Abstract
The hypothesis was tested, whether hydrogen — ion concentration and electric conductivity in river water samples of the Tertiary region of central Amazonia were subject to changes in time and due to nature of storag. Over a period of about two months only changes in pH and conductivity of Rio Negro water samples were found to be significant. The total deviation of both parameters in rain forest stream samples v/as considered negligible for at least a period of 30 days, independant of the nature of storage (laboratory or icebox). The latter results may be generalized more or less unconditionally for the entire Tertiary formations of Amazonia.