Tuesday, 7 February 2012

The Seven Dwarves and Snow White

At my place of work (did I mention I'm an analytical chemist?) we make two primary products, both of them white powders. There's zeolite, which is a crystalline structure made from sodium, aluminium and silicon, used in laundry powder. Then there's FPH, which is aluminium hydrate, and is used as cable insulation. Due to the sort of mixups that happen on an industrial site, we occasionally lose track of what's what.

A few days ago, I was handed samples from seven bags, none of which had labels. 'They're all rubbish', I was told, 'but we need to know what's in them to know where they go'. Okay - no problem.


One of the machines in our lab is an x-ray fluorescence spectrometer, or XRF if you run out of breath. It gives a rough rundown of the elements in a sample, but it has its limits. Specifically, it can't pick up on anything lighter than sodium - so no carbon, oxygen or nitrogen, let alone hydrogen (water doesn't show up!) - and is only really good at estimating the amount of elements heavier than aluminium. But within those limits, it's a good tool. I took Bag Number One (let's call this one Doc) over to the XRF and got measuring.

Five minutes later, I had my results. Amongst a scattering of other elements (including a decent dose of palladium - we think it's actually atmospheric argon, of all things) were 55% aluminium, 25% silicon, and 3% sodium. Allowing for the fact that sodium is only barely detectable, that's exactly what we'd expect in zeolite. On to Bag Two (Grumpy).

Yep, Grumpy was zeolite too.

So was Happy.

So were Bashful, Sneezy and Sleepy.

At this point, I'd tested six near-identical samples, and was getting a bit fed up. Surely six bags of zeolite could only be with a seventh bag of zeolite, right? And even if they weren't, what would it matter? It was all rubbish anyway.

But I'm a scientist. I can't leave a mystery unsolved - even if I think I know the answer. On to Dopey.

Dopey was not zeolite. 2.4% aluminium, 2.4% silicon, 2% sodium - and a whopping 92% chlorine. I hadn't even realised we could detect chlorine. I went and had a word with one of my colleagues, and did some more testing.

Could it be ammonium chloride? Ammonium is made up of undetectable nitrogen and hydrogen, but it stinks to high heaven when you react it with an alkali. That's easy to test - it wasn't.

I tried dissolving a sample of Dopey in simple water, and got 97% dissolution. That means, barring a bit of rubbish (probably zeolite, what with those metal signals) it was a salt. Not ammonium, not magnesium or potassium (both of which would show up strongly on the XRF), but could it be sodium chloride - simple table salt? I'd discounted that because of the low sodium response, but what if that was just chemistry being a pain?

This is where I made my intuitive leap. I don't know any tests for salt, but I did know that we had some in the cupboards. I popped a sample of sodium chloride on the XRF, and five minutes later, bingo: 96% chlorine, 3% sodium. Dopey was sodium chloride - and that meant he wasn't rubbish at all. We use our salt in solution, and we don't particularly care if it's a bit grubby. Dopey could still be used.

(Yes, there is allegory in this somewhere - but we're not done yet)

The very next day, I was given another pot, this time of snow white powder. 'We're pretty sure it's FPH,' I was told, 'but we don't think it's any good...' Back to the XRF we go.

Snow White came out at 85% aluminium, and nothing else significant. She pretty much had to be FPH - but was she worth using? For that, I needed to do some more testing, with actual chemicals this time. I won't bore you with the details - just the result:

Snow White was some of the best FPH I've seen this year.

What's the lesson of all this - in the usual religious context? It's a message about making sure - and doing it for yourself. I could have taken the word of people more likely to know than me, but I chose to check for myself. I could have given up after six failures - but I carried on and succeeded the seventh time. Equally, just because we don't get a response to our first six prayers, we should always keep on praying - the problem isn't at God's end, I promise you that.

But it's also a message about personal testimony. Sometimes it's not six failures and one success, but quite the reverse. We are encouraged to seek confirmation that what we're taught is true - even if we've had it the last six times. Remember, your Sunday School teacher is fallible (I should know - I was one). Your Bishop is fallible. Your Stake President - the Twelve - even the Prophet is fallible, able to get things wrong. There's no special course in Receiving Accurate Revelation, not even for President Monson. So keep checking. Keep praying - about the things you agree with, and the things you don't. This Church isn't supposed to conform to your desires, and it certainly isn't supposed to conform to the Prophet's - this is God's Church, and it's His plan that matters. And God speaks to all of His children equally.

You have a right to personal confirmation - or denial - of the Church's teachings on every subject. Use it.

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