This year we are celebrating the bicentenary of the publication, by William Withering, of An Account of the Foxglove and Some of its Medicinal Uses with Practical Remarks on Dropsy and Other Diseases (1). During these two hundred years digitalis has constantly been to the fore of medical thinking and it is appropriate that we should look back and examine the contributions which studies of this drug have made to medicine as we know it today. Some of the studies have been at the centre of fierce controversy and others have been of seminal importance in the development of new concepts.