Amanda describes her marriage to Elyot as, "two violent acids bubbling about in a nasty little matrimonial bottle." Why would she use those words and what images do they provoke?

In that phrase, Amanda illustrates that both she and Elyot were incredibly temperamental with each other and that both of them were responsible for the violent arguments and tempers. Saying that they were stuck in a "nasty little matrimonial bottle" provokes the image that they were trapped together and that their "bubbling" was contained.