A few years ago, I was commissioned to design and describe some rather
simple "science" experiments for an encyclopaedia to be published by one of
the big publishers of such things in the UK.
It was great fun, demonstrating with a dollop of butter - or low-fat spread
for the health conscious - a child's plastic beaker, an old tin camping mug
and some hot water insulators and heat conduction, that kind of thing. When
it came to the chemistry experiments, the first and easiest to create, I
foolishly thought at the time, would be the crystal garden. Little packet of
copper sulphate crystals, a piece of cotton thread, a lead-free pencil and a
tumbler full of water. How wrong could I have been?
I sent off the text - via floppy disk no less - quite advanced for a
publisher that normally created rather non-technical stuff such as how to
keep your aspidistras flying or crochet a bird-cage cover. And waited
expectantly for commendation from the editorial team and the cheque in the
post.
They liked the melting butter - they had even tried it and made a mess all
over an old copy of the aspidistra booklet. Their "Scientific Advisor",
however, had poo-pooed the idea of using copper sulphate.
I was stunned, remembering a time in junior school (3rd grade) no less when
we grew a copper sulphate crystal garden on the quarry-tiled window-sill of
the classroom and produced some stunning gems. Some were almost an inch long
I seem to recall. When you are seven that's a pretty big crystal! What could
be the problem? Maybe manufacturers had changed copper sulphate somehow
since that time and it does not work so well any more?
No. It turned out that the Scientific Advisor simply could not
allow the cupric salt to be used in the experiment. First off I thought it
must be a question of cost. They would be giving away a few grams of the
stuff with the encyclopaedia and if they could not get an educational
discount it might cut into their profit margin a bit too deeply. I checked
the pricing in Aldrich, or was it the BDH catalogue? CuSO4 did not seem too
expensive, at least not for the less than generous amounts they planned on
supplying so that was not it.
It transpired that the wonderful Ad-vis-or was scared that the kiddies doing
the experiment would ingest said sulphur-containing matter and succumb to
its terrible effects. I thought they must be joking, the part-work was aimed
at 13-16 year olds not infants. (Admittedly, copper sulphate is toxic, but
you get the point) "No. Copper sulphate is listed as a hazardous material
you will have to think of something else less dangerous for our
subscribers", they told me!
I thought carefully, what is so harmful about copper sulphate? Does it not
just give you a case of the runs if you swallow a bit too much? No caustic
effects, no rashes, no chain reactions set off in cytochrome respiratory
enzymes, pretty safe stuff really unless you are very foolish and eat it
like jelly beans, surely there was some mistake? Well, they had the pen
ready for that cheque and the gas bill was due, so who was I to argue?
Alum - that will suffice, I thought, not quite so pretty but it does form
large octahedral crystals so that would be quite impressive nevertheless on
the kitchen table. It's less of a hazard than copper sulphate and quite
handy to have around the house as a styptic. The publisher could even ask
the chemical supplier to add a food dye, I thought, or we could even
incorporate that step into the experiment to make it really exciting!
"No go," they said. What? "You'll have to come up with something even less
hazardous than that". This was bizarre, I racked my brains...the only thing
I could think of was the stuff my junior school teacher had suggested our
using for the homework version of our crystal garden - magnesium sulphate.
Wonderful, the kids would produce tiny, bland, colourless crystals if any at
all.
Anyway, they went along with that - I did not bother to mention that
magnesium sulphate is Epsom salts, a medicinal substance with infamous
purgative properties, so any of the kids with a taste for crystals was in
for a nasty shock. Of course, the experiment could now be deemed "safe"
although the hazards were almost exactly the same as with the original
bright-blue stuff I had suggested. The Ad-vis-or was happy though, his back
was covered.
The experience reminded me of the first few months of the COSHH (control of
substances hazardous to health) safety regulations, which would have us
locking even the most innocuous materials, such as magnesium sulphate, in
airtight containers under armed guard. Well maybe not, a visit to an
undergraduate organic practical lab recently demonstrated that safety
regulations, while providing unwilling penpushers with plenty of work, is
all but disregarded by some laboratory technicians too busy chain-smoking
over the flasks of ether to worry about anyone being stupid in their lab.
The conc sulphuric was still at shoulder height above the bench and an open
bottle of pyridine was left standing overnight in a faulty fume-cupboard
that seemed to generate more noxious vapours than it extracted. The poor
male undergraduates will be worrying (needlessly) about their gonads for
years to come if they find out!
Surprisingly, the bottles of "copious" water were nowhere to be seen. This
vital material is an essential component of any safe laboratory, viz. any
spillage of "such and such" a chemical should be washed immediately with
copious water. Of course, according to the early COSHH handbook - my office
copy at least - this washing applied to every chemical that might be spilt.
