Abstract
The relative conductivity and density of estuarine waters formed by mixing "world" river water with standard seawater have been determined. The results are used to examine the conductivity-density-salinity-chlorinity relationships of estuarine waters of known composition with seawater diluted with pure water (i.e. the new International Equation of State and Practical Salinity Scale). The maximum difference between the true salinity and the value derived from conductivity was 0.047 in dilute solutions; the maximum density difference between the measured and calculated values was $35 \times 10^-6 g\cdot cm^-3$. These results are compared with measurements of waters from the St. Lawrence estuary.