A new exhibition at the Wellcome Collection in north-west London is trenchantly titled Dirt: The Filthy Reality of Everyday Life. You can't encompass the whole human history of dirt – which is what the exhibition seeks to do – without also encompassing the history of cleanliness, but it is the dirt that stands out. To confine ourselves just to exhibits from 19th-century Britain, the evolving microscopes, the adverts for soap, the laundry baskets from the Royal College of Surgeons, a very early carbolic spray, are upstaged by a depiction from 1805 of Peggy Jones, the celebrated Thames-side "Mudlark of Blackfriars", or a Punch cartoon entitled A Monster Soup Commonly Called Thames Water, or a loving watercolour by E H Dixon of The Great Dust Heap at King's Cross – a black mountain of trash that was the main landmark of King's Cross before the railway station was built.
That's the thing about dirt. It's interesting. I still dream about a house at the end of the road I grew up in. It was occupied by a family who didn't do all the things that everyone else did. When the ashtrays got full, they weren't necessarily emptied. When the lady of the house drank a bottle of beer (which she did often), she left the dirty glass on top of the piano for a week or so. (They were all good musicians, perhaps because they never wasted time on cleaning).
Dirt is a badge of authenticity. As Elizabeth Pisani points out in the book accompanying the exhibition, and bearing the same title, when we shop at a farmers' market, "we want dirt on our spuds" – specifically soil, the most useful dirt of all. She also reminds us that "we expect our fictional commandos to be daubed with the grubby marks of battle". (In the films, James Bond gets dirty in an absolutely consistent and very flattering way: a smudge below the eye that accentuates the cheekbone.)
And anything so hated by the Nazis must have its good points. Hitler and co inherited the Deutsches Hygiene-Museum, which grew out of the first International Hygiene Exhibition, held in Dresden in 1911, and they used it as a base for the development of their "science" of racial hygiene. The exhibition features a poster informing the populace: "Jews are lice. They spread typhus." (It should be mentioned that the museum has returned to its salubrious earlier purposes.)
An appreciation of dirt is arguably a symptom of Western decadence, and I wouldn't be writing in the above terms, or at all, if I were one of the Indian scavengers or Dalits – the "broken people" formerly known as untouchables – who clear the waste from vast public latrines. But I suspect that this exhibition will be anxious-making even to those who have always managed to keep the faeces of third parties at arm's length. And when I say this will be especially so for men, the reader will begin to see where I'm heading. The main thrust of the history of dirt has been towards a situation that creates trouble in the home.
The fuse was lit by the cult of domestic cleanliness that developed in Delft in the Netherlands in the 17th century. This is illustrated in the exhibition by paintings including Mother and Child with a Serving Woman Sweeping by Pieter de Hooch, or Interior with a Young Woman Washing Pots by Hendrik Martensz – and others showing spruce interiors inhabited by complacent, presumably anal-retentive householders. This craze for cleanliness and order is associated with the work of Antonie van Leeuwenhoek, who, with the aid of a single-lens microscope, observed, in what he called "batter" scraped from his own teeth, numerous "animalcules". The word "bacteria" would not emerge until the mid-19th century, when the germ theory of disease was developed in the work of Louis Pasteur and Robert Koch. Antibacterial remedies were created in the early 20th century, and so we are armed against an enemy we cannot see.
In her fascinating essay about domestic dirt in the exhibition-accompanying book, Rosie Cox writes: "As germs are invisible to the naked eye, there are no obvious indicators of their successful removal, hence no limit to the amount of cleaning that might be necessary." And so we have the bomb nicely primed, and it is sitting there on the kitchen table of the average home.
It is the women who still do the lion's share of the cleaning. For her 2005 book, Hard Labour, Dr Caroline Gatrell, of Lancaster University Management School, interviewed 40 working couples. She found that the men did more child care than their fathers had done. "The shift," she says, "occurred in the mid-Nineties. With the end of 'jobs for life', and the rising divorce rate, the question became: 'Where is the relationship for life?' And men are increasingly deciding that it's in the relationship with the children." But the men didn't do significantly more cleaning than their fathers had done. According to Dr Gatrell, "Both partners want to work, both want to be with the children. The housework is the bit that nobody wants to do, but the burden falls on the women. The figure usually produced is that they do eight hours more housework a week than their partners."
My own wife might do slightly less than eight hours because three years ago, I deliberately took on more housework myself. Partly, I admit, this was because I was writing a book about it: How to Get Things Really Flat: A Man's Guide to Ironing, Dusting and Other Household Arts.
My interest in the subject arose from the sheer number of my friends who had rows with their wives about housework. They'd come into the pub looking sullen, and I'd ask the trouble: "I didn't empty the dishwasher. Ridiculous, isn't it?" I would agree, but then I might venture, "I hope you don't mind my asking... Have you ever emptied the dishwasher?" They would then resort to legalese. "It's almost inconceivable that I haven't at some point emptied it, even if I can't call to mind a specific instance just now."
