JAGDISH SAHAI, J. :- These are five connected writ petitions in which vires of the Uttar Pradesh Vritti, Vyapar, Ajivika Aur Sevayojan Kar Adhiniyam, 1965 (hereinafter referred to as the Adhiniyam), passed by the Uttar Pradesh Legislature has been challenged on the ground that the same is unconstitutional.

2. The preamble of the Adhiniyam reads:

"An Act to provide for the levy of a tax on professions, trades, callings and employments in Uttar Pradesh." The entry relied upon by the State in No. 60 of the Second List of the Seventh Schedule of the Constitution of India which reads:

"Taxes on professions, trades, callings and employments."

The Adhiniyam has got 24 sections. Cl. (6) of Section 2 of the Adhiniyam defines a 'person' and Cl. (12) defines the 'total gross income'. Those provisions are reproduced below :-

"2 (6) 'person' includes a Hindu undivided family, company, an incorporated body, a firm, a society or any other association of persons;

x x x x

(12) 'total gross income' means the aggregate of income accruing or arising to a person within the State from any profession, trade, calling other than agriculture or employment and includes the value of any perquisite or profit in lieu of salary." Section 3 is the charging section and reads :

"3. Liability to tax. - Any person who, during the previous year or part thereof, carries on a trade, either himself or by an agent or representative, or who follows a profession or calling other than agriculture, or who is in employment, either wholly or in part within the State, shall, subject to the provisions of this Act, pay, from and after the 1st day of April, 1966, for each financial year, a tax in respect of such profession, trade, calling or employment, in addition to any tax, rate, duty or fee which he is liable to pay under any other law for the time being in force in respect of such profession, trade, calling or employment.

Explanation. - For the purposes of this section, a person on leave shall be deemed to be a person in employment within the area in which he was employed immediately before the commencement of leave."

Section 4 provides that the tax payable by any person under the Adhiniyam shall be determined with reference to his total gross income during the previous year. Sec.5 provides that the tax shall be levied at the rates specified in the Schedule and subsection (2) of this section provides that the tax so payable by any person shall not exceed two hundred and fifty rupees for any financial year. Sub-section (3) of this section provides that no person other than a Hindu undivided family shall be liable to pay the tax whose total gross income during the previous year does not exceed three thousand and five hundred rupees. The exemption in the case of a Hindu undivided family is up to six thousand rupees. Section 6 or the Adhiniyam provides that "the assessing authority, the appellate authority and the revising authority shall exercise such powers and perform such duties as may be conferred or imposed upon them by or under this Act". Section 7 provides for the filing of the returns by persons liable to pay the tax.

Section 8 deals with the assessment of the tax by the assessing authority and provides for the procedure for doing so. Section 15 provides for an appeal against an order passed by the assessing authority and Section 16 provides for a revision application against any order "made by the appellate or assessing authority under this Act". Section 20 confers on the assessing authority, the appellate authority or the revising authority the power to rectify any mistake apparent on the face of the record within a period not later than three years from the date of the assessment order sought to be rectified. Section 21 confers on the assessing authority, the appellate authority and the revising authority the powers vesting in a Civil Court under the provisions of the Code of Civil Procedure in respect of enforcing attendance of and examining, any person on oath o