
77 U.S. 543 (1870)
10 Wall. 543
BALTIMORE
v.
BALTIMORE RAILROAD.
Supreme Court of United States.

*547 Messrs. W.H. Norris and G.H. Chandler, for the city, plaintiff in error.
Mr. J.H.B. Latrobe, contra.
*549 *550 Mr. Justice DAVIS delivered the opinion of the court.
It is contended, on the part of the city, that if the tax in question be a lawful exaction by the United States, the burden of it must be borne by the company, and that the obligation of the company to the city is not changed by reason of the imposition and collection of the tax. Whether this be so or not, depends on the nature of the contract between the parties, for the company was authorized to withhold the tax, unless it had contracted with the city to pay *551 it.[*] The position taken by the city is, that the company was bound to pay the full amount of the interest without deduction, because of the following words in the defeasance clause of the mortgage: "And shall pay all and any expense incidental to the issue of any of the bonds." It is, therefore, necessary to construe these words, and there is no difficulty about it, when we consider the subject-matter about which they were employed. The word expense may mean one thing in one case and quite a different thing in another. Its meaning in this case cannot be mistaken.
To carry out the arrangement between the parties required a considerable expenditure of money for printing, clerk hire, stationery, advertising, and similar matters. These expenses were incidental to the issue of the bonds, and it was right and proper that the railroad company  the party to be benefited by the transaction  should pay them. And it agreed to do so; but this agreement cannot be extended to cover the tax in question, for in no sense is it an expense incidental to the issue of the bonds. At the date of the mortgage (1854) there was no tax of the kind, nor any reasonable expectation of one. If there had been, it is easy to see that appropriate words applicable to the subject would have been used. But the words which were used did not relate to the subject of taxation at all, and it is very certain that the possibility of taxation was not in the contemplation of either of the parties to the mortgage.
It is unnecessary to discuss the general rules of law affecting the relations of principal and surety, and to show in what state of case a surety is required to save his principal from loss, because these rules are not applicable to this case. It is always competent for parties capable of entering into a business arrangement to fix the terms of it, and to declare what shall be their respective rights and liabilities under it. If the court can in any case see that this has been done, it is required to give effect to the contract which the parties chose to make for themselves, although, in the *552 absence of a special agreement on the subject, the rule to determine the rights of the parties might be different.
The parties to this suit have made a contract in relation to a matter of interest to both, and have settled what each shall do. To hold one of them responsible for contingencies not provided for, and not even anticipated when the contract was executed, would be to disregard instead of giving effect to the will of the parties.
It is contended, however, by the city, that the securities of a municipality like Baltimore are not taxable by the National government, and therefore the tax in question was an unlawful exaction. This presents an important question; but the city is not in a condition to raise it, and, under the circumstances, can have no cause of action against the company for paying the tax. It is difficult to see in what respect the company failed to discharge its duty in regard to this subject. It occupied the position of a stakeholder, owing the money either to the city or the United States, and wholly indifferent to which of the parties it should be paid. It notified the city that the United States were enforcing the collection of the tax, and did not pay it until it was obliged to do so to avoid the consequences provided for in the act in case of refusal, and not then, without a written protest stating distinctly all the grounds of objection claimed by the city to the assessment and collection of the tax. In this condition of things, if the city felt itself aggrieved by the action of the officers administering the internal revenue laws in a matter of interest to it and not the company, it should have stepped in, and taken upon itself the burden of testing the legality of the assessment and collection of this tax, by instituting proper proceedings to recover back the money. This it was authorized to do by these laws, which not only provide for the manner of collecting the revenue, but also furnish a mode of redress to the party who has suffered injury by their administration.[*]
*553 If there were injury at all, the city sustained it, and, as it did not avail itself of the privilege to sue, it cannot turn round and litigate the legality of the tax with the railroad company. This tax was exacted under color of law, and the company, having notified the city of the demand of the United States and the proceedings taken to enforce it, and having protested against its collection, were justified in paying it.
And it cannot be required in this state of case, on its own behalf, to test the correctness of the ruling of the revenue officers.
JUDGMENT AFFIRMED.
NOTES
[*]  13 Stat. at Large, 284.
[*]  City of Philadelphia v. The Collector, 5 Wallace, 731; Nichols v. United States, 7 Id. 130-1; The Assessors v. Osborne, 9 Id. 571.
