Democratic Sentinel, Volume 17, Number 44, Rensselaer, Jasper County, 17 November 1893 — Component Fact of Irons. [ARTICLE]

Component Fact of Irons.

Nearly all the inks in common wfe contain organic mutter as a part of theooloring matter. The great majority of them are principally a combination of iron with gallio and tannic acids, both of which are organic acids and quite readily decomposed. The action of moisture, light and other agents will, after a while, decompose these salts of iron, leaving only the almost invisible oxide of iron to show where the writing has been. The only really permanent ink is that prepared from some form of carbon, such as lampblack, of which the Chinese or India ink is composed. Carbon resists destructive influences to a remarkable degree, and writings made with such ink will last as long as the paper on which they are written.