NaCl

Ok, a quick note from me before handing over the guest blogger. Does everyone remember the post about invisible art? Well, as I wandered around London yesterday enjoying my day off, I happened upon the exhibition itself! Just so you know it really does exist. It's at the Southbank Centre in London, should you wish to pop along!

Ok, over to the guest blogger...

Remember that chemistry lesson? When you were wondering what use it would ever be I think you’re about to see why you should have paid attention.
Salt has a number of uses. First off, it can preserve: Egyptians used it when mummifying bodies and many cultures use it to preserve food.
There’s a fascinating book on the subject:

You may be surprised to learn that salt also appears, a number of times, in the Bible. In the Old Testament book called Numbers (the 4th book in the index of the Bible): “It is a covenant of salt forever, before the Lord with you and your descendants with you” (Num Ch18 v19). It also appears in the Book of 2 Chronicles (the 14th book in the index of the Bible): “….the Lord God of Israel gave the dominion over Israel to David forever, to him and his sons, by a covenant of salt” (2 Chr ch13 v5). Covenants are binding agreements between two parties so salt was clearly very important in these cases. In the New Testament there are a number of refs to salt. Remember the expression that we use when we say a person is “the salt of the earth” - it’s a direct quote of Jesus’s words recorded in Matthew’s Gospel Ch5 v13.

By the start of the 7th cent AD the city of Venice was using landfill to extend the mainland out to the islands and to produce salt it had begun using a system of “ponds” or pools which had seawater in. (NaCl – that is, sodium chloride - is what gives seawater its salinity). The system works like this beginning, quite naturally, with Pond 1. As the sun evaporates the water its salinity increases. Then it is moved (or pumped) into Pond 2 where more evaporation takes place and Pond 1 is re-filled with a fresh supply of seawater to start the process off again. Once Pond 2 has increased salinity due to the evaporation by the sun acting on it then it’s moved into Pond 3. Ponds 2 and then 1 move their water up and Pond 1 is re-filled. And so the process goes on until the salt begins to solidify and drops to the bottom of the last pond where it can be scraped out. This process saved the problem of just having single ponds which you had to wait for to go through the whole evaporation cycle over and over which could take up to a year from start to finish.

Did you know that Roman soldiers were at times paid in salt? This is where we get the English expression that someone is “worth their salt”. Our word “salary” is derived from the Latin salarium (not solarium!) which, it is believed, referred to money given to soldiers to buy salt. The Romans often located their settlements in areas with easy access to salt because it could be used, as they saw it, to further the development of civilisation and, of course, primarily their empire.

World production of salt is around 300 million tons per year. My little salt cellar holds approx 50gms.

Now, go on admit it, you’re wondering – how many times could I fill my little salt cellar from the world’s production for just one year. Ok, well here goes – 1 kg would supply me with 20 refills (20 x 50g); so 1 tonne would give me 20,000 refills; 1 million tonnes would give me 20,000,000,000 (20 thousand million =20 billion as per the OED); so finally 300 million tonnes would give me 300 x 20 billion = 6,000 billion refills or 6 Trillion refills! And just one 50gm amount lasts me ages & ages. (For comparison purposes think of it this way – there are 31.6 million seconds in a year so if I consumed what would definitely be a fatal - 50 gms/sec – it would take erm…..200,000 years to use up just one year’s production!! Numbers are just too big – blowing a gasket here! Moving on……..

In the county of Cheshire in the UK there is a small town called Northwich (pop. 20,000 as of 2001). Dated pottery fragments found there suggest the town has been associated with salt since at least 600BC and it became more important, as a source of salt, during Roman times. The town’s coat of arms has the Latin motto Sal Est Vita which means salt is life.

There is also an association with salt found in the etymology of the town’s name Northwich. The “-wich” part of the town name itself is believed to derive from the Norse “wic” (or wych) meaning bay and is associated with the traditional way of obtaining salt by evaporating sea water (Wikipedia). The "wich" (or wych) suffix occurs in other towns in the county - Middlewich, Nantwich and Leftwich. In fact anywhere in the UK with a “-wich” ending in its name means that usually there will have been a connection to salt at some point in its history. Therefore a place for making salt became a wych-house; and Northwich was so named because, you’ve guessed it, it’s the most northerly of the “-wich” towns in Cheshire.

