Washed Sand —See Sand, Washed.

Water, Ammonia-Free, H2O—18.02—Use High-Purity Water as defined for Chemical Resistance—Glass Containers under Containers 661.

Water, Carbon Dioxide-Free —See Water, in the introductory section.

Water, Deaerated —See Water, in the introductory section.

Water Vapor Detector Tube— A fuse-sealed glass tube so designed that gas may be passed through it and containing suitable absorbing filters and support media for the indicator, which consists of a selenium sol in suspension in sulfuric acid.

Wright's Stain— A mixture of methylene blue, methylene azure, and the eosinates of both, available as a solid and as a solution in methanol. Use a suitable grade. [NOTE—If a solid is used, dissolve 6.0 g of Wright's stain powder (CAS# 68988-92-1, dark green powder) and 0.6 g of Giemsa stain powder (CAS# 51811-82-6, dark green to black powder or crystals) in 1000 mL of methanol. Stir overnight, and filter before use.]