The letter exhibited with complainant’s bill, and made a part of it, was a clear authority to sell the land. — Wilson v. Troup, J Johns. Ch. 25; 16 Ala. 581.

“ It may be asserted, as a general rule, that in all cases, where an agent has contracted within the sphere of his agency, and the principalis not by the form of the contract bound at law, a court of equity will enforce it against the principal upon principles ex aequo et bono.”— Story on Agency, 209, § 162. Although the deed executed by the agent in this case may be ineffectual as a conveyance of the legal title, because the authority of the agent was not given by a written instrument under seal, it may be upheld in chancery as evidence of a contract to sell. — Story on Agency, 55, § 49 ; Cocke v. Campbell & Smith, 13 Ala. 286 ; Welsh v. Usher, 2 Hill’s Ch. R, 167; 4 Wend. 285 ; Story on Agency, § 160, notes.

The principles above laid down are conclusive in favor of the equity of the appellant’s bill ; and therefore the decree of the court below is reversed, and the cause remanded, at the costs of the appellee.