That it was so was evident from the numerous affirmatory responses. While this was going on, I tore a slip from my pocket-book, and scribbled a name under the table. "Will this spirit communicate in writing with this gentleman?" asked the medium once more. After a moment's pause her hand seemed to be seized with a violent tremor, shaking so forcibly that the table vibrated. She said that a spirit had seized her hand and would write. I handed her some sheets of paper that were on the table, and a pencil. The latter she held loosely in her hand, which presently began to move over the paper with a singular and seemingly involuntary motion. After a few moments had elapsed she handed me the paper, on which I found written, in a large, uncultivated hand, the words, "He is not here, but has been sent for." A pause of a minute or so now ensued, during which Mrs. Vulpes remained perfectly silent, but the raps continued at regular intervals. When the short period I mention had elapsed, the hand of the medium was again seized with its convulsive tremor, and she wrote, under this strange influence, a few words on the paper, which she handed to me. They were as follows: "I am here. Question me. "LEEUWENHOEK." I was, astounded. The name was identical with that I had written beneath the table, and carefully kept concealed. Neither was it at all probable that an uncultivated woman like Mrs. Vulpes should know even the name of the great father of microscopies. It may have been Biology; but this theory was soon doomed to be destroyed. I wrote on my slip--still concealing it from Mrs. Vulpes--a series of questions, which, to avoid tediousness, I shall place with the responses in the order in which they occurred. I.--Can the microscope be brought to perfection? SPIRIT.--Yes. I.--Am I destined to accomplish this great task? SPIRIT.--You are. I.--I wish to know how to proceed to attain this end. For the love which you bear to science, help me! SPIRIT.--A diamond of one hundred and forty carats, submitted to electro-magnetic currents for a long period, will experience a rearrangement of its atoms _inter se_, and from that stone you will form the universal lens. I.--Will great discoveries result from the use of such a lens? SPIRIT.--So great, that all that has gone before is as nothing. I.--But the refractive power of the diamond is so immense, that the image will be formed within the lens. How is that difficulty to be surmounted? SPIRIT.--Pierce the lens through its axis, and the difficulty is obviated. The image will be formed in the pierced space, which will itself serve as a tube to look through. Now I am called. Good night!