I have some old books that sit in the bathroom. I like to flip through them from time to time while sitting there. I have an old book, A Brief History of Ancient, Medieval, and Modern People from 1883. In the section entitled Italian cities, Venice, there is the following...
"In the 14th and 15th centuries the government grew into an oppressive oligarchy, the secret Council of Ten, like the Spartan Ephores, controlling the Doge and holding the threads of life and death. The Dagger, the poisoned ring, the close gondola, the deep silent canal, the Bridge of Sighs and the secret cell beyond - all linger in the mysterious history of the time."
Are the references in the second sentence specific things? What are they referring to?
Well, there are indeed specific objects and places (that is related to the Council of Ten, at least) that the book was referring to. I would only answer the ones I found reliable sources for though:
The Dagger - This can correspond to the legend of El Poaro Fornareto, or the poor baker's boy. There are multiple accounts of how the legends go, but essentially, it is about a poor baker's boy wrongly sentenced by the Council of Ten with death for a crime they did not commit. The legend essentially teaches future members of the council to first consider greatly the consequences and irreversibility of the death penalty before they issue it for criminals.
The Bridge of Sighs and the Secret Cell Beyond- It can refer to the Pontei dei Sospiri, which is the bridge connecting the Palazzio Ducale (where the Council of Ten would have worked out their interrogations) to the Priggio Nuove, or the New Prison, which is referred by the Secret Cell. BTW, the name "Bridge of Sighs" was coined by Lord Byron, who used it in one of his works.
Sources