There was never any commentary offered by Friar Roger Bacon. He wrote for a certain, select audience and explained no fundamentals. There was also no commentary offered by Dr. Charles, the original only “slightly modernized” in his period in 1597. Whether Dr. Charles understood more or less of what was offered by Bacon is anyone's guess. He obviously felt that Bacon's manuscript was at least worth translating and preserving. The rest is up to us.
Any commentary on another’s work is limiting. No one commentator can know all 100% of what the original author is/was presenting, especially with alchemical literature. Perhaps if this effort were re-written ten years from now, much additional insight would surface. Perhaps not.
If there is anyone out there with capabilities beyond what is presented here, I would certainly appreciate the input.
The fact is that Bacon’s manuscript and all writings that use the language of universal pictorial symbolism become timeless. The Bible and all tracts that are written in coded and cryptic styles grow with the expansion of each personal consciousness into fourth dimensional awareness and beyond. All these types of writings are deliberate in that sense. One must keep in mind also that this interpretation of Bacon’s treatise, as that of the Bible and many other esoteric texts from the East or West, is entirely subjective and intensely personal. The methods used to investigate the writings, however, are objective. Paracelsus advised to know “the uses of the cabalists and the old astronomers” when approaching alchemical literature. These methods can be taught and handed down for others to learn. They are done in a certain manner for all the Qabalistic, Rosicrucian, and alchemical writings from the West and labeled the “Western Tradition.” The conclusions from each investigator, however, are subjective and based on the personal level of consciousness within each individual.
The reader may fare better or worse with the original of this same manuscript. But if the same methods were understood, applied conscientiously, and grasped in spirit by different people, it is reasonable to assume that approximately the same conclusions would present themselves. It also presumes that all the personal psychological elements within each individual who reads and studies the original work would necessarily need to be equal. Where would that be found? Be that as it may, I feel my interpretation has successfully rendered the original manuscript at least more, if not totally, accessible to the average reader with the philosophical bent.
Finally, exactly how can anyone know absolutely if one's 'metals' (chakras, force centers) are pure, impure, lacking 'weight,' or any of the other conditions to which alchemical writers are alluding? My first advice would be to not think about it. At this stage of our unfoldment we may all be considered insufficiently impure, so just meditate regardless of the philosophers' admonitions. Meditation heals all the centers simultaneously.
However, if one leans curious yet feels psychologically insufficient to “know thyself,” then Astrology might be considered. Of course this assumes one has some working knowledge with the astrological arts and sciences. Astrology could be considered the Anatomy of Consciousness and may be of considerable value to an earnest seeker.
Researching the astrological aspects between the planets, and the placements of planets in their signs and houses within the natal chart (birth map) might be of some valuable help. But, a caution. This method calls for a very honest probe and a keen judicial assessment of oneself that many of us are not very willing or even able to undertake. Maybe a trusting professional astrologer, or even a psychoanalyst would be the better approach.
The placement of any planet in any of the signs or houses is called its 'dignity.' This means that all the planets are either most favorably or unfortunately positioned in a sign or house that influences the planet (chakra). For example, the Moon rules the sign Cancer, but is exalted in the sign Taurus. Either of these zodiacal signs is a fortunate placement for the Moon (the Ajna Chakra, or metal Silver). Whereas if the Moon were posited in Capricorn, the Moon's detrimental sign, or in Scorpio, the sign of the Moon's fall, the energies flowing through this metal, might be considered challenging and 'impure' for alchemical work, and therefore needing much meditation. Planets can be favorably or ill placed in the twelve houses as well. The combination of house and sign placement may add to or detract from the energies flowing through the 'metal' naturally.
Another consideration is the planet's position with regard to the other planets' relative positions in the birth map. This is called an 'aspect.' There are several aspects in varying degrees of intensity as to their positive or challenging influences. Now we have the combination of each planet's placement in a house, a sign, and its relative position to all the other planets. This may be a complicated assortment calling for quite a high degree in the Art of interpretation. The best way to approach this problem is to read all about these placements and aspects in your birth chart from various astrology books. The very act of researching and discovering the plethora of knowledge behind all this is a meditation in itself. Besides, you would be researching your most favorite subject, YOU! And this would go a long way toward meditating on and ultimately 'purifying' the 'metals.'
The very least that one gains from all this research helps us all.