I'm trying to analyse Shelley's "England in 1819", but I'm having trouble with a certain passage which features a semicolon within two dashes. I find this quite confusing, and,therefore, I'm not sure what the author means. Here is the sentence with some extra lines for context:
Golden and sanguine laws which tempt and slay; Religion Christless, Godless—a book sealed; A senate, Time’s worst statute, unrepealed— Are graves from which a glorious Phantom
Is the senate referring to the "book sealed" (the Bible) or is senate just meaning the parliament here? What does the use of the semicolon and dashes mean?