Letter from Louise Pearce to Michael Heidelberger

In 1919, Heidelberger and Walter A. Jacobs synthesized a variant of the aromatic arsenical Salvarsan, Paul Ehrlich's "magic bullet" for syphilis, which proved effective against trypanosomes, the parasites that cause African sleeping sickness. They called it tryparsamide. Louise Pearce conducted the successful (and to her own health, risky) human field trials of tryparsamide in the Belgian Congo, a colonial region of Africa in which the disease was endemic. In this letter she described her voyage to Africa, the conventional treatment for the disease administered in the local hospital in Leopoldville (today Kinshasa), and Pearce's efforts to enlist sick patients for the trial.