(1) Insofar as the legal consequences of a declaration of intent are influenced by a vitiation of intent or by the knowledge or the constructive notice of certain circumstances, regard will be had not to the person of the principal, but to that of the agent.
(2) If, in the case of a power of agency granted by a legal transaction (authority), the agent has acted in compliance with certain instructions given by the principal, then the latter may not invoke the lack of knowledge of the agent with regard to circumstances of which the principal was aware. The same rule applies to circumstances which the principal ought to have known, insofar as constructive notice is equivalent to knowledge.