Read it through once

From the palace to the gloomy prison is but a step--one might almost jump across the narrow canal that intervenes. The ponderous stone Bridge of Sighs crosses it at the second story--a bridge that is a covered tunnel --you can not be seen when you walk in it. It is partitioned lengthwise, and through one compartment walked such as bore light sentences in ancient times, and through the other marched sadly the wretches whom the Three had doomed to lingering misery and utter oblivion in the dungeons, or to sudden and mysterious death. Down below the level of the water, by the light of smoking torches, we were shown the damp, thick-walled cells where many a proud patrician's life was eaten away by the long-drawn miseries of solitary imprisonment--without light, air, books; naked, unshaven, uncombed, covered with vermin; his useless tongue forgetting its office, with none to speak to; the days and nights of his life no longer marked, but merged into one eternal eventless night; far away from all cheerful sounds, buried in the silence of a tomb; forgotten by his helpless friends, and his fate a dark mystery to them forever; losing his own memory at last, and knowing no more who he was or how he came there; devouring the loaf of bread and drinking the water that were thrust into the cell by unseen hands, and troubling his worn spirit no more with hopes and fears and doubts and longings to be free; ceasing to scratch vain prayers and complainings on walls where none, not even himself, could see them, and resigning himself to hopeless apathy, driveling childishness, lunacy! Many and many a sorrowful story like this these stony walls could tell if they could but speak.