I once read a book (pdf) from imslp or forgottenbooks that was about composition (or harmony), and it had a list of every possible modulation and its emotional association. For example, Up a perfect fifth: uplifting, heraldic and magnificent. Of course it used much more poetic and verbose language. Is anyone familiar with this book? I've forgotten what it was called.
I'd look up under the doctrine of the affections in music.
Below you have the literature and bibliography of this theme.
The book you are looking for could be the one cited of Mattheson or Mersenne.
In der Capellmeister by Mattheson look for “Affecten” and “Modulation”.
Also search for L.c. Mizler (quoted by Mattheson) and Fux (Gradus ad Parnassum)
As you say the Book was in English you might google searching for music, affects, keys, modulation and you’ll find articles or books (secondary literature) mentioning the original book you are looking for. Maybe if you read the title or the name of the author you will recognize it.
E.g. like this:
Have you seen this link:
the book you're looking for may be an English translation of Mattheson's Capellmeister: