A term applied to statutory enactments which divide the people or subjects of legislation into classes, with reference either to the grant of privileges or the imposition of burdens, upon an arbitrary, unjust, or invidious principle of division, or which, though the principle of division may be sound and justifiable , make arbitrary discriminations between those persons or things coming within the same class. State v. Garbroski, 111 Iowa, 496. 82 N. W. 959, 56 L. It. A. 570, 82 Am. St. liep. 524; In re Hang Kie, 69 Cal. 149, 10 Pac. 327 ; Hawkins v. Roberts, 122 Ala. 130, 27 South. 327; State v. Cooley, 56 Minn. 540, 58 N. W. loO; Wagner v. Milwaukee County, 112 Wis. 001, 88 N. W. 577; State v. Brewing Co., 104 Tenn. 715, 59 S. W. 1033, 78 Am. St. Rep. 941.