If I put both terminals of a 9V battery to my tongue I get a definite WOW! When I put it to my skin it gives me no sensation at all. Even when I wet my skin, nothing happens.
What’s going on?
Curiously yours,
js
Even wet skin only presents a relatively low-resistance path along the surface of the skin. At 9 V, only a VERY tiny current flows across the outer layers of skin. Your tongue (and other mucous membranes), however are both thinner and not covered with the insulating layer of dead cells and keratin, and allow current to flow through it more easily. When this happens, the current stimulates nerve endings which result in the WOW!
Skin is a very good insulator. If you test it by holding a voltohmeter, it will register several thousand ohms. (Probably more, but it’s been ages since I’ve done it.) With that kind of resistance, it’s hard to generate enough current to feel. Even when wet, pure water not being much of a conductor, the resistance is still pretty high – enough for a 9V battery to not do much.
Your tongue, on the other hand, is just a big wet mucus membrane with (probably) lots of electrolytes to boost conductivity. Not too mention the proximity of a whole bunch of sensory nerves to send the news to your brain that you’ve done yet another foolish thing.
Is anybody else thinking, “Darwin Award”? Maybe with this twist: that the initial buzz triggers a swallowing reflex, and then it’s down the hatch, with further currents interfering with some critical vagus nerve or something? Should make for a very interesting autopsy, and maybe an item for the pathology journals and textbooks…
Not really. I knew people who had done it in jr. high and I’ve been wondering about it ever since—besides, you don’t have to put the battery in your mouth. No maybe if further tests involved placing it in the rectum…
You’ve never tasted a battery? How else can you tell if it’s got any juice left?
(Don’t try to taste two AA’s in series, though.)
–Cliffy
Who hasn’t put a 9volt battery on their tongue? (rhetorical)
Probably everyone I know did it as a kid.
Why not?
Because you’ll dislocate your jaw trying to open your mouth that wide. 
What about AAA’s? And what if I have a hugh maw and can fit 2 AA’s? I need the Straight Dope or at least someone willing to recusitate me if I try it in the name of science. And of course if it goes horribly, horribly wrong I’ll expect a Darwin.
Not if you have a coin as well.
You know how the lights dim in your house when the heat kicks in? I thought that was happening when I tasted the two bateries , but then I realized it was my vision. So obviously something weird was going on there.
–Cliffy
I don’t know about that, Cliffy. Two AA cells in series is only 3 V; that’s barely enough to detect IME. I’ve done up to 12 V or so across the tongue with nothing more than a strong, almost uncomfortable, tingle. No visual effects that I can recall.
It does seem weird, but that was my experience. I did it three or four times before I realized what was happening. (I quite honetsly thought it was just the heat pump turning on the first time, until I noticed that the sun coming in through the window was dimming as well.) After I realized what was going on, I figured that was as much experimentation as my poor fragile brain could take, so I leave to others to figure out what happened.
–Cliffy
Besides the flashing, have you noticed how the positive and negative poles have a different flavor as the juice is flowing?
Please be careful with your experiments. I know we all sucked batteries when we were kids, but your mentioning of the Darwin Awards remined me of this story
"A US Navy safety publication describes injuries incurred while doing don’t’s. One page described the fate of a sailor playing with a multimeter in an unauthorized manner. He was curious about the resistance level of the human body. He had a Simpson 260 multimeter, a small unit powered by a 9-volt battery. That may not seem powerful enough to be dangerous… but it can be deadly in the wrong hands.
The sailor took a probe in each hand to measure his bodily resistance from thumb to thumb. But the probes had sharp tips, and in his excitement he pressed his thumbs hard enough against the probes to break the skin. Once the salty conducting fluid known as blood was available, the current from the multimeter travelled right across the sailor’s heart, disrupting the electrical regulation of his heartbeat. He died before he could record his Ohms."
Sorry, the link is slightly wrong. When at the Darwin site, perform a search for ‘battery’. This story is titled “Resistance is Futile”
This is the direct link to the story. It is, however, in dispute and remains unconfirmed by Darwin. My personal opinion is that it is bunk.
I’m with QED in the hooey department regarding death by Simpson. 9 volts doesn’t have enough EMF to upset cardiac function, unless perhaps you’ve already opened the thoracic cavity.
I have a Simpson 260 meter in my functional test kit at work. I will report back tomorrow morning at about 7am PST with the results.