In a nod to its apothecary history,  J.R. Watkins has launched new Muscle & Cooling pain relief lines.    J.R. Watkins Muscle Pain Relief line offers penetrating pain relief for muscle strains and soreness and aching joints; the products are made with natural camphor and added magnesium, vitamin D and peppermint. The Cooling Pain Relief line, which offers four products, provides fast-acting pain relief for backaches and joints and is made with natural menthol and added arnica and vitamin ...