30. Bills drawn in a set
When a bill of exchange is drawn in a set according to the custom of merchants, and one of the set is duly stamped, the other or others of the set shall, unless issued or in some manner negotiated apart from the stamped bill, be exempt from duty; and upon proof of the loss or destruction of a duly stamped bill forming one of a set, any other bill of the set which has not been issued or in any manner negotiated apart from the lost or destroyed bill may, although unstamped, be admitted in evidence to prove the contents of the lost or destroyed bill.