RÉSUMÉ
The 1899/1900 arrival of bubonic plague in Argentina had thrown the model status of Buenos Aires as a hygienic city into crisis. Where the idea of foreign threats and imported epidemics had dominated the thinking of Argentina's sanitarians at that time, plague renewed concerns about hidden threats within the fabric of the capital's dense environment; concerns that led to new sanitary measures and unprecedented rat-campaigns supported by the large-scale application of sulphur dioxide. The article tells the story of early twentieth-century urban sanitation in Buenos Aires through the lens of a new industrial disinfection apparatus. The Aparato Marot, also known as Sulfurozador was acquired and integrated in the capital's sanitary administration by the epidemiologist José Penna in 1906 to materialise two key lessons learned from plague. First, the machine was supposed to translate the successful disinfection practices of global maritime sanitation into urban epidemic control in Argentina. Second, the machine's design enabled public health authorities to reinvigorate a traditional hygienic concern for the entirety of the city's terrain. While the Sulfurozador offered effective destruction of rats, it promised also a comprehensive - and utopian - disinfection of the whole city, freeing it from all imaginable pathogens, insects as well as rodents. In 1910, the successful introduction of the Sulfurozador encouraged Argentina's medico-political elite to introduce a new principle of 'general prophylaxis'. This article places the apparatus as a technological modernisation of traditional sanitary practices in the bacteriological age, which preserved the urban environment - 'el terreno' - as a principal site of intervention. Thus, the Sulfurozador allowed the 'higienistas' to sustain a long-standing utopian vision of all-encompassing social, bodily and political hygiene into the twentieth century.