The Chemical Gazette, Volumen5

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Página 95 - ... is, the excess over and above what is necessary to form alkaline or earthy bicarbonates, this excess having the property of slowly decomposing a lather once formed. For this purpose, before measuring out the water for trial, it should be shaken briskly in a stoppered glass bottle...
Página 139 - Hamburg, and asked me whether I could give him a process for effecting this purpose. Now since, as far as I am aware, nothing has been published on this subject, and it is of very general interest, I consider it a duty to communicate the results of my experiments. I had already observed, in experimenting with explosive cotton, flax, &c., that these two substances behave somewhat differently towards concentrated acids; and although it has long been known that strong sulphuric acid converts all vegetable...
Página 306 - ... mere traces of the salt should have collected, washed with the same mixture. The antimony is then precipitated from the solution by sulphuretted hydrogen, and the amount of antimony estimated from the quantity of sulphuret obtained.
Página 137 - ... of sulphur are added ; and then the product resulting from the distillation of 6 oz. prussiate of potash, 3 oz. of the hydrate of sulphuric acid, and 18 oz. water. This mixture is digested in the water-bath until the sulphur is seen to be no longer altered and the liquid has assumed a yellow colour ; it is then heated to boiling, and kept at this temperature until the sulphuret of ammonium has been expelled and the liquid has again become colourless. The deposited, or excess of, sulphur is now...
Página 359 - ... and after being washed and dried is reduced in a platinum or porcelain crucible by hydrogen gas. The fluid filtered from the Superoxide of cobalt is of a pure green colour. It is free from any trace of cobalt. After the removal of the baryta by means of sulphuric acid, the oxide of nickel is precipitated by caustic potash. Even this method did not give exact results on the first trial.
Página 260 - The alloy consists of fifty-six parts of copper, forty and three-quarters of zinc, and three and a quarter of lead ; and, in making the alloy, the patentee uses an additional quantity of zinc, on account of the loss of that material •which occurs during the operation, so as to obtain an alloy containing -the different metals in the above proportions. The lead is said to act a very important part in the alloy, as, without it, the combination of...
Página 359 - A current of chlorine gas is then passed through the solution for several hours : the fluid must be thoroughly saturated with it, and the upper part of the flask above the liquid must remain filled with the gas after the current has ceased. Carbonate of baryta in excess is then added, and the whole allowed to stand for 12 or 18 hours, and frequently agitated. The precipitated...
Página 428 - Ibs. anthracite coal, finely pulverized, are added to each ton of ore containing 10 per cent, of copper. If the ore should be richer in copper, a smaller proportion of salt and lime will suffice, and a greater proportion of anthracite coal will be required. The patentee says he has found that for an ore containing 25 per cent, of copper, 56 Ibs.
Página 366 - ... which I arrived at a good result : A hexagonal or octagonal leaden cylinder is to be prepared, two metres in length, with a diameter of from thirty to forty centimetres. The lead should be from five to eight millimetres in thickness. This cylinder is to be enclosed in a frame made of rod-iron ; to one end of which a crank is to be attached. It is to be placed on a stand, so as to receive with ease a rotary movement. At the centre of the cylinder there is to be an opening or bung-hole through...
Página 140 - If it contained cotton, the cotton threads are found to be wanting in that portion which had been immersed in the acid ; and by counting the threads of the two portions of the sample, its quantity may be very readily estimated. " If the sample has been allowed to remain too long in sulphuric acid, the linen threads likewise become brittle, or even eaten away ; if it were not left a sufficient time in it, only a portion of the cotton threads have been removed : to make this sample useful it must be...

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