# Explain this thing we call "salt" **URL:** \ **Category:** Factual Questions\ **Created:** [January 17, 2006, 6:16pm UTC](https://boards.straightdope.com/t/explain-this-thing-we-call-salt/340384 "2006-01-17T18:16:02Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![tdn](https://avatars.discourse-cdn.com/v4/letter/t/94ad74/32.png) [@tdn](https://boards.straightdope.com/u/tdn)\ **Post date:** [January 17, 2006, 6:16pm UTC](https://boards.straightdope.com/t/explain-this-thing-we-call-salt/340384/1 "2006-01-17T18:16:02Z")
A conversation the other night prompted quite a few questions: 1. It is my understanding that in the olden days, salt was quite a rare commodity, and thus quite valuable. In fact, Roman soldiers were paid in salt, hence the “salary.” True, or urban myth? 2. It is also my understanding that salt was/is mined, and the miners often spend huge amounts of time underground, to the point where they’ll carve elaborate Madonna staues and such out of salt deposits. The reason for this is that they can spend days or weeks on end without returning topside. Is this what happens? 3. Other than its rarity, what use is salt? If it was truly as valuable as gold, why waste it on food? For taste it seems an awful waste, and for preservation it seems that the return wouldn’t be worth it. 4. Is a completely salt-free diet unhealthy? I’ve heard this before, but then it may be that an iodine-free diet is the real problem. 5. Did Medieval soldiers really salt the fields of their enemies? That seems like a costly way to achieve victory. 6. Salt today is cheap and readily available. Where does it come from? ---
**Author:** ![Exapno\_Mapcase](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/exapno_mapcase/32/1051_2.png) [@Exapno\_Mapcase](https://boards.straightdope.com/u/Exapno_Mapcase)\ **Post date:** [January 17, 2006, 6:22pm UTC](https://boards.straightdope.com/t/explain-this-thing-we-call-salt/340384/2 "2006-01-17T18:22:38Z")
All your questions answered and many more. [Salt : A World History, by Mark Kurlansky](http://www.amazon.com/gp/product/0142001619/sr=1-1/qid=1137522044/ref=pd_bbs_1/002-4952855-0071214?%5Fencoding=UTF8) ---
**Author:** ![August\_West](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/august_west/32/18069_2.png) [@August\_West](https://boards.straightdope.com/u/August_West)\ **Post date:** [January 17, 2006, 6:23pm UTC](https://boards.straightdope.com/t/explain-this-thing-we-call-salt/340384/3 "2006-01-17T18:23:25Z")
I just finished reading **Salt** so I’ll answer as many of your questions as I can recall the answers too. 1. Yes, true 2. In Poland there is a saltmine that had an elaborate church carved from the salt and even had salt crystal chandeliers. This type of salt mining is not as common nowadays. 3. Preserving food and flavor, that’s it’s value. People want and need (a little) salt on their food. Using salt to preserve food was MUCH more important 100 years ago than it is now. 4. You do need to have some salt, but I don’t believe it has to be sodium chloride. I think potassium chloride is acceptable. Not sure on this one. 5. No idea 6. Some of it is mined, some is made in evaporating pools of seaater. ---
**Author:** ![bouv](https://avatars.discourse-cdn.com/v4/letter/b/bc8723/32.png) [@bouv](https://boards.straightdope.com/u/bouv)\ **Post date:** [January 17, 2006, 7:07pm UTC](https://boards.straightdope.com/t/explain-this-thing-we-call-salt/340384/4 "2006-01-17T19:07:16Z")
In regards to needing salt, what you need is electrolytes. Salt is a very easy way to get sodium and chlorine, two of the three essntial electroyltes (potassium is the other big one.) Without electroyltes, your muscles can’t contract, you’re nerves can’t transmit signals, and you die. Oddly enough, you could die of two oppsite extremes, dehydation or hyperhydation. If you don’t take in enough electrolytes, your muslces and nerves will take it from wherever else they can in the body, such as the blood and intercellular fluid. When the electrolytes from these places are gone, they have a much lower osmotic pressure, so fluid from the inside of your cells will then have a higher