Section IX-17: Oath of office - Additional oath.

  Before entering upon the duties of his office, each of said
commissioners shall take and subscribe to the oath of office as
prescribed in this Constitution and shall, in addition thereto,
swear that he is not, 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, nor in the bonds, stocks, mortgages,
securities, contract or earnings of any railroad, street railway,
traction line, canal, steam boat, pipe line, car line, sleeping
car line, car association, express line, telephone or telegraph
line; and that he will, to the best of his ability, faithfully
and justly execute and enforce the provisions of this
Constitution, and all the laws of this State concerning
railroads, street railways, traction lines, canals, steam boats,
pipe lines, car lines, sleeping car lines, car associations,
express lines, telephone and telegraph lines, compress and
elevator companies, and all other corporations over which said
Commission has jurisdiction, which oath shall be filed with the
Secretary of State.