The Hermetic science of vibrations - a precise, positive science.

This science of vibrations is as independent of psychic matters as any physical science. Just as the physicist determines by means of numbers, the vibratory frequency of different colours, or by numbers, determines the vibratory frequency of any selected musical tone, so also by means of numbers, can the vibratory key of any thought be determined."

The great singer Caruso demonstrated, using his voice, the power of a vibratory key.

"Often, going into a cafe, he would call for a wine glass. Then tapping the glass to determine the key, he would ask the waiter to place the glass on a table in a distant part of the room.

He would then, by singing the tone to which he had found the glass keyed, with the powerful vibrations of his voice, shatter the glass."

Thoughts, like vocal tones, are vibratory rates.

"Thoughts, like vocal tones are vibratory rates, but they are definite vibrations in astral, rather than physical substance. Like Caruso's voice, they have the power to travel across space and bring about physical changes. And like his voice also, it is their vibratory key, as well as their volume which determines their effect."