L. * N. R. 00. ». GAINES. 275 �ships were unconstitutional. The People v. Salem, 20 Mich. 452; Bay City v. State Treasurer, 23 Mich. 499. �Encouraged by these opinions, Pine Grove township re- fused to pay the bonds sued on, and it was insisted in argu- ment that the federal courts were concluded by the construc- tion which the supreme court of the state had thus placed on the state constitution ;• but the supreme court of the United States held otherwise. The court say: "We have examined these cases with care," and find "that they are not satisfac- tory to our minds." The judgment overruling the decisions of the supreme court of Michigan is predieated mainly on the ground that the question "belonged to the domain of general jurisprudence touching commercial paper." But the reason- ing of the court goes beyond this. "When," say the court, "the bonds were issued there had been no authoritative inti- mation from any quarter that such statutes were in-v:alid." The legislature had passed many acts of this character, and during the period covered by their enactment "neither of the other departments of the state government lifted its voice against them." From this we infer that in ail cases where property has been aequired and investments made under and in virtue of statutory contracts, generally recognized, and be- lieved to be constitutional and valid, in the absence of adju- dications declaring them invalid, the federal courts, in the exercise of their jurisdiction, and in discharge of the duties especially and peculiarly imposed on them of preserving and enforcing the national constitution, and protecting contracts against impairment, are not concluded by the construction which the state courts may, subsequent to the acquisition of Buch property, give to such statutes; but that the federal tribunals will, in ail such cases where the construction given by the state courts "is not satisfactory to their minds," con- strue such statutes for themselves. Such, we understand, is the meaning of the Pine Grove case. Now, we think, this case comes within the principle anhounced, and we shall therefore construe the several statutes involved for ourself. �It is a legal axiom, long recognized, that an exemption from the common burden of taxation cannot be implied from ����
