(2)Where a single sheet of paper, not being paper bearing being impressed hundi stamp is insufficient to admit of the entire instrument written on the side of the paper which bears the stamp, so much pie paper may be sub-joined thereto as may be necessary for the complete writing of such instrument:Provided that in every such case, a substantial part of the instrument shall be written on the sheet which bears the stamp before any part is written on the pie paper sub-joined.
