By "wind", Salerio means his breath used to blow cool air onto hot soup. He compares his breath to wind at sea which might cause a storm and destroy his boat. Notice that Salerio equates his breath, that which sustains his life, with his investments. Salerio and Solanio's understanding of Antonio's melancholy demonstrate the extreme importance of money to these principal characters.
Here, Salerio implies as classed system in which Antonio's stately ships are better than all of the poor merchants's ships. He compares the natural bobbing of ships in the sea to peasants "curtsying" to their lord to show reverence. In this metaphor, the poor merchants's ships curtsy to Antonio's ship because Antonio is a richer, higher class merchant. This imagination of Antonio's ships classifies him and his friends as members of the upper class.
"breed for barren metal..."See in text(Act I - Scene III)
In this metaphor, Antonio argues that money making money is unnatural. Coins are barren, or infertile, and thus should not be able to breed more coins. In other words, more money should not be made from interest.
"Hercules and Lichas..."See in text(Act II - Scene I)
Lichas was Hercules's servant who gave him a poisoned shirt that eventually killed Hercules. When Hercules realized what Lichas had done, he used his strength to throw him into the sea. Here, Morocco uses this story to show that if left to luck, symbolized by dice, it would not have mattered who was stronger in this fight. In this way he touches on a main theme of the play: whether one's fate should be decided by fortune and luck or skill and ability.
Here, Gobbo uses a metaphor that compares his son to a "staff." By this metaphor, Gobbo means that Launcelot supports him in his old age, and laments the loss of this support.
Notice how Jessica picks up the same metaphor that Launcelot used to describe Shylock in the previous scene. Except here, while the house is "Hell" Launcelot is the devil, rather than Shylock, and devil is repurposed to mean entertainer.
This metaphor suggests that the seeker was burned by the very thing that they sought, as in a moth who is burned by the flame. In this way, Portia mocks the suitors for not only their bad choices but their decision to pursue her in the first place.
"livers white as milk..."See in text(Act III - Scene II)
The liver was believed to be the seat of someone's courage. As red blood symbolized strength, courage, and virility, a "white" liver meant someone was a coward. Bassanio uses this metaphor to show that someone's outward appearance may clash with their internal makeup.
"Dardanian wives..."See in text(Act III - Scene II)
"Dardanian wives" is another way to say Trojan wives. Portia's use of this metaphor demonstrates the performed nature of her rescue as it needs spectators.
"swan-like end,..."See in text(Act III - Scene II)
A "swan-like end" means a swan song or final performance before death. It was believed that swans only sang once in their lives while they were dying. Using this metaphor, Portia emphasizes the performative nature of Bassanio's love and choice; she imagines his failure like a final performance.
This exchange metaphorically positions Portia as a torturer and Bassanio as her political prisoner and offers one reason why these two claim to be so emphatically in love with each other. As the "torturer" Portia gets the power she lacks while being constrained by her father's will. Bassanio will become her prisoner in order to relieve himself of debt.
Gratiano compares the lesson that their wives have taught them to roads in summer. The lesson was as unnecessary as fixing roads in the summer time which have not yet been destroyed by weather.
