This specimen is one of 115 samples of "fine and rare chemicals" produced by John Uri Lloyd for display at the Cincinnati Industrial Exposition of 1875. Lloyd was presumably awarded a "blue ribbon" ...

It is a Hell-beast born of fire! Actually, it is a reaction caused by igniting a mixture of Mercury(II) thiocyanate (Hg(SCN)2) and Ammonium chromate (NH4)2CrO4, two highly toxic but highly awesome ...