That doctrine in the law of negligence by which the negligence of the parties is compared, in the degrees of “slight,” “ordinary,” and “gross” negligence, and a recovery permitted, notwithstanding the contributory negligence of the plaintiff, when the negligence of the plaintiff is slight and the negligence of the defendant gross, but refused when the plaintiff has been guilty of a want of ordinary care, thereby contributing to his injury, or when the negligence of the defendant is not gross, but only ordinary or slight, when compared, under the circumstances of the case, with the contributory negligence of the plaintiff. 3 Amer. & Eng. Enc. Law, 367. See Steel Co. v. Martin. 115 111. 358, 3 N. E. 456; Railroad Co. v. Ferguson, 113 Ga. 708. 39 S. E. 306, 54 L. R. A. ‘802; Straus v. Railroad Co.. 75 Mo. 185; Hurt v. Railroad Co.. 94 Mo. 255, 7 S. W. 1, 4 Am. St. Rep. 374.