If any provision of this act, [this article], or the application thereof to the Town of Middletown or to any person or circumstance is held invalid by reason of being deemed in violation of any provision of the Constitution of the State of Rhode Island or otherwise, the remainder of this act, or the application of such provision to said town or to other persons or circumstances shall not be affected thereby. (P.L. 1969, ch. 52, § 2.)