The author's use of language in this sentence from "Ten Days in a Mad-House" serves to create a sense of humor and lightheartedness in what is otherwise a bleak and serious story. The use of the word "amused" indicates that the narrator is not taking the situation too seriously, and the phrase "successful grabbings" has a comical tone to it. The use of the phrase "without so much as by your leave" is also somewhat humorous, as it is an old-fashioned expression that is not commonly used in modern English. Overall, the language in this sentence provides a brief moment of levity in what is otherwise a harrowing account of life in a mental institution.