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mes so concent ated as to corrode the surface, and make it appea speckled.  To se} arate gold from gitt, copper and silver. App y a solution of borax, in water, to the gilt surface, with a fine brush, and sprinkle over it some fine powdered sulphur. Make the piece red hot, and quench it in water. The gold may be easily wiped off with a scratch-brush, and recovered by testing it with lead.  Gold is taken from the surface of silver by spreading over it a paste, made of powdered sal ammoniac, with aqua fortts, and heating it till the mutter smokes, and is nearly dry; when the gold may be separated by rubbing it with a scratch brush. To tin copper and braes. Boil six pounds of cream of tartar, four gallons of water, and eight pounds of grain tin, or tin shavings. After the materials have boiled a sufficient time, the substance to be tinned is put therein, and the boiling continued, when the tin is precipitated in its metallic form.  To tin iron or copper vessels. -Iron which is x be tinned must be previously  steeped in acid materials, such as sour whey, dls tillers' wash, etc.; then scoured, and dipped in melt ed tin, having been first rubbed over with a solution of sal amCheap Beats By Dre moniac. The surface of the tin is prevented from calcining, by covering it witn a coal of fat. Uop|ler vessels must be well cleansed; and then a sufficient quantity of tin with salhttp://www.cheap-beatsbydressale.com/ . ammoniac is put therein, and brought into fusion, and the copper vessel moved about. A little resCheap Dre Beats Headphones in is sometimes added. The sal ammoniac prevents the cop per from scaling, and causes the tin to be fixed wherever it touches. Lately, zinc has been proposed for lining vessels instead of tin, to avoid the ill consequences which have been unjustly apprehended.  To prepare the leaden tree. Put \ an ounce of the super-acetate of lead in powder, into a clear glass globe or wine decanter, filled to the bottom of the neck with distilled water, and 10 drops of nitric acid, and shake the mixture well. Prepare a rod of zinc with a hammer and file, so that it may be a quarter of an inch thick, and one inch long; at the same time form notches in each aide for a thread, by which it is to be suspended, and tie the thread so thaCheap Beats By Dr Dre t the knot shall be uppermost, when the metal hangs quite perpendicular. When it is tied, pass the two ends of the thread through a perforation in the cork, and let them be again tied over a small splinter of wood which may pass between them and the cork. When the string is tied, let the lDiscount Beats By Dre ength between the cork and the zinc be such that the precipitant (the zinc) may be at equal distances from the sides, bottom, and top, of the vessel, when immersed in it When all things arc- thus prepared, place the ves•sel in a place where it may not be disturbed, and introduce the zinc, at the same time fitting in the cork. The metal will very soon be covered with the lead, which it precipitates from the solution, and this will continue to take place until the whole be precipitated upon the zinc, which will assume the form of a tree or bush, whose leaves and branches are luminal, or plates of a metallic lustre.  To prepare the tin tree. Into the same, or a similar vessel to that used is the last experiment, pour distilled water as before, and put in three drachms of muriate of tin, adding ten drops of nitric acid, and shake the vessel until the salt be completely dissolved. Reprace the zinc (which must be cleared from the effects of the former experiment,) as before, and set the whole aside to precipitate without disturbance. In a few hours, the effect will be similar to the last, only that the tree of tin will have more lustre. In these experiments, it is surprising to observe the lamina shoot out as it were from nothing; but this phenomenon seems to proceed from a galvanic action ot the metals and the water.  To prepare the silver tree. Pour into a glass globe or decanter, 4 drachma of nitrate of silver, dissolved in a pound or more of distilled water, and lay the vessel on the chimney piece, or iv some place where it may not be disturbed.