The number and persistent hostility of the aborigines formed a serious obstacle to the progress of this expedition. It was computed that no fewer than 4,000 were met with on the Murray. They were a low type even for Australian savages, and did not give evidence of a single redeeming quality. Addicted to every vice, living in the deepest sink of bestiality, with bodies in many cases rotting with disgusting diseases, they presented a loathsome spectacle, and were avoided whenever possible. Even when not disposed to be openly hostile, their presence at the camp was a terrible nuisance, and they were generally persuaded to leave, or hunted away. Sometimes they would rally their forces, and then prove not only troublesome but really dangerous. Like all savages they were adepts in deceit, and could wait their opportunity when a purpose had to be served. By dint of numbers and strategy together, they nearly succeeded on one occasion in annihilating the expedition. So long as the river maintained its usual width the boat was tolerably safe in the middle of the channel, for the spears of the savages were nearly harmless when they reached the centre of the stream, but their progress was rapidly approaching a spit which stretched far into the channel, and this position was seen to be occupied by blacks numbering more than fifty to one of Sturt's party. The situation was awfully critical, and in a few minutes more appeared to be positively desperate, for the boat grounded in shoal-water, and the explorers were at the mercy of the savages. Happily at this juncture some other natives, who had previously been friendly to the white men, arrived on the scene, and, through a somewhat barbarous style of intercession, prevailed with their sable fraternity in the interest of Sturt, and the murderous attack was immediately abandoned. Travel through an unknown country is usually a series of surprises, and it was no ordinary one that was now in store for the explorers. The spit which had threatened to be so disastrous proved to be an embankment silted up by the entrance of another large river into the Murray. Sturt had already been looking out for the junction of the Darling, which he had discovered on the previous expedition; and the question now to be determined was whether this could be the embouchure of the same river. He had struck the Darling at two points only a few months before, and at both places its water had been found too salt to drink; here, however, it was quite fresh; but in all other respects appearances were in favour of this river, and the Darling Sturt maintained it to be. For years after his decision was disputed, and even ridiculed by an authority of no less weight than Sir Thomas Mitchell. Subsequent exploration finally settled the question in Sturt's favour. The river was and could have been no other but the Darling, and thus another important problem of Australian geography was satisfactorily solved.