TAP FOR EFFERVESCING LIQUIDS.
When a bottle of any liquor charged with carbonic acid under strong pressure, such as champagne, sparkling cider, seltzer water, etc., is uncorked, the contents often escape with considerable force, flow out, and are nearly all lost. Besides this, the noise made by the popping of the cork is not agreeable to most persons. To remedy these inconveniences there has been devised the simple apparatus which we represent in the accompanying cut, taken from La Nature. The device consists of a hollow, sharp-pointed tube, having one or two apertures in its upper extremity which are kept closed by a hollow piston fitting in the interior of the tube. This tube, or "tap," as it may be called, is supported on a firm base to which is attached a draught tube, and a small lever for actuating the piston. After the tap has been thrust through the cork of the bottle of liquor the contents may be drawn in any quantity and as often as wanted by simply pressing down the lever with the finger; this operation raises the piston so that its apertures correspond with those in the sides of the top, and the liquid thus finds access to the draught tube through the interior of the piston. By removing the pressure the piston descends and thus closes the vents. By means of this apparatus, then, the contents of any bottle of effervescing liquids may be as easily drawn off as are those contained in the ordinary siphon bottles in use.
TAP FOR EFFERVESCING LIQUIDS.
CHEMICAL SOCIETY, LONDON, JAN. 20, 1881.
PROF. H.E. ROSCOE, President, in the Chair.
Mr. Vivian Lewes read a paper on "Pentathionic Acid." In March last the author, at the suggestion of Dr. Debus, undertook an investigation of pentathionic acid, the existence of which has been denied. The analyses of the liquid obtained by Wackenroder and others, by passing sulphureted hydrogen and sulphur dioxide through water, are based on the assumption that only one acid is present in the solution, and consequently do not establish the existence of pentathionic acid; as, for example, a mixture of one molecule of H2S4O6 and one molecule of H2S6O6 would give the same analytical results as H2S5O6. Moreover, no salt of pentathionic acid has been prepared in a pure state. The author has succeeded in preparing barium pentathionate thus: A Wackenroder solution was about half neutralized with barium hydrate, filtered, and the clear solution evaporated in vacuo over sulphuric acid. After eighteen days crystals, which proved to be barium pentathionate + 3 molecules of water, formed. These crystals were separated, and the liquid further evaporated, when a second crop was obtained intermediate in composition between the tetra and pentathionate. These were separated, and the mother-liquor on standing deposited some oblong rectangular crystals. These on analysis proved to consist of baric pentathionate with three molecules of water. This salt dissolves readily in cold water; the solution is decomposed by strong potassic hydrate, baric sulphite, hyposulphites, and sulphur being formed. By a similar method of procedure the author obtained potassium pentathionate, anhydrous, and with one or two molecules of water. The author promises some further results with some other salts of the higher thionates.