Explanatory notes
… the rare‑earth metals of heading 28.05 (lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, … as an opacifier in ceramics, for colouring glass, in the preparation of arc‑lamp carbons and as a catalyst in the … and its hydrates, hydrated ceric sulphate, orange‑yellow prisms soluble in water) are used in photography as …