MOST of the documents of early mediaeval times which remain to us containing ink in fairly good condition, like charters, protocols, bulls, wills, diplomas, and the like, were written or engrossed with "Indian" ink, in which respect we of the present century continue to follow such established precedent when preparing important written instruments. It is not remarkable, therefore, that the black inks of the seventh, eighth, ninth and tenth centuries preserve their blackness so much better than many belonging to succeeding ages, including a new class of inks which could not stand the test of time. During the twelfth and first years of the thirteenth centuries there were bitter controversies among Talmudic (Hebrew) scholars, relative to the character of the ink to be employed in the preparation of ritualistic writings. Nice distinctions were drawn as to the real meaning of the word deyo as understood by the Jews of the western part of the world, and the Arabic word alchiber, as then understood nearer Palestine and the other eastern countries. The French Jews were using "tusche" (typical of the "Indian" ink), while the Germans were employing "pomegranate" and "gall" inks. Representatives from interested religious Jewish centers came together and resolved to submit their differences for final adjustment to Maimonides, born in Spain, A. D. 1130 , and died A. D. 1204--the then greatest living Hebrew theologian and authority on biblical and rabbinical laws. Discarding all side issues, their differences were seemingly incorporated into three questions and thus propounded to him: 1. Is the Talmudic deyo identical with alchiber? 2. Of what ingredient should the Talmudic deyo consist, if it is not the same as alchiber? 3. Is alchiber to be understood as relating to the gall-apple and chalkanthum (blue vitriol)? To the first and third questions Maimonides declared that deyo and alchiber were not identical; and for the reasons that the Talmud declares deyo to be a writing material which does not remain on the surface on which it is placed and to be easily effaced. On the other hand alchiber contains gum and other things which causes it to adhere to the writing surface. To the second question he affirmed that the Talmud distinguishes a double kind of deyo, one containing little or no gum and being a fluid, and the other referring to "pulverized coal of the vine, soot from burning olive oil, tar, rosin and honey, pressed into plates to be dissolved in water when wanted for use." Furthermore, while the Talmud excludes the use of certain inks of which iron vitriol was one, it does not exclude atramentum, (chalkanthum, copper vitriol), because the Talmud never speaks of it. He insisted that the Talmud requires a dry ink (deyo).