Volume 1

The tannins : a monograph on the history, preparation, properties, methods of estimation, and uses of the vegetable astringents with an index to the literature of the subject / by Henry Trimble.

  • Trimble, Henry, 1853-1898.
Date:
1892-1894
Catalogue details

Licence: Public Domain Mark

Credit: The tannins : a monograph on the history, preparation, properties, methods of estimation, and uses of the vegetable astringents with an index to the literature of the subject / by Henry Trimble. Source: Wellcome Collection.

    17/182 (page 11)
    THE TANNINS. SECTION I. SOURCES OF THE OAK TANNINS. The sources of the oak tannins, so far as we know at present, are the bark and wood of the oak. It is not known that all the different species of oaks yield the same tannin. Bottinger has claimed that the tannins from the wood and bark are different. It is certain that the galls of Quercus infectoria yield a dif- ferent tannin from that of the bark and wood of some other species of oaks, and it is reasonable to suppose that the tannin from the galls is identical with that from the bark on which the galls are produced, there- fore we may look for a variation in the properties and composition of the tannins from different species. The supply of oak tannin is obtained from the bark of various oak species. The tannin is not prepared on a commercial scale or used in a pure condition, but either as a weak infusion or as an extract. A consid- erable quantity of extract prepared from oak wood is found in commerce. Of the European oaks that are employed for tanning or preparing extract, only a few are worthy of especial