D’Artagnan, whose inquiring disposition we are acquainted with, had not--whatever interest he had in satisfying his curiosity on this subject--been able to assign any cause for these fits of for the periods of their recurrence.
D'Artagnan, de quien conocemos el espíritu investigador y penetrante, por interés que tuviese en satisfacer su curiosidad sobre el tema, no había podido aún asignar ninguna causa a aquel marasmo, ni anotar las ocasiones.