109, 1 Pac. 459. A material alteration in any written instrument is one which changes its tenor, or its legal meaning and effect; one which causes it to speak a language different in effect from that which it ere! apeke. White v. Harris, 69 S. C. 65, 48 8. E. 41, 104 Am. St. Rep. 791: Fovxworthy v. Colby, 64 Neb. 216, 89 N. W. 800, 62 L. BR. A. 398 ; Organ y. Allison, 9 Baxt.