The way to the lake was marked by fresh and lamentable tokens of the sufferings of slaves. “24th June.—­Six men-slaves were singing as if they did not feel the weight and degradation of the slave-sticks.  I asked the cause of their mirth, and was told that they rejoiced at the idea of ’coming back after death, and haunting and killing those who had sold them,’ Some of the words I had to inquire about; for instance, the meaning of the words, ‘to haunt and kill by spirit power,’ then it was, ’Oh, you sent me off to Manga (sea-coast), but the yoke is off when I die, and back I shall come to haunt and to kill you.’  Then all joined in the chorus, which was the name of each vendor.  It told not of fun, but of the bitterness and tears of such as were oppressed; and on the side of the oppressors there was power.  There be higher than they!”

His discovery of Lake Bangweolo is recorded as quietly as if it had been a mill-pond:  “On the 18th July, I walked a little way out, and saw the shores of the lake for the first time, thankful that I had come safely hither.”  The lake had several inhabited islands, which Dr. Livingstone visited, to the great wonder of the natives, who crowded around him in multitudes, never having seen such a curiosity as a white man before.  In the middle of the lake the canoe-men whom he had hired to carry him across refused to proceed further, under the influence of some fear, real or pretended, and he was obliged to submit.  But the most interesting, though not the most pleasant, thing about the lake, was the ooze or sponge which occurred frequently on its banks.  The spongy places were slightly depressed valleys, without trees or bushes, with grass a foot or fifteen inches high; they were usually from two to ten miles long, and from a quarter of a mile to a mile broad.  In the course of thirty geographical miles, he crossed twenty-nine, and that, too, at the end of the fourth month of the dry season.  It was necessary for him to strip the lower part of his person before fording them, and then the leeches pounced on him, and in a moment had secured such a grip, that even twisting them round the fingers failed to tear them off.

It was Dr. Livingstone’s impression at this time that in discovering Lake Bangweolo, with the sponges that fed it, he had made another discovery—­that these marshy places might be the real sources of the three great rivers, the Nile, the Congo, and the Zambesi.  A link, however, was yet wanting to prove his theory.  It had yet to be shown that the waters that flowed from Lake Bangweolo into Lake Moero, and thence northward by the river Lualaba, were connected with the Nile system.  Dr. Livingstone was strongly inclined to believe that this connection existed; but toward the close of his life he had more doubts of it, although it was left to others to establish conclusively that the Lualaba was the Congo, and sent no branch to the Nile.