The finder of a thing may sell it, if it is a thing which is commonly the subject of sale, when the owner cannot with reasonable diligence be found; or, being found, refuses upon demand to pay the lawful charges of the finder, in the following cases:

1. 1. When the thing is in danger of perishing, or losing the greater part of its value; or,
2. 2. When the lawful charges of the finder amount to two-thirds of its value.

R.L. 1910, § 1120.