Mb. Justice Field,

after stating the case, delivered the opinion of the court.

*538 The claim of the appellant that his demand, which passed into judgment May 5, 1881, against both the St. Louis and Keokuk Railroad Company and the St. Louis, Hannibal -and Keokuk Railroad' Company, is entitled to payment prior to the bonds secured by the mortgage or trust deed,- would seem to be answered by the dates of the judgment and mortgage respectively. The judgment was not rendered against the original company until October 3, 1882, and not against both companies until May 5, 1881. The mortgage was executed on the 1st day of August, 1877, five years before the first judgment and nearly seven years before the second.

It does not appear in the record precisely what the services were which were rendered by the complainant, or for what purposes advances by him were made. This' is not material, ho-wever, as no claim is made, because of the nature of those services and advances, to a lien on the property of the original company, under the statute of the State. It does not appear that any proceedings were taken to establish such a lien. Independently of that statute, there was no lien upon any property of the railroad company for the demand of the complainant. .It stood like any ordinary debt against a corporation, which could only be enforced by legal proceedings establishing its validity and amount by judicial determination, and-then by process upon the judgment obtained, in- subordination to any previously existing liens upon the property.

In some States — and this is the case in Missouri — statutes make judgments of their courts liens upon the real property of the judgment debtor, and the same rule applies in such States to judgments in the courts of the United States. But in all cases the judgments become liens only from the time they arc rendered, or notice thereof is.filed in the register’s office of’the county where the property is situated. They are subordinate to any prior mortgage upon the property. This doctrine is so familiar that it is surprising that any other can be supposed to exist. The property of a railroad company is not held under any such trust to apply it to the payment of its debts as to restrict its use for any other lawful purpose, it matters not how meritorious the demand of the creditor may *539 be. He must .obtain a lien upon the property of the company, or security in some other form, or he will have to .take his chances with all other creditors to obtain payment in the ordinary course of legal proceedings for the collection of debts.

In Thompson v. White Water Valley Railroad Co., decided at the present term, 132 U. S. 68, it was held that the claim of bondholders of the company secured by a. mortgage upon its railroad, and all property then appertaining thereto, or which the company might afterwards acquire, had priority over \a claim of contractors to a lien upon the rents and profits of a portion of the road constructed by them subsequently to the mortgage. It was earnestly contended that they had an equitable lien upon the earnings of that portion of the road because with their moneys it was constructed. But the court replied that the work was not done at the request of the mortgagees, but upon a contract with the lessee of the road, by ■ which the latter stipulated, as one of the considerations of the lease, to construct that part of the line, and that with those contractors the bondholders secured by the mortgage had no relations, and therefore incurred to them no obligation. In the opinion of the court reference, was made to the case of Galveston Co. v. Cowdrey, 11 Wall. 459, 481. In that case there were several creditors, and it was contended that priority should be given to the last creditor, for he had aided in preserving the property. But the court answered that this rule had never been introduced into our laws, except in mari-' time cases, which stood on a particular reason; that by the common law -whatever is affixed to the freehold becomes a part of the realty, except certain fixtures erected by tenants, which did not affect the question; that rails put down upon the company’s road become a part of the road, and that the rule also applies to those permanent fixtures which are essential to the successful operation of the road; they become the property of the company, as much so as if they existed when the mortgage was executed. The case of Thompson v. White Water Valley Railroad Co. was much stronger than the one now before.us; for there a special contract existed between the lessee company and the contractors that such lien should *540 exist; while here there was no contract that the complainant’s; claim should be a lien upon'any property.

In Dunham v. Railway Co., 1 Wall. 254, 267, it was held that a mortgage by a railroad company of its road •“ built and to be built” took precedence, even as regards'the unbuilt portion, over the claim of a contractor who had himself finished .it under an agreement with the company that he should retain fits possession and apply its earnings to the liquidation of the debt to him, and who had in accordance with such agreement taken possession of the road and retained it. The mortgage was 'executed and recorded before the contract for the, completion of the road was made; and the court- said: “ All of the bonds, except those subsequently delivered to the contractor, had, long before that time, been issued, and were in the hands of innocent holders. The contractor, under the circumstances-, could acquire no greater interest in the road than was held by the' company. He did not exact any formal conveyance, but if he had, and one had been executed and delivered, the rule would be the same. Registry of the mortgage was notice to all the world of the lien of the complainant, and in that point of view-the case does not even show a hardship upon the contractor, as he must have known, when he •accepted the agreement, that he took the road subject to the rights of the bondholders.”

. We do not attach any weight to the objection that the transfer by the old company of its entire property to the new company was illegal and ultra vires, and, therefore, to be disregarded. However such a transfer might be considered in a suit- to set it aside, the objection does not lie in the mouth of the appellant, for he has proceeded against the new company ,and obtained, upon the assumed validity of such transfer, a-decree that it pay his judgment, which is founded upon a demand that company agreed to assume, as part of the consideration of the transfer.

• There is no evidence in the record .before us that the parties who took the bonds issued by the St. Louis, Hannibal and Keokuk Railroad Company had any notice, actual or constructive of the demand of the complainant. But if they had, it *541 "would not have affected their rights. That demand was not then reduced to judgment, and created no lien upon the property of the company, nor any restriction upon the company’s right to use it for any lawful purpose. The bonds were given to ráise the necessary funds to complete the road of the company, and_ the mortgage was executed to secure their payment. They were negotiable instruments, and in the hands of the purchasers cannot' be impeached for any neglect of the company issuing-them to pay the demands of other creditors. Ve are ■ unable to perceive any ground upon which their priority over the claim of the appellant can be in any way impaired.

_ We do not question the general doctrine invoked by the appellant, that the property of a railroad company is a trust fund for the payment of its debts, but do not perceive any place for its application here. That doctrine only means that the property must first be appropriated to the payment of the. debts of the company before any portion of it can be distributed to the stockholders; it does not meaii that the property is so affected by the indebtedness of. the company' that it cannot' be sold, transferred, or mortgaged to bona fide purchasers for a ■valuable consideration, except subject to the liability of being. appropriated to pay that indebtedness. Such a doctrine has no existence. The cases of Curran v. State of Arkansas, 15 How. 304, 307, and Wood v. Dummer, 3 Mason, 308, give no countenance to anything of the kind.

Judgment affirmed.