It is also of great use to housekeepers, sailors, and others, and for cleane ing cloth, to clean woollen clothes from grease, tar, &c.; and will be found advantageous for many other purposes. If it should meet with the approbation of the Society, I have no objection to prepare it for sale, 1 am, Sir, Your obedient Servant, RICHARD CATHERY, Process for preparing Ox-Gall in a concentrated state, by by Mr. Cathery. Take a gall fresh from the ox, and put it into a basin, let Method of preit stand all night to settle, then pour it off from the sediment paring it. ̧ into a clean earthen mug, and set it in a saucepan of boiling water over the fire, taking care that none of the water gets to artists. Certificates were received from Mr. Gabriel Bayfield, No. Testimonies of 9, Park Place, Walworth; and Mr. William Edwards, No its usefulness 9, Poplar Row; both botanical colourers; stating, that they have used the ox-gall prepared by Mr. Cathery, and find it to answer better than gall in a liquid state; that this preparation is free from disagreeable smell, and is much cheaper, as one ox-gall thus prepared will last one person for two years, and he as fresh as if just taken from the ox. A Certificate was received from Mr. James Stewart, No, and at sea, 26, St. Martin's Street, Leicester Square, stating, at be lately belonged to his Majesty's ship the Vestal frigate, and that he took out with him, in a voyage to Newfoundland, a large pot of the prepared ox-gall, for the purpose of wash ing his greasy clothes for two years; that he found it very serviceable, and to keep its virtue as well as the first day. *Gall will keep some time, if merely boiled so as to separate the 'bu minous part, agreeably to the directions of Mr. J. Clark, or professor Proust. See Journal, vol. XVII, p. 341. C. XVIII. Arbor Diana which it is formed. XVIII. Letter from Mr. VITALIS, Professor of Chemistry at Rouen, to Mr. Bouillon-Lagrange, on the Amalgam of Mercury and Silver called Arbor Dianæ®. THE process mentioned by Baume, which is generally capable of be followed for obtaining the peculiar amalgam of mercury and ing taken out of the vessel in silver, known in chemistry by the name of arbor Dianæ, is not the only one capable of affording those beautiful crystalline figures, that distinguish this curious production. I have obtained the same object by an alteration in the common method, that enables me very easily to remove the metallic arborization from the liquid in which it is formed, and thus to keep it in another vessel unaltered. Process, Method of removing it. Probably the different, The process is very simple. In the nitric solutions of mercury and silver, both fully saturated, and diluted with the quantity of water directed by Baumé, I suspend 5 or 6 drachms of very pure mercury, tied up in a piece of fine linen doubled. The metallic solutions soon penetrate to the mercury enclosed in the cloth; and we presently perceive clusters of beautiful needles forming round it, and adhering to the nucleus of mercury. These needles gradually increase in bulk, and in a short time extend above an inch in length. When the metallic arborization ceases to increase, the bag loaded with beautiful needly prisms, which appear to me to be tetraedral, is to be taken out; and, by means of the silk thread, with which it was tied up, fastened to a cork. The whole is then to be suspended under a small glass jar, in the midst of which the metallic crystals may be preserved as long as we please. I have a crystallization of this kind in my laboratory, which has retained all its beauty these two years. The solidity of the metallic crystals obtained by my meproportions of thod, compared with the weakness of the threads that form the amalgam the common arbor Dianæ, lead me to suppose, that the proportions of mercury and silver are not the same in the two cases; and I would have endeavoured to ascertain the difference, if Mr. Vauquelin, to whom I have communicated the fact, had not undertaken, to remove every doubt on this head by a comparative analysis. Annales de Chim. Vol. LXII, p. 93. The -The different configurations of the crystals too may give as are the rise to some interesting researches, which I have not yet had shapes of the time to pursue. crystals. SCIENTIFIC NEWS. MR. Heinekin having exposed a solution of very pure Solution of atic acid form ed? carbonate of potash to the action of the galvanic pile, found, carbonate of potash decomthat in three or four days the liquid next the negative pole posed by galvahad acquired a golden yellow colour; and a very decided nism, smell of oximuriatic acid was perceptible. With the ni- and oximuritrates of silver and of mercury the yellow liquid formed a grumous precipitate; and it completely destroyed the colour of litmus blue, and of ink. The liquid next the positive pole was highly caustic. The conclusions he draws are, that potash and oximuriatic acid are composed of the same principles, or of carbon, hidrogen, and oxigen in different proportions. may be It is a circumstance not a little remarkable, that Mr. Opinion of Curandau and Dr. Davy were led to form similar notions Mr Curaudau on the simple of the oximuriatic acid about the same time at Paris and nature of oxiLondon. From the circumstances of the times it muriatic gas. presumed, that there could be no communication between them; but it is probable, that, though the merit of discovery