"Upon the question of the permanency of nut-gall and iron inks, the answers were more varied; one answering no, and four answering directly yes, the remaining answers being in brief that such inks were permanent if properly made. "To the question, 'Do you consider carbon ink the only permanent ink?' the answers were varied and contradictory. Most of the manufacturers said a carbon ink could not be permanent, because carbon was insoluble; and some said that no chemical union could exist between carbon and the other ingredients in ink. Others claimed that carbon was the one permanent color, and cited the old Indian and Chinese inks which have stood for centuries as illustrations of its permanency. These statements were so widely different that I pursued the inquiry further, and found it was conceded that, if a process could be discovered by which carbon could be dissolved and made to retain its color, no known substance would make so permanent an ink; but that there was no such process, and in the inks now made the carbon was simply held in suspension in the ink without any chemical union; but I found also that improvement has been made, and that it is possible to combine the carbon with chemicals which will cause the carbon to embody itself. More than ordinary care should, however, be exercised in the purchase of carbon inks, for the lack of chemical union would cause a tendency to precipitate the carbon if the ink were improperly made. "The replies to the inquiry, 'Do you advise generally against the inks known as writing fluids, when permanency is the first requisition?' were in a way the most unsatisfactory, and savored somewhat of advertising. One manufacturer made no fluid, and had no opinion to express. Most of the others made fluids. Nine advised generally against their use; four recommended them in preference to ink; and the others either advised generally against them, but recommended their own, or qualified the answer in such a way as to throw doubt on them. "The argument in their favor seems to be that their fluidity makes them permeate the paper, and, in the change of color which usually takes place after using, a dyeing of the paper results. The objections are, that to obtain the fluidity body must be sacrificed, and there is not enough substance deposited upon the paper. The objections made by two manufacturers of fluids I give in their own words.