Here it is again:

In one of these yogis, the infused energy acted aggressively like an effervescent substance bubbling in a liquid. It appeared like a stick of fire. In the other, it appeared as a blue-white light which emanated a glow of white light. These were their appearances which represent nothing besides their condition, the way an incandescent light has a glow which represents nothing besides the burning sensation and action of the filament.