We take it, then, that it is no longer to be questioned that the Federal courts in determining cases before them are to be guided by the following rules: 1. When administering state laws and determining rights accruing under those laws the jurisdiction of the Federal court is an independent one, not subordinate to but coördinate and concurrent with the jurisdiction of the state courts. 2. Where, before the rights of the parties accrued, certain rules relating to real estate have been so established by state decisions as to become rules of property and action in the State, those rules are accepted by the Federal court as authoritative declarations of the law of the State. 3. But where the law of the State has not been thus settled, it is not only the right but the duty of the Federal court to exercise its own judgment, as it also always does when the case before it depends upon the doctrines of commercial law and general jurisprudence. 4. So, when contracts and transactions are entered into and rights have accrued under a particular state of the local decisions, or when there has been no decision by the state court on the particular question involved, then the Federal courts properly claim the right to give effect to their own judgment as to what is the law of the state applicable to the case, even where a different view has been expressed by the state court after the rights of parties accrued. But even in such cases, for the sake of comity and to avoid confusion, the Federal court should always lean to an agreement with the state court if the question is balanced with doubt.

The court took care, in Burgess v. Seligman, to say that the Federal court would not only fail in its duty, but would defeat the object for which the national courts were given jurisdiction of controversies between citizens of different States, if, while leaning to an agreement with the state court, it did not exercise an independent judgment in cases involving principles not settled by previous adjudications.

It would seem that according to those principles, now firmly established, the duty was upon the Federal court, in

the present case, to exercise its independent judgment as to what were the relative rights and obligations of the parties under their written contract. The question before it was as to the liability of the Coal Company for an injury arising from the failure of that corporation, while mining and taking out the coal, to furnish sufficient support to the overlying or surface land. Whether such a case involves a rule of property in any proper sense of those terms, or only a question of general law within the province of the Federal court to determine for itself, the fact exists that there had been no determination of the question by the state court before the rights of the parties accrued and became fixed under their contract, or before the injury complained of. In either case, the Federal court was bound under established doctrines to exercise its own independent judgment, with a leaning, however, as just suggested, for the sake of harmony, to an agreement with the state court, if the question of law involved was deemed to be doubtful. If, before the rights of the parties in this case were fixed by written contract, it had become a settled rule of law in West Virginia, as manifested by decisions of its highest court, that the grantee or his successors in such a deed as is here involved, was under no legal obligation to guard the surface land of the grantor against injury resulting from the mining and removal of the coal purchased, a wholly different question would have been presented.

There are adjudged cases involving the meaning of written contracts having more or less connection with land that were not regarded as involving a rule in the law of real estate, but as only presenting questions of general law touching which the Federal courts have always exercised their own judgment, and in respect to which they are not bound to accept the views of the state courts. Let us look at some of those cases. They may throw light upon the present discussion.

In Chicago City v. Robbins, 2 Black, 418, 428, which was

an action on the case for damages, the question was as to the right of the city of Chicago-which was under a duty to see that its streets were kept in safe condition for persons and property-to hold one Robbins liable in damages for so using his lot on a public street as to cause injury to a passer-by. The city was held liable to the latter and sued Robbins on that account. The state court, in a similar case, decided for the defendant, and it was contended that the Federal court should accept the views of the local court as to the legal rights of the parties. But this court, speaking by Mr. Justice Davis, said: "Where rules of property in a State are fully settled by a series of adjudications, this court adopts the decisions of the state courts. But where private rights are to be determined by the application of common-law rules alone, this court, although entertaining for state tribunals the highest respect, does not feel bound by their decisions."

