; and, therefore, if it be an oxide, it is not likely that it should be deprived of oxygen by any simple che mical attractions. The fact of its forming a substance approaching to an acid, when combined with a metallic substance, tellurium, is opposed to the idea of its being a gaseous metal, and perhaps to the idea that it is simple, or that it exists in its common form in the amalgam of ammonium. Muriatic acid gas is a compound of a body unknown in a separate state, and water. The water cannot be decompounded unless a new combination is formed; but it is decomposed by the metals; and in these cases hydrogen is elicited in a manner similar to that in which one metal is precipitated by ano. ther; the oxygen being found in the new compound. That nitrogen is not a metal in the form of gas is almost de monstrated by the nature of the fusible schistance from ammonia, and the general analogy of chemistry would lead to the motion of its being compounded. 1. The properties which seem to be inherent in certain bodies, and which are either developed or concealed, according to the nature of their combinations: thus, sulphur dissolved in water manifests acid properties; and the same quantity of sulphur, in its simple state, or in combination with hydrogen or oxygen, seems to combine with the same quantity of alkali. 2. The facility with which metallic substances are revived, in cases in which hydrogen is present. 3. Oxygen and hydrogen are bodies that in all cases seem to neutralize each other, and, therefore, in the products of combustion, it might be expected that the natural energies of the bases would be most distinctly displayed, which is the case: and in oxymuriatic acid, the acid energy seems to be blunted by oxygen, and is restored by the addition of bydrogen. The solution of the general question concerning the presence of hydrogen in all inflammable bodies, will be influenced by the decision upon the nature of the amalgam from aminonia; and a matter of so much importance cannot be hasty decided decided on. The difficulty of finding any multiple of the quantity of oxygen which may be supposed to exist in hydrogen, that might be applied to explain the composition of nitrogen from the same basis, is against the simplest view of the subject. "But, still the phlogistic explanation, that the metal of ammonia is merely a compound of hydrogen and nitrogen, or, that a substance which is metallic, can be composed from substances not in their own nature metallic, is equally opposed to the general tenour of our chemical reasonings." Mr. BRANDE has laid before the Society some observations, accompanied with cases and experiments, on the effects of magnesia in preventing an increased formation of the uric acid; with remarks on the composition of urine. Mr. HOME's enquiries into the functions of the sto mach led him to consider that the generality of calculous complaints might possibly be prevented, by introducing into the stomach such substances as are capable of preventing the formation of the uric acid. On putting this theory to the test of experiment, it was found, by an examination of the urine, that, in several instances where there was an increased formation of uric acid, magnesia diminished it in a much greater degree than had been effected by the use of the alkalies. The paper read before the Royal Society contained the result of Mr. Home's and Mr. Brande's labours, with a view to establish a fact of so much importance in the treatinent of those diseases. One case mentioned, is that of a gentleman sixty years of age, who had been in the habit of indulging in the free use of acid liquors, had repeatedly passed small calculi composed entirely of uric acid; his urine at all times deposited a considerable quantity of that substance in the form of red powder, and occasionally in larger crystals. The alkaline medicines were tried, without effect, though continued a year and upwards. The patient was directed to take fifteen grains of magnesia three times a-day, in an infusion of gentian; in a week the uric acid was found to have diminished in quantity, and the use of magnesia being persevered in for eight months, there were during that time no calculi voided, nor any material deposit in the urine. The patient was also much troubled with heart-burn, and with a sense of weight and uneasiness about the region of the stomach, both of which symptoms likewise disappeared. In another case the gentleman had during four years occasionally voided considerable quantities of uric acid in the form of red sand, and had once passed a small calculus. His urine was generally more or less turbid, and after taking any thing which disagreed with the stomach, even in a slight degree, the red sand often made its appearance. He made trial of the alkalies, but without success. He was now directed to take magnesia, in the dose of twenty grains every night and morning, in a little water: for three days his bowels were much relaxed, but they afterwards became regular. He persevered in its use six weeks, and during that period his urine was several times examined, and was found to contain no superabundant uric acid, and he had not the slightest return of his complaint, though