tannin

• In the same circumstances tannin (gallo-tannin) produces a blue-black image; catechu-tannin(43) and quino-tannin give green, etc. Employed as a developer, potassium ferricyanate develops an image in prussian blue, and auric chloride one in the characteristic violet metallic gold. —  Photographic Reproduction Processes
• The bark contains a great deal of tannin, and it has become to some extent an article of commerce The leaves of the eucalyptus have a leathery appearance and generally stand in a vertical position, so that one side receives as much light as the other. —  The Land of the Kangaroo Adventures of Two Youths in a Journey through the Great Island Continent
• We must, therefore, not only ameliorate the acid, but also the flavor and the astringency, of which the tannin is the principal cause. —  The Cultivation of The Native Grape, and Manufacture of American Wines
• It was found that the husks still contained sufficient of acids, tannin, aroma, coloring matter, and gluten. —  The Cultivation of The Native Grape, and Manufacture of American Wines
• This comprises fining with some gelatinous substance, and, as a precaution against ropiness and other maladies, liquid tannin is at the same time frequently added to supply the place of the natural tannin which has departed from the wine with its reddish hue at the epoch of its first fermentation The operation of bottling the wine next ensues, when the Scriptural advice not to put new wine into old bottles is rigorously followed. —  Facts About Champagne and Other Sparkling Wines

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