Sec. 18.  The state, any county or city may make internal improvements and may engage in any industry, enterprise or business not prohibited by Article XX of the Constitution, but neither the state nor any political subdivision thereof shall otherwise loan or give its credit or make donations to or in aid of any individual, association or corporation except for reasonable support of the poor, nor subscribe to or become the owner of capital stock in any association or corporation. 

[Amended Nov. 5, 1918]