Questions of economics and hygiene. Recovering and using excrement in Italian cities and countryside in the late 19th century

In the 19th century in Europe, two problems directly related to the use of human and animal excrement intersected. The first was the need to find more and more fertilisers for cultivated land. This problem was solved by searching for new fertilising substances, such as Pacific guano1 or the seeds of oil plants.2 Consequently, and in view of the need for abundant organic material to fertilise fields, agronomic literature began to consider the possibility of systematically and industrially using organic residues from the cities, and thus not only the traditional organic fertiliser from animal excrement. The second problem was precisely the disposal of organic remains, especially in large urban centres.3 Municipal waste raises three main problems: the collection of the material, its storage, including the identification of storage areas, and lastly, its utilisation. Each of these three phases created numerous hygienic and public health complications. This had been a focus of attention for centuries. In fact, since the Middle Ages, different solutions were experimented with in order to solve the problem of disposing of urban excreta,4 and the question has recently become highly topical as a result of the debate on sustainability and the recovery of organic agriculture.5 As we demonstrate with this paper, the need for fertilisers and the recovery of urban and rural excreta are two intertwined and mutually influencing issues.