It is curious to observe that the water flowing over certain rocks, as in this instance, imbibes an appreciable, though necessarily most minute, portion of the minerals they contain.

The water of the Chobe up to this point is of a dark mossy hue, but here it suddenly assumes a lighter tint; and wherever this light color shows a greater amount of mineral, there are not mosquitoes enough to cause serious annoyance to any except persons of very irritable temperaments.
The large island called Mparia stands at the confluence.

This is composed of trap (zeolite, probably mesotype) of a younger age than the deep stratum of tufa in which the Chobe has formed its bed, for, at the point where they come together, the tufa has been transformed into saccharoid limestone.
The actual point of confluence of these two rivers, the Chobe and the Leeambye, is ill defined, on account of each dividing into several branches as they inosculate; but when the whole body of water collects into one bed, it is a goodly sight for one who has spent many years in the thirsty south.

Standing on one bank, even the keen eye of the natives can not detect whether two large islands, a few miles east of the junction, are main land or not.

During a flight in former years, when the present chief Sekomi was a child in his mother's arms, the Bamangwato men were separated from their women, and inveigled on to one of these islands by the Makalaka chief of Mparia, on pretense of ferrying them across the Leeambye.