A rehearing was granted in this cape in order to give fuller consideration to the difficult questions of constitutionality and statutory construction involved. Upon such consideration, we adhere to and adopt the following part of our former opinion:

The other point, in our opinion, presents the most difficult question in this case. Section 12' provides that when there are no available funds in the city treasury with which to pay for property purchased at the delinquent sale, the tax collector shall make demand upon the city council that a “suitable amount” be included in the next tax levy to provide funds with which to make such payment. Section 16, subdivision (a), states that the city council must, upon demand by the tax collector as provided in section 12, levy a “special tax” for the purpose of paying for lands “purchased or to be purchased” at such tax sales, but “not to exceed for each local improvement ten cents on each one hundred dollars of assessable property”. The question is whether section 16 (a) operates as a limitation on the amount of tax, so that the maximum which might be levied each year for the purposes stated would be ten cents on each one hundred dollars of assessable property. This issue has been briefed and argued several times by able counsel for the parties and amici curiae, and it may be reasonably concluded that the various possible interpretations of these sections have been fully explored. Notwithstanding this thorough consideration, there remains the gravest doubt as to the intention of the legislature to provide an unlimited tax, and we have finally come to the conclusion that this doubt must, in accordance with settled principles, be resolved against the taxing power and in favor of the taxpayer.

The arguments of counsel for the bondholders in favor of an unlimited tax proceeds by pointing out that the city must, under section 12, purchase the property at the sale, and pay the delinquent assessments; that in order to do so, it must transfer available funds from its treasury into the bond redemption fund; and that the tax collector must then make demand for a tax levy in a “suitable amount” to provide funds with which to make such payment. From these provisions of the statute they draw the conclusion that there is a mandatory duty on the part of the city to meet by a sufficient tax levy the obligation assumed by the purchase of the lands. Under this theory, section 16 (a) is explained chiefly as a means of collecting limited sums in anticipation of the future purchase of lands.

The objection to this construction is that it gives too much effect to section 12, and not enough effect to section 16 (a). Section 12 provides that when there are no available funds in the treasury, the tax collector shall delay the entry of the certificate of sale until such funds are available, “making demand in the meantime upon the city council that a suitable amount be included in the next tax levy for the purpose of providing funds with which to make such payment”. It will be observed that this section provides for a demand for a tax levy, but not for a tax. The section gives no authority to the city council to levy any tax. It may be argued that it would be absurd to require the city to purchase the property, and then provide for no means of payment; and that from the obligation to purchase and the duty of the tax collector to make a demand for a tax levy, the municipal power to levy the tax may be inferred. But the imposition of a tax by inference or implication, no matter how logical or reasonable it may seem, is universally condemned by the authorities, which lay down the rule that the tax must be based upon an express statutory authority, and that doubts will be resolved against the taxing power. (See Merced County v. Helm, 102 Cal. 165 [ 36 Pac. 399 ]; Connelly v. San Francisco, 164 Cal. 101 [127 Pac. 834]; Estate of Potter, 188 Cal. 55 [ 204 Pac. 826 ]; Whitmore v. Brown, 207 Cal. 473 [ 279 Pac. 447 ].) In any event, the supposed necessity for the inference of the power to tax from the provisions of section 12 arises from a failure to give adequate consideration to section 16 (a).

Section 16 (a) does expressly authorize the levy of a tax. It provides that the city council “may” levy “a special tax” to pay for lands “purchased or to be purchased”. The authority thus given is within the discretion of the council to exercise, and there is little doubt that under that authority, the city may build up a fund in anticipation of the future purchase of lands. But this is not the whole effect of section 16 (a). It provides that the. city council “may, and in the event of demand Toy the tax collector therefor as provided in section twelve hereof must” levy the tax. Here we have a mandatory requirement. It directly refers to section 12; it expressly covers the subject upon which section 12 is silent—the power to levy a tax; and to remove any doubt as to the interdependence of the two sections, it conditions the levy of the tax under section 16 (a) on the demand of the tax collector under section 12.

Under this analysis, which gives to both sections the meaning apparent therefrom, and does not extend nor diminish the effect of either by implication, we have a construction which is not unreasonable, and which violates no rule of statutory construction. Such an interpretation, moreover, avoids the cardinal error of imposing a tax by inference from language which does not clearly authorize it. There are, perhaps, as contended by petitioner, certain practical difficulties which may follow from this conclusion. Thus, where there are ample funds in the treasury, previously raised by taxation, the whole of the delinquent assessment must be paid out of such funds, section 12 providing that the city “shall pay and transfer into said redemption fund the amount of the delinquent assessment and of the delinquent interest thereon”; but if the treasury is depleted, only the ten-cent levy under section 16 (a) can be made; with the result that the immediate payment in full of the delinquent assessments, a duty resting upon the city under section 12', is dependent upon the fortuitous circumstance that money is in the treasury and available at the time of purchase. But upon reflection, this is not wholly unreasonable. It may well be that the city should be required to meet its obligation under the statute in full with available funds, if they are sufficient in amount, but that it should not be forced to meet it, when sufficient funds are not available, by a ruinous tax. Such a distinction could well have been within the contemplation of the legislature, and the alleged inconsistency constitutes no fundamental objection to the construction we have adopted.

It follows that the statute under consideration is constitutional, and that if the allegations of the petition are true, a mandatory duty rested upon respondents to levy and collect a tax' to meet the delinquent assessments, such tax, however, being limited to ten cents on each one hundred dollars of assessable property, as provided in section 16 (a) of the act. The judgment is therefore reverse'd, with directions to the lower court to permit petitioner, if it desires, to amend its petition in accordance with the conclusions reached herein, and thereafter to proceed to a trial of the issues, if any, raised by the answer thereto.