Glycerine in Tanning.

Practical Magazine 24, 1876

(Chemistry applied to the Arts, Manufactures, &c.)

According to the statement of a practical tanner in the Gerber, glycerine is specially suited for preserving green skins. By salting they are kept damp, but rendered less useful for various purposes. Carbolic acid preserves them well, but has a tendency to dry them in some measure. All disadvantages may be avoided by treating the skins with a mixture of glycerine and carbolic acid. The carbolic acid increases the preserving effect of the glycerine, while the glycerine keeps the skins perfectly soft and fresh, just as they were directly after slaughter. Both substances are entirely without any injurious action on the substance of the skins, which are freed from them by simply washing, and are then in exactly the same condition for working as ordinary green skins. The fresh skins are covered on the inner side with a mixture of ninety parts of crude dark glycerine and ten parts of carbolic acid, by means of a plasterer's brush, and afterwards treated and packed as usual. It remains to be ascertained by experience whether the advantages of this method are equivalent to the increased cost. For the softening of tanned hides glycerine is not to be recommended; it makes tanned leather stiffer and more brittle than before. Nor is any leather grease containing glycerine of any use, since glycerine is soluble in water.