Reading the Ascended Masters is not easy; yet, hardly anything worthwhile is. This is a profound reading on true alchemy: transforming the lower metals of the human consciousness into the Gold of the Higher Self; the only alchemy that counts.
From reading this book, I see some of the reviews here seem to miss the point; the book is self-empowering: that your Higher Self (something inside you) be in control of your life.
Relating the word to "all chemistry" has nothing to do with the etymology of the word but rather with a play-on-words metaphoric meaning as already explained in the book: it takes chemical processes, heat, and other conditions to produce change. Transmutation (transformation) is what Alchemy is about.
Saint Germain refers to his and Jesus' Ascension as taking place in the physical. This can make some people uncomfortable but it doesn't take away from the knowledge in it.
And yes, the book is by The Summit Lighthouse and not by the earlier I AM or Bridge to Freedom.
It is a gift about the experiment in the laboratory of you own being on elevating the soul to spirit. Read it if you are serious about wanting self-transformation; it goes into a great deal that, if understood, studied and followed may very well transform your life.