"The Cesium song 01" joke

Oh Cesium
(Tune, Oh Christmas tree)

Oh Cesium, oh Cesium,
Thy spectrum doth us please-ium.
Thy sky-blue lines in plasma's fire,
Do dreams of icy lakes inspire.
Oh Cesium, oh Cesium,
Thy spectrum doth us please-ium.

Oh Cesium, oh Cesium,
When held, you never freeze-ium.
Thy gently smoking silver spheres,
When dropped in water, please the ears.
Oh Cesium, oh Cesium,
When held, you never freeze-ium.

Oh Cesium, oh Cesium,
You put us at our ease-ium.
You tend the seconds of the day,
So that our watches never stray
Oh Cesium, oh Cesium,
You put us at our ease-ium.

---Songs of Cesium #34