Hum... The guy's call to fame was inventing the "dictatorship of the proletariat" thing and calling for people to create it.
And if you just study his ideas for the economic theory, it was mostly just flat wrong, and the good parts have already been extended into much more useful theories so you won't get anything from it.
Vespuccia
They didn't speak English in Spain back then, but I'm not sure how they would handle the Italian.