No law shall be passed except by bill, and no bill shall be so altered or amended on its passage through either house as to change its original purpose.
Ala. Const. art. IV, § 61 — under Legislative Department.
Ala. Const. art. IV, § 61
Laws to be passed by bills; restrictions on amendments to bills
No law shall be passed except by bill, and no bill shall be so altered or amended on its passage through either house as to change its original purpose.