"Employment" shall not include service performed by lessees engaged in mining under lease agreements unless the individual lease agreement or the practice in actual operations under such agreement is such as would constitute the lessees employees of the lessor at common law.
[Part 2:129:1937; renumbered in error 2.19:129:1937, 1945, 299; A 1949, 257; 1951, 253; 1951, 474; renumbered 2.9:129:1937 and A 1955, 698]