The Collected Papers of Paul Ehrlich, Volume III: Chemotherapy is a collection of Paul Ehrlich's papers on chemotherapy, including his early studies with dyes, arsenical compounds, salvarsan, and neosalvarsan. Obituary notices and personal tributes to Ehrlich are included. This book is comprised of 52 chapters and begins with an introduction to Ehrlich's contributions in the field of chemotherapy. It then presents his early work, including his clinical study of the therapeutic value of methylene blue in human malaria; his lectures on athreptic functions, trypanosomes, and immunity, with special reference to the relationship between the distribution and action of antigens; his research on salvarsan as a treatment for syphilis; and his experiment on the chemotherapy of spirilloses. Ehrlich's experiments on the effects of salvarsan on trypanosomiasis of the mouse, spirochaetosis of fowls, and syphilis of the rabbit are also described. This volume will be a useful resource for scientists and other practitioners in medicine, especially those involved in chemotherapy.