As one of the last entries made in the Talmud (a great collection of legal decisions by the ancient Rabbis, Hebrew traditions, etc., and believed to have been commenced in the second century of the Christian era) is claimed to belong to the sixth century, mentions gall-apples and iron (copper) vitriol, it must have referred to "gall" ink. Further investigation discloses the fact that such galls were of Chinese origin and as we know they do not contain the necessary ferment which the aleppo and other galls possess for inducing a transformation of the tannin into gallic acid, no complete union could therefore obtain. Hence the value of this composition was limited until the time when yeast and other materials were introduced to overcome its deficiencies. Hotz-Osterwald of Zurich, antiquarian and scholar, has asserted that with the exception of the carbon inks employed on papyrus, the writing pigments of antiquity and the Middle Ages have scarcely been investigated. The dark to light-brown pigment, hitherto a problem, universally used on parchment, he contends upon historical, chemical and microscopic evidence is identical with oeno-cyanin and was prepared for the most part from yeast, and was first employed as a pigment. Contrary to the general opinion it contains no iron, except frequently accidental traces, and after its appearance in Greece in the third century, it formed almost exclusively the ink of the ancient manuscripts, until displaced by the gallate inks, said to have been introduced by the Arabians. These accidental traces of iron were due to the employment of iron vessels in the making of the ink. My own observations in this direction confirm and establish the fact that it was the custom in the early centuries of the Christian era to utilize yeast or an analogous compound as part of the composition of ink, to which was added sepia, or the rind of the pomegranate apple previously dissolved by heat in alkaline solutions. This analogous compound was probably the material procured from wine lees (dregs), deposited after fermentation has commenced, and which after considerable application of heat yields not only most of the tannin contained in the stones and fruit stalks, but a viscid compound characteristic of gelatine and of a red-purple color which in course of time changes to brown. Bloxam says that the coloring matter of grapes and of red wine appears to be "cyanin." One of the methods of treating wine lees, as translated in the eighteenth century from an old Italian secreta, is sufficiently curious to partly quote: