UNSTOPPERING.—This operation is much more likely to be required than the one last described, for the stoppers of decanters, smelling-bottles, &c., from various causes, frequently become fixed, and many are the fractures both of bottles and stoppers, caused by the misdirected efforts to remove them. In treating of the various means that may be employed, we will mention them in the order in which they should be tried, beginning with the simpler and more easy, and passing on to those which are more effectual, and at the same time, unfortunately, more dangerous. The first method, then, that should be tried, is to press the stopper upwards with the fore-finger and thumb of the left hand (the other fingers holding the neck of the bottle), and at the same time giving the stopper a succession of short, sharp, light taps, with the wooden handle of a chisel, knife, or small hammer; care must be taken not to strike the stopper with sufficient force to break it, and it should be borne in mind that it is not the force of the blow, but the vibration, or jar, which is effectual in loosening it; should this plan be found ineffectual after a short trial, it may probably be from the stopper being cemented by some substance, such as the dried sugar of a sweet wine. In such cases we should endeavour to dissolve the cement by a suitable solvent, which should be placed in the groove between the stopper and the bottle; thus, if the stopper is cemented with sugar, gum, or salt, water may be used; in many circumstances, oil is advantageous, or spirit, or even strong acid may be used; whatever liquid is employed it should be allowed to remain some days, being renewed if requisite, and the tapping, &c., should be again had recourse to. Should these methods fail, a piece of cloth may be dipped in very hot water and wrapped round the neck of the bottle, when the heat causes the expansion of the glass, and if the stopper be tapped or twisted _before_ the heat has had time to enlarge it, its removal may be effected; this operation must necessarily be a quick one, for if the stopper is heated and enlarged, as well as the bottle, it is obvious that no benefit will result. In the laboratory it is often customary to heat the bottle, not by a strip of cloth dipped in hot water, but by turning it rapidly over the flame of a lamp; in this way there is more danger of cracking the bottle, and the plan is not to be recommended in general, although employed with considerable success by those who, like operative chemists, are constantly in the habit of applying heat to glass vessels; it will at once be seen that the plan is fraught with great danger if applied to bottles containing inflammable liquids, as spirits, &c. [Illustration: _Fig. 6._]