(a) The following arrangement of siphon is little known, though used at various times, and for various purposes, the last 20 years. It simply consists in having the ends of an equal legged siphon bent up as in Fig. 272. When the above is once charged, and the openings kept level, it will draw the liquid from a vessel, stopping, of course, when the level of the liquid reaches that of the openings, but start into action again if the level of liquid rises. Chemical readers will find a glass tube, bent as above, very handy in the laboratory for decanting, as, when not in use, it can be hung ready charged on a nail against the wall. The principle may be applied to a couple of rain water-butts, with the object of not cutting the casks in any way below the water-line, obviating oozing and dropping - the common complaint about the connection of water-butts. It answers very well. Fig. 273 is the arrangement. Put a long turn-up on the overflow siphon - about 9 in. - so that evaporation can take place to some extent without interfering with the stability of the water in the pipe.
For charging the two long siphons, have a small gas tap soldered on the top of each, through which to suck out the air, after which screw up the little nut or plug of taps very tight, so that they cannot be opened by meddlesome fingers. The overflow may be charged in a tub of water, and afterwards adjusted on edge of cask, so as to keep the level about 1 in. from top when raining heaviest. The siphon for laboratory use above mentioned could be improved by making one of the legs straight, and fixing it to a piece of rubber tube with a pinch tap. Arranged thus it could be carried about without fear of up-5 setting the balance of the water in the two legs.
(6) The numerous experiments in disinfecting with sulphurous anhydride have shown that the chief difficulty in the way of various applications of it re* side in the imperfection of the apparatus designed for holding and distributing this liquefied gas under strong pressure. As this agent is called upon to render great services in a host of cases in which the sulphurous acid produced by the direct combustion of sulphur, and without pressure, cannot be used, it is of importance to prevent to as great a degree as possible any leakage, and to be able under all circumstances to easily bottle, carry, handle, and apply this powerful disinfectant. After many experiments, Dr. Victor Fatio, of Geneva, has succeeded in constructing for this purpose an apparatus that permits of quickly and safely charging siphons from the fountains in which the anhydrous sulphurous acid is delivered to consumers.
Fig. 274 shows one of the siphon apparatus being charged with sulphurous acid from one of Pictet's metallic fountains. The specially arranged siphon is provided at the upper part with a tube, by means of which it is put in communication with the fountain through a bent tube. To the siphon there is adapted a key which permits of opening and closing it before and after the introduction of the liquefied gas. Another key is fitted to the fountain. At the upper part of the device, which rises when the siphon is full, there is a handle for tightening it up. For disinfecting a room by means of a siphon of sulphurous acid, it suffices to empty some of the liquid into a basin and allow it to evaporate. By means of a rubber tube running through a hole in the door or wall, a room may be disinfected from a siphon placed outside. (La Nature.) (c) Bode and Wimpf have designed a new kind of siphon, which is of great use for siphoning off acid, caustic or poisonous liquids. Its special feature is due to the fact that it is not set by suction, but by blowing, so that the liquid to be siphoned off can never get into the month. Fig. 275 representthe construction.
The tube D is surrounded by a wider one C, closed at the top, and provided with a ball valve B at the end £. On putting the apparatus into a liquid, the ball valve is raised, and the tubes C and D are filled to the height of the surrounding liquor. If now air be blown into the tube H, the valve is closed, and the liquid being driven from C into D and F sets the siphon to work. The blowing is then discontinued and H is closed. If it be desired to.interrupt the flow, it is only necessary to blow again a little stronger through H. The valve B is now pressed into its seat, and no liquor being able to enter the siphon, it empties itself. The siphon need never be removed from the liquid, either at the start or at the end. C. Gerhard, of Bonn, and the Moncheberg Pottery, are prepared to supply the siphon to the trade. It can be made of glass, earthenware, ebonite, rubber, and metal. It is also intended to fit Woulffs bottles with this siphoning arrangement, as shown in Fig. 276, for drawing oft* acids in the course of the manufacture. (Chem. Zeit.)
(d) When, at an elevated point in a meadow, there exists a spring or vein of water that cannot be utilised at a distance, either because the supply is not sufficient, or because of the permeability of the soil, it becomes very advantageous to accumulate the water in a reservoir, which may be emptied from time to time through an aperture large enough to allow the water to flow in abundance over all parts of the field. The storing up of the water permits of irrigating a much greater area of land, and has the advantage of allowing the watering to be effected intermittently, this being better than if it were done continuously. But this mode of irrigating requires assiduous attention. It is necessary, in fact, when the reservoir is full, to go and raise the plug, wait till the water has flowed out, and then put in the plug again as accurately as possible - a thing that it is not always easy to do. The work is a continuous piece of drudgery, and takes just as much the Longer to do in proportion as the reservoir is more distant from one's dwelling. In order to do away with this inconvenience, Giral, of Langogne (Lozere), has invented a sort of movable siphon that primes itself automatically, however small be the spring that feeds the reservoir in which it is placed.