This vibrantly colored chemical was originally created for use as a fabric dye. Kittisak Kaewchalun via iStock/Getty Images Plus The internet is abuzz with tributes to a liquid chemical called ...

A solution of methylene blue in an erlenmeyer flask. The trending dye was invented by German chemist Heinrich Caro in 1876. Photograph by asikkk, Getty Images If you’ve spotted someone recently with a ...

Methylene blue was developed in the 1800s as a cobalt blue synthetic dye for textiles, but it also has some medicinal uses. It's approved to treat a rare blood disorder called methemoglobinemia.