Salt Mine Spell

I have a magus that wants to make a salt mine by creating a supply of salt, sticking it in the ground near the covenant, then 'discovering' it to give the appearance of mundane wealth generation.

For both spells, should the requisites add to the magnitude? For the first spell, I'm not sure if Perdo is the right Technique here for the purpose, and I'm presuming the Rego is necessary to separate out the water so it doesn't just dissolve back into the ocean. For the second spell, should it actually be a gemstone that's 1000 cubic inches rather than 1 because it's targeting 1000 units of salt? Are there other rules overlooked in the construction of these spells?

Are you sold on this method of salt production?

I remember researching this at one point, then losing my notes, but Romans used solar evaporation and open pan techniques to produce salt from sea water. Within the Ars Magica paradigm, PeAq to destroy water would or should (to my thinking) destroy the actual salt water, not just the water and leave the salt (Perdo destroys something or makes it worse). I think if you wanted to separate the salt from the water you would have to use Rego Aquam, Base 3 (no requisites required, either) to evaporate the water, which was obviously understood and consistent with a mythic paradigm.
So, I would just flood an area with sea water, much as modern facilities do A simple ReAq spell to bring it in, and then a simple ReAq spell to evaporate the water. Maybe Base 4 control liquid in a forceful but calm way to bring the water into your pans. Certainly not so violent as creating a massive wave, and then having nothing but salt left. You could even have a cover operation going with supplemental income of actually producing salt by normal means...

So Poseidan's Pan would be...

...presuming you have the salt moved out of the ocean directly?

Well, you're not moving the salt out of the water, you're moving the water out of the sea water, leaving the salt behind.

So it would just be ReAq Base 4 to move the water into the pans (Control liquid in a forceful, but calm way[...] fast but constant current) . I'd say that you have to have it run for a duration, as a momentary effect would just flow back into the ocean, but that is probably arguable (current implies volume moved over a period of time).

Then to remove the water from the pans, it would be ReAq Base 3 (change a liquid into the corresponding solid or gas). This would be a momentary effect.

Mind you, I'm not doing any of the math on calculating how much salt you can get from seawater, I'm just saying this is how I would approach it...

Can you not target the salt directly for some reason, with ReTe(Aq) or an equivalent, possibly with Part target to isolate the component?

I'd say no, not while it's mixed with the water. At the very minimum, I'd consider the Size based on the water size, not on the salt size. (At least, I've always assumed that to target a Part of a giant, you need extra magnitudes over the base Corpus Individual, even if said Part is small).

As for how much salt you can get out of water, it's relatively easy. Very roughly, for every 30 weight units of sea water you get one weight unit of salt. But salt is roughly twice as heavy as water, so you need roughly 60 cubic paces of sea water to get one cubic pace of salt. Base Individual for water is a pool 5 paces across and two paces deep. It's not clear if it's circular, in which case it's slightly less than 40 cubic paces, or square, in which case it's 50 cubic paces. All told, a Base Ind of water holds a little less than a cubic pace of salt (about 2/3rds to 5/6ths), let's say about 1 ton of salt.

I think I consume about 1Kg of salt/year, and random internet sources say that was a "family"'s yearly consumption in the middle ages; so let's say 1Kg of salt was what a well-off person or a poor family consumed. A salt miner was able to mine 1000 times that, i.e. 1 ton i.e. the salt from 1 Base Ind of water. I'd say the production of miner is worth 1 Mythic Pound, from how much unskilled labor is worth in covenants. Another way to find the worth of 1Kg of salt, is that in 15th century london it was worth about a half a penny, i.e. a ton would be worth about 2 pounds of silver -- but there was a significant increase in prices in from 1220, plus taxes etc., so I guess 1 MP for 1 ton is about right.

So, once again. A base Ind of Aquam yields about 1 ton of salt, worth about 1 Mythic Pound, and enough salt for 1000 rich people or 1000 poor families. To ensure a Typical source of income (100MP/year), you could in theory just go to the seaside for a day every year with a couple of grogs, dig a largish hole on the beach (about 120 cubic paces, say 2x8x8), and while standing in the sea cast a ReAq5 (Base 4,+1 Touch) spell to bring into the hole a Base Ind of sea-water, and ReAq5 (Base 3,+2 Voice) spell to evaporate the water and leave the salt, repeating the process 100 times. With a decent Rego Aquam total you can probably handle that as a non-fatiguing spontaneous spell, the entire process takes less than half an hour (300 rounds) plus the time to dig the hole (a few grog hours while you take your sun tan!). Assuming salt counts as sand for the purposes of Terram, what you get is about 7-8 base Individuals of Terram. It would take a simple ReTe 10 spell (Base 3, +1 Touch, +1Conc, +1Siz) to move the stuff.

