"Humanity will yet attain it," he replied. "Step by step men have stumbled along towards the goal that the light of coming centuries is destined to illuminate. They have studied, and are still engaged in studying, the properties of grosser forces, such as heat and electricity, and they will be led by the thread they are following, to this and other achievements yet unthought of, but which lie back of those more conspicuous." [Illustration: "WE FINALLY REACHED A PRECIPITOUS BLUFF."] We finally reached a precipitous bluff, that sprung to my view as by magic, and which, with a glass-like surface, stretched upward to a height beyond the scope of my vision, rising straight from the surface of the lake. It was composed of a material seemingly black as jet, and yet when seen under varying spectacular conditions as we skirted its base it reflected, or emitted, most gorgeously the brilliant hues of the rainbow, and also other colors hitherto unknown to me. "There is something unique in these shades; species of color appear that I can not identify; I seem to perceive colors utterly unlike any that I know as the result of deflected, or transmitted, sunlight rays, and they look unlike the combinations of primary colors with which I am familiar." "Your observations are true; some of these colors are unknown on earth." "But on the surface of the earth we have all possible combinations of the seven prismatic rays," I answered. "How can there be others here?" "Because, first, your primary colors are capable of further subdivision. "Second, other rays, invisible to men under usual conditions, also emanate from the sun, and under favorable circumstances may be brought to the sense of sight." "Do you assert that the prism is capable of only partly analyzing the sunlight?" "Yes; what reason have you to argue that, because a triangular bit of glass resolves a white ray into seven fractions that are, as men say, differently colored, you could not by proper methods subdivide each of these so-called primary shades into others? What reason have you to doubt that rays now invisible to man accompany those capable of impressing his senses, and might by proper methods become perceptible as new colors?" "None," I answered; "only that I have no proof that such rays exist." "But they do exist, and men will yet learn that the term 'primitive' ray, as applied to each of the seven colors of the rainbow, is incorrect. Each will yet be resolved, and as our faculties multiply and become more subtle, other colors will be developed, possessed of a delicacy and richness indescribable now, for as yet man can not comprehend the possibilities of education beyond the limits of his present condition."