The U.S Botanic Garden at the foot of Capitol Hill - improbable creation when you think about it but more of its history later - can cheer a cold city person in an instant. Not only immersion into a tropical (nearly fantastical) world of sights and smells but of a host of lectures and exhibits to take a person's mind off wintry woes. The banana plant currently is showing off two multi=colored sinuous bloom at one entrance to the conservatory. A kindly docent not far away sits behind a desk in front of a cocoa tree explaining the varied uses of that plant's product with display items to touch and smell. Lo, the wonder: nuts from the shell of the bean that makes cocoa, soap and delicious chocolate. In a lecture hall at that moment a guest ethane-economic botanist from New York is giving a slide show about medical uses of tropical herbs and plants - starting with the Sumerian age 2500 years ago when cannabis and opium were known. Then to the papyrus rushes of Egypt that became bandaids with the use of honey. An hour's worth of exotic information, a trip on the screen to healers in Micronesia. The surprise of the day: kava taken in cupfuls by that area's natives does as well or better than valium. Who dares think modern medicine knows it all?