after stating the case as above, delivered the opinion of the court.
The constitution of Arkansas of 1874 provides that “all property subject to taxation shall be taxed according to its value, to be ascertained in such manner as the general assembly shall direct, making the same equal and uniform through*101out the staije,”' and that “no one'species of property, from which a tax may be collected, shall be taxed higher than another species of property of equal value.”
The following property is declared to be exempt from taxar tion: “ Public property used exclusively for public purposes; churches used as such; cemeteries used exclusively as such; school buildings and apparatus; libraries and grounds used exclusively fór school purposes; and buildings and grounds and materials used exclusively for public charity.” And the constitution declares that “ all' laws exempting property from taxation-other than is provided” therein “shall be void.”
As thus seen, no part of the property of railroad cpmpanies in 'the state is exempt from taxation, and any law which exempts it is in express terms declared to be void. But laws which indirectly produce such exemption must be equally inoperative. That cannot be accomplished indirectly which the organic law declares shall not be done directly-. The assessment of property, that is', the appraisement and estimate-of its value, is the basis upon which the amount of the tax is fixed. A law', therefore, omitting from assessment portions of any particular property, thus lessening the estimate of it.s value, has the effect of’ exempting it to that extent from taxation. That result cannot be accomplished, as well observed by the Supreme Court of the state, under the guise of regulating the duties of assessors.
When, therefore, under the advice of the Attorney General, the Board of Bailroad Commissioners treated as invalid the direction of the statute, that the value of embankments, tunnels, cuts, ties, trestles, and bridges should not be included in the estimate of the "railroad track, it obeyed the constitution, rather than the-legislature. 'It may not be a wise .thing, as a rule, for subordinate executive or ministerial officers to undertake to pass upon the constitutionality of legislation prescribing their duties,, and to disregard it if in their judgment it-is invalid. This may be a hazardous proceeding to themselves, and productive of .great inconvenience to the public; but still the determination of the judicial tribunals can alone settle the legality of their action. An unconstitutional act is not a law; *102it binds no one, and protects no one. Here the conflict between the constitution ■ and the statute was obvious, and the Board had the advice of the highest legal officer of the state: and ■ his conclusion was sustained, by the judgment of the . Supreme Court of the state. The unconstitutional part of the statute was separable from the remainder. The statute ■declared that, in making its statement of the value of its property, the railroad company should omit certain items; that clause being held invalid, the rest remained unaffected, and could be fully carried out. An exemption, which was invalid, was alone taken from it. It is only when different clauses of an act are so dependent upon each other that it is evident the legislature would not have enacted one of them without the other — as when the two things provided are necessary parts of one system —■ that the whole act will fall with the invalidity of one clause. When there is no such connection and dependency, the act will stand, though-different parts of it are rejected.
As to the objection which the counsel of the plaintiffs in error in the State case, and of the appellants in the Federal case, raise, that the action of the Board of Railroad Commissioners was in conflict with that clause of the Fourteenth Amendment of the Constitution of the United States, which declares that no state shall deprive any one of property without due process of law, we can only say, we do not perceive'its application. The complaint of the plaintiffs in error and appellants is, that the Board of Railroad Commissioners did not follow the act of the legislature. If that act was valid, no ground lay for complaint that the state had done anything to deprive the company, of its property without due process of law. If the act was, in the particulars mentioned, unconstitutional, as the Supreme Court of the state afterwards held, there was no just ground ;of complaint that the Railroad Commissioners had refused to follow its directions.
In the State case the writ is dismissed, there being no Federal question immolved. In the Federal case, the decree of the court below is affirmed.