Section 14-126. Resignations, absence on leave

a. A member of the force,
  under penalty of forfeiting the salary which may  be  due  such  member,
  shall not withdraw or resign, except by permission of the commissioner.
    b.  Absence,  without  leave,  of  any  member  of  the force for five
  consecutive days shall be deemed and held to be a resignation,  and  the
  member  so  absent shall, at the expiration of such period cease to be a
  member of the force and be dismissed therefrom without notice.
    c. Leave of absence, other than for sickness, exceeding thirty days in
  any one year shall be granted or allowed to any  member  of  the  force,
  only  upon  the  condition  that such member shall waive and release not
  less than one-half of all salary and claim thereto during such absence.