That Irishman and the Ague

O’Connor Power suffered from attacks of an acute, violent fever.  Was the disabling ague a recurrence of malaria or of typhus? The symptoms might be heavy, dry eyes, severe headache and deep weariness, followed, for several days, by alternate bouts of shivering and sweating until the fever ran its course.

Ague:  An intermitting fever with cold fits succeeded by hot. The cold is, in popular language, more particularly called the ague, and the hot the fever. (Dr  Johnson)