10 H. P. B., defines the Akasha in the following terms:  S. D., II, 538.  "Akasha the astral Light can be defined in a few words:  It is the Universal soul, the Matrix of the Universe, the Mysterium Magicum from which all that exists is born by separation or differentiation.  In the various occult books it is called by different terms and it would be of value perhaps if we enumerate some of them here:  There is one universal element with its differentiations.
 
Homogeneous     Differentiated.
1. Undifferentiated      1. Astral Light.
     cosmic substance     2. Sea of fire.
2. Primordial ether.      3. Electricity.
3. Primordial electric entity.     4. Prakriti.
4. Akasha.      5. Atomic matter.
5. Super-astral light.      6. The serpent of evil.
6. Fiery serpent.     7. Ether, with its four divisions,
7. Mulaprakriti.     air, fire, water, earth. "
8. Pregenetic matter.