Abstract: A test device and method is described for directly determining the liquid phase water content of organic solvents and indirectly the liquid phase water content of solids. The device and method utilize a reagent composition consisting basically the dried residue of a mixture of a colorimetric indicator material, preferably a cobaltous or cuprous salt, and a polymeric water barrier material, such mixture incorporated into a matrix which is contacted with or immersed into the liquid test sample, removed therefrom and the color change of the test composition correlated with a standard color chart to give a quantitative result of the amount of water in the test sample. When the method is applied to solids, the water must first be extracted from the solid using a substantially anhydrous extracting fluid such as reagent alcohol.