An obligation arising from contract of the parties or the operation of the law. Riddell v. Ventilating Co., 27 Mont. 44, 69 Pac. 241. That which the law requires to be done or forborne to a determinate person or the public at large, correlative to a vested and coextensive right in such person or the public, and the breach of which constitutes negligence . Heaven v. Pender, 11 Q. B. Div. 506; Smith v. Clark Hardware Co., 100 Ga. 163, 28 S. E. 73, 39 L. R. A. 607; Railroad Co. v. Ballentine, 84 Fed. 935, 28 C. C. A. 572.