To see the impossibility of every other solution, join in the long and microscopic hunt for the ultimate particle, the atom; and if found, or if not found, to a consideration of its remarkable powers. Bring telescopes and microscopes, use all strategy, for that atom is difficult to catch. Make the first search with the microscope: we can count 112,000 lines ruled on a glass plate inside of an inch. But we are here looking at mountain ridges and valleys, not atoms. Gold can be beaten to the 1/340000 of an inch. It can be drawn as the coating of a wire a thousand times thinner, to the 1/340000000 of an inch. But the atoms are still heaped one upon another. Take some of the infusorial animals. Alonzo Gray says millions of them would not equal in bulk a grain of sand. Yet each of them performs the functions of respiration, circulation, digestion, and locomotion. Some of our blood-vessels are not a millionth of our size. What must be the size of the ultimate particles that freely move about to nourish an animal whose totality is too small to estimate? A grain of musk gives off atoms enough to scent every part of the air of a room. You detect it above, below, on every side. Then let the zephyrs of summer and the blasts of winter sweep through that room for forty years, bearing out into the wide world miles on miles of air, all perfumed from the atoms of that grain of musk, and at the end of the forty years the weight of musk has not appreciably diminished. [Page 256] Yet uncountable myriads on myriads of atoms have gone.