It would be repugnant to principle, and in direct contradiction to every adjudged case, to support this action of trespass against the master for this act of his slave, which was not done at his command or by his assent. From all the cases it is to be collected that where the act of (390) the servant is willful, and such that an action of trespass and not an action on the case must be brought, the master is not responsible, unless the act is done by his command or assent. But where mischief ensues from the negligence or unskillfulness of the servant, so that an action on the case must be brought and not an action of trespass, then the master will be answerable for the consequences in an action on the case, if it is shown that the servant is acting in the execution of his master's business and authority. It is true that a man is liable for trespasses committed by his cattle in treading down the herbage on another's soil; but that is because he is bound to keep them within a fence, otherwise they will wander and probably do much mischief; but he is not bound to keep his slaves confined, and if he were, it would be a monstrous thing to charge him with their depredations.