Right of finder of goods, may sue for specific reward offered.—

The finder of goods has no right to sue the owner for compensation for trouble and expense voluntarily incurred by him to preserve the goods and to find out the owner; but he may retain the goods against the owner until he receives such compensation; and, where the owner has offered a specific reward for the return of goods lost, the finder may sue for such reward, and may retain the goods until he receives it.