“It may be found, perhaps, that one of the last sparkles of modern science, the beautiful green spectrum of silver, is nothing new, but was, notwithstanding the paucity “and great inferiority of their optical instruments”, well-known to the ancient chemists and physicists.
Silver and green were associated together as far back as the days of Hermes. Luna, or Astarte (the Hermetic silver), is one of the two chief symbols of the Rosicrucians. It is a Hermetic axiom, that “the cause of the splendor and variety of colors lies deep in the affinities of nature; and that there is a singular and mysterious alliance between color and sound.”
The kabalists place their “middle nature” in direct relation with the moon; and the green ray occupies the centre point between the others, being placed in the middle of the spectrum. The Egyptian priests chanted the seven vowels as a hymn addressed to Serapis; and at the sound of the seventh vowel, as the “seventh ray” of the rising sun, the statue of Memnon responded.
Recent discoveries have proved the wonderful properties of the blue-violet light — the seventh ray of the prismatic spectrum, the most powerfully chemical of all, which corresponds with the highest note in the musical scale.
The Rosicrucian theory, that the whole universe is a musical instrument, is the Pythagorean doctrine of the music of the spheres. Sounds and colors are all spiritual numerals; as the seven prismatic rays proceed from one spot in heaven, so the seven powers of nature, each of them a number, are the seven radiations of the Unity, the central, spiritual SUN.
“Happy is he who comprehends the spiritual numerals, and perceives their mighty influence!”, exclaims Plato. And happy, we may add, is he who, treading the maze of force-correlations, does not neglect to trace them to the invisible Sun!
Future experimenters will reap the honor of demonstrating that musical tones have a wonderful effect upon the growth of vegetation. And with the enunciation of this unscientific fallacy, we will close the chapter, and proceed to remind the patient reader of certain things that the ancients knew, and the moderns think they know.”
H. P. Blavatsky
The Mark Of God: Understanding Your "I AM Presence" 