Yes, it's quite good. The story in 'Apothecary Diaries' is full of interesting characters and a unique setting. It combines elements of mystery, historical fiction, and a bit of fantasy which makes for a really engaging read.
There are also some online libraries that might have it for free. For example, Open Library. They have a large collection of books including light novels. You can search for 'Apothecary Diaries' there. However, make sure to check the legality of the source in your region.