The new process consists in mixing with the solvent (of whatever nature it may be) a certain quantity of alcohol, and macerating therein the India-rubber or gutta-percha, which will expand very little, and at the end of twenty-four hours, it will be in the state of paste, suitable for being moulded into any desired form. The patentee prefers to employ as a solvent, sulphuret of carbon, chloroform, sulphuric ether, naptha, essential oils of coal, or turpentine, and to add thereto from five to fifty per cent. of alcohol. The caoutchouc is mixed with the alcoholized solvents in all proportions, varying from equal parts to thirty parts of the latter, to one of the former, according to the thickness of the solution required, and after one or two days, the paste is submitted to the ordinary process of masticating, if the solution is made of equal parts, or when it is made of small quantities of the solvent; in other cases it is not necessary. The patentee adopts the same system when treating gutta-percha. He dissolves it in the alcoholized sulphuret of carbon, and dilutes it until it arrives at the consistence of thick syrup of sugar. In this state he permits it to remain three or four days, during which time, the impurities will be precipitated or rise to the surface; and then he draws off the gutta-percha in a state of complete purity. It will be seen that the character of the invention is the mixture of alcohol with the solvent used for dissolving caoutchouc, and gutta-percha. As alcohol is the liquid which most quickly precipitates India-rubber from its solutions, the patentee avails himself of this property, by causing the alcohol, by means of a solvent, to enter into the interior parts of the India-rubber, or to detach all the adherent atoms which form the mass of the caoutchouc. By the addition of the alcohol, the particles are rendered less adherent among themselves, and are easily separated by pressure, retaining the form resulting from this pressure, and not returning to their ordinary form. On the solvent and the alcohol being evaporated, the caoutchouc will return to its original state. All liquids which possess the properties of alcohol may be mixed with the solvents. The principle of this invention is the causing matters which are not of a solvent nature, to be introduced into the body of the India-rubber by means of a solvent, such matters having the property to disunite the parts constituting the mass of India-rubber, and destroy the adherence of the particles, whether these matters are combined with the solvents, or introduced by themselves. TO WILLIAM EDWARD NEWTON, of the Office of Patents, 66 Chancery Lane, London, England. For improvements applicable to Boots, Shoes and other coverings for, or appliances to the feet. [Sealed 6th of June, 1850.]