(35 ILCS 105/18) (from Ch. 120, par. 439.18)
    Sec. 18. If any clause, sentence, Section, provision or part of this Act or the application thereof to any person or circumstance shall be adjudged to be unconstitutional, the remainder of this Act or its application to persons or circumstances other than those to which it is held invalid, shall not be affected thereby. In particular, if any provision which exempts or has the effect of exempting some class of users or some kind of use from the tax imposed by this Act should be held to constitute or to result in an invalid classification or to be unconstitutional for some other reason, such provision shall be deemed to be severable, with the remainder of this Act without said provision being held constitutional.
(Source: Laws 1955, p. 2027.)