In Lane v. Vick, 3 How. 464, 472, 476, the nature of the controversy was such as to require a construction of a will which, among other property, devised certain real estate which, at the time of suit, was within the limits of Vicksburg, Mississippi. There had been a construction of the will by the Supreme Court of the State, 1 How. (Miss.) 379, and that construction, it was insisted, was binding on the Federal court. But this court said: "Every instrument of writing should be so construed as to effectuate, if practicable, the intention of the parties to it. This principle applies with peculiar force to a will. The parties in that case were not the same as those now before this court; and that decision does not affect the interests of the complainants here. The question before the Mississippi court was, whether certain grounds, within the town plat, had been dedicated to public use. The construction of the will was incidental to the main object of the suit, and of course was not binding on any one claiming under the will. With the greatest respect, it may be proper to say, that this court does not follow the state courts in their construction of a will or any other instru

ment, as they do in the construction of statutes. Where, as in the case of Jackson v. Chew, 12 Wheat. 167, the construction of a will had been settled by the highest courts of the State, and had long been acquiesced in as a rule of property, this court would follow it, because it had become a rule of property. The construction of a statute by the Supreme Court of a State is followed, without reference to the interests it may affect, or the parties to the suit in which its construction was involved. But the mere construction of a will by a state court does not, as the construction of a statute of the State, constitute a rule of decision for the courts of the United States. In the case of Swift v. Tyson, 16 Pet. 1, the effect of section 34 of the Judiciary Act of 1789, and the construction of instruments by the state courts, are considered with greater precision than is found in some of the preceding cases on the same subject."

In Foxcroft v. Mallett, 4 How. 353, 379, the object of the action was to recover certain land in Maine. The case turned in part on the construction to be given to a mortgage of certain land to Williams College, and to local adjudications relating to those lands, which, it was contended, were conclusive on the parties. "But," this court said, "on examining the particulars of the cases cited to govern this (3 Fairfield, 398; 4 Shepley, 84, 88; 14 Maine R. 51), it will be seen that the construction of the mortgage to the college, in respect to this reservation or condition, never appears to have been agitated. If it had been, the decision would be entitled to high respect, though it should not be regarded as conclusive on the mere construction of a deed as to matters and language belonging to the common law, and not to any local statute. 3 Sumner, 136, 277.”

In Russell v. Southard, 12 How. 139, 147, the controlling question was whether in any case it was admissible to show by extraneous evidence that a deed on its face of certain real estate in Kentucky was really intended by the parties as a security for a loan and as a mortgage. The court, speaking

by Mr. Justice Curtis, after citing adjudged cases sustaining the proposition that evidence of that kind was admissible in certain States, said: "It is suggested that a different rule is held by the highest court of equity in Kentucky. If it were, with great respect for that learned court, this court would not feel bound thereby. This being a suit in equity, and oral evidence being admitted, or rejected, not by the mere force of any state statute, but upon the principles of general equity jurisprudence, this court must be governed by its own views of those principles"-citing Robinson v. Campbell, 3 Wheat. 212; United States v. Howland, 4 Wheat. 108; Boyle v. Zacharie 6 Pet. 635, 658; Swift v. Tyson, 16 Pet. 1; Foxcroft v. Mallett, 4 How. 353, 379.

In Yates v. Milwaukee, 10 Wall. 497, 506, the question was as to the nature and extent of the right of an owner of land in Wisconsin, bordering on a public navigable water, to make a landing, wharf or pier for his own use or for the use of the public. There was a question in the case of dedication to public use, and the city of Milwaukee sought to change or remove the wharf erected by the riparian owner in front of his lot. This court, speaking by Mr. Justice Miller, said: "This question of dedication, on which the whole of that case turned, was one of fact, to be determined by ascertaining the intention of those who laid out the lots, from what they did, and from the application of general common law principles to their acts. This does not depend upon state statute or local state law. The law which governs the case is the common law, on which this court has never acknowledged the right of the state courts to control our decisions, except, perhaps, in a class of cases where the state courts have established, by repeated decisions, a rule of property in regard to land titles peculiar to the State."

In Louisville Trust Co. v. City of Cincinnati, 76 Fed. Rep. 296, 300, 304, which was a suit by a Kentucky corporation, it became necessary to determine the force and effect of a mortgage originating in a state statute of Ohio and certain