They feel no shame because they still seem to believe it's the woman's role. In the North of England, where I'm from, the attitude is particularly ingrained, and it stems from industrial society. If a man's wife did all the housework, that proved he funded her existence – that she didn't have to go to the factory as he did. It was chivalry, of sorts. A man who did the housework, especially one who wore an apron, was a "dolly mop", sexually suspect.
Men are allowed to be dirty, and we're back to the smudge on James Bond's cheek. It proves their virility, at least up to a certain age, because stubble doesn't look good on a 70-year-old, and nobody wants to be a "dirty old man". Women are granted a much more limited licence to be dirty, as in the slogan daubed on the back of the grubby white van: "I wish my wife were this dirty." But the author doesn't really mean it. Castigated in the Bible for their uncleanness at a certain time of the month, women are ever on the alert for the perpetuation of such slurs, and are socially graded according to how well they dodge them. In her 1974 book, Housewife, Ann Oakley asked how many women were ever seen with greasy and neglected hair compared with the numbers of men happy to look like that. It's still a good question in 2011, when women are under so much stress on this front that they seek relief in magazines showing female celebrities un-made-up.
I will certainly go a week without washing my hair, and if my wife remarks on it, I'm capable of saying, "Well, you haven't bought any shampoo." But I'm not a completely typical male. Even before I wrote my book, I'd dabbled in cleaning, and I've liked vacuuming since I was a boy, when a clergyman pointed out its appeal to me: "Vacuuming's like mowing the lawn. You can see where you've been." The same is true of dusting, though most people who dust neglect to use a slightly damp cloth, or a cloth with microfibres that act as little hooks; the result is that, when they're in another room congratulating themselves on a job well done, the dust is settling back to where it was when they started.
If you dust right, you'll know when you've finished the job. But how do you know when you've cleaned the kitchen? I'll do that job to my complete satisfaction, and my wife will walk in and say, "I thought you were going to clean the kitchen." It'll turn out that the glass table wasn't burnished to her standards, or that I hadn't bothered to put away the olive oil. (But I think olive oil should be kept out.) As for whether I've properly disinfected the kitchen... she's rather in the dark about that, as are most women and most men – though women are more tyrannised by the question. As Rosie Cox writes, advertisers have for at least a century "played on housewives' fears, fostering ever-greater anxiety about dirt".
In writing my book, I quizzed women. I'd ask, "How do you clean a wooden chopping board?" I was looking for answers such as "Use a food-safe disinfectant", or "Scrub it with salt and water" (the traditional butcher's method). Instead I'd get evasive, defensive replies: "I don't think I've ever done more than give it a quick wipe over with a cloth, and do you know what? My children haven't had a day's illness in their lives."
I spoke to some microbiologists, and they were all unexpectedly keen on hot soapy water. In a nutshell, there's no point disinfecting unless you've first thoroughly cleaned, and if you're going to do only one or the other, then it's better to clean – to remove the germs rather than try to kill them... always remembering that the germs go on to the cloth. (So there should be a high turnover of cloths.) The microbiologists were also suspicious of fashionable sanitisers, which presume to clean and disinfect at the same time, and which are ostentatiously used in cafés and restaurants, supposedly to demonstrate high levels of hygiene.
One of the scientists in particular was bemused by my wife's loo-cleaning habits. I told Dr Val Curtis, of the London School of Hygiene and Tropical Medicine, that my wife cleaned the loo with disinfectant twice a week. (I do it about once a month.) "Well, that's very nice," she said, "it'll make your loo look and smell nice and people won't say bad things about you... But what about the other days of the week? I mean, why not disinfect it every day? One gram of faeces contains more bacteria than there are people on the planet. But the point is to clean."
According to Dr Curtis, the most important things to clean are your own hands after using the loo. And if you really are hell-bent on disinfecting, then disinfect the flush handle, the part of the loo everyone touches. I told my wife, who said, "Why don't you start doing that, then?" I said, "I might well." And so I do – sometimes.
Revisiting my conversation with Dr Curtis, I thought again of the Dalits of India, and called to mind a fact adduced in the book accompanying the Wellcome exhibition: that germs from faeces cause more deaths today than malaria, tuberculosis and HIV/Aids put together. So my reflections on my domestic cleanliness prompted consideration of the wider picture, but for most men visiting the exhibition, the opposite will happen. Consideration of the wider picture will quickly give way to reflections on their own domestic hygiene. And in nine out of 10 cases, a feeling of guilt will follow.
Dirt: The Filthy Reality of Everyday Life runs from 24 March to 31 August at the Wellcome Collection, 183 Euston Road, London NW1 2BE. See www.wellcomecollection.org for details.
The accompanying book is published by Profile Books at £20.