Then, you'd need to sell it over a year. To guarantee your Typical (100MP) source of income, your customer base needs to be one hundred thousand well-off people (or poor families) who get all their salt from you. That's the population of a pretty large area! I guess your main problem with salt is not producing it, but selling it while dealing with all the taxes, monopolies etc. -- and not disrupting the existing mundane market too much :smiley:

Personally, I'd allow it, it's equivalent to the Aquam guidelines for affecting the blood in a person's body. You're affecting something you can't see, but you know to be present, with a requisite for its containing vessel.

I'd agree with you on basing this on the larger of the size modifiers for the water and the salt, but your interpretation of "Part" target would make the core rulebook's "Pit of the Gaping Earth" impossible, as you'd have to have a large enough target to affect the whole planet just to make a small pit.

The main purpose of part target seems to be to allow you to affect small pieces of things you would otherwise be unable to affect.

Seems like ReAq(Te) would be fine, wouldn't it? It's a natural process, just evaporating the water. (Anyone who's gone swimming in the ocean and been out in the sun afterward knows this.) I think you'd want to move the water to a reasonable space first. Otherwise I would think you'd need T: Part and you'd have to worry about the ocean water remaining running in and flooding the newly made salt.

Sounds like a clever non-Creo wealth-creation method to me. You're not really creating wealth, so no issue with the rules about how much money is simply created. You're just using magic to make your work easier.

Not sure why you need a Terram requisite to evaporate the water, as I said, this process was understood by the Romans. So if the Romans were evaporating water naturally, it stands to reason that a spell that evaporates water would just evaporate water and leave the salt.

I just don't like using PeAq to destroy the water and leave the salt, because it's using Perdo to dry/make something better. I'll note, if you're personally fine with that, the gudeline to completely dry something out (the size of a small house) is a PeAq Base 4 guideline. It doesn't fit with my aesthetic, but I can see others going this way. I would still do a separate ReAq spell to move the salt water into ponds, because I don't like combining spells to do separate and distinct effects into one spell and then saying it's a requisite. Sometimes it is necessary, but I'm not sure that's the case here.

You're absolutely right. For some reason I'd thought ReAq(Te) was used to turn water into ice, but I was wrong. ReAq should be sufficient on its own.

I wouldn't even use the Terram requisite (EDIT: two posts managed to beat mine to the punch :slight_smile:). Just evaporate the water with ReAq base 3, after moving it into a reasonable space with ReAq 4, and scoop up the salt. One casting at Base Ind size would produce 1 ton, i.e. roughly 1 Mythic Pound worth, of salt. So frankly, I wouldn't even bother adding magnitudes for size: cast each spell 100 times and you have gained an year's worth of Typical income.

I agree. The big issue, as with most "commodity production" schemes, is selling the stuff. You need a really, really large consumer base (of the order of 100000+ people), or at least a small army of peddlers (at least a few dozen, who'll probably take a 50%+ cut on the profits -- I'd say they'd turn the Typical source into a lesser one). This, in turn, will make some level of interference with mundanes almost inevitable. But it's a pretty nice scheme.

ezzelino, where are you getting that people in the middle ages ate less salt? Salting meat was an extremely common preservation technique, and while middle ages peasants probably weren't eating huge amounts of meat and were eating a lot of grains (bread) and vegetables. A lot of the vegetables had to be pickled for long term preservation. Pickling also uses a fair amount of salt...

I think they ate more salt than we eat today, but I don't have anything that backs that up.

I think an important issue is the amount of salt produced. A quick search lists salinity around 3,5%. For simplicity I assume a cubic pace is a cubic meter, and this weighs about 1000 kg, producing 35 kg salt.

Base individual for Aquam is a pool 5 paces across and 2 paces deep at the centre. For simplicity let's assume an average depth of 1 pace for a volume of around 20 cubic meters or a mass of 20.000 kg. this derives 700 kg salt.

Rego Aquam lists Base 3 to shift water into ice or steam, imho this sounds like the evaporation proces. Base 4 at the maximum. At Range Touch this is a level 5 spell.
Provided you have a20 cubic meter pool and access to the sea you could "create" 700 kg salt easily.

Alas, I can no longer find the source, but it was about salt mining and how a miner could extract about a ton/year, which would be sufficient for 1000 families. I agree, it seems lowish to me too. Still, the bulk of the medieval peasant's food was grains, and some (fresh) vegetables.So, as you point out, maybe they ate very salty meat, but they ate very little meat. From what I know of agrarian societies, people tended to eat most of their vegetables fresh, rather than pickling them, which was pretty expensive.

Incidentally, I recently found another source stating that around 1350, 1 ton of salt was sold in Venice, including taxes, for about 33ducats, i.e. about 100g of gold. I would say that's roughly 2 pounds of silver, but again, there are taxes and a century of inflation (since 1220) involved, so I think a fair figure is:
1 Base Individual of Sea Water yields
1 Ton of Salt worth approximately
1 Mythic Pound

City & Guild describes salt as 120 MP per ton.

That's a bit of a difference. I wonder if ezzelino's pricing for that time was based on the fact that Venice was trying to establish a monopoly in multiple products, including salt. They did use salt as a loss leader in selling other goods, too.