The nurturing debate: salt water

Hello there

Here we are with the magical nurturing debate again :slight_smile: In this thread the target is salt water.

I have been tinkering with the OoH as terraforming magicians able to influence their local economy. After reading TSE the fact that a lot of islands are nort taken over because they are barren because they lack water just struck me as something that the OoH could solve easily enough with ritual magic…. Or not so ritual magic.

An island is surrounded by salt water. If the magi could transform (muto) part of the water into fresh water for (say) moon duration, could they use it to feed plants and animals (and humans) without problems?

I am asking for moon because it is the longest period available before ritual magic, and shorter periods would imply that the water is still “acting” while the effect ends.

What do you think? Could I Rego some water into an artificial lake once per month and have it nurture the island’s fauna and flora?

If not, you always have the option of CrAq rituals, but having so much water around….


Make it a Rego craft spell and you have no problem , plus you extract the sea salt for use by inhabitants.
Sea water does not normally provide nourishment , so i don't think you can Muto it into fresh , nourishing water , imho.

Given that it is Muto, I could change a horseshoe to have nourising water.... I assume that you mean that I cannot REGO it into nourishing water?

In any case water is water. The fact that sea water contains salt should not be a huge impediment if you can raze mountains, transform into a cloud of mist and cast lightning bolts from your finger tips, right?

Modern logic says we if we were about to instantly transform salt water into fresh water, we should be able to drink that fresh water. However, magically, that transformed water will eventually transform back into salt water. Modern thinking says that the water will already have "passed through" your system by the time it transforms back.

However, if I have this right , consider the matter in a natural philosophy sense you have incorporated that transformed water into your body through retentive and digestive forces. So, your humors absord and incorporate this water, which is at the time nutrative. However, when magic sustaining the transformation of salt water to fresh water ends, the water you have absorbed and incorportated suddenly transforms from nutrative to non-nutartive. Therefore, I would think, that suddenly a large part of the water (wet, cold matter) in your body would suddenly be transformed into salt water. Assuming I have this right, that would be bad.

No, you could use rego craft magic to undertake the perfectly mundane process of removing the salt from the water... a totally non-magical change which I think was actually understood at the time... or would at least be achievable through natural philosophy/alchemy... that therefore would not suffer any of the pitfalls of muto transformation.

Ah right. true. So it ends up being mundane water and mundane salt. Cool. 8) Sound slike the good solution.

Still, if you could NOT do this and had to muto (major magical deficiency in Rego, for example), do you think it could work?


I'd considered using a Natural Philosophy reagent to accomplish something similar, but never got to test it in play.

In any case, I'd agree that Rego Aquam Craft Magic would be the most feasible method for hermetic magi to make potable water.

heh, to each one his own. I just imagined mechanician reed and pump system that separates the water from salt using a filter (useful resource for a patron) and sends the fresh water into a deposit :mrgreen:


No, then the water would still be salt water underneath, and isn't really sustaining.

My understanding is that Clouds of Rain and Thunder produces perfectly ordinary rain. Why not just use that?

I agree with Lucius. If all the water you've been drinking for the past month suddenly turns unhealthy, then most of the water in your body becomes unhealthy at the same time, leaving you very, very thirsty at best. You do have one precedent in Lungs of the Fish, where the end of the spell does not mean that all the airy nutrition you drew from the transformed water suddenly goes away, but breathing and drinking are two different tasks. For one thing, it's obvious that any air you take in is quickly expelled. Water not so much.

I think that was explained somewhere by (IIRC) timothy ferguson or another fount of knowledge.

IIRC, it's something like "air doesn't nourishes, it just helps in assimilating the elements, no natural air or not makes no difference"

I think that your best bet for using Muto would be one of the guidelines for changing a liquid into a mixture of liquids, or of liquids and solids, using Muto to set up an actual, mundane separation process. You could change salt water into a mixture of liquid water and solid salt with a base 5 (and a Terram requisite), for instance. If you do it right, and are quick to get rid of the salt before it dissolves again, you would be left with fresh water. You would need some actual manpower and equipment.

Yup, RegoAq is the thing to use to desalinate the water. Using Muto, as already mentioned risks being very unhealthy, and if used for agriculture, what you´re really doing is putting a LOT of salt in the ground, even with Month duration, some of that salt will still end up not too far below the surface, and eventually the dirt will be unable to sustain any plants.

For once, I almost completely agree with Direwolf.
Rego Aquam to remove the salt mimicking a mundane process already known to the ancients -- just boil the water and capture the vapours, which is exactly the same technique used for distilling alcohol.
Muto Aquam is dangerous for agriculture because it complely ruins the ground once the effect ends.

The one thing I disagree with is that the salt-water-turned-into-sweet-water is not nourishing. Salt water is not nourishing water minus nourishment, it is nourishing water plus salt -- a substance that, like a mild poison, unbalances the humours. If you Muto salt water, it stays nourishing but you remove the negative effects of the salt (a little like Mutoing wine into pure water), and if you expel it before Moon (something feasible if you use it for drinking rather than irrigation) you suffer no ill effects.

True and true.


Yes thats exactly right. One thing that's important to remember is that salt water is not bad unwholesome water, it's perfectly good healthy life giving water that has salt in it. People knew enough not to drink it because of the salt, but the water was still seen as life giving because after all fish and all sorts of other living things (many of them considered quite good to eat) live in it.

In the medieval mindset there would have been such a thing as water that has gone bad. Before we understood pasteurization and microbiology people knew stored or stagnant water would "spoil" after a varying amount of time and become unhealthy to drink and generally inimical to life. This effect could be seen in both salt and "fresh" water left standing.

For these reasons I think that Perdo would also be perfectly feasible for removing the salt from sea water. Your not improving any aspect of the water when you eliminate the salinity. Unhealthy stagnant salt water with the salt perdo's out would still be a bad idea to drink. But healthy clean sea water with all it's salt removed would be fine.

Why the Sea is Salt
In Mythic Europe these sort of tales may be true.

Why not Perdo Aquam? Destroy the saltiness of sea water. Its even in the guidelines (ArM5, p123), base 15. Since water can naturally be without saltiness the salt wouldn't come back when the spell ends. (edit: Oh, maine75man already said this)

I don't really see how Rego would work... The way I think about it, I would consider saltiness to be a property (and not dissolved NaCl because that doesn't feel very medieval) of the water. So Rego could splash it about or turn it into ice or gas but not affect the salinity. Hmm.. well.. this got me thinking. Salt was made by evaporating seawater in shallow basins and scraping it up, so Rego magic should be allowed to do the same thing (ArM5, p124: base 3 for evaporation). Making salt like that might even provide a nice income for a coastal covenant, never thought about that before.

Making salt is easy, and it is an extremely expensive commodity in medieval times. The main problem is that it tends to be the monopoly of the local ruler, so the problems with hermetics doing that is that it can bring legal problems for them in the mundane sphere. It was understood in medieval times.- Venice (foe example) has had active saltworks since its founding in the 6th century. I guess they knew that it could be separated via evaporation et al, so I would not consider the rego approach to be "unmedieval" :slight_smile: