The Book: The Master Mind of Mars by Edgar Rice Burroughs. Originally published in 1927, the edition read was published by Ballantine Books in 1973.

The Setting: Mars. Surprised?
The Story: A John Carter fan boy gets himself to Mars, apprentices to a mad scientist, falls in love with a beautiful mind transferred to a horrible body, and resolves to return that mind to its (also beautiful) body. He teams up with an assassinated assassin, a guard in the body of a noble, and a great white ape with half the brain of a man. Then they fight their way in the pursuit of what must be right, and manage to position themselves as a god while doing it (nope, that’s not an agreement problem). Which helps them on their way. It all works out in the end – everyone ends up in the right bodies, and the fan boy marries the beautiful mind, and its attendant beautiful body. And John Carter is best man at his wedding!
The Science: MAD SCIENCE. So the WWI soldier spends the first part of the book learning to become a surgeon under the character I assume the title refers to. The Mad Scientist is interested only in science, with no eye toward what we Earthlings might call ethics. So, in addition to fixing broken down organs and replacing limbs and all manner of humanitarian whatnot, he’ll also transfer your brain into another body that you like better, for money naturally. Or put your brain in an animal. Or half your brain in an animal. You know, for science.
While organ transplants are now pretty well established (and still pretty freaking awesome), and stuff like face transplants actually happen, Martian medicine seems significantly more advanced – what with allowing brains to be transferred and everybody wakes up okay. What bugs me is how the mad scientist would put together half and half brains. I’m pretty sure that you can’t just cut a brain in half and it’ll be just fine and dandy. The right and left lobes have fairly distinct sets of responsibilities, if you will. So I am skeptical that you could reconcile the halves of two different, if similar species. But maybe the mad scientist was just that good. He seemed to be.
The Reaction: The book was alright. I read most of it on a 4 hour flight (and am typing this now IN THE AIR! SCIENCE!). I feel like Burroughs is stuck in a kind of rut. Even though the girl didn’t actually get herself kidnapped or lost, it was still a rescue mission. And there’s the shock value. The brain replacement bit is a bit, well, shocking. Right up there with human taxidermy (oh god, I’m going to get google hits for that now, aren’t I?). So while it was a fine adventure story, it was nowhere near the caliber of the early books. And what’s with the earthman? Does he not feel ethically conflicted about some of this shit that went down? I mean, really! Brain swapping! I’m glad that Burroughs began to put more time between volumes – I think the stories could use some refreshing.
The Cover: Cover art by Gino D’Achille. This cover features the dreaded white ape of Mars carrying (fighting?) a red man of Mars. And a white ape is a protagonist for a while, and he does fight red men. So I guess that’s fine. If a bit dull.
Next Up: The Skylark of Space by Edward E. Smith.