6. Before alienating or otherwise disposing of land acquired by way of expropriation for the purpose of putting a railway into operation, or before using such land for purposes other than railway purposes, the owner thereof must offer it, at the price at which he acquired it,
(1) to the expropriated party, where the railway has not been put into operation;
(2) to the Government, where the railway has been put into operation.
If the offer is refused, the owner of the land may dispose of it as he wishes.