Gutta-percha may be mixed and ground together with almost an endless variety of substances, which substances are usually regarded as of little or no value in themselves; but being combined with gutta-percha, are thus transformed into valuable articles of mechanical manufacture. Much of the gutta-percha which is introduced into the market is nothing but a mixture of dirt, bark, and mineral substances, which entirely destroy its value. Great care should therefore be observed in its selection, _as its purity makes its value_. Gutta-percha must be mixed or combined with what may be denominated imperishable substances, or _substances which the gutta-percha renders imperishable_. In many of its combinations found in commerce, it is entirely destroyed and the manufactured article made worthless. In very many instances which have come to our knowledge, boots and shoes have been thus rendered of little or no value, and were justly returned to the manufacturers. Kid and leather shoes, with baked or burnt upper stock, and combinations of _rubber_ cement, rot or decompose the fibres of all cloth or leather to which it is applied that contains any oleaginous substances. Thus kid and leather shoes, with baked or burnt upper stock, and combinations of RUBBER cement, which rot or decompose the fibres of all cloth or leather, which contain any oleaginous substance to which it is applied, have been thrown upon the market, thus producing a prejudice in some minds, and destroying confidence in their utility. In England and France, where the use of gutta-percha is better understood and appreciated, it has been used in its application to shoes for several years. Gutta-percha soles are prepared to suit the various sizes of boots or shoes, and are thus sold in packages. Prepared cement in small boxes with directions is an article generally for sale. Thus any person can mend his shoes without the aid of the cobbler. The process is exceedingly simple, the sole requiring only to be warmed and pressed upon the shoe with the hand. Thousands are thus enabled, especially in the manufacturing districts of those large commercial centres, to mend their own shoes at less than one-half the usual cost, and in a much superior manner. Foreigners, on arriving in this country, are greatly surprised at our lack of enterprise in this direction, and loudly call for the gutta-percha taps, especially after using the miserable, half-tanned, and poorly made, sewed or pegged trash, which is so abundant, quantities of which are sent to our Southern and Western markets. This is well illustrated by the anecdote of a Southern negro, who, having worn a pair of these cheap, roughly-constructed brogans, and finding them falling to pieces, said to his master, “What make these shoes come to pieces so soon?” “Why,” said the master, in reply, “those shoes _grow_ at the East on trees.” “Is dat it, massa; well, den dese was _picked before dey was ripe_.”