Saturday, January 10, 2009

The Invention Of Air

It's been a good couple of weeks for 18th-century British luminaries. While the collapse of Waterford Wedgwood on Monday provoked a flurry of media articles about its illustrious founder Josiah Wedgwood, the publication of Steven Johnson's new book, The Invention of Air, has simultaneously thrust another Enlightenment figure, Joseph Priestley, into the limelight.

Like Wedgwood, Priestley was a core member of the Lunar Society, a small group of Midlands-based industrialists, intellectuals and 'natural philosophers' (the 18th century term for scientists), who used to meet at each full moon to discuss the experiments and inventions they were working on.

(There was nothing sinister about the timing of these meetings: in the days before street lighting, the full moon simply made it easier for the Society's members to find their way home in the early hours of the morning.)

None of the Lunar Society's members were professional scientists; in the late 1700s there was no such thing. 'Natural philosophy' was a fashionable hobby for anyone who had sufficient money, free time and intellectual curiosity to dedicate to it. Neither were their scientific experiments particularly rigorous, at least not compared with the way scientific research is conducted today. Experimentation was largely driven by an enthusiasm for creating unusual effects, rather than for patiently testing and refining theories.

As a result, experiments were often more showmanship than science. The painting that Chuffy! mentioned in the comments of my Wedgwood post depicts a natural philosopher 'performing' an experiment in which a bird in a jar is observed to fall unconscious when the air around it is sucked out with a pump. Similarly showy experiments demonstrating the strange and recently-discovered properties of electricity were also very popular.

Joseph Wright of Derby, An Experiment on a Bird in the Air Pump, 1768

The above painting slightly pre-dates Joseph Priestley's experiments on air, but it's easy to imagine Priestley in the role of Wright's natural philosopher.

Priestley performed hundreds of experiments involving air and the absence of it, using a succession of unfortunate mice to observe how long an animal could survive in conditions such as a sealed jar; a sealed jar with the air sucked out of it; a sealed jar with a mint plant growing in it; and, most famously, a sealed jar filled with a gas Priestley had created from burning mercury calx, in which a mouse miraculously survived for half an hour or more.

Despite the fact that these experiments earned Priestley the Copley Medal, the equivalent in its day of Nobel Prize, Priestley was barely aware of what he'd discovered. He thought he had created air that was free of 'phlogiston', a gas that medieval scientists believed was released by burning substances and which, when absorbed to saturation point by the surrounding air, caused fires to go out. Even though the phlogiston theory was already obsolescent in Priestley's time, he continued to believe in it, preventing him from seeing that what he had actually done was to create pure oxygen.

One of the many themes of Johnson's book is to question the 'Great Man' approach to history by showing that Priestley, in isolation, was in fact quite a rubbish scientist. He performed hugely important experiments and made hugely important discoveries, but consistently failed to apprehend their meaning. If Priestley had been operating in an intellectual vacuum, his contribution to scientific progress might have been negligible.

Fortunately, what he did very well was to share the information about his experiments with anyone who was interested. When Priestley discovered that, contrary to expectations, a mint plant not only flourished happily in a sealed jar but also allowed a mouse sealed in the same jar to stay alive for a surprisingly long time, it was his chum Benjamin Franklin who realised that Priestley had stumbled upon something of fundamental importance to the way our planet works:

"That the vegetable creation should restore the air which is spoiled by the animal part of it looks like a rational system, and seems to be of a piece with the rest."
Franklin glimpsed in the experiment something that Priestley couldn't see: that plants and animals need each other to survive, not just in tiny microcosmic environments like Priestley's sealed jar, but also on a planetary scale. If he'd thought about it any more, Franklin might have anticipated ecosystem theory by about two hundred years, but he was too bound up with the revolutionary politics of the nascent United States to devote much time to thinking about Priestley's mint experiments.

The fact that both Franklin and Priestley were as active politically as they were scientifically gives Johnson's book its major theme: how the interconnectedness of different disciplines (science, business, religion, politics) in the 18th century fuelled an explosion in scientific discovery, political progress and cultural advancement. Whereas today, scientists are scientists, politicians are politicians, captains of industry are captains of industry and religious leaders are religious leaders, during the Enlightenment it was eminently possible to be all of these things simultaneously - with each discipline informing and illuminating the others.

The free flow of ideas between disciplines is one of the reasons for the sudden flowering of science and culture in the late 18th century. In his book, Johnson also argues for the significance of geographical location, both at the micro scale (in the late 18th century, intellectuals from different walks of life congregated in the coffee-house opposite St Paul's cathedral, excitedly discussing their ideas while hopped up on this new imported brew) and the macro one (Johnson makes a lot of the fact that the Lunar Society was based adjacent to the coalfields of the north of England; the great store of energy laid down in the carboniferous era - thanks to the very process of photosynthesis that Priestley and Franklin had glimpsed - fuelling intellectual progress as well as the furnaces and engines of the world's first factories.)

Information flows, patterns repeating at different scales and the importance of geographical location are all classic Steven Johnson themes and are presented very well and very entertainingly in The Invention of Air. Which is just as well, because as a biography it's not great: Johnson seems far more interested in what Priestley symbolised than what Priestley was actually like. But perhaps this is deliberate - after all, Johnson doesn't subscribe to the Great Man view of history, preferring to see progress as a collaborative and often accidental process that owes more to information exchange and quirks of geography than to individual genius.

(Which incidentally makes a nonsense of the first two endorsements on the back cover of the book, praising Johnson for presenting Priestley as ' of the most fascinating personalities of his era' and as 'a new American hero'.)

