15. If in the opinion of the Government it is expedient or necessary so to do for the purpose of securing fulfilment of any contract on which a default has taken place, it may appropriate to the contract any jute or jute manufactures belonging to the defaulter, or it may buy jute or jute manufactures elsewhere and so appropriate it, and in either or both of such cases the defaulter shall be liable for any loss which the Government may sustain on account of the default, but shall not be entitled to any gain on the purchase made against such default.