Until the early thirties the chemotherapy of malaria was comparatively simple, even if unsatisfactory. Quinine, inherited from the seventeenth century, still held sway, and directions for its use were fairly straightforward, although the experts, of course, each had a particularly favoured way of using it A second drug, plasmoquine (pamaquin)1, heralded with an appropriate fanfare because it was the first synthetic drug for malaria, appeared in 1926, but in the early thirties it was still in an experimental stage, and in any event no one suggested that it would rival quinine or that it would have more than special uses ancillary to quinine. Then, in 1931, atebrin (mepacrine) was announced, and as research with it proceeded, particularly by Field and his colleagues in Malaya, it became clear that the role of quinine was being challenged. If war had not broken out in 1939 the outcome of the challenge would, perhaps, never have been properly known, for the Germans had pushed on from atebrin and developed resochin (chloroquine) and sontochin (sontoquine) both of which were receiving field trials when war came. © 1951, Oxford University Press. All rights reserved.