Life Soup

Afew hours​ after Jean-Paul Sartre was injected with mescaline by his friend Daniel Lagache, a psychiatrist at the Sainte-Anne Hospital in Paris, Simone de Beauvoir phoned to check in on the first-time tripper. Her call came as a reprieve. As Sartre told her in a scrambled voice, she had interrupted a losing battle against a mass of octopuses. He had been promised a safe experience. An intern who had also taken mescaline found himself gambolling through fields of flowers, so Sartre’s nightmarish visions could hardly be the drug’s fault. But he had never liked slimy sea creatures. As a child he had almost fainted after seeing an engraving of a moonlit quay with a shadowy sea monster emerging to drag a hapless drunk to his death.

The blurriness of Sartre’s poor vision was fertile ground for his hallucinations. Indistinct shapes could morph into scuttling cephalopods and crustaceans. After his mescaline experience, he claimed to have continued to hallucinate three or four crabs who followed him around for a year. Each morning, he later told John Gerassi, he would greet them: ‘My little ones, how did you sleep?’ He got used to the crabs, but other sea creatures – molluscs in particular – remained objects of horror. Sliminess had something to do with it. Being and Nothingness (1943) concludes with the idea of the visqueux. Sliminess is horrible to Sartre because it has neither the reassuring inertia of a solid nor the yielding shapelessness of a liquid, but a clinging contamination that envelops and consumes the investigator. The visqueux, for Sartre, is the ultimate ‘revenge’ of unconscious matter (‘being-in-itself’) against conscious matter (‘being-for-itself’).

There are mucilaginous monsters in Susanne Wedlich’s Slime that Sartre might have found even more horrendous than octopuses. The hagfish transforms seawater into a suffocating slime ‘that will even gag a shark’. Anomalocaris was a metre-long armoured shrimp-like creature – mercifully extinct – that once roamed the Cambrian seas ‘like a wolf’, embracing its prey to feed them into its razor-studded mouth. The cellular slime-mould Dictyostelium discoideum, formed when hundreds of thousands of amoebae coalesce into a ‘faceless, see-through slug’, is an existentialist nightmare straight out of a B-movie shocker: Revenge of the Being-in-Itself.

Early in her book, Wedlich admits that she can’t give an easy definition of slime. A purely physical one doesn’t work. We don’t learn much by defining slime as ‘an extremely aqueous and viscously fluid hydrogel’. Slime is also phenomenological, ‘a thing in between a feeling and a description’. We may agree that mucus and mayonnaise have the same viscosity, but disagree as to whether this makes my sandwich disgusting. Cultural differences show up clearly in food, but they hide in other areas too. Slimy things are everywhere, but there is no universal concept of sliminess.

Since cells are jellied bags of proteins, there’s no such thing as a slime-free creature. A ‘natural history’ of slime, as Wedlich’s English subtitle promises, fast overflows its boundaries and threatens to become a history of all life on earth. Rather than agonise over how to narrow the lens, she goes the other way, including things that may not be slimy per se so long as they catch her attention ‘in a slime-like way’. The original German title (‘The Book of Slime’) describes it better. Wedlich appeals to slime’s own lack of ‘hard borders or distinct divisions’ to explain the book’s organisation into loose chapters that can be read ‘in sequence or independently’. The excuse is unnecessary: the book isn’t marred by its formlessness.

Although Slime focuses on biology, Wedlich first deals with her readers’ presumed revulsion. As Sartre noted, ‘sliminess’ for most of us denotes a host of human and moral characteristics: a handshake, a smile or a thought can all be ‘slimy’. It is a type of contaminated morality. (During the Second World War, Wittgenstein remarked disconcertingly to a friend: ‘Things will be terrible when the war is over, whoever wins. Of course, very terrible if the Nazis won, but terribly slimy if the Allies win.’) According to Sartre, we might assume that we have, on the one hand, the physical experience of sliminess, and, on the other, slimy behaviours and attitudes. By projecting our knowledge of the human world onto sliminess we imbue slime with a moral character. But this begs the question. In order to make the connection between the physical and the moral, Sartre argues that we have to be able to perceive a certain moral baseness in both. He draws two conclusions: that moral qualities are always charged with physical sensation, and that the physical sensation of sliminess has an innate moral quality. If he’s right, I think it’s unlikely to be separable from the way our bodies are made: slimy on the inside, with a non-slimy outside. If we were conscious slugs that wore our sliminess externally, we might have an equal but opposite revulsion: for the dry, the hard, the parched.

