An Object never appears in its proper Colour, but where the Light illumining it is of the same Colour with it self: this is seen very sensibly in the Colours of Stuffs, the enlighten'd folds of which, throwing Reflex's or casting Light on the opposite folds, show them in their natural Colours. Gold-Leaves have the same effect, when they reflect their Light reciprocally from one to another; whereas when they receive their Light from any other Colour, they appear very different.