In Ambrosini v. United States, 187 U.S. 1 (1902), in which the Federal war revenue tax act, providing for stamp taxes on bonds, was held inapplicable to bonds required from licensees under the dram shop act of Illinois, the court declared (p. 8): "The question is whether the bonds were taken in the exercise of a function strictly belonging to the State and city in their ordinary governmental capacity, and we are of the opinion that they were, and that they were exempted as no more taxable than the licenses."