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March 23, 1918


JAMA. 1918;70(12):849. doi:10.1001/jama.1918.02600120029014

The "laborious and diligent search after truth," which is the dictionary's interpretation of research, ordinarily exhibits so much of a routine character and so much reiterated effort in traditional directions that the suggestion of something novel is always decidedly refreshing. In this spirit we refer to somewhat startling observations by Zwaardemaker,6 physiologist at the University of Utrecht, leading him to the hypothesis that radioactivity possesses peculiar significance for the automaticity of the heart beat. He has pointed out that of the comparatively small group of elements — essentially twelve in number — which make up animal tissues, two possess a very characteristic atomic property which may enable them to exert unusual influences. Iron is ferromagnetic, but this property is concealed by the presence of other elements in the body. Potassium is reputed to be radioactive.7 Although its radioactivity is of extremely low order and therefore very little pronounced,