This was a big recycling week for me. When the big blue bin was dumped into the big green truck, the noise of crashing glass flushed birds from the trees and brought neighbors to their windows. “If recycling is going to save the Earth,” they thought, “that Davis boy is sure doing his part.”

         But some neighbors were at the party, and they knew the score. They were among the thirty or forty brave friends willing to show up, drink alcohol, and let me experiment on them. I was curious about blood alcohol content (BAC). Could my peeps have a few drinks and then guess whether they were above or below the magic .08 percent that could earn them a night in the slammer? To find out, I purchased a breath testing device and did some reading about standard police roadside tests.

         I decided to employ three of the most popular: The one leg stand, the basic walk-the-line, and of course the horizontal gaze nystagmus. To pass that last one, the subject must say the name of the test three times fast.

         Ha ha, that’s just a little ocular spasm joke. It’s a bitch to pronounce, though, so let’s just call it HGN. Here’s an oversimplification of how it works: If you ask a drunk chick to hold her head still and watch your finger as you move it from side to side, you’ll see her eyes move in a jerky fashion rather than tracking smoothly. And if you have her look at something held more than 45 degrees off center, her eyes will twitch towards the center. “More twitchy is more drunky,” said one classic specimen (at .11).

         Even people at twice the legal limit were pretty good at walking heel to toe and standing on one foot. If you ever find yourself unable to do either one of these, I’d say forget about driving and have somebody take away your cell phone before you start drunk-dialing your ex. Both of those things became a bad idea several beers ago.

         Even if you can do the balance part of the tests, cops will ding you if you can’t follow directions. This is where my friends lost points, particularly the men. “Don’t start until after I finish demonstrating the test” proved to be especially challenging to them. Maybe “Simon Says” would be a good drunk test. I’ll have to try that next time.

         I did the testing in a side room, where guests attempted the three physical tests before guessing what the “alcohawk” breath tester showed their actual BAC.

         At first, people guessed pretty close. But after a few hours of drinking, they started guessing low. They didn’t feel as drunk as they actually were, possibly because they were getting used to the feeling. This is consistent with super-drunk people thinking they can, say, fly. Or kiss well.

         I looked at a lot of twitchy eyes. It took a while to get the hang of knowing what to look for, but HGN was a pretty good indicator of drunkenness. Everyone above the .08 limit had fairly obvious eye reactions.

         Except this one woman- let’s not name names- who tested at .09 but showed absolutely no sign of intoxication, other than saying I was cute. Don’t worry- her license plate number has been forwarded to the authorities.

         Nobody was allowed to drive away unless they were legally sober, so some people had to wait until their livers did a little blood scrubbing. But a couple people just got drunker, just sitting there drinking water. Presumably, food in their systems had slowed absorption of the alcohol. This was an interesting revelation- a person could get behind the wheel sober and be over the line before they got home.

         Admittedly, my experiment was sloppy science, but hey, this isn’t exactly a medical journal. My friends and I got some perspective on what .08 really means, and it was fun to bring a somewhat taboo subject to the surface of a party.

         A few people were amazed to see that they’d probably driven legally drunk many times without knowing it. Personally, the point at which I know I shouldn’t be driving turns out to be .08. You know that little chart you get in your DMV mailing that estimates how many drinks an hour you can safely have? It turns out to be, for me at least, pretty accurate. I always figured they exaggerated that thing, but I guess not.

         My breath tester cost a hundred bucks, and there’s another decent one for around $65. There are even disposable one-test devices. Do a web search for “breath tester” and you’ll see some options. Might make a good gift for somebody. That or a larger recycling bin.