48. Juv., VI, 489: "Isiacae sacraria lenae"; cf. Friedländer,
_Sittengeschichte_, I^6, p. 502.
49. In a recent book Farnell has brilliantly outlined the history of the
ritual of purification and that of the conception of purity throughout
antiquity (_Evolution of Religion_, London, 1905, pp. 88-192), but
unfortunately he has not taken Egypt into account where the primitive forms
have been maintained with perhaps the fewest alterations.