ignis fatuus

This was doubtless a true ignis fatuus, and the circumstances necessary to produce it were then present, viz.

Thus far the Hofrath; who vanishes, as is his wont, too like an Ignis Fatuus, leaving the dark still darker.

Still the ignis fatuus of a shorter route to India tantalized the early navigators.

He had not been imposed upon by his fancy; he had not been deceived by some ignis fatuus.

It is, in truth, a shadow as intangible as our own; an ignis fatuus of our being.