Section IX-16: Qualifications of commissioners.

  The qualifications of such commissioners shall be as follows:
To be resident citizens of this State for over two years next
preceding the election, and qualified voters under the
Constitution and laws, and not less than thirty years of age; nor
shall such commissioners, or either of them, be, directly or
indirectly, interested in any railroad, street railway, traction
line, canal, steam boat, pipe line, car line, sleeping car line,
car association, express line, telephone or telegraph line,
operated for hire, in this State, or out of it, or any stock,
bond, mortgage, security, or earnings of any such railroad,
street railway, traction line, canal, steam boat, pipe line, car
line, sleeping car line, car association, express line, telephone
or telegraph line, compress or elevator companies; and if such
Commissioner shall voluntarily become so interested, his office
shall become vacant; and if any Corporation Commissioner shall
become so interested otherwise than voluntarily, he shall, within
a reasonable time, divest himself of such interest; and failing
to do this, his office shall become vacant.  Nor shall any such
commissioner hold any other office under the government of the
United States, or of this State, or any other state government,
and shall not, while such Commissioner, engage in any occupation
or business inconsistent with his duties as such commissioner.