Simmons, Justice.
The defendants in error made returns of their property for State and county taxation for the year 1891 to *718the tax-receiver of Richmond comity, and he accepted the returns without objection. Afterwards a board of assessors, under an act of the legislature approved October 15th, 1885, entitled “an act to provide a board of assessors of real and personal property subject to taxation for the county of Richmond, and for other purposes” (Acts 1884-5, p. 449), assessed the property of the defendants in error, and increased the valuation beyond that given in the returns. Executions for taxes based on these assessments were issued, and the defendants in error filed tlieir petition to enjoin the tax-collector and the sheriff from further proceeding to enforce the executions, upon the .ground that the act referred to was repugnant to that clause of the constitution which forbids special legislation in any cáse for which provision has been made by an existing general law. (Code, §5027.) An answer was filed by the tax-collector and the sheriff, the substance of which is stated in the report which precedes this opinion; and the tax-receiver filed a petition to be made a party defendant, adopting this answer as his own and consenting that the case be heard instanter. The invalidity of the act was conceded, and may now be regarded as settled, under the decision of this court in the case of Stewart, tax-collector, v. Collier, 91 Ga. 117. It was claimed, however, that the tax-receiver acted under a mistake of law; that he was dissatisfied with the returns, and but for his belief that the returns had to be passed upon by the board of assessors under the act in question, he would have assessed the property himself and would have insisted upon the appointment of arbitrators according to section 840 of the code. The respondents prayed that the petitioners be required to do equity and to submit their returns to three disinterested persons, under the provisions of the section referred to, who should fix an assessment upon the property, and that the petitioners be *719required to pay a tax for the year 1891 upon the assessment so made. The court refused the prayer of the tax-receiver to be made a party, a demurrer to the answer was sustained, and an injunction against the enforcement of the executions was granted.
The authority of the tax-receiver to assess property where a return has been made is derived from section 839 of the code, and is limited to the time prescribed in that section. The language of the section is as follows : “Each return shall be scrutinized carefully by the tax-receiver, and if, in his judgment, he shall find the property embraced in the return, or any portion of it, returned below its value, he shall assess the value at once or within thirty days thereafter.” The courts cannot enlarge or extend the scope of the statute by granting further time if the tax-receiver fails to act within the time prescribed; nor can they, at his instance, require the tax-payer to submit to an assessment by arbitrators, under section 840 of the code. Certainly the fact that the tax-receiver believed or relied upon the belief of others that an invalid local statute was valid and superseded the law above referred to, so far as the particular county was concerned, and that his failure to act was due to this cause, could not give the court any power in the matter. The principles which authorize a court of equity to relieve against mistake have no application to the case. The tax-receiver is bound to know the law regulating his official duty; and for his error of judgment in reference thereto, no responsibility can attach to the tax-payer. (Code, §§3121, 3122, 2636. And see 15 Am. & Eng. Enc. of Law, “Mistake,” p. 634 et seq.) Moreover, mistake implies action, and here there was no action at all. See Culbreath v. Culbreath, 7 Ga. 70; also Adams v. Guerard, 29 Ga. 673, where it is said: “ Those mistakes from which relief has been granted were mistakes which occurred in doing something, not in doing *720nothing; they were mistakes of action, not of mere in action. When one has contracted or acted on a false assumption of fact or of law, equity may relieve him from the effects of the action, and will not begin to count time against him until the discovery of the mistake; but where he has simply lain still, under a mistaken assumption of either fact or law, without having ever acted at all, it is not a question when time will begin to be counted against his relief, but it is a case where no relief will be granted at any time from the effects of his inaction.”
The court was clearly right in granting the injunction, as well as in the other rulings complained of.
Judgment affirmed.