The Marble Faun, Volume II by Nathaniel Hawthorne

Along with the lamp on Hilda's tower, the sculptor now felt that a light had gone out, or, at least, was ominously obscured, to which he owed whatever cheerfulness had heretofore illuminated his cold, artistic life. The idea of this girl had been like a taper of virgin wax, burning with a pure and steady flame, and chasing away the evil spirits out of the magic circle of its beams. It had darted its rays afar, and modified the whole sphere in which Kenyon had his being. Beholding it no more, he at once found himself in darkness and astray.

This was the time, perhaps, when Kenyon first became sensible what a dreary city is Rome, and what a terrible weight is there imposed on human life, when any gloom within the heart corresponds to the spell of ruin that has been thrown over the site of ancient empire. He wandered, as it were, and stumbled over the fallen columns, and among the tombs, and groped his way into the sepulchral darkness of the catacombs, and found no path emerging from them. The happy may well enough continue to be such, beneath the brilliant sky of Rome. But, if you go thither in melancholy mood, if you go with a ruin in your heart, or with a vacant site there, where once stood the airy fabric of happiness, now vanished, -- all the ponderous gloom of the Roman Past will pile itself upon that spot, and crush you down as with the heaped-up marble and granite, the earth-mounds, and multitudinous bricks of its material decay.