Congressional Serial Set Volume 5753 (Paperback)

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. 1910 Excerpt: ...made from three test tubes. The test tube A is changed in no way from its original form; B is perforated in the bottom with a hole about 1 cm. in diameter and fits tightly within A; and C, Bo selected that it fits loosely within B, is drawn out to a email capillary tube. When the apparatus is to be used, the capillary of 0 is pushed through the hole of B, packed loosely with cotton; B is filled to the depth of from C to 8 cm. (about two-thirds of its contents) with granular calcium chloride, and B and C are adjusted as shown. To the test tube, C, is fitted a one-hole stopper, through which passes a short glass tube which is closed by a rubber cap and plug. Upon removing the plug and applying suction to the short tube the reagent employed to liberate the volatile product to be determined is drawn up through this capillary until C is sufficiently filled. Upon replacing the plug the reagent remains within C, held by atmospheric pressure. The tubes A and B may be so selected that very little of the product evolved can escape between them, but in case they fit very loosely a ring of paraffin melted into the mouth of A, about B, by means of a hot iron or wire, seals the joint securely. A very convenient way to attach the paraffin is to melt it between A and another tube, which fits A as does B and may be removed by a turning motion, leaving the ring into which B will fit, and which then requires very little heating to make a tight joint. If care be used in taking apart A and B at the close of an experiment, such a ring of paraffin remains in place and may be used many times without replacement, being remelted by a touch of the hot wire before every new experiment. In making the determination the substance under examination is weighed and placed in the bottom of A...