It contained nearly two hundred grains of a white powder, a few particles of which he carried to his lips. The extreme bitterness of the substance precluded all doubt; it was certainly the precious extract of quinine, that pre-eminent antifebrile.

This powder must be administered to Herbert without delay. How it came there might be discussed later.

"Some coffee!" said Spilett.

In a few moments Neb brought a cup of the warm infusion. Gideon Spilett threw into it about eighteen grains of quinine, and they succeeded in making Herbert drink the mixture.

There was still time, for the third attack of the malignant fever had not yet shown itself. How they longed to be able to add that it would not return!

Besides, it must be remarked, the hopes of all had now revived. The mysterious influence had been again exerted, and in a critical moment, when they had despaired of it.

In a few hours Herbert was much calmer. The colonists could now discuss this incident. The intervention of the stranger was more evident than ever. But how had he been able to penetrate during the night into Granite House? It was inexplicable, and, in truth, the proceedings of the genius of the island were not less mysterious than was that genius himself. During this day the sulphate of quinine was administered to Herbert every three hours.

The next day some improvement in Herbert's condition was apparent. Certainly, he was not out of danger, intermittent fevers being subject to frequent and dangerous relapses, but the most assiduous care was bestowed on him. And besides, the specific was at hand; nor, doubtless, was he who had brought it far distant! And the hearts of all were animated by returning hope.

This hope was not disappointed. Ten days after, on the 20th of December, Herbert's convalescence commenced.

He was still weak, and strict diet had been imposed upon him, but no access of fever supervened. And then, the poor boy submitted with such docility to all the prescriptions ordered him! He longed so to get well!

Pencroft was as a man who has been drawn up from the bottom of an abyss. Fits of joy approaching delirium seized him. When the time for the third attack had passed by, he nearly suffocated the reporter in his embrace. Since then, he always called him Dr. Spilett.

The real doctor, however, remained undiscovered.

"We will find him!" repeated the sailor.

Certainly, this man, whoever he was, might expect a somewhat too energetic embrace from the worthy Pencroft!

The month of December ended, and with it the year 1867, during which the colonists of Lincoln Island had of late been so severely tried. They commenced the year 1868 with magnificent weather, great heat, and a tropical temperature, delightfully cooled by the sea-breeze. Herbert's recovery progressed, and from his bed, placed near one of the windows of Granite House, he could inhale the fresh air, charged with ozone, which could not fail to restore his health. His appetite returned, and what numberless delicate, savory little dishes Neb prepared for him!

"It is enough to make one wish to have a fever oneself!" said Pencroft.

During all this time, the convicts did not once appear in the vicinity of Granite House. There was no news of Ayrton, and though the engineer and Herbert still had some hopes of finding him again, their companions did not doubt but that the unfortunate man had perished. However, this uncertainty could not last, and when once the lad should have recovered, the expedition, the result of which must be so important, would be undertaken. But they would have to wait a month, perhaps, for all the strength of the colony must be put into requisition to obtain satisfaction from the convicts.

However, Herbert's convalescence progressed rapidly. The congestion of the liver had disappeared, and his wounds might be considered completely healed.

During the month of January, important work was done on the plateau of Prospect Heights; but it consisted solely in saving as much as was possible from the devastated crops, either of corn or vegetables.