You see a small drawstring bag, perhaps half the size of a man's clenched fist. It looks to be made of old burlap or possibly even the cloth from an old shirt. It isn't too heavy, but it does look like it's full of dirt or sand or something.
The victim becomes very sickly, pale, and feverish until the end of the scene. Upon contact with the target, the powder causes the victim's Strength and Dexterity to be reduced by one for the rest of the scene. The effects of this talen may not be 'stacked' by using more than one dose per target, per scene.