Upon a trial for forging any bill or note purporting to be the bill or note of an incorporated company or bank, or for passing or attempting to pass, or having in his possession, with intent to pass, any such forged bill or note, it is not necessary to prove the incorporation of such bank or company by the charter or act of incorporation, but it may be proved by a general reputation, and persons of skill are competent witnesses to prove that such bill or note is forged or counterfeited.