Summary
This paper presents a survey of some aspects of Rio Negro water quality in the vicinity of Manaus, Amazonas, Brazil. Measurements of temperature. pH, electrical conductivity, light penetration (Secchi), saprophyte and total coliform bacteria, were carried out from January through December of 1977. The samples were collected at two depths at eleven places along the river and from two streams at the outskirts of the town. The results are discussed from a sanitary point of view and the autopurification capacity of the river is emphasized.