Meyer reagent

Mey·er re·a·gent

(mī'ĕr), a solution of phenolphthalein with sodium hydroxide, in water (glass-distilled); in the presence of minute traces of blood, the solution becomes purple or blue-red. [W. Meyer]

Meyer,

Willy, U.S. surgeon, 1854-1932. Meyer reagent - a solution to detect minute traces of blood.