
82 U.S. 671 (1872)
15 Wall. 671
HAFFIN
v.
MASON.
Supreme Court of United States.

*673 Messrs. J. Hubley Ashton and H.F. Averill, for the plaintiff in error.
Mr. G.H. Williams, Attorney-General, and Mr. C.H. Hill, Assistant Attorney-General, contra.
*674 Mr. Justice DAVIS delivered the opinion of the court.
In the view we take of the case, it is not necessary to notice anything that occurred at the trial, except the refusal of the court, on the request of the plaintiffs, to charge "that the defendants were liable in this action, and that the plaintiffs were entitled to judgment for the value of the property seized and sold by the defendant, Mason." The refusal to give this instruction was excepted to and is assigned for error. If, in the state of this record, both these defendants were not liable in an action of trespass, the charge, as prayed, was incorrect, and therefore properly refused.
We are not required to consider whether the assessor was not liable, because the proposition which the court was asked to sanction assumed the liability of both, and a party cannot assign for error the refusal of an instruction to which he has not the right to the full extent as stated, nor is the court bound to modify the instruction moved for by counsel, so as to bring it within the rules of law.[] If the plaintiffs wished *675 to test the question whether, under the evidence in the case, they could not recover against the assessor alone, they should have fashioned their instruction to meet that emergency.
If they did not choose to do this, they are precluded from raising the question here, and the only point for decision is whether the court below erred in refusing the instruction in the terms in which it was presented.
A ministerial officer, in a case in which it is his duty to act, cannot on any principle of law be made a trespasser. This court, in the recent case of Erskine v. Hohnbach,[*] applying this doctrine to a collector of internal revenue, say, that his duties in the enforcement of a tax-list are purely ministerial, and that "the assessment duly certified to him is his authority to proceed, and, like an execution to a sheriff, regular on its face, issued by a tribunal having jurisdiction of the subject-matter, constitutes his protection."
The assessment in this case, duly certified by Hyatt, the assessor, was received in evidence without objection, and no point was raised as to its form or sufficiency. If, then, the assessor had the right to decide the question, whether the plaintiffs were liable to the increased taxation, the list delivered by him to the collector, properly certified, was his warrant to seize and sell the property, in case the taxes were not paid, after he had made demand for them.
It was not the business of the collector to inquire into the case to ascertain whether the assessor had reached a proper conclusion upon the matter submitted to his judgment, nor had he any right to refuse to enforce the assessment.
The act of June 30th, 1864,[] confers authority on the assessor to make an increased enumeration in case the distiller has not rendered a true account of his business, and directs the manner of proceeding, in order to find out the deficiency. This mode was not pursued by the assessor, and as the case stands, it would seem that the plaintiffs have been adjudged to pay a large amount of money without the opportunity to be heard, and which they swear they do not owe the United States. It is presumed the assessor had *676 grounds for his action, which would relieve the case of its apparent hardship, but whether he had or not, the collector is protected. This officer had the right to suppose the taxes were due, and that all proper steps had been taken to ascertain this fact. If he could not rightfully act on this supposition, it is difficult to see how he could be protected in collecting taxes, when the authority of the assessor to levy them was given by law, and the precept for their collection was regular on its face. It follows, from these views, that the Circuit Court was right in refusing the instruction as prayed for, and that, on the ground that the collector was not a trespasser, the judgment must be
AFFIRMED.
NOTES
[]  Catts v. Phalen, 2 Howard, 382; Buck v. Chesapeake Insurance Co., 1 Peters, 159.
[*]  14 Wallace, 613.
[]  Section 14, 13 Stat. at Large, 226, 227.
