As a general rule, according to experiments by M. Schultz, it has been found that the point of solidification of fluids is lowered by substances dissolved therein, and that gases dissolved in fluids exercise the same effects. Pure acetic acid fuses at 16 ; this is lowered to 15'2 when a current of carbonic acid is transmitted through this acid. It is well known that hydrochloric acid gas and ammonia gas lower the freezing temperature of water in which they are dissolved ; so do carbonic acid and sulphurous acid gas ; and it has been ascertained by M. Schultz that nitrogen, oxygen, and hydrogen gases exert the same effect when dissolved in water. Numerous experiments were made by him with the view of ascertaining the effect of an increase of pressure brought to bear upon the absorption of various gases by water, and the lowering of the freezing point of that liquid in consequence thereof. By the phenomenon of regelation is understood that property exhibited by ice of freezing together to a solid mass, when pieces of that substance are pressed together at the temperatare of 0. After quoting the opinions of Messrs. Faraday, Forbes, Thomson, and Helmholtz on this subject, the au-thoi says : " When we take it for granted that regelation is the formation of ice from water anew, we must bear in mind that only pure water, or water, at least, not saturated with air, is suitable for this purpose." THE English papers state that 20,087,809 passengers /availed themselves of the London Underground Railroad ior the half year ending July 30, and that a complete extension of this n.eans of communication is soon to be commenced. Day by day the necessity for similar facilities of travel in this city is becoming more and more apparent; and the difficulties of constructing an underground railroad will only be increased by delay. Workers in this great center of industry are only too sensible of the advantages which would be afforded by an unimpeded and expeditious system of conveyance. There is no lack of capital to begin and complete such an undertaking, and the inventive genius of the country can place in the hands of thos3 willing to engage in the work, means and appliances which will render an under ground way here incomparably safer and more healthful than that now established in London. Besides the certainty of receiving handsome returns for the money invested, the promoters of this enterprise will enjoy the satisfaction of having done much to further the public welfare. THE Melbourne papers give some particulars relative to a meat-preserving process, the merits of which, it would appear, had been satisfactorily tested. The meat having been cured was taken on a voyage to England and back in the ship Mary TJiompson. The meat was in a cask, and had been preserved in fat. The Captain of the vessel exposed the meat to very severe trials on the way home, placing the cask on deck for days together under a tropical sun, and at other times leaving it for lengthened periods in the neighborhood of the cook's galley. When the cask was opened, the meat proved to be in a perfectly sound condition, and was capital eating. The advantage of the process over others is that the meat is preserved in large joints, from which, however, all bone is extracted before they are placed in the cask. A little bisul-phate of lime is used in the operation of curing, but its taste was not in the slightest degree perceptible. THE Brooklyn Union says that in connection with the erection of the East River bridge, the Brooklyn terminus of which is to be the site of St. Ann's Episcopal Church, corner of Washington and Sands streets, a plan has been discussed for widening Washington street on the westerly side, making it one hundred feet in width, with twenty feet promenade sidewalks on each side of the carriage-way extending from the bridge terminus to the City Hall square. It is understood that the Government has arranged for the purchase of of the church property situated at the corner of Washington and Johnson streets, and that at the next meeting of Congress an appropriation will be made of money to erect on it a post office and United States Court building. THE workingmen of England are determined that the productions of their brains are not to be at the mercy of unprincipled capitalists. One indication is given by the following. A deputation lately waited upon John Bright, at the office of the Board of Trade, for the purpose of asking him to bring in a bill early nest session to protect the inventions that might be exhibited at the Workingmen's International Exhibition to be held next year. Mr. Bright expressed his entire sympathy with the object of the deputation, and promised to comply with thei? request. A COMMITTEE appointed by theFrench Academy of Sciences have under consideration a communication by M. Berthault. This gentleman Suggests various means of utilizing the excess of force produced in working a locomotive. He shows that it might be ued in causing a stronger adhesion of the wheels to the rails, so as to prevent the train from running off, and that it might likewise be applied to the illumination of the carriages by ttleetrieity, tmd Ten to mUing the tele* gmph Is metta PROTECTION OP WOOD PROM FIRE.