Ch.VIIL] Franchises. — Mi77es. 145 wheresoever they fly; and 3dly, a subject may claim a property in swans ratione prwilegii, as if the King grant to a subject the game of wild swan in a river {a). 8. Mi7ies, It is quite clear, that by his prerogative the King is entitled to all mines of gold and silver which may be disco- vered, not only in his own but even in a subject's lands, witliin his dominions [b). The danger of rendering a subject too formidable, by vesting in him so immense a treasure as a mine of gold or silver might afford, is the reason assigned for this royal prerogative {c). But mines containing baser metal, belong to the subject in whose lands they are discovered {d). It was formerly held, that if such mines contained gold or silver, the whole mine belonged to the King; because gold and silver, being the nobler and more valuable metals, should attract the less valuable ; and because a subject cannot hold property jointly with the Sovereign, and the King's property, though ever so small, ought not to be lost by mixture with the subject's {e). The injustice of such a doc- trine called for a remedy ; and, accordingly, it was enacted by the statute 1 William and Mary, sess. 1. c. 30. s. 4. " That no mine of copper, tin, iron, or lead, should be adjudged a royal mine, although gold or silver might be extracted out of the same." And it is further provided, by the statute 5 and 6 William and Mary, c. 6. that " the owner of any mine wherein any ore shall be discovered, opened, found, or wrought, and in which there is copper, tin, iron or lead, shall hold and enjoy the same mine and ore, and continue in the possession thereof, and dig and work the said mine or ore, notwithstanding that such mine or ore shall be pretended, or claimed to be a royal mine." " Provided, that the King, and all claiming any roy^l mine.» under him, shall have the ore of any such mine, (other than tin ore in the counties of Devon and Cornwall, ) paying to the proprietor or owner of the said mine, wherein such ore shall be found, within thirty days after the said ore is or shall be raised and laid upon the banks of the said mine, and before (a) 7 Co. 16, 17. (rf) Ibid. 323. 2 Inst. 578. 12 Co. (A) The case of Mines ; Plowd. 315, l^. 6. 5 Bac. Abr. 513. 1 Bla. Com. 295. (e) Plowd. 323, 328, 336. (f) Plowd. 316. L tlie