pressure, and travel outside the cells to the blood and intercelluar fluid. Since there are very few electrolytes in the blood now, your kidneys will remove as much water as they can to balance the pressure, and you die of dehydration. OK, so you drink some water, but you still need electrolytes. Your body exhausted whatever reserves it had left in the blood and other fluid, and used that all up. So now suddenly, with no electrolytes in your cells, and none to draw on from the blood, the osmotic pressure of everything is screwed up. Your kidneys work overtime to try and remove as much fluid as possible, but if you keep drinking, they can’t keep up, and you continue to just retain more and more fluid, in your blood, in your cells, and in the intercelluar fluid. Eventually, cells start to swell and burst, water collects in your lungs and brain, and you die. Death can occur from several things. Heart failure from the electrolyte imbalance, you could drown from the water in your lungs, or the water in your skull can put too much pressure on your brain and kill you. So, in short, salt is good for you. ---
**Author:** ![CookingWithGas](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cookingwithgas/32/485_2.png) [@CookingWithGas](https://boards.straightdope.com/u/CookingWithGas)\ **Post date:** [January 17, 2006, 7:16pm UTC](https://boards.straightdope.com/t/explain-this-thing-we-call-salt/340384/5 "2006-01-17T19:16:31Z")
> [@tdn](#): > > 1. Is a completely salt-free diet unhealthy? I’ve heard this before, but then it may be that an iodine-free diet is the real problem. If by salt-free you mean no added salt, it is possible to get more than enough salt naturally through a variety of foods without have to add any in home preparation or at the table. Just about all commercial foods have salt, and the average American gets way more than enough. If by salt-free you mean absolutely zero salt then see below. > [@August West](#): > > 1. You do need to have some salt, but I don’t believe it has to be sodium chloride. I think potassium chloride is acceptable. Not sure on this one. [Your body needs some sodium](http://www.feinberg.northwestern.edu/nutrition/factsheets/sodium.html), generally from sodium salt. Not much, though. If an adult’s only source of sodium was table salt, a quarter of a teaspoon would still be more than enough. ---
**Author:** ![Squink](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@Squink](https://boards.straightdope.com/u/Squink)\ **Post date:** [January 17, 2006, 7:32pm UTC](https://boards.straightdope.com/t/explain-this-thing-we-call-salt/340384/6 "2006-01-17T19:32:54Z")
> [@August West](#): > > I don’t believe it has to be sodium chloride. I think potassium chloride is acceptable. Not sure on this one. Blood plasma typically runs about 140mM NaCl. If you try to replace that with KCl you’ll end up killing yourself. ---
**Author:** ![CalMeacham](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/calmeacham/32/35_2.png) [@CalMeacham](https://boards.straightdope.com/u/CalMeacham)\ **Post date:** [January 17, 2006, 7:41pm UTC](https://boards.straightdope.com/t/explain-this-thing-we-call-salt/340384/7 "2006-01-17T19:41:59Z")
In regards to #3, I recall being taught that far and away the biggest user of salt is industry – more than the food industry. Exactly what they’re using all that salt for I don’t know, but there are lots of uses for it in chemical reactions and surface treating. ---
**Author:** ![Cervaise](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cervaise/32/16693_2.png) [@Cervaise](https://boards.straightdope.com/u/Cervaise)\ **Post date:** [January 17, 2006, 7:51pm UTC](https://boards.straightdope.com/t/explain-this-thing-we-call-salt/340384/8 "2006-01-17T19:51:52Z")
> [@Exapno Mapcase](#): > > [Salt : A World History, by Mark Kurlansky](http://www.amazon.com/gp/product/0142001619/sr=1-1/qid=1137522044/ref=pd_bbs_1/002-4952855-0071214?%5Fencoding=UTF8) Seconding the recommendation. ---
