If your Nerve, deny you — Dentist

Brass arms and Flesh door appear oddly in this poem. It's Dickinson's experience or imagination of tooth extraction, a fearsome process denying one's nerve and soul.

If your Nerve, deny you－¹
Go above your Nerve－
He can lean against the Grave,
If he fear to swerve－

That's a steady posture－⁵
Never any bend
Held of those Brass arms－
Best Giant made－

If your Soul seesaw－⁹
Lift the Flesh door－
The Poltroon wants Oxygen－
Nothing more－

(F.329/J.292)

[1] Nerve:: nerve of the tooth.
[2] Go above, Nerve:: to skip the nerve, a hint on anesthesia.
[3] lean against the Grave:: anesthesia, a feeling close to death.
[4] swerve:: to change one's posture during tooth treatment.
[5-6] steady, Never, bend:: a steady posture after the laughing gas.
[7] Brass arms:: instruments for dental treatment.
[9] seesaw:: to move up and down; to tremble.
[10] Flesh door:: the mouth.
[11] Poltroon:: a coward. Oxygen:: a hint on laughing gas with portion of oxygen. This poem was written around 1862.

But our learned champion for laughing gas gives us to understand that the more oxygen we combine with nitrogen, the more exhilarating and healthful it is. ─ New York Dental Journal (1862)

The dentist remarked, "that he believed that a man might be made so drunk by this gas, or some similar agent, that dental or other operations might be performed upon him without any sensation of pain on the part of the patient." This conversation occurred in August, 1840, and the man who uttered the startling and entirely novel proposition was Horace Wells. Four years passed by, and in the same city a traveling lecturer (Colton by name) administered to several persons the "laughing gas," amongst others, to a certain dentist. ─ American Medical Gazette and Journal of Health (1858)