Here's the blog page where I first saw the link to it:-
While the Mutus Liber hasn't quite reached the Internet fandom level of the Voynich Manuscript, there's still plenty out there on it. It is (as far as anyone knows) from no earlier than 1677: here are two "translations" of it:-
And here (for the interested) is a link to a page on Serafini's Pulcinellopedia. Enjoy!