Postgraduate demonstrators around the country could be seen busily washing
spillages of that most hazardous material "deionised water" with the
ubiquitous copious water for fear of retribution at the hands of the lab
tech.
Safety matters. Of course but standards do change and some rules, such as
the copious water one are there to be broken. My A-level chemistry teacher
used to brag of the days when she worked in industry and everyone washed
their hands in benzene. As an undergraduate we swapped the benzene for
acetone to get rid of those nitric acid stained fingers(!) after a
particularly gruelling practical session. I dare say another solvent - soapy
water or something equally as astringent and toxic - has superseded even
this organic by now.
I must dash, the kettle has just boiled and I have a packet of hydrated
CuSO4 to dissolve and a piece of thread to tie around a pencil...
Elemental Discoveries
Issue 47
With a grain of salt
What do bags of rice, asteroids, a pile of salt and a sand dune have in
common? They are all granular media, of course!
Collections of small solid particles, like rice, or grains of sand, behave
in many peculiar ways, according to University of Stuttgart physicist Hans
Herrmann. He and his collaborators Stefan Luding, also at Stuttgart and
Raffaele Cafiero of PMMH, ESPCI in Paris, France, are building on earlier
work by using statistical mechanics to understand many of the strange
phenomena that occur in granular media.
For instance, they hope to explain the world's biggest sand dune - 'El
Purpur', in Peru, as well as why brazil nuts always rise to the top of a
carton of smaller mixed nuts. One of the team's most recent discoveries
[[reported in Physica A: Statistical Mechanics and its Applications, 2001,
295, 93-100]] shows that granular media display a pronounced deviation from
classical Boltzmann statistics in several important ways.
Liquids, the ultimate in granular media, generally follow Boltzmann's rules,
but, with particles much bigger than atoms and molecules, a granular medium
can behave sometimes like a liquid sometimes like a solid, so Boltzmann
fails. Herrmann and his colleagues point out that granular media are
dissipative systems, in other words, collisions between grains are inelastic
so energy is lost when the system is in motion, such as might occur when
wind blows across a sand-dune or when salt is shaken from a salt cellar.
In an ideal system, a statistical analysis reveals deviation from Boltzmann
caused by clustering of particles in which the grains in a cluster are
slower moving than those between clusters. Herrmann suggests an analysis
using Constantino Tsallis' work might be the most lucrative in terms of
increasing understanding.
Sam Edwards and Dmitri Grinev of the University of Cambridge describe an
effect important not only in understand salt and sand dunes but in the
handling of powders and other granular materials in the chemical and
pharmaceutical materials - from explosive compounds to aspirin tablets.
Edwards and Grinev have alighted on the idea that a complete picture of
granular media will not be possible without a better understanding of the
transmission of stress between 'interacting' particles in the medium. They
have developed a statistical-mechanical approach to deriving the equation
which links stress to the packing geometry. The concept of how grains pack
together is closely linked to how forces are transmitted between them. Their
theory helps to explain experimental data on reversible and irreversible
behaviour of vibrated granular media and, says Grinev, gives a clear
physical picture of the compaction phenomenon.
So, next time you're tramping across the desert dunes or simply sprinkling
salt on your meal…consider just how complicated tiny grains can be.
Elemental Discoveries
Issue 47
Lingua Franca
"After standing in the fridge overnight, we stirred the solution..."
The definitive scientific article is long-winded, convoluted and flowery. It
is couched in jargonistic terms and pompous prose. It relies on the passive
usage of tenses and formal syntactical, grammatical and punctatorial
definition, phraseology and construct.
Well, that is what a proverbial scientist from another planet – Mars
perhaps? - might think of the scientific literati were they to peruse just
one or two of the countless, almost infinite stack of journals published
round the world and on the web. Of course, each discipline must define and
use its own terms and language. There is no point in every paper published
having to redefine the wheel or in more native terms defining something as
"simple" as what is meant by the term "covalent bond" despite the fact that
a scientist outside the discipline might not know even in vague terms. Some
papers though just stretch the point a little too far – and not a small
number of them are found among the chemistry journals.
One area in which a scientist can rapidly alienate any reader regardless of
their intellectual ranking is in the creation of acronyms and their
associated concatenated nouns. In order to make a paper entirely opaque to
the non- specialist most scientists will opt for the more the merrier
attitude. Recently, one well-known chemistry journal published a series of
papers covering the various advances in one particular field of
spectroscopy, nuclear magnetic resonance. Fine, NMR that is reasonably well
known even to non-chemists, although to appease the sensitivities of medics
and biologists and the general public the use of NMR for imaging in
hospitals tends to go under the name MRI thus dropping the "nuclear". I
cannot think why...
