Question about Sci-fi Chemistry

I'm hoping that someone here can help me better understand "chemistry" from a sci-fi classic. In Philip Wylie's Gladiator (1930), the main character is born with super strength, super speed, and bulletproof skin thanks to a prenatal injection by his scientist father. The source of these powers is said to be "alkaline radicals." I understand that this is a real concept, but it's well over my head. Can someone please explain what this is, especially in regards to biology?

I want to learn more about the subject because it might reveal why Wylie chose the term. I've read that he was a fan of science and consulted with experts, so I doubt he picked it at random. (Note: I'm not suggesting that this can actually result in super powers.) Is it related to metals in anyway? I ask because the narrative compares the main character's flesh to iron and not meat. Thank you in advance for any help.

Mods, please let me know if there is a more appropriate place for this.