**Author:** ![bouv](https://avatars.discourse-cdn.com/v4/letter/b/bc8723/32.png) [@bouv](https://boards.straightdope.com/u/bouv)\ **Post date:** [January 17, 2006, 8:25pm UTC](https://boards.straightdope.com/t/explain-this-thing-we-call-salt/340384/9 "2006-01-17T20:25:03Z")
> [@CalMeacham](#): > > In regards to #3, I recall being taught that far and away the biggest user of salt is industry – more than the food industry. Exactly what they’re using all that salt for I don’t know, but there are lots of uses for it in chemical reactions and surface treating. Your location says MA, so I assume you’re familiar with the havock reaped by road salt upon your car? Imagine the thousands (millions?) of miles of road that have to be coated with salt almost every time it snows in the north. That accounts for a lot of salt usage. ---
**Author:** ![Crandolph](https://avatars.discourse-cdn.com/v4/letter/c/7cd45c/32.png) [@Crandolph](https://boards.straightdope.com/u/Crandolph)\ **Post date:** [January 17, 2006, 8:25pm UTC](https://boards.straightdope.com/t/explain-this-thing-we-call-salt/340384/10 "2006-01-17T20:25:37Z")
#5: [Salting the earth](http://en.wikipedia.org/wiki/Salting_the_earth) ---
**Author:** ![CalMeacham](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/calmeacham/32/35_2.png) [@CalMeacham](https://boards.straightdope.com/u/CalMeacham)\ **Post date:** [January 17, 2006, 8:36pm UTC](https://boards.straightdope.com/t/explain-this-thing-we-call-salt/340384/11 "2006-01-17T20:36:19Z")
> [@](#): > > Your location says MA, so I assume you’re familiar with the havock reaped by road salt upon your car? Imagine the thousands (millions?) of miles of road that have to be coated with salt almost every time it snows in the north. That accounts for a lot of salt usage. Ah – I’d forgotten that. Actually, Rochester is much bigger on salt, per square foot. When I was living in Salt Lake City they ran out of salt one winter, which I thought was the most ludicrous thing I’d ever heard about a city government. Apparently, for some reason, they couldn’t just go out and shovel it up. Nonetheless, despite all the road saltage, I’m not sure that’s what they meant by “industrial use.” ---
**Author:** ![Freddy\_the\_Pig](https://avatars.discourse-cdn.com/v4/letter/f/a587f6/32.png) [@Freddy\_the\_Pig](https://boards.straightdope.com/u/Freddy_the_Pig)\ **Post date:** [January 17, 2006, 8:39pm UTC](https://boards.straightdope.com/t/explain-this-thing-we-call-salt/340384/12 "2006-01-17T20:39:09Z")
> [@tdn](#): > > 1. It is my understanding that in the olden days, salt was quite a rare commodity, and thus quite valuable. In fact, Roman soldiers were paid in salt, hence the “salary.” A given volume of gold has _always_ been far more valuable than the same volume of salt. The fact that salt was used as commodity money at certain times and places only indicates that it’s relatively durable and fungible, not that it’s as valuable as gold. > [@](#): > > . . . why waste it on food? For taste it seems an awful waste, and for preservation it seems that the return wouldn’t be worth it. Before refrigeration, how else would one preserve meat? This is why soldiers and sailors were issued “salt beef” and “salt pork”. ---
**Author:** ![Capt.Ridley\_s\_Shooting\_Party](https://avatars.discourse-cdn.com/v4/letter/c/cc9497/32.png) [@Capt.Ridley\_s\_Shooting\_Party](https://boards.straightdope.com/u/Capt.Ridley_s_Shooting_Party)\ **Post date:** [January 17, 2006, 8:55pm UTC](https://boards.straightdope.com/t/explain-this-thing-we-call-salt/340384/13 "2006-01-17T20:55:55Z")
> [@](#): > > Nonetheless, despite all the road saltage, I’m not sure that’s what they meant by “industrial use.” Making chlorine. ---
**Author:** ![CalMeacham](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/calmeacham/32/35_2.png) [@CalMeacham](https://boards.straightdope.com/u/CalMeacham)\ **Post date:** [January 17, 2006, 9:35pm UTC](https://boards.straightdope.com/t/explain-this-thing-we-call-salt/340384/14 "2006-01-17T21:35:41Z")
Industrial uses of salt (much beyond road salting. Chlorine is a big part, but not all): [http://www.saltinstitute.org/31.html](http://www.saltinstitute.org/31.html) ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [January 17, 2006, 10:29pm UTC](https://boards.straightdope.com/t/explain-this-thing-we-call-salt/340384/15 "2006-01-17T22:29:54Z")
