The Philosophical Magazine (Volume 26) - Softcover

Book may have numerous typos, missing text, images, or index. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. 1807. Excerpt: ... and which has much resemblance to that of burnt onions, M. Antoine, however, compares it to the odour of caramel, The alkalis form with it soluble' salts, and that of soda, among others, of a fresh savour, slightly bitter, and which; leaves in the mouth a taste like that of green nuts. Barytes. strontian, or lime; united to this acid give very insoluble salts, susceptible of solution in an excess of acid, but difficultly: a,ll of them present themselves tmder the form of flakes more or less light. It possesses the remarkable property of decomposing, in general, all the earthyacetates without having recourse to double affinities : it also decomposes several metallic solutions, and in a remarkable manner those of iron, which it precipitates white though at the maximum ; those of copper it precipitates of a blueish green, The acetate of lead is also precipitated in white flakes, which are insoluble in vinegar. • If in place of employing this free acid we take one of its alkaline combinations, precipitates are obtained, in the solutions, of aluminous and magnesian salts; but it is necessary that the latter be very much concentrated, without which the precipitates, are redissolved immediately. [To be contipued.] VIII. Description of an improved Air-Pump, By T. Sylvester, Esq. To Mr. Tilloch. Kjke of the principal causes of the imperfections in th,e air-pump arises from the difficulty in opening the valves at the bottom of the barrels, which imperfection was thought to have been remedied by the introduction of stop-cocks ; but experience shows that, however accurate they may be when new, after a little use they became faulty. I here send you a description of an air-pump, which I lately executed, without either valves or stop-cock, I have supplied their place by a slide, which is shi...