Museums such as the British Museum weren't the only site of anthropological studies: with the New Imperialism period, starting in the 1870s, zoos became unattended "laboratories", especially the so-called "ethnological exhibitions" or "Negro villages". Thus, "savages" from the colonies were displayed, often nudes, in cages, in what has been called "human zoos". For example, in 1906, Congolese pygmy Ota Benga was put by anthropologist Madison Grant in a cage in the Bronx Zoo, labelled "the missing link" between an orangutan and the "white race"—Grant, a renowned eugenicist, was also the author of "The Passing of the Great Race" (1916). Such exhibitions were attempts to illustrate and prove in the same movement the validity of scientific racism, which first formulation may be found in Arthur de Gobineau's "An Essay on the Inequality of Human Races" (1853–55). In 1931, the Colonial Exhibition in Paris still displayed Kanaks from New Caledonia in the "indigenous village"; it received 24 million visitors in six months, thus demonstrating the popularity of such "human zoos".