Sentence 9, right before the last sentence: I was better dress'd than ever while in his service, having a genteel new suit from head to foot, a watch, and my pockets lin'd with near five pounds in steerling silver.
It's pretty evident that he is miffed about his brother saying nothing to the family about how Franklin was doing in Philadelphia. To counter that, he describes his clothing to suggest that his brother was a bit jealous because he no doubt still dressed the way Franklin used to when he was employed by his brother.
