Within the film version of The Prestige, it is established that
Angier has engineered his magic trick so that the figure on the platform would be dropped into a tank of water to kill them, for they were, as he was, still alive.
In comparison, within the novel
No such mechanism is mentioned, although it is established that there is a body left behind after every performance of the "trick", buried in the crypt.
My interpretation of the novel's events is that only biological material is duplicated, and that the soul (or, as Tesla calls it, the "life energy") is transported, meaning that what Angier calls "the prestige materials" is always inert. Is there any evidence that is indeed what is meant to be shown (keeping in mind that, since most of the novel is epistolary, we've got a serious case of unreliable narrators)?