To get salt out of the ground it has to be mined. Once the traditional (c.16th cent) method of sending men into a hole in the ground, to manually dig it out became unviable in terms of cost, producers moved to what is called “solution mining” (c.17th cent) where fresh water is pumped down a well to dissolve the salt. The salted water (brine) is then pumped back to the surface where the salt can then be extracted. The difficulty with this method is that as more salt is dissolved & drawn out, it leaves holes underground where the solid salt used to be; then land above can easily subside and this is what happened in the Cheshire area. The ignorance or deliberate avoidance of the consequences of their actions back in the 19th cent led to the salt extractors causing many areas to subside and holes to form at ground level. These holes then would fill with rain water adding to the whole problem. Indeed, in Northwich itself, there are horrendous examples of buildings leaning and damage to shops, private houses etc.

The social and practical impact of salt extraction in this area is highlighted by displays & storyboards in the SALT Museum located in the refurbished workhouse (built c.1838) in Northwich. I hope to visit it some time before the autumn and will report back.

In more modern times (1972) the group Steeleye Span released an album called Below The Salt. You, like me, may have wondered where they got the title from. In the Middle Ages, when families & their servants ate together, the salt would be placed in the middle of the table separating the two. The servants were then referred to as sitting “below the salt”. Incidentally the album contains an acapella track sung entirely in Latin which got to No.14 in the UK charts – Gaudete. I’m sure you remember that famous opening chorus: “Gaudete, gaudete, Christus est natus ex Maria virgine, Gaudete” (Translation: Rejoice, rejoice, Christ is born of the Virgin Mary, Rejoice).

You must have heard people talk of someone “rubbing salt into the wound” as a way of saying a bad situation has been made worse by whatever that person did. However did you know that the origin of it goes back to days of sail and punishment by flogging on board ship. Once the skin was broken and bleeding, salt was rubbed in to prevent infection (and therefore ultimately the loss of a crewman) but it was a very painful experience for the person concerned.

There are a number of “sal” expressions and derivations in the English language. Let’s look at a few:

1. You’ve probably heard of the compound sal volatile (pronounced sal volatilly) which is the Latin name for what we refer to as smelling salts. You know the scene in a play or film when someone faints and the salts are used to “bring them round”. Workplaces used to have some in their first aid boxes for emergencies and I’ve seen them used a couple of times. They act by releasing a small amount of ammonia gas which produces a reflex in the nose causes the person to inhale.

2. Do you know the expression people use when they don’t believe something is true – they say you have to take what another person says with a “pinch” or “grain” of salt. (The latin is cum grano salis.) The expression dates back to Roman times (with Pliny the Elder) and refers to one of the ingredients of an “antidote to poison”. Threats of poison in food were therefore said to be taken “with a grain of salt”: the inference being that the effects would be less serious if the salt was taken. The lessening effect, in modern times, has been transferred but inverted to mean a lessening of the truthfulness of a particular statement.

3. The word “salad” means salted dish and “salami” is a sausage which contains a lot of salt.

4. Remember those films again with safecrackers blowing up the safe to get the money. They were called Petremen (pronounced Peter-men) referring to the substance they used which was actually called “saltpetre” or potassium nitrate - a component of gunpowder. Originally saltpetre meant salt of rock – the “petre” bit coming from one of the Latin cases of petra meaning rock. However did you know that it can also be used as a preservative. I’m not joking, if you check Amazon you will find it on sale (4oz for £2.25 from one supplier) for curing beef.

5. A sailor can be referred to as an “old salt” – the reason coming from the preservative qualities of salt for their meat & fish which were soaked in brine.
If you get a chance have a read of Mark Kurlansky’s book (in the pic at the beginning). I really enjoyed it and it’s got to be THE authority on the subject and kept me interested from start to finish. (It’s 452 pages with a 12 page Bibliography!). Thanks to him for some of the historical stuff used in this article.

So you see salt can be a very interesting substance and far more important than you thought. Hope this has not been too much of an assault on your brain and senses (haha).