We are not sure about the date of this manuscript, perhaps 1600.
Like many of its contemporary sources it uses an example of two notes (an interval) and then shows how you could use an ornament to go from one note to the next. In a type of table-format the book suggests several options for the same interval; by learning those by heart you get a sense for the style and possibilities.
Unfortunately there are no examples of how to apply these ornaments to actual pieces.
Interesting are the ricercares, which can inspire us to improvise our own.
Finally Virgiliano gives 10 rules for improvising diminutions which are very helpful.
A translation can be found here:
Solo / Ensemble
Type of Thing you Learn
Diminutions, Diminution, Ornamentation, Passaggi, Cadenze, Ricercare