Book recently purchased by Sherlock Holmes

"This is a queer old book I picked up at a stall yesterday — De Jure inter Gentes — published in Latin at Liege in the Lowlands, in 1642. Charles’s head was still firm on his shoulders when this little brown-backed volume was struck off.”
“Who is the printer?”
“Philippe de Croy, whoever he may have been. On the flyleaf, in very faded ink, is written ‘Ex libris Guliolmi Whyte.’ I wonder who William Whyte was. Some pragmatical seventeenth century lawyer, I suppose. His writing has a legal twist about it." (
Sherlock Holmes)