Several kinds of liquid having been poured into a vessel through one mouth, it is required that through the same pipe they shall flow out separately at pleasure. Let A B (fig. 22) be a vessel closed at the neck by the partition C D; and let there be in it several vertical partitions, extending to the partition C D and making as many chambers as we wish to pour in liquids. Suppose, for the present, that these are two in number, and let the partition be E F. In the partition C D pierce fine holes, as in a sieve, opening into each chamber, and air holes, G, H, close to the partition, also opening into the chambers: again, at the bottom let there be small tubes, K, L, communicating with the chambers and opening into the common pipe M. If, having first closed the vents G, H, and the pipe M, we pour one of the liquids through the mouth of the vessel, it will enter into neither chamber, as the air has no means of escape: but if one of the vents be opened, the liquid will pass into that chamber to which the vent belongs; and if, after closing this vent again, we pour in the other liquid and set free the other vent, the liquid will pass into the other chamber. Now let all the vents and the sieve-like holes be closed, and, on opening the pipe M, no discharge can take place until one of the vents be opened; when, the air having found an entrance, the liquid contained in that chamber will flow out. If this vent be closed and the other opened, the same result will follow. 23. _A Flow of Wine from one Vessel, produced by Water being poured into another._ [Illustration: Diagram of apparatus as described in text] If of two vessels standing on a pedestal one be full of wine and the other empty, whatever quantity of water be poured into the empty vessel, as much wine shall flow from the other. The following is the construction. On any pedestal, A B (fig. 23) let there be two vessels, C D, E F, having their mouths closed by the partitions G H, K L. Let the tube M N X O pass through the pedestal and bend upwards into the vessels, reaching very nearly to the partitions at M and O. In E F place a bent siphon, P R S, the bend being near the vessel’s mouth, and one leg, shaped like a water-pipe, passing outside. Through the partition G H let a funnel, T U, descend almost to the bottom of the vessel, its tube being soldered into the partition. Into the vessel E F pour wine through a hole, Q, which must afterwards be carefully closed again. Now, if we pour water into the vessel C D through the funnel, the contained air will be forced out, and pass through the tube M N X O into E F, and, in its turn, force out the wine contained in E F: and this will happen as often as we pour in the water. It is evident that the air forced out has an equal bulk with the water poured in, and that it will force out as much wine. If no bent siphon be used, but merely a pipe at S, the effect will be the same, unless the force of the water be too great for the pipe.