Declaration of Vital Essence

The Declaration of Vital Essence is a paper note

Location
It can be found in Nipton in a heavily booby-trapped house (east of the general store with sandbags) in a tool cabinet in the kitchen across from the front door.

Behind the scenes
The note is a reference to the character General Jack D. Ripper from the film Dr. Strangelove, who was obsessed with "Purity of Essence" and the protection of his precious bodily fluids.