Practical physics

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1894 Excerpt: ...or, still better, by being thickened and ground as a stopper. A glance at the figure will shew the arrangement. The drying tubes can then be removed and replaced with facility, and a perfectly airtight connection is ensured. The space in the little cups, M, M, M, M, between the narrow tubes and the limbs of the inverted U's is closed by mercury. Care must be taken to close the ends of the inverted U's with small bungs during weighing, and to see that no globules of mercury are adhering to the glass. The connecting tubes c between the drying tubes should be of glass and as short as possible. Two drying tubes must be used, and weighed separately before and after the experiment; the first will, when in good order, entirely absorb the moisture, but if the air is passed with too great rapidity, or if the acid has become too dilute by continued use, the second tube will make the fact apparent A thermometer, x, to determine the temperature of the air passing into the tubes is also necessary. To take an observation, the tubes are weighed and placed in position, the vessel A filled with water, the syphon tube filled, and the tube at the end of the drying tubes closed by means of a pinch-tap. Then, on opening the tap at T, no water should flow out; if any does therei is some leak in the apparatus which must be made tighL before proceeding further. When assured that any air supplied to the aspirator will pass through the drying tubes, the observation may be begun. The water is run out slowly (at about the rate of 1 litre in ten minutes) into a litre flask, and when the latter is filled up to the scratch on the neck it is removed and weighed, its place being taken by another flask, which can go on filling during the weighing of the first This is repeated until the aspi...