As the transfer from paper to stone depended mainly on the greater or lesser powers of adhesion between one material and another, it was natural that in my many experiments with such various ingredients I should observe that a mucous fluid, as, for instance, the gum solution, resisted the adhesion of the greasy ink. Nearer still to the new invention did the following experiment bring me: I noticed that if there happened to be a few drops of oil in the water into which I dipped paper inscribed with my greasy stone-ink, the oil would distribute itself evenly over all parts of the writing, whereas the rest of the paper would take no oil, and especially so if it had been treated with gum solution or very thin starch paste. This fact led me to investigate the behavior of paper printed with common printing-ink. A sheet of an old book was drawn through thin gum solution, then laid on a stone and touched carefully everywhere with a sponge that had been dipped into a thin oil color. The printed letters took the color well everywhere and the paper itself remained white. Now I laid another clean white sheet on this, put both through the press, and obtained a very good transfer, in reverse, of course. In this manner, if I used great care, I found I could make fifty and more transfers from the same sheet. If I allowed such a transfer to dry thoroughly and then treated it like the original sheet, why should it not produce transfers that are like the original, not reversed? So thought I, and the result showed that I had not been wrong! Only for the first transfer I needed to use a somewhat stiffer color that had been dried more with litharge of silver, and then to let the transfer dry for at least four or six days. So I came to find that I could print without a stone, from the paper alone; and this process, depending solely on chemical action, was totally, fundamentally different from all other processes of printing.