Section 4. Whenever by any Act or Regulation now in force or hereafter to be in force, any duty of customs or e

4. Whenever by any Act or Regulation now in force or hereafter to be in force, any duty of customs or excise or in the nature thereof is leviable on any given quantity, by weight, measure or value, of any goods or merchandize, a like duty shall be leviable according to the same rate on any greater or less quantity.