In Act 1, Scene 2 of Volpone, the audience is privy to a planning session between Mosca and Volpone as they prepare to fleece the latter’s prospective heirs. In Act 1, Scene 3, as Voltore earnestly arrives at Volpone’s side bearing gifts for the supposedly dying man, Jonson sets up an extended sequence of dramatic irony:
Mosca: You still are what you were sir. Only you,
Of all the rest, are he commands his love,
And you do wisely to preserve it thus,
With early visitation, and kind notes
Of your good meaning to him, which, I know,
Cannot but come most grateful. Patron, sir.
Here's Signior Voltore is come —Volpone: What say you?
Mosca: Sir, Signior Voltore is come this morning
To visit you.Volpone: I thank him.
Mosca: And hath brought
a piece of antique plate, bought of St Mark,
With which he here presents you.Volpone: He is welcome.
Pray him to come more often.
Voltore has no reason to suspect he is anything other than Volpone’s favorite, as Mosca says upon his arrival. Likewise, he has no reason to suspect that Volpone’s bid to see him more often is anything other than a sick man’s wish to see his heir. The audience, however, can plainly see the grift playing out before them: it is only after Mosca announces the gift of the antique plate that Volpone seeks Voltore’s return, which will presumably entail even more gifts.
Throughout Volpone, the audience is generally made aware of Volpone and Mosca’s various machinations well before any of the rest of the cast, raising the tensions of the play and empowering the audience to deliver their own judgements of the situation.
In Act 1, Scene 5, Corvino arrives at Volpone’s side with a gift of a pearl and a diamond. In a moment of particular dramatic irony, after Corvino declares that seeing Volpone in his sick bed is a “pitiful,” Mosca confides:
Tut, forget, sir.
The weeping of an heir should still be the laughter
Under a visor.
There are multiple layers of dramatic irony in this sequence. First and foremost, of course, is the fact that Volpone is not at all ill, as "pitiful" as he might look. The audience is, by now, well aware of this fraudulent sickness, but the suitors are a long way from catching on. Second is Mosca’s own word of advice to Corvino. While Corvino would presumably think that the “laughter under a visor” should be his own—after all, he suspects that Volpone will soon pass and leave him his fortune—the audience knows that Mosca is collaborating with Volpone on this fraud and, in fact, the weeping of the various prospective heirs is leading to quite a bit of laughter on the part of the criminal duo, especially since Corvino and his peers are giving up various treasures.
Mosca’s observation that even weeping should be a mask for other emotions points to his sinister vision of interpersonal relationships, in which all emotions only serve the purpose of being a means to an end—all motivated purely by greed. His ability to speak directly to various characters in the play without having them suspect his true motivations is evidence of his mastery of deception.
The entirety of Act 2, Scene 1 is a masterpiece of dramatic irony in which Peregrine toys with Sir Politic Would-Be, who will agree with anything he says. Peregrine goads him into making up more and more ridiculous stories. The audience is well aware of the farce, but Sir Politic himself is quite out of the loop:
Peregrine: I have heard, sir,
That your baboons were spies, and that they were
A kind of subtle nation near to China.Sir Politic: Ay, ay, your Mamuluchi. Faith, they had
Their hand in a French plot, or two; but they
Were so extremely given to women as
They made discovery of all; yet I
Had my advices here, on Wednesday last,
From one of their own coat, they were returned,
Made their relations, as the fashion is,
And now stand fair for fresh employment.Peregrine [aside]: —Heart!
This Sir Pol will be ignorant of nothing—
It seems, sir, you know all.
Baboons, it's safe to say, are incapable of espionage, and yet Sir Politic Would-Be latches on to Peregrine's observation and responds with a made-up anecdote of his own in order to keep up. Jonson stokes the dramatic irony of the scene by including frequent asides from Peregrine, which the audience is privy to but Sir Politic is not: here, Peregrine conveys his astonishment that Sir Politic refuses to be ignorant of anything. Because of this additional perspective on the situation, the audience is as aware as Peregrine of Sir Politic's buffoonery.
In Act 3, Scene 2, Mosca sees Bonario in the street and recognizes him as Corbaccio’s son. Bonario rebukes Mosca for his “baseness,” dismissing him as a vile and immoral creature. When Mosca explodes in a fit of emotion at these accusations, Bonario realizes he may have been too “harsh” with the man:
This cannot be a personated passion! —
I was to blame, so to mistake thy nature;
Pray thee forgive me and speak out thy business.
Unbeknownst to Bonario, however, Mosca is well aware of his own impudence. The audience has just witnessed Mosca’s soliloquy in the previous scene, during which Mosca revealed his pride in his parasitic status and how his natural talent for deception will only help him gain status and power. As Mosca persuades Bonario of his innocence, therefore, Jonson builds the dramatic irony of the scene—the audience and Mosca know the extent to which the latter will go to continue his ruse, and the extent to which, as a parasite, he will "feed" on any character who crosses his path.
Sure enough, just as soon as Bonario rethinks his impression of Mosca, Mosca begins to toy with him about “his business”:
Sir, it concerns you, and though I may seem
At first to make a main offence in manners,
And in my gratitude unto my master,
Yet, for the pure love which I bear all right,
And hatred of the wrong, I must reveal it.
This very hour your father is in purpose
To disinherit you –
Pretending to double-cross his own master Volpone, Mosca lets Bonario in on Corbaccio’s disinheritance, which, of course, Mosca and Volpone have orchestrated together. This sequence shows Mosca’s shape-shifting, manipulative brilliance in full swing, and—after his soliloquy—the audience can fully appreciate the dramatic irony of the moment as Bonario himself falls prey to the parasitic plan.
In Act 5, Scene 5, Volpone leaves Mosca alone in his house as he leaves to check in on the court proceedings. Soliloquizing on his machinations to the audience, Mosca builds upon the metaphorical animal identities of the play's characters and reveals his plot against Volpone, or "the fox."
[...] My fox
Is out on his hole, and ere he shall re-enter,
I’ll make him languish in his borrowed case,
Except he come to composition with me.[...]
So, now I have the keys and am possessed.
Since he will needs be dead afore his time,
I'll bury him, or gain by him. I'm his heir,
And so will keep me, till he share at least.
To cozen him of all were but a cheat
Well placed; no man would cònstrue it a sin.
Let his sport pay for 't. This is called the fox-trap.
Volpone has left his "hole," or burrow—that is, he has left his house, which is where Mosca now plots against him. Mosca's plan to fleece Volpone for his fortune, meanwhile, builds upon this metaphor when Mosca opts to give it the name of "the fox-trap." Mosca is now using the language of the hunt and establishing himself as the hunter—an aristocratic occupation befitting his newfound disguise as a member of the nobility, which he displays for Volpone and the audience at the beginning of this scene.
Mosca's great strength in Volpone is his ability to manipulate his identity and his status through the versatility of his language, and moments like this soliloquy show his skill in full form, thus creating some dramatic irony for the audience—only they are privy to the nature of Mosca's ambition, as he sets out to write his own story by moving against Volpone.
