Granting the right of the legislature to classify persons and property for purposes of taxation, the requirements of due process of law and of the additional provision found in the federal Constitution and in almost all if not in all of the stare constitutions that all laws shall be uniform, make it necessary that the assessment of all persons and property within the class or district selected for taxation shall be according to a uniform rule. Cooley sttates the principle as follows: "As to all taxation apportioned upon property, there must be taxing districts and within these districts the rule of absolute uniformity must be applicable. A state tax must be apportioned through the State, a county tax through the county, a city tax through the city; while in cases of local improvements, benefiting in a special and peculiar manner some portion of the State or of a county or city, it is competent to arrange a special taxing district within which the expense shall be apportioned." 3l And again: "The rule of apportionment must be uniform throughout the taxing district, applicable to all alike, but the legislatures have no power to arrange taxing districts arbitrarily, and without reference to the great fundamental principles of taxation that the burden must be borne by those upon whom it justly rests. The Kentucky and Iowa decisions hold that, in a case where they have manifestly and unmistakably done so, the courts may interfere and restrain the imposition of municipal burdens on property which does not properly belong within the municipal taxing district at all" 32

30 179 U. S. 89; 21 Sup. Ct. Rep. 43; 45 L. ed. 102.

All that the rule of uniformity requires is this, that within the classes or districts taxed the law shall operate according to a uniform rule. Thus, for example, it has been generally held that a city levying a general tax may not discriminate between different wards or sections, for all property within a taxing district must be taxed alike.33

31 Cooley. Const. Lim., 7th ed., 711.

32 Const. Lim.. 7th ed., 724. The cases referred to are Morford v Unger, 8 Iowa, 82: City of Covington v. Southjrate. 15 B. Monr. 491; Arbegust v. I. msville. 2 Bush, 271; Swift v. Newport, 7 Bush, 37.

33 This does not hold true where, by special contract made at the time a rural district is incorporated into the city, special treatment with reference to taxation has been promised. The rrfiptlOTl of certain pieces of property from taxation where this exemption has been for some public purpose or in return for consideration received, docs not violate this principle.