Dantrolene—a nitrofurantoin derivative—was developed by Snyder et al. in 1967. After initial discovery of its muscle relaxation potential, investigations in a number of species demonstrated dose-dependent reductions in skeletal muscle tone that were long lasting, relatively nontoxic, and free of adverse effects such as respiratory impairment. Ellis et al. then published a number of papers investigating the means by which dantrolene produced these effects. Using a series of classic physiologic models, Ellis investigated potential sites of action for the new drug, eventually narrowing this down to the intracellular calcium-release mechanism. Ellis went on to play a pivotal role in the discovery of dantrolene’s effectiveness for the treatment of malignant hyperthermia, after reading a scientific bulletin about muscle rigidity in pigs affected by porcine stress syndrome, contacting Gaisford Harrison and sending dantrolene to him for trial.