“The Book of Secrets” is a medieval work wrongly attributed to Albertus Magnus, the 13th century Dominican friar and bishop, famous for his alchemical experiments and scientific interests. The work may have been written by one of Albert the Great's students. It does incorporate some authentic material from Albert's writings on the magical properties of gem stones. This edition is based on a 16th century English revision of the originally Latin work. It was popular during the Elizabethan Age and new editions were published well into the 17th century.
This version of “The Book of Secrets” was promoted as a work of entertainment value only, but it does fit right into the worldview of the 16th century, which was still largely “superstitious” and “magical” by later standards. It's a worldview based on the supposed efficacy of natural magic and astrology. Peculiar herbal cures or magical brews from unclean animals play a central role, and so do the magical properties of minerals. The English edition was more “respectable” than the Latin original, leaving out whole sections on magic and necromancy. However, it does include a whole number of magical tricks to silence barking dogs, something useful for thieves and burglars!
The magic is often based on correspondences. Since the lion is bold, wearing the skin of a lion makes a man bold. Since the mule is barren, any between mules and women make the latter barren, too. Why hemorrhoids disappear if you sit on a lion skin is less clear. Nor is it immediately obvious why the heart of a blackbird placed under the head of sleeping man will force him to tell you all his secrets! Also typical of medieval works is the strong dependence on ancient authorities (or at least the pretense of such dependence). Works rightly or wrongly attributed to Aristotle, Plato or Alexander the Great are frequently referenced. Of course, the trick of claiming Albertus Magnus wrote the whole thing is another example of this.
I admit that I didn't find “The Book of Secrets” to be particularly interesting, but it's a nice edition with copious notes and some illustrations. If you're into natural magic and similar things, it might perhaps have some “entertainment value”. I therefore give it three stars.