We have only to look down a microscope to convince ourselves of the alteration in our experience that it would mean if we were to become sufficiently diminished. The tiniest solid particles in fluids can be seen to be in a continuous state of agitation--inexplicable until it was pointed out that this mysterious “Brownian” movement was the inevitable result of impacts by the faster-moving molecules of the fluid. Many living things that we can still see are small enough to live permanently in such agitation; the longest diameter of many bacteria is but half a micron (a two-thousandth of a millimetre), and there are many ultra-microscopic organisms which, owing to their closer approximation to molecular dimensions, must pass their lives in erratic excursions many times more violent than any visible Brownian motion. If we could shrink, like Alice, at the persuasion of some magic mushroom, the rain of particles on our skin, now as unfelt as midges by a rhinoceros, would at last begin to be perceptible. We should find ourselves surrounded by an infinity of motes; titillated by a dance of sand-grains; bruised by a rain of marbles; pounded by flights of fives-balls. What is more, the smaller we became, the more individuality and apparent free-will should we detect in the surrounding particles. As we got still smaller, we should, now and again, find the nearly uniform bombardment replaced by a concerted attack on one side or the other, and we should be hurled for perhaps double our own length in one direction. If we could conceivably enter into a single inorganic molecule, we should find ourselves one of a moving host of similar objects: and we should further perceive that these objects were themselves complex, some like double stars, others star-clusters, others single suns, and all again built of lesser units held in a definite plan, in an architecture reminding us (if we still had memory) of a solar system _in petto_. If we were lucky enough to be in a complicated fluid like seawater, we should be intrigued by the relations of the different kinds of particles. They would be continually coming up to other particles of different kinds, and would then sometimes enter into intimate union with them. If we could manage to follow their history, we should find that after a time they would separate, and seek new partners, of the same or of different species. Some kinds of the units, or people as we should be inclined to call them, would spend most of their existence in the married state, others would apparently prefer to remain single, or, if they married, would within no long time obtain divorce. We should be forcibly reminded of life in some cosmopolitan city like London or New York. If there existed a registrar to note down the events of these little beings’ existence, and we were privileged to inspect the register, we should find that each had its own history, different from that of every other in its course and its matrimonial adventures.