Humidifier

FIG. 1 is a first perspective view of a humidifier showing my new design; FIG. 2 is a second perspective view thereof; FIG. 3 is a front view of FIG. 1 ; FIG. 4 is a rear view of FIG. 1 ; FIG. 5 is a left side view of FIG. 1 ; FIG. 6 is a right side view of FIG. 1 ; FIG. 7 is a top plan view of FIG. 1 ; and, FIG. 8 is a bottom plan view of FIG. 1 . FIG. 9 is an enlarged view of portion of FIG. 1 ; FIG. 10 is an enlarged view of portion of FIG. 1 ; FIG. 11 is an enlarged view of portion of FIG. 1 ; and, FIG. 12 is an enlarged view of portion of FIG. 2 The broken lines in the drawings depict portions of the humidifier that form no part of the claimed design.