As quoted by Luis Bunuel here:

Connoisseurs who like their martinis very dry suggest simply allowing a ray of sunlight to shine through a bottle of Noilly Prat before it hits the bottle of gin. At a certain period in America it was said that the making of a dry martini should resemble the Immaculate Conception, for, as Saint Thomas Aquinas once noted, the generative powers of the Holy Ghost pierced the virgin’s hymen “like a ray of sunlight through a window–-leaving it unbroken.”