In scientific and astrological works, the numerals, as, in Sanskrit, are expressed by symbolical words.
From this early astrological use the form of "glory" or "nimbus" has been adapted or inherited under new beliefs.
All these physical theories are blended with a mystical theosophy, of which the most remarkable example is, perhaps, the chemico-astrological speculations of Paracelsus (1493-1541).
He also finished his Tabulae Directionum (Nuremberg, '475), essentially an astrological work, but containing a valuable table of tangents.
The denotation of elements by symbols had been practised by the alchemists, and it is interesting to note that the symbols allotted to the well-known elements are identical with the astrological symbols of the sun and the other members of the solar system.