It's a view that resonates well today: one of the things I like very much about Twitter, for example, is that you get intellectuals from different disciplines - including Steven Johnson himself - discussing their thoughts and ideas in a public forum where anyone can follow and contribute to the conversation, like an Information Age version of the London coffee-house.

Whether Twitter will give rise to a new Enlightenment remains to be seen, but one of the messages of this book is that the oxygen of information exchange can cause important ideas to grow and flourish, resulting in bursts of progress that change the world for the better. And I like that thought very much.


Christopher Campbell-Howes said...

Super post. (But where is Lavoisier?)

The free flow of ideas between disciplines is one of the reasons for the sudden flowering of science and culture in the late 18th century. Ah, too true. The New Critics and reductionists have a lot to answer for.

Dave said...

As I commented at my place last week, I was born at least 100 years too late. I see myself as a dilettante clergyman, cycling around my parish, stopping to make observations about naure, carving pictish runes onto stones and collecting previously-undiscovered fossils.

Specialists spoil things for the rest of us.

Tim Footman said...

Franklin mint. Hee hee.

patroclus said...

Dad: Yes, sorry about Lavoisier, I do seem to have left rather a lot out. Like the whole section about Priestley's role in the founding of America, which I'm ashamed to say I found a bit dull.

Dave: That all sounds brilliant - can I join you? Although, for the last time, it's Oghams, not runes.

Tim: You can be my headline writer any time.

John Cowan said...

The full moon simply made it easier for the Society's members to find their way home in the early hours of the morning.

And greatly reduced the chances of being mugged due to the darkness, in fact.

Dave said...

I'm not sure Victorian clergymen were encouraged to emulate Dr Who, and travel around with a young female companion.

The idea, though, has always appealed to me.

Thumper said...

Great post.

I think the whole phlogiston story illustrates perfectly how science is often counter-intuitive. I think there's this misconception where ccience as being "common sense", but in the experiments with the mice in the bell jars, common sense would have pointed to a gas being released.

patroclus said...

John: Yes indeed, although when Priestley's house, laboratory and equipment get burned to the ground by an angry mob, he proves to be quite sanguine about it.

Dave: Brilliant, I'll dig out my fossil-hunting bustle and stonemason's parasol.

Thumper: Hello! Yes, it would appear that science is more the result of tinkering, false starts and blind alleyways than the application of common sense. The chaotic nature of scientific enquiry in the Enlightenment is brilliantly described by Neal Stephenson in 'Quicksilver', where Robert Hooke and chums are holed up in some country seat performing weird and unspeakable experiments on dogs.

Dave said...

I'm sure you didn't have either time or inclination to read it, but the relevant post (including some remarks from ladies who seem to have loosened their stays somewhat, and your father in a derby, riding a velocipede) was here.

patroclus said...

Ooh, I must have missed that one when I was in Slough. Good fun.

Karen's Mouth said...

Yes! What a great post. The science is ALL about the tinkering. If ever I go to a prof-level lecture and they start banging on about their Nature paper, Nobel prize or whatever, their stories always involve "and then we got this really weird result".

I'm quite keen on communicating science to school children, but with the emphasis on the fact it's ALL about lateral thinking and solving sticky problems rather than making colourful explosions, which is what a lot of school engagement stuff is based on.

And I think science is once again at a stage where discipline hoping is highly valued. I think each specialism has gone off and sorted the basics, and now they're all being encouraged to form collaborations. I'm funded by a fellowship specifically created for interdisciplinary work, and lots of funders offer similar grants. And someone (Royal Society?) run a MP/scientist exchange programme. All we need now is a full moon to meet by.

Sorry. Long comment.

patroclus said...

Thank you KM. I wish you'd been my science teacher - I was so rubbish at science that I never even made it to O-Level in chemistry or physics, which I really regret. It was all (and still is) utterly mystifying to me.

The MP/scientist exchange programme is interesting - especially as Steven Johnson's book starts out by quoting Mike Huckabee telling someone not to ask him anything about science, because he's a politician and politicians don't 'do' science.

Jayne said...

You are either the cleverest person I know or you have waaaay too much time on your hands. Possibly both. Actually it must be the former as I know you've got a kitten to nurture.

Am far too stoopid to write an intelligent and informed comment. I shall go back to looking at the picture of the piglet squid and giggling.

Karen's Mouth said...

What? Good grief that's so depressing. I guess that's what it's primarily aimed at, MPs that 'don't do science' but it's good for the scientists too, to see how their work might have an actual application - something that scientists aren't generally very good at! Off the top of my head, I've got a feeling that the guy who invented ultrasound could see no good use for it beyond confirming elephants are pregnant. But maybe I dreamt that.

I wish you'd been MY science teacher! I hated it. Science at school bears no relation to actual science. If my dad hadn't been a scientist I never would have gone near it. Stories like the ones in your post are exactly what's needed. Your blog on the curriculum, I'm all for it.

Lucy Diamond said...

God, I am just so deeply impressed that you can write such amazing blogposts when the blue kitten is still a young babe - all I was capable of was watching Phil 'n' Fern for about a year after giving birth. You rock!

patroclus said...

Crikey, thanks all. Blue Kitten-wise I'm very fortunate to have the lovely Mr BC at home 99% of the time, sharing nappy-changing duties, taking the Kitten for walks, entertaining her with (frankly terrifying) silly faces etc. I can't imagine I'd have time to blurble about 18th century scientists if he wasn't here. I'm very aware that I have things very easy compared with almost all other mothers.