A Frenchman, Marc Dax, read a paper at Montpellier in 1836, pointing out that paralysis of the right side of the body was often associated with loss of speech, while patients whose left side was paralysed could usually talk normally. This suggested that the left hemisphere controlled not only the right side of the body, but speech also. Dax’s hypothesis turned out to be correct. Speech in the majority of humans is the concern of the left, not the right hemisphere.