A broker who has instructions to buy for his principal mortgages, or other first-class discount paper, who violates them and invests the money on his own judgment, is responsible for the consequent loss to his principal, though Civil Code, Art. 2987, declares that brokers shall not be responsible "for events which arise in the affairs in which they are employed." Soudieu v. Faures, 12 La. Ann. 746. See also Sec. 229, 230.