While NMR, IR (infra-red), UV (ultra-violet), UV-VIS (visible – not really
an acronym at all) might all be readily absorbed. One particular paper began
waffling on about 1D NMR INADEQUATE. Huh? Not just an acronym but a
mnemonic. But, aren't mnemonics meant to help the reader? To be fair, the
technical editors at this particular journal tend to define the acronym at
the first mention of such things in each paper, unlike several of their
rival journals, which shall remain anonymous but they know who they are. In
this instance it turns out that the acronym/mnemonic represents
"one-dimensional nuclear magnetic resonance incredible natural abundance
double quantum transfer experiment [spectroscopy]". See it is obvious now. I
presume from this that the inventor of the technique had a somewhat weird
sense of humour or at the very least a strange loathing for technical
editors. Many readers will perhaps identify with the sentiment although it
is badly misplaced.
Another related paper had NMR up for reckoning again, this time with INEPT
and rather bizarrely SLITDRESS techniques being described. INEPT is perhaps
what the technical editor felt when they could not find the definition. It
is "insensitive nuclei enhanced polarisation transfer" while the lewd
SLITDRESS is "slice interleaved depth resolved surface coil spectroscopy"
for anyone who is not past caring by this point.
The concatenation of nouns and adjectives in this manner is what the late
Robert Schoenfeld one time Editor of the Australian Journal of Chemistry
described as a German vice! The Germans even have a specific term for it:
Hauptwortkombinationenzusammensetzungsbedufnis. Makes the acronyms look
easy! To make the most of Hauptwork...whatever, it is always best to pad out
the acronym when spelt out in full so that the reader will be absolutely
none the wiser. For instance, one might say "A slice interleaved depth
resolved surface coil spectroscopy literature survey". The kind of thing not
to do on a Friday afternoon.
It is on points of grammar that scientific writing can be best used to
maximise opacity of a particular paper. For instance, when chatting in the
coffee room one chemist might say to another, "We had an idea that the
nitrogen was quaternary, so we boiled it up with acid and ran the
spectrum..."
Fair enough, why not use something similar in the paper? Perhaps,
"We suspected that the nitrogen was quaternary, so we heated the compound
with acid and recorded its NMR spectrum..." A little more precise and fairly
pleasant to read. However, chemists – with a few well-known literary
exceptions - tend not to be satisfied with phrases that are so smooth and
flowing – almost readable in fact. The sentence that would end up gracing
the printed page would inevitably read something like this, "In order to
determine whether the nitrogen atom centre was of a quaternary nature, the
compound X was heated under reflux at atmospheric pressure in the presence
of and acid and following exhaustive work-up the product extracted was then
subject to examination with NMR spectroscopy to elucidate a definitive
structure and conformational analysis..."
Aaaah, much better, n'est ce pas? There is, however, one area where chemists
simply cannot simplify their prose without drawing a picture and that is in
chemical nomenclature but even then some try to make things as easy(?) as
possible. Whereas biotechnology has resorted to naming things in note form
for instance hedgehog and sonic genes on the drosophila genome, chemists
still have the likes of "After standing in the fridge overnight, we isolated
the sample of {4,34-dimethyl-
1,4,7,10,13,16,19,22,25,28,31,34,37,40,43,46,49,52,55,5
-icosaazatricyclo[56.2.2.2.2.2.7,10,28,31,37,40]hexacontane using a
supercritical mixed solvent system and subjected it to INADEQUATE NMR..."
Try figuring that one out after a hard day in the library...
Next month: redefining the simultaneous anachronistic non-syntactic
deconstruction of tautological self-repetitious verbiage in the
humanities...Not!
Bibliography
For a precise, concise and very useful guide to "writing proper" try the
late Robert Schoenfeld's The Chemist's English, VCH, 1986, 2nd edn.
Schoenfeld takes apart the English language in such a lucid way that there
is literally no room for verbiage nor ambiguity once he has finished. You
might spot one or two literal references from Schoenfeld in this article
although please don't rush to tell me where the grammar trips up – no
pedants illuminating my split infinitives non-hyphenated compound
adjectives, pendant or dangling participles, pur-lease.
It would be nice to think Schoenfeld's book or at least part of it could
make it on to the web at some stage where so much dodgy writing proliferates
at a greater rate than in the scientific literature.
Additionally, David Lindsay's "A guide to Scientific Writing", Longman
Cheshire, 1990, covers much ground in how to avoid the common pitfalls of
jargonistic and long-winded writing.