Young man, this very temptation is a part of thy trial." With that, Mejnour placed the key in his hands; and at sunset he left the castle.
For several days Glyndon continued immersed in employments which strained to the utmost all the faculties of his intellect.

Even the most partial success depended so entirely on the abstraction of the mind, and the minuteness of its calculations, that there was scarcely room for any other thought than those absorbed in the occupation.

And doubtless this perpetual strain of the faculties was the object of Mejnour in works that did not seem exactly pertinent to the purposes in view.

As the study of the elementary mathematics, for example, is not so profitable in the solving of problems, useless in our after-callings, as it is serviceable in training the intellect to the comprehension and analysis of general truths.
But in less than half the time which Mejnour had stated for the duration of his absence, all that the mystic had appointed to his toils was completed by the pupil; and then his mind, thus relieved from the drudgery and mechanism of employment, once more sought occupation in dim conjecture and restless fancies.

His inquisitive and rash nature grew excited by the prohibition of Mejnour, and he found himself gazing too often, with perturbed and daring curiosity, upon the key of the forbidden chamber.