Rarely can the character of London have been analysed more extensively than over the past few weeks. The announcement of the city's success in bidding to host the 2012 Olympic Games prompted excited talk of the capital's rejuvenation: Trafalgar Square, scene of violent anti-poll tax riots 15 years earlier, played host to a spectacle of civic self-congratulation. The raw horror of the 7 July bombings swiftly put paid to such self-confidence, however. Even as guests on the Today programme's 8.50am slot were discussing the renaissance of the East End of London, the Beeston bombs were ripping through the Underground. London - the meaning of London - was under attack.
So much of what we understand as London was a creation of the Victorian era. The Circle Line that the terrorists blew up is one of many monuments to 19th-century engineering. Tavistock Square was the location of Charles Dickens's resplendent 18-room house, in which he composed his finest London novel, Bleak House. Round the corner, at Russell Square, is Great Ormond Street Hospital, Dickens's celebrated feat of civic philanthropy. And so it goes on, from Aldgate East to Edgware Road.
It is Liza Picard's ambition to guide us through life in the metro-polis during the mid-19th century's "age of equipoise". Victorian London is the latest in a series of celebrated studies: Elizabeth's London, Dr Johnson's London and Restoration London. These are not urban histories in the academic sense, but nitty-gritty social histories of the city. Picard enjoys recounting the gruesome daily mechanics of living in what Cobbett described as "the great wen" and Lord Rosebery called "a tumour, an elephantiasis".
In Victorian London, she delivers up the expected fare with admirable thoroughness: the Great Exhibition, Joseph Bazalgette's sewers, Henry Mayhew. But where she really excels is in describing everyday, below-stairs life. Sewage and sanitation feature heavily - not just water closets and the Great Stink, but the inner workings of the Victorian bathroom. The Victorians displayed impressive ingenuity when it came to ablutions. Jacuzzis - or gas-heated "geysers" - were common in the 19th century. As standards of personal hygiene improved, however, the stench of London only got worse. Picard is right to focus on this smell, which, despite having been a constant backdrop to life in the capital, is often left unmentioned in urban histories.
Readers are offered an intriguing overview of London's creaking transport infrastructure: the hundreds of steamships dangerously plying their trade along the Thames (killing hundreds in explosions and crashes); the arbitrary tolls and turnpikes across the city's roads and bridges; and the sheer amount of walking that went on. Communications are another of Picard's strengths. By the middle of the century there were 12 postal deliveries (one per hour) in London every day. Meanwhile, the shift in postal payments from recipient to sender entailed a move from knockers on front doors to letter boxes.
The problem with Victorian London, however, is that it is simply too comprehensive. In the accompanying press release, Picard, who used to work in the office of the Solicitor of Inland Revenue, describes her methodology: "As a lawyer, I have a liking for primary evidence . . . I have a practical mind. I have always been interested in how people lived. The practical details are rarely covered in social history books . . . The only answer appeared to be to write a book myself." Lawyers are different creatures from historians, however - as can be deduced from recent legal investigations such as the Saville inquiry into the Bloody Sunday shootings. Tribunals staffed by lawyers are adept at uncovering the factual truth - who shot whom, what was hidden where - but often fall down on the more fundamental questions of causation and responsibility. Why something happened, who was responsible, what were the cultural or social triggers - the legal mindset tends to overlook such matters.
And so it is with Picard. She presents a masterly brief on London, but with little sense of the relative significance of events, of how things differed from one period to the next. This is a gazetteer - or encyclopaedia - of the social history of the city, with everything from bus timetables to pew rates. Despite her numerous books about London, Picard provides no insights into its transformation between, say, Restoration and Victorian times, or of how streetscaping evolved between Nash's Regency and the slum clearances of the 1860s.
Perhaps most disappointing of all is the lack of any discussion of contemporary approaches towards the meaning of the city. From William Cobbett and Thomas De Quincey to Sidney Webb, the nature of London - its size, its inequalities, its relationship to other cities, its political profile - was debated endlessly. De Quincey was both horrified and mesmerised by the "labyrinth of London" and its vast, anonymous populace, which he described as "a pageant of phantoms". Webb was worried by the deterioration of London's genetic stock and the effect this would have on Britain's imperial fortunes. The threat of the city, the debauchery of the city, the thrill of the city: these were perpetual subjects for Victorian novelists, pamphleteers and poets. Yet Picard has deci-ded to ignore them all, in favour of a "facts, facts, facts" approach based on manuals, diaries and journalistic accounts.
Similarly, she fails to place London within a broad economic context. One of the most interesting features of Victorian London was its multi-layered commercial composition. In addition to the clerks and lawyers who worked in the City (whom Picard describes superbly), there were the worlds of society and the royal court (which demanded a highly flexible service economy), as well as Britain's most advanced manufacturing sector. The watchmakers of Clerkenwell, the shipbuilders of Millwall, the chemical workers of Stratford, the rubber manufacturers of Hackney, the calico printers of Wandsworth and the tanners of Southwark comprised an industrial hub that underwrote London's financial dominance. Yet the capital also stood at the heart of a global imperium. London was the new Rome and its architecture, ports, politics and leisure reflected this imperial status. It was an increasingly multi-ethnic city, with new cultures and peoples constantly arriving. Picard fails to place London within this imperial setting, however. She offers a fascinating description of the Alhambra music hall in Leicester Square (where the Odeon cinema now is), but provides no detailed account of the style and meaning of Moorish architecture or oriental amusements.
Following on from The Victorian House by Judith Flanders, Picard provides a rich, startling insight into the lives of the mid-Victorians. But urban history is more than social history, and London is more than the sum of its parts. It contains meanings and messages - to which the 7 July terrorists have so terribly added.
Tristram Hunt is the author of Building Jerusalem: the rise and fall of the Victorian city (Weidenfeld & Nicolson)