My first step, of course, was to find suitable apartments. These I obtained, after a couple of days’ search, in Fourth Avenue; a very pretty second floor, unfurnished, containing sitting-room, bedroom, and a smaller apartment which I intended to fit up as a laboratory. I furnished my lodgings simply, but rather elegantly, and then devoted all my energies to the adornment of the temple of my worship. I visited Pike, the celebrated optician, and passed in review his splendid collection of microscopes — Field’s Compound, Hingham’s, Spencer’s, Nachet’s Binocular (that founded on the principles of the stereoscope), and at length fixed upon that form known as Spencer’s Trunnion Microscope, as combining the greatest number of improvements with an almost perfect freedom from tremor. Along with this I purchased every possible accessory — draw-tubes, micrometers, a camera lucida, lever-stage, achromatic condensers, white cloud illuminators, prisms, parabolic condensers, polarizing apparatus, forceps, aquatic boxes, fishing-tubes, with a host of other articles, all of which would have been useful in the hands of an experienced microscopist, but, as I afterward discovered, were not of the slightest present value to me. It takes years of practice to know how to use a complicated microscope. The optician looked suspiciously at me as I made these valuable purchases. He evidently was uncertain whether to set me down as some scientific celebrity or a madman. I think he was inclined to the latter belief. I suppose I was mad. Every great genius is mad upon the subject in which he is greatest. The unsuccessful madman is disgraced and called a lunatic.

Mad or not, I set myself to work with a zeal which few scientific students have ever equaled. I had everything to learn relative to the delicate study upon which I had embarked — a study involving the most earnest patience, the most rigid analytic powers, the steadiest hand, the most untiring eye, the most refined and subtle manipulation.

For a long time half my apparatus lay inactively on the shelves of my laboratory, which was now most amply furnished with every possible contrivance for facilitating my investigations. The fact was that I did not know how to use some of my scientific implements — never having been taught microscopies — and those whose use I understood theoretically were of little avail until by practice I could attain the necessary delicacy of handling. Still, such was the fury of my ambition, such the untiring perseverance of my experiments, that, difficult of credit as it may be, in the course of one year I became theoretically and practically an accomplished microscopist.

During this period of my labors, in which I submitted specimens of every substance that came under my observation to the action of my lenses, I became a discoverer — in a small way, it is true, for I was very young, but still a discoverer. It was I who destroyed Ehrenberg’s theory that the Volvox globator was an animal, and proved that his “monads” with stomachs and eyes were merely phases of the formation of a vegetable cell, and were, when they reached their mature state, incapable of the act of conjugation, or any true generative act, without which no organism rising to any stage of life higher than vegetable can be said to be complete. It was I who resolved the singular problem of rotation in the cells and hairs of plants into ciliary attraction, in spite of the assertions of Wenham and others that my explanation was the result of an optical illusion.

But notwithstanding these discoveries, laboriously and painfully made as they were, I felt horribly dissatisfied. At every step I found myself stopped by the imperfections of my instruments. Like all active microscopists, I gave my imagination full play. Indeed, it is a common complaint against many such that they supply the defects of their instruments with the creations of their brains. I imagined depths beyond depths in nature which the limited power of my lenses prohibited me from exploring. I lay awake at night constructing imaginary micro-scopes of immeasurable power, with which I seemed to pierce through all the envelopes of matter down to its original atom. How I cursed those imperfect mediums which necessity through ignorance compelled me to use! How I longed to discover the secret of some perfect lens, whose magnifying power should be limited only by the resolvability of the object, and which at the same time should be free from spherical and chromatic aberrations — in short, from all the obstacles over which the poor microscopist finds himself continually stumbling! I felt convinced that the simple microscope, composed of a single lens of such vast yet perfect power, was possible of construction. To attempt to bring the compound microscope up to such a pitch would hav............