Effervescent or carbon tablets are tablets which are designed to dissolve inwater, and release carbondioxide. Theyare products of compression of component ingredients in the form ofpowders into a dense mass, which is packaged in blister pack, or with a hermeticallysealed packagewith incorporated desiccant in the cap. To use them, they aredropped into water to make a solution. The powdered ingredients are also packagedand sold as effervescent powders ormay be granulated and sold as effervescentgranules. Generally, powdered ingredients are first granulizedbefore being made into tablets.