Continuing, my guest argued as follows: "Do not lakes exist on the earth's surface into which rivers and streams flow, but which have no visible outlet? Are not such lakes saline, even though the source of supply is comparatively fresh? Has it never occurred to you to question whether capillarity assisted by surface evaporation (not evaporation only as men assert) is not separating the water of these lakes from the saline substances carried into them by the streams, thus producing brine lakes? Will not this action after a great length of time result in crystalline deposits over portions of the bottoms of such lakes, and ultimately produce a salt bed?" "It is possible," I replied. "Not only possible, but probable. Not only probable, but true. Across the intervening brine strata above the salt crystals the surface rivers may flow, indeed, owing to differences in specific gravity the surface of the lake may be comparatively fresh, while in the quiet depths below, beds of salt crystals are forming, and between these extremes may rest strata after strata of saline solutions, decreasing in gravity towards the top." Then he took his manuscript, and continued to read in a clear, musical voice, while I sat a more contented listener than I had been previously. I was not only confuted, but convinced. And I recalled the saying of Socrates, that no better fortune can happen a man than to be confuted in an error. MY UNBIDDEN GUEST CONTINUES READING HIS MANUSCRIPT. CHAPTER XXI. MY WEIGHT DISAPPEARING. We halted suddenly, for we came unexpectedly to the edge of a precipice, twenty feet at least in depth. "Let us jump down," said my guide. "That would be dangerous," I answered; "can not we descend at some point where it is not so deep?" "No; the chasm stretches for miles across our path, and at this point we will meet with the least difficulty; besides, there is no danger. The specific gravity of our bodies is now so little that we could jump twice that distance with impunity." "I can not comprehend you; we are in the flesh, our bodies are possessed of weight, the concussion will be violent." "You reason again from the condition of your former life, and, as usual, are mistaken; there will be little shock, for, as I have said, our bodies are comparatively light now. Have you forgotten that your motion is continuously accelerated, and that without perceptible exertion you move rapidly? This is partly because of the loss of weight. Your weight would now be only about fifty pounds if tested by a spring balance." I stood incredulous. "You trifle with me; I weigh over one hundred and fifty pounds; how have I lost weight? It is true that I have noticed the ease with which we have recently progressed on our journey, especially the latter part of it, but I attribute this, in part, to the fact that our course is down an incline, and also to the vitalizing power of this cavern air."