The next day passed with only a continuation of the lad’s feebleness. His emaciated hands clutched the bed clothing. They continued giving him doses of the willow powder, but the reporter anticipated no result from it. “If,” said he, “before to-morrow morning we cannot give him a more powerful febrifuge than this, Herbert will die!” The night came—doubtless the last night for this brave lad, so good, so clever, whom all loved as their own child! The sole remedy against this pernicious fever, the sole specific which could vanquish it, was not to be found on Lincoln Island! During the night Herbert became frightfully delirious. He recognized no one. It was not even probable that he would live till morning. His strength was exhausted. Towards 3 o’clock he uttered a frightful cry. He was seized by a terrible convulsion. Neb, who was beside him, rushed, frightened, into the adjoining chamber, where his companions were watching. At the same moment Top gave one of his strange barks. All returned to the chamber and gathered round the dying lad, who struggled to throw himself from the bed. Spilett, who held his arms, felt his pulse slowly rising. Five o’clock came. The sun’s rays shone into the chambers of Granite House. A beautiful day, the last on earth for poor Herbert, dawned over Lincoln Island. A sunbeam crept on to the table beside the bed. Suddenly Pencroff, uttering an exclamation, pointed to something on that table. It was a small oblong box, bearing these words:—— _Sulphate of quinine._ CHAPTER LIII. AN INEXPLICABLE MYSTERY—HERBERT’S CONVALESCENCE—THE UNEXPLORED PARTS OF THE ISLAND—PREPARATIONS FOR DEPARTURE—THE FIRST DAY—NIGHT—SECOND DAY—THE KAURIS—CASSOWARIES—FOOTPRINTS IN THE SAND—ARRIVAL AT REPTILE END. Spilett took the box and opened it. It contained a white powder, which he tasted. Its extreme bitterness was unmistakable. It was indeed that precious alkaloid, the true anti-periodic. It was necessary to administer it to Herbert without delay. How it came there could be discussed later. Spilett called for some coffee, and Neb brought a lukewarm infusion, in which the reporter placed eighteen grains of quinine and gave the mixture to Herbert to drink. There was still time, as the third attack of the fever had not yet manifested itself. And, indeed, it did not return. Moreover, every one became hopeful. The mysterious influence was again about them, and that too in a moment when they had despaired of its aid. After a few hours, Herbert rested more quietly, and the colonists could talk of the incident. The intervention of this unknown being was more evident than ever, but how had he succeeded in getting in to Granite House during the night? It was perfectly inexplicable, and, indeed, the movements of this “genius of the island” were as mysterious as the genius himself.