MOED abbreviated in short, commonly known as Brooker's Merocyanin is an organic dye which exhibits an interesting property of solvatochromism. Which means it produces different color in different solvents.

I can make my favorite color with any pen

These turn white when they’ve been in the sun too long
Напиток белеет, когда слишком долго находятся на солнце.

Rhodamine B solutions at different concentrations

Left to right: 1 ppm, 10 ppm, 100 ppm, 1000 ppm, pure powder

Methylene blue

Poured methylene blue on some surgical towels after the case was done and this happened. Anyone know what this reaction was?

I was tracking down some specific reagents for a project in our campus chemical store. The place is absolutely massive and packed with tall shelves and rolling ladders. While digging around the back, I spotted this ancient-looking bottle of 'Bismarckbraun Extra' (Vesuvin).

I was quite curious, so I looked up the company details on the label. It reads 'C.A.F. Kahlbaum, Chemische Fabrik, Adlershof bei Berlin' and includes the 'GmbH' tag. The company only became a GmbH in 1913 and then sold off its chemical division by 1921. That means this exact bottle has been sitting around for well over a hundred years.

What makes it even more bizarre is that our university wasn't even founded when this reagent was produced. It has clearly been opened and used at some point in the past, but there is still some of the original substance left inside. It is absolutely mad to realise I am holding a piece of history that is literally older than the entire institution I am studying at. I thought you lot might appreciate seeing it.