Cadmium yields one line only (the least refrangible of the triplets at cadmium 17) 3261 17. Oscillation frequency 30654-4.

Zinc and zinc oxide give nothing but a continuous spectrum.

Kayser and Runge record lines in the arc-spectrum of strontium at 5543-49, 4607-52, 4226-91, and 4077.88.