The contribution of non-European cultures to science and technology, primarily to chemistry, has gained very little attentions until now. Especially the high technological intelligence and inventiveness of South American native populations shall be put into a different light by our contribution. The purpose of this essay is to show that mainly in the area of chemical practices the indigenous competence was considerable and has led to inventions profitable nowadays to millions of people in the western world and especially to the pharmacy corporations. We would like to illustrate this assumption by giving some examples of chemical practices of transformation of substances, mainly those unknown in the Old World. The indigenous capacity to gain and to transform substances shall be shown here by the manufacture of poisons, such as curare or the extraction of toxic substances of plants, like during the fabrication of manioc flower. We shall mention as well other processes of multi-stage transformations and the discovery and the use of highly effective natural substances by Amazonian native populations, such as, for example, rubber, ichthyotoxic substances or psychoactive drugs.

Comenta quatro trabalhos do Simpósio sobre fronteiras territoriais e identidades socioculturais: as causas e os significados da variabilidade artefatual dos registros arqueológicos, apresentados no XIII Congresso da Sociedade de Arqueologia Brasileira. Posteriormente, busca entender a relação entre práticas, teorias e discursos na arqueologia brasileira, tomando como exemplo o Programa Nacional de Pesquisas Arqueológicas.

Comments four papers of a symposium about territorial frontiers and socio-cultural Identities: reasons and significance for the variability of artifacts in the archaeological record presented during the XIII Congress of the Society of Brazilian Archaeology. Afterwards, it tries to understand the relation between practice, theory and discourse in Brazilian archaeology, mainly in the context of the National Archaeological Research-Program.