Whenever the performance of the duties of the agency, itself requires the possession of professional skill, the agent entering on such an agency, impliedly warrants that he possesses such skill, and that he will exercise such skill in performing the duties of the agency.3 Where the principal understands the agent does not possess the skill which the case would require, the agent would be excused for not showing such skill. Ordinarily the matter of skill required depends upon the undertaking, and the circumstances and importance of the service. An agent who engages himself to perform the work of the agency, is in duty bound in any event to use the skill he possesses.