A huge variety of slimy things could trigger our revulsion, but only some do. Sartre claimed in Being and Nothingness that ‘observation’ of young children proved they were instinctively repulsed by all that is slimy. It seems more likely he was universalising his own particular phobias. As Wedlich points out, young children will quite happily eat worms; only if they grow up in a culture in which worms are taboo will they learn to stop. ‘We are born to be disgusted’ by slime, but must be taught which slime ought to disgust us. Human bodies are never slimier than during sex, but most of us don’t experience this as a difficulty. To describe humanity as slimy is true (if misanthropic); to single out certain practices or bodies as ‘slimy’ is to reveal one’s prejudices. The misogyny of Sartre’s warning against the ‘sweet and feminine’ visqueux is one of the slimiest moments in his writing.

There does seem to be something universal about the feeling of disgust that slime provokes, even if its valences differ. That ‘slime’ is an easily translatable concept helps Wedlich’s case. She links it to the risk of contamination: our bodies use mucus as a barrier to soak up pathogens which are themselves slimy. Her translator, Ayça Türkoğlu, deploys an impressive and viscous vocabulary. Both German and English have slimy words for slimy things. The smack and suck of saliva make for squelching prose. Frogspawn looks like ‘slimy star snot’. Differences in translation do exist, however. German-speaking friends tell me that schleim is more neutral than in English; you can tuck into a warm bowl of Haferschleim, for example (‘oat slime’, or oatmeal). And even in English, slime has ebbed and flowed. Wycliffe’s 14th-century translation of the Bible has God creating Adam ‘of the sliym of erthe’. In most later versions, the first man emerges from ‘dust’. The imagery has stuck in modern Christianity. ‘Ashes to ashes, dust to dust’ is an oddly desiccated summary of life’s viscous circle: a euphemism posing as a proverb.

It’s unclear why ‘sliym’ slipped out of the English Eden. Perhaps it made the account in Genesis too close to spontaneous generation. Lucretius wrote of the way moist soil could have given rise to humans without the need for divine intervention. In contrast, dust is inert, needing an injection of moist vitality to come alive. As Daryn Lehoux argued in Creatures Born of Mud and Slime (2017), spontaneous generation was ‘the last stand’ of the ancient scientific worldview. Wedlich is careful to distinguish the slime that ‘just happens’ when mud and water mix from ‘true’ biological slimes. But without knowing the origin of the substance in front of you, inorganic slime can often seem part of what William Ian Miller, in The Anatomy of Disgust (1997), called ‘the organic world of generative rot … life soup, fecundity itself’. For most of history, as Lehoux points out, spontaneous generation was a fact, not a theory. The distinction between muddy slime and living slime makes sense in a modern biological framework. It didn’t always.

Lorenz Oken, a German natural philosopher born in 1779, thought that life had not only begun as a primordial slime but that this slime could still be found forming today. He argued that this slime ‘has its origins in, and is in its essence of, the sea, not mixed with it through the dissolution of rotting substances’. For Oken, the ‘whole ocean’ was alive. In England he was accused of heresy for suggesting that ‘globules of slime’ were the basis of life. Coleridge avidly read (and annotated) Oken’s works, judging him ‘a man of genial Talents’. But in one marginal note he asks: ‘Was Oken drunk when he wrote this?’ Coleridge rejected Oken’s idea of monadic slime-globules as an explanation for the stuff of life. Next to a passage about ‘Life-Atoms’, Coleridge writes that ‘Atheism has driven Oken mad: unless Oken was mad. And Atheism found him.’ Yet the image of a slime-filled sea was widespread at the time. Even before reading Oken, Coleridge had written in The Rime of the Ancient Mariner that ‘slimy things did crawl with legs/Upon the slimy sea.’ This slime is notably non-Okenian, arising because the sea is rotting, rather than being the stuff of life. Later in the poem, his shipmates all dead, the Mariner is not entirely alone: ‘a thousand thousand slimy things/Lived on; and so did I.’ (In the Lyrical Ballads version there are a ‘million million’ of them.)

