Henry Dale and the discovery of acetylcholine

In 1936 Sir Henry Dale of London and Professor Otto Loewi from Graz shared the Nobel Prize in Physiology or Medicine for their work on chemical neurotransmission. This paper uses much unpublished archival material to augment an examination of Dale's work, from his discovery of naturally occurring acetylcholine in 1913, through to evidence of its role as a neurotransmitter at autonomic ganglia, post-ganglionic parasympathetic nerve terminals and the neuromuscular junction.