Yes i agree with much of what has been said about these symbols. I recognise the style of the symbols as Alchemy symbols for the 7 main elements. I think i can identify the symbol for lead in the circle. The circle and the writing of the symbols may be something for protection or for blessing, or maybe it has a scientific meaning. I have not been able to research any further but my advice is to search the net for alchemy symbols. This link may be a place to start your search,
http://www.hexagongirl.com/y/22-Alchemy&Symbols.html
Achille marozzo´s Opera Nova, was published in a time when major works on Alchemy, Occultism and Sciense were published. Henry Cornelius Agrippa 1486-1535 was a important person of Renaissance esoterica. So was John dee 1527-1608, scientist and occultist, he was also Queen Elisabeths Scientific advisor. Maybe even the italian Giovanni Pico della Mirandola´s Opera Omnia can be of interest.
/Björn Sollander
ARMA-Uppsala
Sweden