Step 1: Touch the plant with your hand, wait 1 hour for negative effects to develop.
Step 2: If step 1 produces no negative effect, touch the plant to more sensitive skin, such as the inside of your forearm. Wait another hour for negative effects to develop.
Step 3: If step 2 produces no negative effect, touch the plant to the area around your mouth. Wait another hour.
Step 4: After touching your mouth with the unknown plant and seeing no ill effects, chew up a tiny bite of the plant in your mouth and spit it out, and then wait another hour.
Step 5: Ingest a tiny amount of the plant and wait an hour for negative effect.
Step 6: If no ill effects are felt at this point, the plant is likely safe for you to eat.
This is a very long and difficult process, but it's the safest way to determine if the plant will kill you. If you see a lot of one type of plant that you think you might be able to eat, it's worth the wait to figure out if it's poisonous or not. Once you've identified an edible plant, you can continue eating it without going through this process again.
Also, often (always?) the poison's in the dose. A little might be safe to eat, more not so much. So I'd go really easy when eating something new.
1. Mash it and hold in the pit of your elbow for an hour. If no irritation, go to step 2.
2. Hold it in your mouth for an hour. If no irritation, go to step 3.
3. Eat a bite and wait a few hours. If no irritation, go to step 4.
4. Eat a small amount and wait a few hours. If no irritation, it's probably safe to eat.
Urushiol (Poison Ivy et al.) usually takes about 4-6 hours to start showing symptoms.
"But how is that possible? He's surrounded by fruit!"
3 minutes without air
3 days without water
3 weeks without food
So you're probably not going to die without food if you go even for some days without it. In fact, many people regularly fast for days on end, some (such as people on hunger strikes) have fasted for weeks.
Of course, all of the above rules of thumb are subject to modifications based on things such as the amount of physical exertion you're under, your health, the weather, etc. If you're doing lots of exercise in the heat, you're going to need a lot more water than if you're lying still in the shade.
It's on page 103 in the FM 21-76 US ARMY SURVIVAL MANUAL: http://www.preppers.info/uploads/FM21-76_SurvivalManual.pdf
- poison takes 1 hour to kill you, party is in 1 hour.
- you have 4 prisoners you don't mind sacrificing to find out which bottle is poisonous but obviously you'll need to do all your sampling now because otherwise you won't know which bottle not to use in time for the party.
EDIT:16 not 17 bottles of wine.
This is the kind of problems that AI machines would try to solve, wrongly. Humans still score better understanding that some theoretical problems must not be solved.
I get that it's a game, but can't let this slip into the memesphere unchecked.
People are a superset of prisoners. Some of our largest problems as a society are a result of our not acting as such.
I quite like the mathematics of the puzzle, I also like justice and am aware that justice is a product of language in many instances, as many people interact with the world through language without giving much thought to it.
In fact, my statement was meant to ridicule the assumption that prisoners are worthless to point out they are people.
Except 17. Fencepost error on my part maybe?
Use binary search to find the poisoned bottle among bottle 1 to 16. If you fail to find a poisoned bottle, it is the 17th
Common presentation uses 1000, gives it away to use a power of two.
A really fun extension to it is to suppose that you use the same criteria (a thousand bottles, consumption of the smallest amount will kill, but after a delay that means you must perform a one-pass test) but _two_ bottles are poisoned. What is the minimum number of prisoners you need for your test to find the two poisoned bottles precisely and what is the procedure?
(This is _substantially_ harder.)
Ah, preppers.
It will pass all your tests without causing any irritation but still kills you in the end:
"There are no negative symptoms from eating this fungus until 6–24 hours after ingestion"
Not necessarily. Plants aren't so stupid and there are poisons designed to catch you at the middle and long term. Peas have those for example.
Better studying a little botany instead. Euphorbiaceae is a wery widespread family, relatively easy to recognize by its very specialized flowers. All are very poisonous and you can't eat it, but some of them can still be handy. Can provide you wit car tires, torches, fuel, killing your enemies and treatments for diarrhea, expelling worms and, as a nice special bonus, remedy for genital herpes. Yeah, they know what a real survivor needs.