The inventor says—“My invention consists _firstly_, in certain improved methods of preparing gutta-percha for manufacturing purposes. If the gutta-percha to be operated upon, is not very impure, it may be at once submitted to the process hereafter described. * * * * If impure, the gutta-percha may be cleansed by the process as laid down by R. A. Brooman, March 11, 1845.” Mr. Hancock continues—“According to one of my improved methods of preparing gutta-percha, I place it in a plastic state in a cylindrical screw press, kept hot by a steam jacket, or otherwise, and having the bottom perforated with numerous holes, and _squeeze_ it through the strainer and perforated bottom, from which it falls in a much purified state. “This operation may, if necessary, be repeated; I then transfer the gutta-percha in this purified state, to a masticating machine, such as is commonly employed in the preparation of caoutchouc, and kept hot by any suitable means, and work and knead the gutta-percha until it is brought to the consistence of dough or putty. According to another of my modes of preparing gutta-percha, instead of passing it through the screw-press, as before described, I take the plastic mass and pass it a number of times between heated rollers, kept hot by hot water, steam, or any other convenient means. Or, thirdly, I take the gutta-percha as imported, and dissolve it by means of rectified oil of turpentine, or any other suitable solvent, and filter the solution while warm, through flannel, or felt, or fine wire gauze, after which I distil off the solvent, and evaporate the residuum to the consistence of dough or putty.” _Secondly_, “My invention consists in making a compound, elastic, water-repellent substance for manufacturing purposes, by combining gutta-percha with an elastic and water-repellent substance, called “jintawan.” I combine the two substances in a masticator, and then operate upon the two materials by that machine; at the same time adding any coloring matter that may be desired, continuing the operation of the machine, until they are intimately blended together. And I make the triple combination of ‘gutta-percha,’ ‘jintawan,’ and ‘caoutchouc,’ and by means of a masticator, in the same manner. For the purpose of making these combinations. I vary the proportions of the two, or of the three substances which I combine according to the quality which it is desired that the combined substance shall possess.” * * * * *