Section 50. Liability of corporation to employees of contractor

An action
  may be maintained against any railroad corporation by  any  laborer  for
  the  amount due him from any contractor for the construction of any part
  of its road, for ninety or any less number of days' labor  performed  by
  him  in  constructing  such  road,  if  within  twenty days thereafter a
  written notice shall have been served  upon  the  corporation,  and  the
  action  shall  have  been commenced after the expiration of ten days and
  within six months after the service of such notice, which shall  contain
  a  statement  of  the month and particular days upon which the labor was
  performed and for which it was unpaid, the price  per  day,  the  amount
  due,  the  name  of  the  contractor from whom due, and the section upon
  which performed, and shall be signed by the laborer or his attorney  and
  verified  by  him to the effect that of his own knowledge the statements
  contained in it are true. The notice shall be served by  delivering  the
  same  to  an  engineer,  agent  or  superintendent  having charge of the
  section of the road, upon which the labor was performed, personally,  or
  by  leaving it at his office or usual place of business with some person
  of suitable age or discretion; and if the corporation has no such agent,
  engineer or superintendent, or in case he can not be found  and  has  no
  place  of  business  open,  service  may  in  like manner be made on any
  officer or director of the corporation.