Posted by Victor Mair

https://languagelog.ldc.upenn.edu/nll/?p=72543&utm_source=rss&utm_medium=rss&utm_campaign=battery-powered-prayers

https://languagelog.ldc.upenn.edu/nll/?p=72543

[This is a guest post by Alexander Bazes]

I was delighted to discover this well-researched (and very entertaining) YouTube video about the Baghdad Battery by Penn Museum archaeologist Dr. Brad Hafford (I have reached out to him with my recent article on Sino-Platonic Papers and welcome his criticism).

"The Baghdad Battery? Archaeologist Reacts!" (33:02)

Towards the end of his lecture (~25:00), Dr. Hafford discusses a likely ritualistic role played by the Baghdad Battery and similar objects that have been found at the archaeological sites of Tel Umar and Csestiphon. I find his explanation quite plausible given that the devices from Tel Umar were found in close association with other ritual objects, including three incantation bowls (Waterman, Leroy. "Preliminary report upon the excavations at Tel Umar, Iraq." 1931, 61-62). I find Dr. Hafford’s discussion of Sasanian-period incantations written on papyrus and lead sheets particularly interesting, as I believe it was probably the corrosive capabilities of the Baghdad Battery and similar artifacts that were employed by its users for ritual purposes. For example, I speculate that the artifact discovered at Csestiphon, which contained ten bronze tubes, each filled with rolls of papyrus and sealed, was intended to produce a corrosive effect on the outside of the tubes, thereby releasing the prayers inside.

In recreating the Khujut Rabu artifact, my starting assumption was that if this object had once functioned as a battery, then it almost certainly would not have been the first device of its kind to have been made. The language of the artifact’s design, therefore, ought to portray a history of trial and error whereby its makers found the best way––for them––to get the results they wanted. Nothing about it should be superfluous. In connection to this, I further assumed that this battery necessarily would have had enough power to provide some kind of visual feedback––otherwise, makers would never have discovered the device’s electrochemical effects nor how to improve upon them.

I designed my experiment therefore to ask the doubly biased question, “How can I read the Khujut Rabu artifact as having been a good battery for c.100-300 CE?” and focused on those design elements that seemed most counterintuitive. In doing so, I found that those oddities (namely solder on the copper vessel and the unglazed ceramic jar it sits in) are the very things that would have enabled the Baghdad Battery to work so well, comprising an entire second source of voltage for the device. Biases? Confirmed!

But what if we assume that the Khujut Rabu artifact absolutely was not a battery? What might a craftsperson read from its design, even though its function remained obscure to them?

Well, the first thing any metalworker would notice is that either the maker of this artifact was deliberately trying to corrode their handiwork or they had very little experience with metals. Not being a chemist, I suspect the actual mechanism of how the Baghdad Battery’s “outer cell” (solder + caustic potash + ceramic) functions may be more complicated than I have described. Whether or not oxygen from the air forms part of the equation (my theory), the fact remains that this specific arrangement of materials, filled even with water, will lead to extreme corrosion of both the solder and the iron rod.

And so herein lies the reason most crafted items are not easily mistaken for fully-functional batteries: people don’t like their stuff to corrode, and a battery is designed to do just that. Because corrosion provides visual feedback, makers can easily adjust how they do things to prevent it, thereby leading to an extreme dearth of maybe-batteries in the world.

If the Khujut Rabu artifact is indeed an ancient battery, it might be assumed there was once necessarily some other apparatus it was plugged into (e.g. an electroplating setup). While I believe this is quite plausible, I also think it equally likely that the device was merely plugged into itself. In other words, the battery’s purpose may have been solely to corrode the iron rod inside the copper vessel and the solder seams on its outside. Were a written prayer wrapped around the iron rod, then the author would soon receive visual evidence of an energetic influence having passed through their prayer, ultimately busting through the solder seams of the vessel and releasing the “genie” from the bottle.

Given that Mesopotamia already had its own ancient alchemical systems and that the Khujut Rabu artifact is contemporary with the development of the Greek Corpus Hermetica in Egypt, I find little reason for surprise that ritualists from this period would have been incorporating alchemical practices into their work.

Selected readings

• "Volts before Volta" (1/3/26)
• Alexander Bazes, “The Baghdad Battery: Experimental Verification of a 2,000-Year-Old Device Capable of Driving Visible and Useful Electrochemical Reactions at over 1.4 Volts", Sino-Platonic Papers, 377 (January, 2026), 1-20.

https://languagelog.ldc.upenn.edu/nll/?p=72543&utm_source=rss&utm_medium=rss&utm_campaign=battery-powered-prayers

https://languagelog.ldc.upenn.edu/nll/?p=72543