Final answer:
John and Lorraine want to leave Mr. Pignati's house quickly because they are anxious about the L & J Fund not being a real charity.
Step-by-step explanation:
In Chapter 5 of the book, John and Lorraine want to leave Mr. Pignati's house quickly because they are anxious since the L & J Fund is not a real charity. This is indicated in the text when John tells Lorraine that it is impossible to be both free and poor, and they need to dump the contents of their jewel box into their pockets as an extra caution. This shows that they are concerned about the illegitimacy of the charity and the potential consequences for them.