The affidavit for the order of publication, in the proceedings taken by the present defendant against the *370unknown owners of the land in controversy, was fatally defective within former decisions on that subject, and the court acquired no jurisdiction. The action was against all persons, as unknown owners, having any interest in the land, and the affidavit stated no cause of action against any one. Slocum v. Slocum, 17 Wis. 150; Rankin v. Adams, 18 id. 292. There being, therefore, no judgment in the action, the question arises as to the- effect of the last clause of section 1, chapter 409, Laws of 1865, which declares that “ all orders of publication heretofore or hereafter made under section ten of chapter 124 of the Revised Statutes, shall be evidence that the court or officer authorized to grant the same was satisfied of the existence of all facts requisite to the granting of such order or orders, and shall be evidence of the existence of such facts.” The proceedings in question were taken, and the supposed judgment rendered, in the year 1861. If it was competent for the legislature to make this declaration, then it was competent for it to have declared that to be a judgment which before was no judgment, and binding upon the party against whom formally rendered, when before he was not bound at all; for such is the direct result. It is a proposition not to be discussed at this day, that the legislature has no such power; and the court below, therefore, erred in the instruction given to the jury upon this question.
But inasmuch as the tax deed, upon which those proceedings were instituted, was given in evidence by the defendant, and as we are of opinion that the defendant was entitled, by virtue thereof, to a verdict in his favor for the whole land, the error of the court becomes immaterial; and it also becomes immaterial for us to consider the objections taken to the other deeds. The only question arising upon that deed is, whether it is open to impeachment for irregularities merely. It was executed in 1861, upon a sale made and certificate issued in 1857. By the statute in force at the time of the sale, the deed to be executed and delivered to the purchaser was made *371conclusive evidence that all the proceedings had been regular. See Smith v. Cleveland, 17 Wis. 556, in which the validity of the statute was expressly affirmed. When the sale takes place under such a statute, and the purchaser becomes entitled, by virtue of his contract, to such a deed, we think the same effect must be ascribed to the deed, whenever executed or under whatever law, as was given to it by the law in force when the sale was made. The principle is, that the law then in force enters into and forms part of the contract, regulating its obligation and defining the rights of the parties; and that the purchaser acquires a vested interest as to all provisions beneficial to himself and constituting a material inducement to the purchase, which the legislature cannot afterward impair or destroy. This principle is fully sustained by the case above referred to, and the authorities there cited. It is a principle which applies to and governs the obligation of all other contracts, the terms and conditions of which are regulated by law; and, unless an exception is to be made of contracts for the purchase of lands at sales for unpaid taxes, which we conceive cannot be, it applies to and must govern the contract in question, and effect must be given to the deed according to the law in force when the purchase was made and the certificate executed. The deed cannot, therefore, be impeached, nor the title of the defendant disturbed, for the irregularities complained of.
The objection that the word “ certificate,” instead of “ certificates,” is recited in the deed, there being more than one parcel of land conveyed, is obviated by a reference to the statute then in force, which authorized the treasurer, in granting a certificate, to include therein as many parcels of land bid off by any person as he might desire. R. S. 1849, ch. 15, § 133.
And the question decided in Burrows v. Bashford, 22 Wis. 103, does not arise here. The proceedings taken by the defendant to quiet the title being void, no effect can be given to them. The plaintiff cannot insist that they are void for some pur*372poses, and valid for others — that the defendant had in fact no action under the act of 1859, and yet that he waived the conclusiveness of his deed by bringing one.
It follows from these views that the judgment must be affirmed.
By the Court. — Judgment affirmed.