I am not convinced by the provenance history of the VMS

[Oscroft]

Voynich famously said: 

• "When the time comes, I will prove to the world that the black magic of the Middle Ages consisted in discoveries far in advance of 20th-century science."
  

What was he referring to here? Did he see something in the VMS that alludes to "discoveries far in advance of 20th-century science" ? What on earth could he be talking about here?

Might he possibly have been exuding bovine-sourced fertiliser to big up his own importance? Has anyone ever done that before?