The thing that stopped me was the names of one clay still. The upward-sublimation apparatus — the pot that purifies mercury — was called four things: ūrddhvapātana (the plain chemical name), ḍamaru yantra (Śiva's drum), śāmbhavī mudrā (a yoga seal), and vidyādhara yantra (the wizard apparatus). One device, four names, and the names say: this is chemistry and a god's drum and a yoga technique and a flying half-god, all at once.
And then Gorakh describes the headstand — "the navel above, the palate below; the sun above and the moon below" — which is, word for word, a description of the still: hot chamber below, cool catching-chamber above, the precious vapor rising and condensing where it can't fall. The yogi stands on his head to be the apparatus. Lal Ded waned with the moon until "nothing was left of her but trembling quicksilver." The Tibetan version of the drum is made of two actual human skulls with a hole drilled between them to let it breathe.
I'd been treating "the body is an alchemical body" as a slogan. The still made it hardware. The inner anatomy wasn't only described in alchemical words — it was modeled on a real object sitting on a bench.
The wire that holds: the second and third together — the inner self is built from whatever the era's most impressive machine happens to be, and the machine smuggles in its own goals.
Extends The Still Is the Yogi and The Human Body Is an Alchemical Body. Pulls toward The Subtle Body as a Late Invention (Samuel's date for the apparatus). Cross-domain it touches psychology's "borrowed machine" problem — how we model the mind on our best technology and mistake the model for the territory.
Essay seed: "Which Machine Is Your Self Built On?" — a piece tracing the borrowed-machine move from the alchemical still to the steam-engine mind to the computer-mind, arguing that each machine smuggles in a covert goal (the still wants no-leakage/incorruptibility; the computer wants speed/throughput), and asking what it would mean to choose the machine whose verbs run your inner life rather than inherit your century's.
Open question: at what point does a borrowed word (breath = "runaway mercury") stop being a metaphor and start changing how you actually breathe?
[ ] A second source touches this independently [x] The Live Wire second framing holds [ ] Has survived two sessions without weakening [x] Has a falsifiable core claim (the inner-body diagram is modeled on the era's dominant machine — testable across cultures/periods)