Note 1 — Chapter I

The subdued quality of the light in normal dreaming—the usual absence of sunshine and generally even of colour—has long been noted. 'We never dream of being in the sunshine,' says Henry Dircks (Lancet, 11th June 1870, p. 863), though too absolutely; 'light and shade form no requisite elements.... The liveliest and most impressive dream is, in reality, a true night scene, very dubiously lighted up, and in which the nearest objects are those which we principally observe and which most interest us.'