Streets of shame
'London 1753', British Museum, 020 7323 8299, until Nov 23

An exhibition depicting London in 1753, the year the British Museum was founded, is dominated by Hogarth's horrifying, squalor-filled images.

If London 1753 were not such a good exhibition, I'd say the Prints and Drawings Department of British Museum had pulled a fast one. Billed as a celebration of life in London in the year when the 250-year-old museum was founded, it could just as easily have been called "William Hogarth and his World".

William Hogarth, Gin Lane, 1 February 1751. Etching and engraving with engraved lettering. 385 x 320mm.

For, although there are sparkling impressions of prints after Reynolds, Thomas Frye, Thomas Hudson and Zoffany, magnificent watercolours by the brothers Thomas and Paul Sandby, and objects including Chelsea and Bow porcelain figures, bronzes, maps and manuscripts on view, all play second fiddle to Hogarth's exuberant prints.

This is as it should be. Just as 19th-century Paris is the city of the Impressionists, and just as Berlin in the 20th belonged to the Expressionists, we still see 18th-century London through Hogarth's eyes. No other British artist so completely identified himself with the city of his birth.

Like Dickens, Hogarth celebrated the squalor and the spectacle of London life. During his rambles through the city, his eye fell on prostitutes and parvenus, apprentices and aristocrats, the up-and-coming and the down-and-out. Much of the Georgian city depicted in his prints has disappeared, but we can still see from the location of the spire of St George's Bloomsbury in the distance that his famous print Gin Lane is set in slums not far from the British Museum, or note that in Plate 12 of the series Industry and Idleness the Lord Mayor's procession to the Guildhall passes through Cheapside. But then Hogarth's contemporaries would have recognised the setting for virtually every one of his London views.

Hogarth is called the father of English painting because he was the first artist to have painted pictures in genres we now take for granted, from middle-class portraits to moralising genre subjects and scenes from Shakespeare. The show, selected and catalogued by Sheila O'Connell, represents all these facets of his genius, but then uses objects and comparative material to enrich and enliven even the most familiar images.

Take, for example, Hogarth's great portrait of Captain Thomas Coram. The standard critical line is that, by allowing the kindly sea captain to pose without a full-bottomed wig, wearing a plain suit, wool stockings and a rough coat without embroidery, Hogarth adapted the conventions of aristocratic portraiture to accommodate a middle-class sitter. All this is true enough. But such considerations are less important for understanding the portrait than the question this show asks about Coram himself.

What had the wealthy ship's captain actually done to merit Hogarth's friendship and approbation? Certainly, Coram had founded London's first hospital for orphans in 1739, and Hogarth sat on the board of governors. But what brings home to us the reality of Coram's charitable work is a collection of "foundling tokens" hanging next to James McArdell's mezzotint after Hogarth's portrait. These are the objects mothers left with the babies they abandoned, so that if, at some future date, their luck changed they could return to identify and claim their child.

If inanimate objects can be described as anguished, these resonate with the pain of separation. Each is a novel in itself. Whoever left their child clutching a finger ring with a tiny gold padlock and key inscribed in Latin "Take care of me or you will lose me" had both the money and the education to look after the infant she was leaving at the gates of Captain Coram's institution. But was it a "she"? Or was it a young father disposing of an unwanted infant after the death in childbirth of a wife or mistress?

Speaking to us just as eloquently - but of poverty and degradation - are a gambling token in the shape of a fish and an enamelled bottle label lettered "ALE". Without Coram's charitable intervention, we realise, the children attached to these tokens would have been killed at birth or died in early childhood.

Similarly, Hogarth told the harrowing tale of a country lass who falls from virtue and dies of syphilis in his early narrative cycle, The Harlot's Progress. But he was not the only artist of the period to treat the subject of prostitution. When you juxtapose his depiction of a whore's life with brothel scenes by artists such as Louis Philippe Botard or Charles Mosley, you find that these lesser artists guffaw so loudly at their own broad humour that they tell you very little about what a prostitute's life was actually like. Hogarth alone shows us the relative comfort in which a woman lucky enough to find a wealthy protector might live, as well as the utter squalor she could expect if she lost her looks or became ill.

And disease was pretty much what the women and their clients could expect - at least if we take James Boswell's medical history as typical of the period. On view (a first, I think, for the BM) is a pair of 18th-century pigskin condoms, tied at the base with two pretty pink ribbons, and accompanied by an impeccable label informing us that they are re-useable.

The show is a cornucopia of information about both London and British social history. But one subject runs through the exhibition: the chronic addiction of Londoners to violence. Whether in Hogarth's Gin Lane, The March to Finchley or his scathing portrait John Wilkes, you feel the ubiquitous presence of the London mob - at its least destructive, drinking itself stupid and then pissing, puking, drooling, groping and brawling in the streets; at its worst, a seditious tinderbox that any demagogue could incite to revolution.

You can choose almost any of his prints at random and see the moral degradation in which the British of all classes lived. Take The Cock Pit, a horrid image capturing the sheer nastiness of an entertainment in which the birds were fitted with cockspurs, the more efficiently to tear teach other to shreds. A manuscript list of the rules of conduct in a cockpit include the interesting information that men who didn't settle their wagers were suspended in wicker baskets from the ceiling before being expelled from the rooms.

For the first time I understood that the otherwise inexplicable shadow that hangs over Hogarth's image represents just such a miscreant, whose profile we see only by implication. He got off lightly. If you were caught by the law and sentenced to the more public humiliation of the stocks, you could easily be beaten to death. Hangings were public events. And I was fascinated by Pierre Charles Canot's etching after George Budd's view of the huge crowds that gathered to watch the beheading of two Jacobite noblemen at the Tower. After their deaths, as Hogarth's print The Rewards of Cruelty makes plain, they could expect their cadavers to be dissected in public, and their hearts and livers fed to dogs.

Even religion was steeped in violence. Whitefield's Chapel in Tottenham Court Road, built in 1756, was the world's largest non-conformist place of worship, seating up to 8,000 people. Hogarth, who had to have his say on pretty much every significant social and political issue of his time, responded with the etching Enthusiasm Delineated in 1761, a rollicking satire on the fainting, gibbering credulity of evangelical believers, crossed with a somewhat obscure attack on Roman Catholicism.

Hogarth, I sometimes suspect, understood these social evils so well because he was part of the problem. At least in his prints, he was as violent as the subjects he depicts. The evidence here suggests that the British have had a genetic disposition towards violence, which the deportation of criminals in the 19th century and two world wars in the 20th have, until now, kept in check.

And, while it is true that the exhibition covers high culture too - in prints that take note of the presence in London of the young Mozart, George Frederick Handel, the sculptor Louis-Franois Roubiliac and the collector and man of letters Horace Walpole - the city that most visitors to this show will recognise is Hogarth's stewpot for the simple reason that, in all fundamental respects, it hasn't changed.

Gallery opening times
Sat - Wed 10.00 - 17.30, Thurs - Fri 10.00 - 20.30
Great Russel Street, London
Underground stations: Holborn, Tottenham Court Road, Russell Square, Goodge St
Bus routes: New Oxford Street: 7, 8, 19, 22b, 25, 38, 55, 98 Tottenham Court Road, northbound and Gower Street, southbound 10, 24, 29, 73, 134 Southampton Row: 68, 91, 188