When any person, in this section and §§ 42-1-420 to 42-1-450 referred to as "contractor," contracts to perform or execute any work for another person which is not a part of the trade, business or occupation of such other person and contracts with any other person (in this section and §§ 42-1-420 to 42-1-450 referred to as "subcontractor") for the execution or performance by or under the subcontractor of the whole or any of the work undertaken by such contractor, the contractor shall be liable to pay to any workman employed in the work any compensation under this title which he would have been liable to pay if that workman had been immediately employed by him.