The House of Mirth: Book II, Chapters I and II

The beginning of the second book of Edith Wharton's The House of Mirth has managed to be the greatest point of confusion thus far. The first chapter is easy to follow at first, but as soon as Mr. Selden runs into Miss Bart for the first time, the book suddenly takes a turn into confusion. Selden is making observations of Miss Bart and thinks, "She was 'perfect'"(Wharton, 155). Then in the very next paragraph, the story jumps to Selden going to dinner with Mr. Silverton. Wait-- What!? So random! This section only went downhill from this point. Next thing I know, the novel is back to Miss Bart who is going to breakfast with the Dutchess, and then Miss Bart goes to the Casino to gamble. What ever happened to Miss Bart being done with gambling debts? Then to make matters worse, there is some scene with Mr. Dorset falling on the ground having a "fit", and then he gets up and says he is getting a lawyer. Is Wharton attempting to piece together the most random events possible? The only non confusion that was witnessed in this section was the argument between Miss Bart and Mrs. Dorset. Even with understanding that scene, I can not decide which character I find more at fault.