Fluent in several languages, Edgar Allan Poe employed words often because of their sounds and connotations as well as their denotations. For instance, it seems that Poe prefers those of Latin derivation in his story "The House of Usher"; perhaps the antiquity of this language parallels that of the Usher mansion and the family tree, as well. One such example of this use of Latin words is in the description of the family in the third paragraph:
it was this deficiency, perhaps, of collateral issue, and the consequent undeviating transmission, from sire to son, of the patrimony with the name which had, at length, so identified the two as to merge the original title of the estate in the quaint and equivocal appellation of the "House of Usher"--an appellation which seemed to include, in the minds of the peasantry who used it, both the family and the family mansion.
In addition to his use of antiquated and more formal words, much of the structure of the sentences in this narrative also demonstrates Poe's knowledge of Romance languages and Latin with their more formal structure than commonplace English. One instance of this use of Latin-type sentence structure is the placement of the subject of the sentence at the end:
To an anomalous species of terror I found him a bounden slave.
Such a long sentence as this one is not to be found often, either, and certainly not in informal language:
A cadaverousness of complextion; an eye large, liquid, and luminous beyond comparison; lips somewhat thin and very pallid, but of a surpassingly beautiful curve; a nose of a delicate Hebrew model, but with a breadth of nostril unusual in similar formation; a finely moded chin, speaking, in its want of prominence, of a want of moral energy; hair of a more than weblike softness and tenuity; these features [features, here, is the subject of the sentence], with an inordinate expansion above the regions of the temple, made up altogether a countenance not easily to be forgotten.
Indeed, Poe's story of "The House of Usher" exhibits much formal language. This language in such sentences as
A settle apathy, a gradual wasting away of the person, and frequent although transient affections of a partially cataleptical character, were the unusual diagnosis.
creates a mysterious, antiquated atmosphere--one that shrouds a horrific conclusion to Poe's bizarre tale.