Following the theoretical line of French Discourse Analysis, looking mainly at the teachings of Michel P�cheux, Eni Orlandi and Freda Indursky, as well as the perspective of enunciative studies as theorised by Jacqueline Authier-Revuz, our research looks at heterogeneity and crossings in Euclides da Cunha's discourse in some clippings from the work "Um para�so perdido - reuni�o de ensaios amaz�nicos". Euclides came to the Amazon in the service of the Brazilian government, heading the "Mixed Brazilian-Peruvian Commission for the Reconnaissance of the Upper Purus", in December 1904 and remained here until December 1905. Leaving aside the technical reports he produced for Itamarati, the author wrote several texts during his stay in the Amazon, texts whose scientific and journalistic crossings are the focus of this work. We have chosen some clippings from this writing (essays and letters) that will also allow us to understand the author's discourse and his position, observing aspects such as the ideology to which he was affiliated, as well as the dominant theoretical thinking and the historical conditions of production in the late 19th and early 20th centuries.