d in order to cure it," said Spilett to Cyrus Harding, "we need a
febrifuge."

"A febrifuge," answered the engineer. "We have neither Peruvian bark,
nor sulphate of quinine?"

"No," said Gideon Spilett, "but there are willows on the border of the
lake, and the bark of the willow might, perhaps, prove to be a
substitute for quinine."

"Let us try it without losing a moment," replied Cyrus Harding.

The bark of the willow has, indeed, been justly considered as
a succedaneum for Peruvian bark, as has also that of the
horse-chestnut-tree, the leaf of the holly, the snake-root, etcetera.
It was evidently necessary to make trial of this substance, although not
so valuable as Peruvian bark, and to employ it in its natural state,
since they had no means for extracting its essence.

Cyrus Harding went himself to cut from the trunk of a species of black
willow, a few pieces of bark; he brought them back to Granite House, and
reduced them to a powder, which was administered that same evening to
Herbert.

The night passed without any important change. Herbert was somewhat
delirious, but the fever did not reappear in the night, and did not
return either during the following day.

Pencroft again began to hope. Gideon Spilett said nothing. It might be
that the fever was not quotidian, but tertian, and that it would return
next day. Therefore, he awaited the next day with the greatest anxiety.

It might have been remarked besides that during this period Herbert
remained utterly prostrate, his head weak and giddy. Another symptom
alarmed the reporter to the highest degree. Herbert's liver became
congested, and soon a more intense delirium showed that his brain was
also affected.

Gideon Spilett was overwhelmed by this new complication. He took the
engineer aside.

"It is a malignant fever," said he.

"A malignant fever!" cried Harding. "You are mistaken, Spilett. A
malignant fever does not declare itself spontaneously; its germ must
previously have existed."

"I am not mistaken," replied the reporter. "Herbert no doubt contracted
the germ of this fever in the marshes of the island. He has already had
one attack; should a second come on and should we not be able to prevent
a third, he is lost."

"But the willow bark?"

"That is insufficient," answered the reporter; "and the third attack of
a malignant fever, which is not arrested by means of quinine, is always
fatal."

Fortunately, Pencroft heard nothing