as powerfully as in any prismatic experiment; nay, the force of the physical colours is owing principally to the circumstance that light is always acting with and behind them.
584.
Lichtenberg, who of necessity followed the received theory, owing to the time and circumstances in which he lived, was yet too good an observer, and too acute not to explain and classify, after his fashion, what was evident to his senses. He says, in the preface to Delaval, "It appears to me also, on other grounds, probable, that our organ, in order to be impressed by a colour, must at the same time be impressed by all light (white)."
585.
To procure white as a ground is the chief business of the dyer. Every colour may be easily communicated