is equally due to both these gentlemen, if it be not a fallacy as some suppose, the priority rests with Mr. Curaudau, as his paper was read to the French Institute on the 5th of March, 1810. union with The following is one of the experiments, on which Mr. Oximuriatic Curaudau founds his opinion. By combining oximuriatic gas forms a gas directly with nitrate of silver a precipitate is formed, metallic silver, without any oxigen being disengaged; and, as the weight of the precipitate thrown down is proportional to that of the gas employed, he infers, that it is a compound of the muriatic radical and silver. He infers farther, that in this process the hidrogen of the acid disoxidates the silver; and the silver thus disoxidated enters directly into combination with the muriatic radical, so as to form a muriuret of silver. Hence we see, why potash in the humid way, and carbon in the the dry, will not decompose this salt: and why, on the other hand, hidrogen so easily effects the reduction of the metal. and with 0-03 The proportions assigned by Mr. Curaudau to the muriatic acid are one part of hidrogen to thirty-three of oximuriatic of hidrogen tomp ses muriatic acid. Three meteoric stunes. Circumstances of their fall. The stones docribed. gas. On the 23d of November, 1810, at half after one in the afternoon, three atmospheric stones fell in the commune of Charsouville, canton of Meung, department of the Loiret. Their fall was accompanied by a series of detonations, which preceded it, and lasted some minutes. The sound of the explosions, to the number of three or four, followed by a rumbling noise occasioned by the echoes, was heard as loud at Orleans as at the place where the stones fell. It is said it was equally loud at Montargis, Salbri, Vierzon, and Blois, at all which places it excited alarm, being supposed to arise from the blowing up of a powder magazine. The explosions must therefore have taken place at a great height. The fall of these stones was perpendicular; and without the appearance of any light, or ball of fire. One fell at Montelle but has not been found. The other two fell one at Villenai, the other at Moulin Brûlé. All these places are within the distance of a mile. One of the stones weighed about twenty pounds; it made a hole in the ground just large enough for its admission, in a perpendicular direction, driving up the earth to the height of eight or ten feet. The stone was taken out half an hour afterward, when it was still so hot, that it could scarcely be held in the hands. It had a strong sinell of gunpowder, which it retained till it was quite cold. The second stone formed a similar hole three feet deep. It weighed forty pounds, and was not taken out of the ground for eighteen hours after its full, when it was without heat. These stones were both shapeless masses, irregularly rounded at all their angles. They contain rather more ferrugmous globules, than those that fell at l'Aigle, in Nor mandy; these globales are somewhat larger; and the colour of the stone, when broken, is lighter. They are quickly oxided, very heavy, sufficiently hard to scratch glass, broken with difficulty, and the fracture is irregular and and very fine grained. The external crust is a quarter of a line thick, and of a blackish gray colour. The substance of the stone is marked with a few black lines, irregular, very distinct, and from half a line to two lines broad. They traverse it indiscriminately in all directions, like the veins of certain marbles. Does not this seem to indicate, that they existed previous to their fall, and were formed in the same manner as rocks, and not in the atmosphere? The day when these stones fell was remarkably calm and serene; the sun shone as bright as in one of the finest days of autumn; and not a cloud appeared above the horizon. East Indies & C Directions for sailing to and from the East Indies, China, Directions for New Holland, Cape of Good Hope, and the interjacent sailing to the parts, compiled chiefly from Original Journals at the East India House, and from Journals and Observations made during Twenty-one Years Experience navigating in those Seas; by James Horsburg, F. R. S. Part I, published 1809, quarto, 389 full pages with side notes, contents, and a copious index.-Part II, corresponding size and type, 506 pages, just published. Sold by Black, Parry, and Kingsbury. This valuable publication cannot fail to be of great utility to British navigators, who trade to the southward of the equator, as well as those belonging to his Majesty's navy. Exclusive of sailing directions and local descriptions of winds, weather, currents, ports, headlands, islands, coasts, dangers, &c., the geographical situations of all the particular headlands, islands, ports, and dangers, are stated from actual observations of sun, moon, and stars, or by good chronometers. The necessity of a work of this nature has long been known to navigators; as, former directories having been compiled from a mass of heterogeneous and very inco rect materials, obtained when ships were navigated by dead reckoning, prior to the application of marine chronometers and lunar observations to nautical science; and these directories, for the greater part, having been generally transcribed from each other for nearly a century up to the present time: they are constantly fraught with errour, and of little use in the present improved state of navigation. Upon |