I claim, 1st, So constructing the frogs of railways that the frog plate and the rail or track sections, guard rails, and frog point are separate from each other, and so that the rail sections and guard rails and frog point can be inserted in or attached to and detached from the frog plate, for the uses and purposes set forth. 2d, So constructing the frogs of railways or the frog plate, that the track rails of any railway can be extended upon and combined with such frog plate to form the track or rail section of the frog, substantially as and for the purposes set forth. 71,906.--HARVESTER.--Henry W. Pell, Rome, N.Y. I claim. 1st, The carriage, C, supported at both ends on wheels or rollers, cc, running on a guide way, S, substantially as and for the purposes specified. 2d, The rib or groove joint between the friction rollers and guideway, to sustain the lateral pressure, as set forth. 3d, The clevis pin or whiffletree bolt, B, attached to the center of the carriage, C. 4th, The independent attachment of the draught clevis to the whiffletree bolt to permit the independent oscillation of the whiffletree without affecting the clevis. 71,907.--MEDICAL COMPOUND.--M. Perl, New Orleans, La. I claim the medical compound herein described, when made by the process and composed of the ingredients herein specified, in the proportions stated, for the purpose set forth. 71,908.--MACHINERY FOR SHAVING AND SLOTTING SCREWS.--Elijah S. Pierce, Hartford, Conn. I claim, 1st, The combination of the cam, M, the sliding frame, Y, the spindle, A, the pulley, P, the clamp, C, the spring, S, and the rest, R, or their equivalents, with a shaving tool, and one or more nicking saws, substantially as herein specified. 2d, The combination of the sliding frame, Y, the spindle, A, and the clamping device, C, with a shaving tool and one or more saws, substantially as described, for the purpose of shaving, nicking, and turning screw blanks or other similar articles, while held in the same jaws. 71,909.--DOUBLE SCREW.--Elijah S. Pierce, Hartford, Ct. I claim the double screw herein described and shown, as a new article of manufacture. 71,910.--APPARATUS FOR PRESERVING MEATS, FISH, POULTRY, AND OTHER PERISHABLE ARTICLES.--Charles F. Pike, Piovidence, R.I.