But there was another way besides this by which the defendant could be charged with a duty and made liable [184] in case, and which, although less familiar to lawyers, has a special bearing on the law of carriers in later times. If damage had been done or occasioned by the act or omission of the defendant in the pursuit of some of the more common callings, such as that of a farrier, it seems that the action could be maintained, without laying an assumpsit, on the allegation that he was a "common" farrier. /1/ The latter principle was also wholly independent of bailment. It expressed the general obligation of those exercising a public or "common" business to practise their art on demand, and show skill in it. "For," as Fitzherbert says, "it is the duty of every artificer to exercise his art rightly and truly as he ought." /2/ When it had thus been established that case would lie for damage when occasioned by the omission, as well as when caused by the act, of the defendant, there was no reason for denying it, even if the negligent custody had resulted in the destruction of the property. /3/ From this it was but a step to extend the same form of action to all cases of loss by a bailee, and so avoid the defendant's right to wage his law. Detinue, the primitive remedy, retained that mark of primitive procedure. The last extension was made about the time of Southcote's Case. /4/ But when the [185] same form of action thus came to be used alike for damage or destruction by the bailee's neglect and for loss by a wrong-doer against whom the bailee had a remedy over, a source was opened for confusion with regard to the foundation and nature of the defendant's duty.