Purified
Take a chunk of wood, a stump split down the center. Build a roaring fire. Feed it all day. Reach in to the furnace-hot coals and scoop some out onto a chunk of bark. Now, burn out the center of your log with those coals to make a bowl-shape out of the wood. You must scrape off the encrusted black charcoal from time to time so your log doesn't develop a crack all the way through. While you're waiting for the log to smolder, place some rocks (ideally pumice) in your fire to heat up.
About ten hours later, you'll have a container capable of holding hot water, as well as some well-roasted rocks. Fill your container with water, then drop your hot rocks in, one by one. When you see bubbles, add enough rocks to maintain the boil for at least two minutes.
You've killed off enough water-borne bacteria to safely drink that water, now. I hope you didn't dehydrate to the point of death in the process!
You could also make stew or tea in this fashion, if you're so inclined.
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Maybe you don't want to wait a full day for a vessel you can boil water in. If you have a water source nearby, you can dig a hole a couple of feet away from the river or stream bank and wait for water to seep through the ground. Like groundwater coming out of rocks, your hole will contain water free of bacteria that can make you sick. You can stick your face into the hole once the water has filled it--give it an hour--or fill up a bottle, if you have one. No guarantees that your water will be free of mud, but a sock or coffee strainer might help you out there.
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Contrast these methods to the more common chemical treatment of water with iodine or chlorine while camping, or using a LifeStraw. The primitive ways take time. Energy. Investment.
Zoom out a little farther. Flip on a tap--out comes water, hot or cold, as you like. It's so easy, you don't even have to think about what it took to get that water to you. The water spurts out like magic. Wasting it is meaningless, there's always more rushing out of the tap, filling up your tub, your sink, your glass.
Step back in. Imagine if you had to boil all that water with hot rocks in a hollowed out tree stump. Perhaps you might not be so profligate with it.
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It's hard to live in two worlds. I come back from a day with Trackers to a gas furnace, a hot water heater, electric stove top. All the amenities of civilization. A task that was nigh-on sacred a few hours before--water is the stuff of life, to go without it is to die in days, to purify it enough for human consumption can be hours of work--becomes routine. I fill the kettle up at the sink. I flip a switch on the stove. My water boils in minutes. I pour it into a mug. I sip my tea, remembering the tea from a few hours ago that took hours to produce.
These aren't value judgments. It is not good or bad to make tea one way and not the other. But in the old way, I'm not just making tea. I'm living my life. In purifying the water, I purify myself. I sweat and work in service of the sacred. In the new way, I'm just making tea, delicious as it might be.
Photo taken by Grey. Kellen making a bowl out of a log using coals.