I claim the ornamental design for a travel container for powdered substances, as shown and described.
FIG. 1 is a perspective view of the travel container for powdered substances showing my new design;
FIG. 2 is right side perspective view thereof;
FIG. 3 is a right side perspective view thereof;
FIG. 4 is a right side view thereof;
FIG. 5 is a left side view thereof;
FIG. 6 is a rear view thereof;
FIG. 7 is a front view thereof;
FIG. 8 is a top view thereof; and,
FIG. 9 is a bottom view.
The present application is directed to the shape and contour of the design illustrated in the drawings. The broken line showing of the shoulder position device is for the purpose of illustrating environmental structure and forms no part of the claimed design.