A simple, rapid method for measuring the percentage of water in alcohols used for dehydrating tissues.

A method is described for determining the concentration of water in alcohols that have been used for dehydrating specimens. The alcohol to be tested is added dropwise to 5.0 ml of xylene, counting the number of drops that causes turbidity, then the number of additional drops required to make the liquid transparent again. The amount of alcohol required to clear the turbidity increases steeply with water content, providing an easy and reliable assay method for water content of 90% to 97% alcohol baths. Alcohol containing 2% or less water does not become turbid when xylene is added.