—We learn from the Deutsche Industrie Zeitung of July 1, that at one of the collieries at Ibbenbilren, Westphalia, the woodwork is protected from fire by being painted with a mixture consisting of 5 parts of alum, 7 parts of rye-meal paste, and 30 parts of previously washed, i. e., finely divided, clay (this mixture is used for woodwork not exposed to open air); for woodwork, so ox-posed, a mixture is used consisting of 2J parts of crystallized sal ammoniac, 1 part of white vitriol (commercial sulphate of zinc), 2 parts of joiners' glue, 30 parts of zinc white, and 30 parts of water. These mixtures have been found to prevent wood bursting into flame on ignition, and to greatly delay its destruction even when severe fires are raging. AN OLD SWINDLE REVIVED.—Dailey & Co., No. 208 Broadway, N. Y., recently advertised in our paper for agents to sell a certain article. The notice was handed to us by a respectable advertising agent, and we had no suspicion that it was intended to perpetrate a swindle, but it appears to be a renewal of the old counterfeit money dodge. A perusal of this circular itself will at once show its true character, and no honest person can be deceived by it. Nevertheless we consider it our duty to expose the villains. We placed the circular in the hands of the authorities some days ago. ANOTHEB cable is coming soon, a concession having been granted by Count Bismarck to a company for the laying of a submarine cable between Northern Germany and the United States, the landingof that cable at a suitable point of the North German coast on the North Sea; and the construction of all appliances required for working the cable, which is to be constructed in the best known manner, and its manufacture is to be commenced within six months after the date of the eon-cession, and the whole line to be completed within two years after that date. THE freight opposition among the railroad companies which gave the public the temporary advantage of transporting goods to the West at low rates, as noticed in last week's issue, shows symptoms of abating, and a return to the old tariff may soon be expected. Erie and the New York Central have raised their prices to 38 cents per hundred pounds to Chicago. Since August 2, when the low rates commenced, the depots have been filled with Western-bound freight. THE surveys for the East River Bridge are now finished, and the line of the bridge and approaches located. The timber for the founding of the piers is now lying at Red Hook, ready to be bolted together, previous to being sunk into position. It is thought by some that it will take three years before the work is so far advanced as to enable the cables to be stretched across the river, and that six years will elapse before the bridge can be thrown open to the public. A METHOD of protecting iron vessel s against rust and corrosion has been proposed by MM. Dance and Bertin. They contemplate the conversion of the hull of the iron vessel into a galvanic battery, by placing, inside the hull, pipes and tanks made of zinc and filled with sea water, and connected by means of bolts and rivets in metallic contact with the outer side of the vessel. They also design to use strips of zinc on the iron plates of the vessel immersed in the water. THE London DaUy News in an article on the new patent law of Canada says that the whole principle and practice of that law may be concisely summed up in the word " spoliation." A pretty plain hint is also given to the Canadians that a persistence in such a policy, which is shown also in all their outside relations, is more than likely one of these days to result in their being thrown entirely on their own resources. THE leather and hide trade of Nashville has greatly increased since the war. The Nashville butchers take off about ten thousand hides a year, and nearly that number of Texas and Mexican hides arrives there during the same period. There were three hundred and seventy tanners in Tennessee before the war, and more than five times as much leather was made then as now. ON the railroads in France electricity is taking the place of human watchfulness. On many lines there are contrivances where the passing of a train is automatically announced to neighboring stations. The cari pass over connecting wires, and the train records itself before and behind, so that its progress and appearance are alike indicated. KEY RINGS.—We have received from C. A. Wentworth, Boston, Mass., specimens of some neat rings for holding bunches of keys, made after his patent. After the keys are put on, the ring springs to its place and is secured by a slotted button, the whole forming a very useful device for the purpose. THE Chinese laborers are making advances into the country. A dispatch says that five hundred will shortly be sent to St. Joseph, Missouri, whence they will be distributed to various points, and that agencies are to be established there , and at St. Louis and Springfield in the same State. AN exchange says it has been discovered that the common hardhack, Spircea tomentosa, that grows plentifully in nearly every pasture, can be used in tanning leather as a substitute for sumac. A company has been formed in Boston which has advertised for one hundred tuns of hardhaok. AKBw Bteam roller, weighing fifteen tunes, recently or dered from England for Prospect Park, Brooklyn, m iwrivwJ. It is to ba pat into opMntiea m m early day.