( 1 ) INTRODUCTORY facts: In order to appreciate the contours of controversy between the parties relevant introductory facts are required to be noted at the outset. The appellant in First Appeal No. 48 of 1974 is Dhrangadhra Municipality which is at present functioning under the Gujarat Municipalities Act but which was earlier a district Municipality under the Bombay District Municipal Act 1901 The respondent in the first appeal is Dhrangadhra Chemical Works. Dhrangadhra Municipality was the original defendant while Dhrangadhra Chemical Works was the original plaintiff in Civil Special jurisdiction suit No. 76 of 1963 which was filed in the Court of Civil Judge (S. D.) Surendranagar to recover Rs. 6 29 66 on the ground that the said amount was illegally retained and collected by the defendant Municipality from the plaintiff towards octroi. Special Civil Application No. 1729 of 1977 has been moved by the plaintiff directly in this Court against the State of Gujarat and defendant-Municipality challenging the vires of Gujarat Act 6 of 1978 viz. Dhrangadhra Municipality (Imposition of tax) Validation Act 1977 For the sake of convenience we shall refer to Dhrangadbra M