[Territorial jurisdiction of sanitary risk and demographic statistics: the "tuberculous buildings" of the unhealthy block of Saint-Gervais (1894-1930)].

The assumption of contagion is often employed as an argument for the demarcation of areas considered dangerous to public health. This article examines how it was used in the case of the insalubrious district of Saint Gervais (Paris). The district was identified thanks to statistics available from the health records of Parisian apartment houses, which have been kept since 1894. The author's main concern is the existence of "maisons meurtrières (deathtraps) denounced by contemporary documents although deaths from tuberculosis were progressively decreasing. The examination of statistics giving the number of inhabitants and fatalities from tuberculosis in each apartment building shows that, with the exception of those with furnished rooms, only a small proportion of these dwellings actually had a high death rate from tuberculosis between 1894 and 1930. It also shows that the delimitation of the insalubrious area was based on the idea that the illness was irreversible, allowing the "deathtraps" discovered in earlier stages to be added to those found in each subsequent check. This method made it possible to designate "infected districts" and to justify a policy of city planning.