A lawyer should always treat adverse witnesses and suitors with fairness and due consideration, and he should never minister to the malevolence or prejudices of a client in the trial or conduct of a cause. The client cannot be made the keeper of the lawyer's conscience in professional matters. He has no right to demand that his counsel shall abuse the opposite party or indulge in offensive personalities. Improper speech is not excusable on the ground that it is what the client would say if speaking in his own behalf.