[26] By a curious coincidence, the atomic constitution of matter still finds its strongest proof in optical phenomena. Light is propagated by transverse waves, and such waves are only possible in a discontinuous medium. But if the luminiferous ether is composed of discrete particles, so also must be the matter which it penetrates in all directions.

[27] Ar. De Gen. et Corr., I., viii., 325, b, 5.

[28] Eurip. Frag. Incert. Fab., CXXXVI. Didot, p. 850. [I am indebted for this version to Miss A. M. F. Robinson, the translator of the Crowned Hippolytus.]

[29] Curtius, Griechische Geschichte, 342-5 (3rd ed.).

[30] Zeller, op. cit., p. 791.

[31] Ar. De Coelo, III., iii., 302, a, 28.

[32] M. Antoninus, XII., 28.

[33] Zeller, Ph. d. Gr., III., b, p. 669.

[34] Even regulating the calendar by the sun instead of by the moon seems to have been regarded as a dangerous and impious innovation by the more conservative Athenians—at least judging from the half-serious pleasantry of Aristophanes, Nub., 608-26. (Dindorf.)

[35] σύμβολον δ’ οὔ πώ τις ἐπιχθονίων πιστὸν ἀμφὶ πράξιος ἐσσομένας εὗρεν θεόθεν.—Ol., XII., 8-9.