Protometalic

Protometals Pro`to*met"als, n. pl. A finer form of metals, indicated by enhanced lines in their spark spectra (which are also observed in the spectra of some stars), obtained at the highest available laboratory temperatures (--Lockyer); as protocalcium, protochromium, protocopper, protonickel, protosilicon, protostrontium, prototitanium, protovanadium. -- {Pro`to*me*tal"ic}, a. [Webster 1913 Suppl.]