> [@Squink](#): > > Blood plasma typically runs about 140mM NaCl. If you try to replace that with KCl you’ll end up killing yourself. That’s probably only one of a large range of reasons; another one is that sodium ions are an essential component of the nervous system. ---
**Author:** ![AskNott](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/asknott/32/5790_2.png) [@AskNott](https://boards.straightdope.com/u/AskNott)\ **Post date:** [January 17, 2006, 10:34pm UTC](https://boards.straightdope.com/t/explain-this-thing-we-call-salt/340384/16 "2006-01-17T22:34:46Z")
A good deal of salt goes into the purification of water for household and commercial use. Also, even at a grain of salt per statement, per listener, the public speech of government officials causing a huge amount of salt to be taken. (You can take that with a grain of salt.) 😉 ---
**Author:** ![Squink](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@Squink](https://boards.straightdope.com/u/Squink)\ **Post date:** [January 17, 2006, 10:39pm UTC](https://boards.straightdope.com/t/explain-this-thing-we-call-salt/340384/17 "2006-01-17T22:39:35Z")
> [@AskNott](#): > > A good deal of salt goes into the purification of water for household and commercial use. And Pickles. You can’t make a proper pickle without a good 10% NaCl brine. ---
**Author:** ![Tim\_T-Bonham.net](https://avatars.discourse-cdn.com/v4/letter/t/46a35a/32.png) [@Tim\_T-Bonham.net](https://boards.straightdope.com/u/Tim_T-Bonham.net)\ **Post date:** [January 17, 2006, 11:10pm UTC](https://boards.straightdope.com/t/explain-this-thing-we-call-salt/340384/18 "2006-01-17T23:10:17Z")
> [@tdn](#): > > 1. Did Medieval soldiers really salt the fields of their enemies? That seems like a costly way to achieve victory. Not Medieval. The usual references to this are from ancient times, most notably the Rome-Carthage wars. And not “achieve victory”. This takes place after you have already won. It’s mainly a plan to prevent future wars, by making the fields infertile, severely limiting the food supply & thus the population of the enemy country, which should make it harder for them to fight a war with you in the future. For example, it was after Rome won the _third_ war with Carthage that they are alleged to have salted the land around Carthage (for 50 miles/80 km, which seems like a great exaggeration, given ancient economics). They wanted to reduce the chances of future wars with Carthage. A somewhat similar modern technique was the division of Germany into 4 regions after WWII, which eventually became East & West Germany. After 3 big wars in Europe since Germany became one nation, other countries (especially France), wanted to ensure that they couldn’t start another one. That persisted for 50 years or so, and I have relatives who fought in WWII who objected strongly to the reunification of Germany. ---
**Author:** ![Rysto](https://avatars.discourse-cdn.com/v4/letter/r/ecccb3/32.png) [@Rysto](https://boards.straightdope.com/u/Rysto)\ **Post date:** [January 18, 2006, 12:21am UTC](https://boards.straightdope.com/t/explain-this-thing-we-call-salt/340384/19 "2006-01-18T00:21:41Z")
> [@bouv](#): > > Your location says MA, so I assume you’re familiar with the havock reaped by road salt upon your car? Imagine the thousands (millions?) of miles of road that have to be coated with salt almost every time it snows in the north. That accounts for a lot of salt usage. Is that NaCl, though? I was under the impression that a different compound is used. ---
**Author:** ![Rysdad](https://avatars.discourse-cdn.com/v4/letter/r/7cd45c/32.png) [@Rysdad](https://boards.straightdope.com/u/Rysdad)\ **Post date:** [January 18, 2006, 12:55am UTC](https://boards.straightdope.com/t/explain-this-thing-we-call-salt/340384/20 "2006-01-18T00:55:57Z")
> [@tdn](#): > > 1. Salt today is cheap and readily available. Where does it come from? [From here, for example.](http://www.dnr.state.oh.us/news/feb03/0228saltcolumn.htm) Cleveland rocks = rock salt 🙂 [Next page](https://boards.straightdope.com/t/explain-this-thing-we-call-salt/340384.md?page=2)