Section 18. Mines in Saint Lawrence county

The proprietors of any mines or
  veins of lead or copper in the county of  Saint  Lawrence,  may  demise,
  lease, or rent the same for a period not to exceed twenty-one years from
  the  date  of  any such lease, to any foreign individual or company, and
  such lessee may take, hold, work, use or convey the same during the said
  term, in the same manner and subject to the same liabilities as if  such
  lessee were a natural born citizen.