In what circumstances will a motion to quash an indictment for duplicity be successful?

In McGregor v. United States, 134 F. 187, 194, 69 C.C.A. 477, 484, the motion to quash the indictment for alleged duplicity was based on the fact that some of the counts charged that the defendants conspired to defraud the United States, and other of the counts charged that the defendants, being officers and agents, or officers and clerks, violated certain sections of the Revised Statutes by receiving money [203 F. 931] from an alleged co-conspirator for procuring, or aiding to procure, a contract mentioned in the counts relating to the conspiracy.