Curare, the South American arrow poison, is a brew concocted with ritual mystery from a variety of plants by the witch doctor of certain tribes. The natives dip their arrow points into the viscous preparation, and small animals that are wounded by the arrow become paralyzed and fall prey to the hunter. Desiccated curare is a brittle brown substance. Its unique pharmacologic action was discovered 100 years ago by Claude Bernard and his contemporaries, who stated that curare causes paralysis of the voluntary muscles by interrupting the transmission of nerve impulses at the neuromyal junction. The muscle, although no longer responding to stimulation of its motor nerve, remains capable of contraction if its fibers are stimulated directly. Attempts to introduce curare into therapy met with little success as long as no reliable purified preparation was available. With the advent of purified preparations of uniform potency (purified Chondodendron tomentosum extract [intocostrin®]