1 November 18

My chartreuse tie celebrates the synthesis of fluorescein (in 1871) by Johann Friedrich Wilhelm Adolph von Baeyer, who was born on 31 October 1835. Fluorescein is an important "tracer" compound, useful in detecting tiny amounts of metals, other organic compounds, etc. The powder itself is dark red, but in solution it displays vibrant chartreuse. I first encountered fluorescein as an indicator for some titrations in quantitative analytic chemistry, in 1972-1973! Adolf von Baeyer won the Nobel Prize in Chemistry in 1905.