he had put himself under no unusual restraint of living. The other cases given in this paper are equally to the point; from which Mr. B. infers that the effects of magnesia taken into the stomach are in many respects different from those produced by alkalies, in those patients in whom there is a disposition to form a superabundant quantity of uric acid. We have now an account of some experiments with soda, magnesia, and lime, to ascertain the effects on healthy urine, when taken under the same circum stances. With respect to the soda, the effect of the alkali upon the urine was at its maximum in a quarter of an hour after it had been taken into the stomach, and in less than two hours, the whole alkali passed off. A similar conclusion was drawn from the experiment where soda with an excess of carbonic acid was used, The experiments on magnesia shew that, even in large doses, it neither produces so rapid an effect upon the urine, nor so copious a separation of the phosphates, as the alkalies; and on this its value as a remedy in calculous disorders seems materially to depend. The lime was found to be of but little use in complaints of this sort. ABSTRACT ABSTRACT OF THE PUBLIC LAWS ENACTED BY THE BRITISH LEGISLATURE. Passed in the 50th Year of the Reign of George III. 1. OR continuing certain duties on malt, sugar, tobacco, and snuff, in Great Britain; and on pensions, offices, and personal estates, in England; for the service of 1810. 2. For raising 10,500,000l. by exchequer bills, for the service of Great Britain for 1810. 3. Ditto 1,500,000l. ditto. 4. To indemnify such persons in the United Kingdom as have omitted to qualify themselves for offices and employ ments, and for extending the times limited for those purposes respectively, until 25th March, 1811; and to permit such persons in Great Britain, as have omitted to make and file atidavits of the execution of indentures of clerks to attornies and solicitors, to make and file the same on or before the first day of Hilary Term, 1811. 5. To prohibit the distillation of spirits from corn or grain in Great Britain, for a limited time; and to continue, until four months after such prohibition, an act of last session of parliament, to suspend the importation of British or Irishmade spirits into Great Britain or Ire land. 6. To enable the Prince of Wales to grant leases of certain lauds and premises called Prince's Meadows, in the parish of Lambeth, in Surrey, for the purpose of building thereon. 7. For punishing mutiny and desertion, and for better payment of the army and their quarters. 8. For settling and securing a certain annuity on Viscount Wellington, and the two next persons to whom the title shall descend, in consideration of his eminent services. 9. To continue, until 25th March, 1811, so much of an Act of the 47th of his present Majesty, as allows a bounty on British plantation raw sugar exported. 10. For making perpetual certain of the provisions of an Act, 5 George I. for preventing clandestine running of uncus tomed goods, and for frauds relating to the customs. 11. To continue, until 25th March, 1815, several laws relating to the encouragement of the Greenland whale fisheries. 12. To continue until 25th March, 1812, an Act, 46 of his present Majesty, for permitting the importation of masts, yards, bowsprits, and timber for naval purposes, from the British colonies in North America, duty free. 13. To continue an Act, 44th of his present Majesty, for permitting the expor tation of salt from the port of Nassau, in the island of New Providence, the port of Exuma, and the port of Crooked Island, in the Bahama Islands, in American ships coming in ballast; and amend and continue an Act, 48th of his present Majesty, for permitting sugar and coffee to be exported from his Majesty's colo nies or plantations to any port in Europe to the southward of Cape Finisterre, and corn to be imported from such port, and from the coast of Africa, into the said colonies and plantations, until 25th March, 1813. 14. For the regulation of his Majesty's Royal Marine forces while on shore. 15. To grant his Majesty duties upori spirits made or distilled in Ireland from corn; to allow drawbacks on exportation thereof; to make further regulations for encouragement of licensed distillers; and for amending laws relating to distillery in Ireland. 16. For further continuing, until 25th March, 1811, an Act, 41st of his present Majesty, for prohibiting exportation from, and permitting the importation into, Ireland, duty free, of corn and other pro visions. 17. To continue until 25th March, 1811, an Act for regulating drawbacks and bounties on exportation of sugar from Ireland. 18. For further continuing, until 25th March, 1811, bounties and drawbacks on exportation of sugar from Great Bri tain; and for suspending countervailing duties and bounties on sugar when the duties imposed by an Act, 46th of lus present Majesty, shall be suspended. 19. For further continuing, until 25th March, 1811, an Act, 39th of his present Majesty, for prohibiting exportation from, and permitting importation to, Great Britain of corn, and for allowing importation of other articles of provision, without payment of duty. 20. |