The foregoing analysis is so simple and clear, that the attentive reader will at once comprehend the natural as well as chemical differences existing in gutta-percha and India-rubber, being not only chemically, but mechanically and commercially different. BOOK II. CHAPTER I. PREPARATION OF STOCK. In the preparation of the leather for outer soles, after it has been stripped up in the common form, remove all the loose flesh by skiving or splitting, or any other process. The stock should be thoroughly dry. Then raise a thick and even fibre on the flesh side, (_remembering always, that the adhesive quality is in proportion to the thickness of the fibre_) with a common card or rasp, or other convenient tool. The cement should be applied hot, with a coarse paint brush, as evenly as possible, then expose the leather to dry air a day or two, in order to allow the solvent to evaporate. If the first coat is too thin, apply a second in the same manner, until the leather is well coated. Then the leather should be again exposed, as before, until completely dry. It may then be wet in water, in the _usual_ form, until properly tempered or prepared. The leather is then in a condition to be rolled, or hammered. If hammered it should be _first_ cut up into soles. If rolled it may be placed in a cutting machine, and cut up in the usual form. Sole leather is cut to the best advantage by hands with the proper patterns, or “dies.” After the soles are properly rounded to the desired pattern, for all thin edged work the cement should be featheredged, from the edge of the sole at a proper distance, in order to secure a good finish. This process prevents the cement from adhering or sticking to the upper, when the sole is pressed on. MIDDLE SOLES, AND SPUR, OR SPRING LIFTS. After they have been properly fitted, ready for use as in the common form, the parts should be dried and a thick fibre raised, as before described for the outer sole, only that a fibre should be raised on _both sides_, as will be readily understood. Cement on _both_ sides. This process may be done before cutting into soles or lifts, at the option of the manufacturer. TO PREPARE IN-SOLES. Cut from thin leather skirting or shavings. After properly fitting to the pattern or last, the edges of the in-sole should be reduced to a proper thickness. A strong fibre should be raised on the side on which the cement is to be applied, the stock being previously dry. Then cement as before. One coat is sufficient if the cement is thick. If not, spread again upon the edge, as that portion of the sole should receive the thickest coating, for the purpose of holding, with great firmness the linings or upper, when lasted, as the shoe may require. TO PREPARE COUNTERS OR STIFFENINGS.