Note 10 — Chapter II · THE MATERIALISTIC ATOMISTS: LEUCIPPUS AND DEMOCRITUS

Van’t Hoff was first to explain the cause of a known difference in their behavior toward a beam of polarized light of two distinct substances—both of which are called amyl alcohol—the chemical formation of which is identical (i. e., composed of the same number and kinds of atoms)—by a difference in the order in which the four different groups of molecules are arranged in space about the central carbon atom; the arrangements in the two cases being such that one molecule has the same arrangement as the mirror image of the other—equivalent to the difference between a right-hand and a left-hand glove. Democritus could, possibly, on his theory, have arrived at such an explanation; whereas Aristotle, on his theory of the elements, could not possibly have done so—any more than could Empedocles (495-436 B. C.) have done so with his “four elements.”

As for the primal substance (“air”) of Anaximines (588-54 B. C.) and the “fire” of Heraclitus (535-475 B. C.), Dr. Gompertz contends that these were implicitly recognized as being composed of “minute, imperceptible particles” (“Greek Thinkers”, Vol. I, Page 323).