No one has had a better opportunity to show how easy it is to convert the juice of the grape into sparkling wine through a series of simple operations whose details are known and accurately determined, so we believe it our duty to recommend those of our readers who are particularly interested in this subject to read Mr. Salleron’s book on sparkling wine.  We shall confine ourselves in this article to a description of two of the apparatus invented by the author for testing the resistance of bottles and cork stoppers.

It is well, in the first place, to say that one of the important elements in the treatment of sparkling wine is the normal pressure that it is to produce in the bottles.  After judicious deductions and numerous experiments, Mr. Salleron has adopted for the normal pressure of highly sparkling wines five atmospheres at the temperature of the cellar, which does not exceed 10 degrees.  But, in a defective cellar, the bottles may be exposed to frost in winter and to a temperature of 25 deg. in summer, corresponding to a tension of ten atmospheres.  It may naturally be asked whether bottles will withstand such an ordeal.  Mr. Salleron has determined their resistance through the process by which we estimate that of building materials, viz., by measuring the limit of their elasticity, or, in other words, the pressure under which they take on a new permanent volume.  In fact, glass must be assimilated to a perfectly elastic body; and bottles expand under the internal pressure that they support.  If their resistance is insufficient, they continue to increase in measure as the pressure is further prolonged, and at every increase in permanent capacity, their resistance diminishes.

[Illustration:  Fig. 1.—­MACHINE FOR TESTING BOTTLES.]

The apparatus shown in Fig. 1 is called an elasticimeter, and permits of a preliminary testing of bottles.  The bottle to be tested is put into the receptacle, A B, which is kept full of water, and when it has become full, its neck is played between the jaws of the clamp, p.  Upon turning the hand wheel, L, the bottle and the receptacle that holds it are lifted, and the mouth of the bottle presses against a rubber disk fixed under the support, C D. The pressure of the neck of the bottle against this disk is such that the closing is absolutely hermetical.  The support, C D, contains an aperture which allows the interior of the bottle to communicate with a glass tube, a b, which thus forms a prolongation of the neck of the bottle.  This tube is very narrow and is divided into fiftieths of a cubic centimeter.  A microscope, m, fixed in front of the tube, magnifies the divisions, and allows the position of the level of the water to be ascertained to within about a millionth of a cubic centimeter.

A force and suction pump, P, sucks in air through the tube, t, and compresses it through the tube, t’, in the copper tube, T, which communicates with the glass tube, a b, after passing through the pressure gauge, M. This pump, then, compresses the air in the bottle, and the gauge accurately measures its pressure.