The Persian Letters of Montesquieu was a prohibited book, but, for all that, there were a hundred editions of it before it had been published twenty years, and every schoolboy could find a copy on the quays for a dozen halfpence.

Bayle's Thoughts on the Comet, Rousseau's Emilius and Heloisa, Helvetius's L'Esprit, and a thousand other forbidden pieces were in every library, both public and private.

The Social Contract, printed over and over again in endless editions, was sold for a shilling under the vestibule of the king's own palace.

When the police were in earnest, the hawker ran horrible risks, as we saw a few pages further back; for these risks he recompensed himself by his prices.

A prohibition by the authorities would send a book up within four-and-twenty hours from half a crown to a couple of louis.