Every era finds a different way to enlist slime into its prevailing theories. Slime can soak up any number of metaphysical preconceptions and hold them in sticky suspension. In the early 20th century, the spiritualist movement picked up on ideas about ‘cellular slime’ to ground its metaphysical claims. The ‘milky-white emissions’ of ectoplasm that showed up beautifully in photographs convinced figures like Arthur Conan Doyle that the spirit world could tangibly intersect with our own. Wedlich mentions props such as ‘fluttering gauze’, but doesn’t explain that the production of ectoplasm was often intensely visceral. The medium’s medium was cheesecloth, sometimes fisted into a tight ball and swallowed, to be regurgitated in a clotted white string steeped in gastric juices. The sliminess of ectoplasm came not only from a ferment of philosophical and scientific ideas, but from the practical constraints of what mediums could accomplish with nothing up their sleeves.

The age of molecular biology was less kind to slime. One of the most important tools of the field in its formative years was X-ray crystallography, which allowed researchers to work out the structure of proteins. It works best on small, well-ordered, soluble molecules. Slime proteins are not only large and messy, but have evolved to bind water. It has taken recent improvements in other methods to allow glimpses of the tangles that they form inside us. Despite being up to 99 per cent water by mass, slimes are far from structureless. They are made of molecules that expand thousands of times when wet, holding water in a loose interlocking network – or, as Wedlich puts it, ‘water in chains’.

The discovery of the structure of DNA in 1953 was a particularly bad moment for slime. To the early molecular biologists, the double helix was proof that, despite a superficial sliminess, at the fundamental level life was about information. As Matthew Cobb has written, a generation which had spent the Second World War cracking codes and programming computers was primed to use these new metaphors for biology. The later elucidation of gene regulation in E. coli by François Jacob and Jacques Monod showed the way cells could convert sugary ooze into discrete logic: if glucose is not present and lactose is then make lactase to digest it. It was as if, once you drained away the slime, bacteria were revealed as tiny circuit boards, digital computers whirring away beneath the stickiness.

This logic extended beyond bacteria. The conceptual division of the eukaryotic cell into the ‘brain’ of the DNA in the nucleus and the ‘body’ of the cytoplasm enforced a powerful dualism. Since nuclear DNA was what mattered, the rest of the cell was merely a slimy vehicle, devoid of information. In the 1960s, when Lynn Margulis wanted to study heredity in mitochondria, there was disagreement as to whether they even had DNA. Suspecting that mitochondria had once been free-living organisms, Margulis suggested that the eukaryotic cell had arisen from a symbiosis, with the capture and collaboration of the mitochondrial ancestor in the Precambrian era, more than a billion years ago. She wasn’t the first to suggest this unorthodox idea, but she was the first to live to see herself vindicated. In 1979 it was found that the mitochondrial genome – a tiny smidgen compared to the huge nuclear genome – uses a slightly different genetic code. Slime can be full of surprises. The theory of symbiogenesis is a reminder of the value of studying the soft edges of biological knowledge.

Margulis also did research into communities of bacteria living together in ‘biofilms’. Most bacteria don’t live free, floating adrift as single cells, but combine and stick together on surfaces. The earliest fossils of biofilms date back at least 3.5 billion years. Stromatolites are built by successive layers of bacteria in shallow water. As grains of sand and dirt accumulate in each layer, the bacterial sediments build upwards. The result resembles ‘a stony pile of pancakes’ more than anything we’d recognise as living. Modern stromatolites can still be seen in a few places, such as Shark Bay in Western Australia. They grow so slowly that when Wedlich visits she can easily make out the tracks of camel-drawn wagons that passed over the stromatolites a century ago. Like the scientists in Stanisław Lem’s Solaris, she says, we may fail to recognise life that doesn’t give us the biological clues we expect.

Wedlich excels at drawing such analogies, giving Slime an eclectic and rich bibliography. One of the pleasures of a book like this should be following up the references, but because there are no footnotes it’s impossible to know where in the bibliography the curious or the sceptical should go for more. (At one point we’re told that the womb may not be sterile, ‘according to a disputed publication’ that we get no further details about.) It’s a shame, because Wedlich clearly put effort into choosing these studies: in her acknowledgments she regrets not having space to include a discussion of spiggin, the unique slime secreted by the kidneys of male sticklebacks and used to build their nests. As she notes, there is no evolutionary problem that doesn’t seem to have been solved somewhere with slime.