Down's (1866) essay and its sociomedical context.

The inaccuracy of J. L. H. Down's formulation of the syndrome that now bears his name is recognized widely. The basis for his ideas are not, however, because they are to be found in the concepts of human development prevalent in his day. In this paper Down's essay is de-constructed, and his key concepts are related to the scientific literature of the era. The ideas within which Down developed his thoughts are found, for example, in contemporary writings on medicine, ethnography, public health, and genetics.