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The Leidenfrost Effect is a described as follows on Wikipedia:

The Leidenfrost effect is a physical phenomenon in which a liquid, close to a surface that is significantly hotter than the liquid's boiling point, produces an insulating vapor layer that keeps the liquid from boiling rapidly. Because of this repulsive force, a droplet hovers over the surface, rather than making physical contact with it.

One of the consequences of the effect is that it allows for someone to briefly interact with substances that are extremely hot or cold such as liquid nitrogen or molten metal, and come away unscathed. (Do not try this at home.)

Here is a video of someone brushing their wet hand through molten metal and avoiding being burned:

https://www.reddit.com/r/interestingasfuck/comments/vtsvle/man_able_to_touch_molten_metal_with_bare_hands/

This was also covered in MythBusters:

In the 2009 season 7 finale of MythBusters, "Mini Myth Mayhem", the team demonstrated that a person can wet their hand and briefly dip it into molten lead without injury, using the Leidenfrost effect as the scientific basis.

This question seemed to come up repeatedly and one of the comments on Reddit claimed that Leidenfrost himself proved the Leidenfrost Effect by touching molten metal, but I was unable to find any sources to back up that claim.

Is there any evidence that Leidenfrost himself demonstrated this by touching molten metal, and if not, then who was the first person with enough courage to actually touch molten metal in order to demonstrate the effect?

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  • $\begingroup$ The relevant work is Johann Gottlieb Leidenfrost, De aquae communis nonnullis qualitatibus tractatus, Duisburg: Hermann Ovenius 1756. The relevant part appears to starts at section 15: "XV. De Fixitate Aquae Diversa in Igne." Google scan. From a quick perusal, I understand that Leidenfrost dropped water from a narrow glass tube into a heated metal spoon when he observed the effect. $\endgroup$
    – njuffa
    Sep 20, 2022 at 5:27
  • $\begingroup$ Jearl Walker, "Boiling and the Leidenfrost effect." Fundamentals of physics. (2010): E10-1, includes a picture of the author dipping their fingers into pot of molten lead: " After wetting my hand, I dipped all my fingers into the lead, touching the bottom of the container (Fig. 5). The contact with the lead was still too brief to result in a burn. Apparently, the Leidenfrost effect, or more exactly, the immediate presence of film boiling, protected my fingers. " $\endgroup$
    – njuffa
    Sep 20, 2022 at 20:39
  • $\begingroup$ Thanks. So it seems that Leidenfrost tested with dropping of water (but not his own wet hand, unless there's another text you didn't find), and the earliest case you've found so far is someone named Jearl Walker testing by dipping their hand in molten lead in 2010. Thanks again. $\endgroup$
    – azoundria
    Sep 21, 2022 at 20:07

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