Luc Sante joins the short list of famous Belgians with a brace of books that catalogue weird tales and odd facts. Geoff Dyer ticks off a literary trainspotter
Luc Sante is an interesting example of a writer who is not quite interesting enough to live up to the expectation his writing engenders. Ambitious, intelligent and original, his two new books are constantly breaking the promises made at their outset. Then, for a few paragraphs or pages, you get glimpses of the qualities which - if sustained - would make him a consistently impressive writer instead of an intermittently intriguing one. Even so, it seems strange that his first book (which came out in the US in 1991) has taken so long to get published here.

Low Life (Granta, pounds 7.99) grew out of a fascination with New York's Lower East Side. It might have found expression in hip, druggy fictions - verbal equivalents of the art-snaps by photographer Nan Goldin, in whose world (as Sante explains in Goldin's I'll Be Your Mirror) he moved in the late 1970s. Instead, the neighbourhood drew him back obsessively into the past. Each 100-year-old tenement appeared on his retina "accompanied by a grimly ironic caption: The NINETEENTH CENTURY".

"Haunted by these ruins", Sante "wanted desperately to see them when they were built". This desire could only be realised through a Herculean labour of idiosyncratic research. The result is an immensely detailed compilation of anecdote and fact about "drinking, drugging, whoring, murder, corruption, vice and miscellaneous mayhem in old New York".

The novelty of the undertaking lies precisely in its oxymoronic quality. Sante is concerned with the period 1840-1919 but, as he points out in an alluring preface, his book is also "about New York City today". New York "does not hark back to a heroic past, lacks its Romulus and Remus", but the city's past makes itself felt perpetually in the present. Places that acquired a bad name by being associated with a Dutch tannery, for example, "continue to bear a stigma". No one remembers the tannery "but it was succeeded by a rookery, then by two generations of tenements, and then by a housing project now gone to seed. The project's decay is in some measure a consequence of the odour of that tannery."

Stated briefly, this suggestive idea augurs well but, in the text itself, is all but buried by the weight of the evidence required to substantiate it. Paradoxically, the attempts to lay bare the past are often obscured by the procedure of indiscriminate accretion.

After the hopes raised by Sante's preface, what we get is simultaneously rich in fact and modest in intellectual reach. All said and done, Low Life is best seen as a transatlantic equivalent of The Victorian Underworld by Kellow Chesney. Sante does not try to work his material into a narrative; his concern is to unearth his discoveries and display them.

Riots, murders and drug abuse always make for diverting reading but, with no focus other than its temporal and topographic limits, Low Life is a compilation, a resource - invaluable for anyone writing a novel set in the period - rather than a satisfying book in its own right.

Having dredged up so much information, writing, for Sante, tends to become synonymous with accumulating lists and statistics. One "estimate from the turn of the century posited an average of 2.5 million pounds of manure and 60,000 gallons of urine on the streets every day" - but, as readers, we never imaginatively inhabit these streets. The book is all background. Sante tells us lots about the New York b'hoys of the 1830s and 1840s, for example, but we get a much clearer sense of these proto-punks when refracted through the prism of the poet's life in David Reynolds's Walt Whitman's America.

Sante's second book promises to be a far more cunning work of art. The Factory of Facts (Granta, pounds 12.99) opens with a virtuoso "Resume" that offers elaborate versions of his biography. According to the first and most reliable, Luc was born in Belgium in 1954. When the iron foundry where his father was employed closed down, the Santes emigrated to America. Months later they went back to Belgium before re-emigrating - and re-returning, again and again.

The effect of this deepening linguistic and cultural dislocation on Luc is one of the themes of the autobiographical essays that make up this book. Others are ideas of home, of origins and - echoing the impersonal project of retrieval in Low Life - the persistence of the past. Setting out these concerns, Sante comes up with one of the best analyses of the development of personality I have ever read: "each of us is made, less by blood or genes than by a process that is largely accidental, the impact of things seen and heard and smelled and tasted and endured in those few years before our clay hardens. Offhand remarks, things glimpsed in passing, jokes and commonplaces, shop displays and climate and flickering light and texture of walls are all consumed by us and become part of our fibre... Every human being is an archaeological site. What passes for roots is actually a matter of sediment, of accretion, of chance and juxtaposition."

In the pages that follow Sante takes on the role of an "archaeological detective", investigating the sites of his own formation. At times this method yields insights that rank with any found in the autobiographical excavations of Wordsworth: "the insect buzz of a single-engine light aircraft" was not just "an essential ingredient of summer" but a "first intimation of what it was going to be like, one day, to remember".

In a narrative compiled from the shavings of memory, Sante's sense of "Belgianness", of what makes Belgium a country, emerges from splintered impressions whose resonance lies in their unmeditated arbitrariness: "Varnished wood. Silent children. Well-bred-dogs, unassertive houseplants... The ability to sit for long hours... Tinted house windows. Symmetry. Monuments. The perpetual immanence of rage, blasphemy, running amok. Trees like fists." His evocation of Magritte - a visionary "of boredom, the peculiarly overcast Belgian Sunday afternoon boredom" - is similarly compelling.

These are glimpses of Sante at his glimpsing best. Then, as he continues his survey of Belgian writers and artists, he lapses into the habit of Low Life, of accretion and survey. Intensely imagined moments, when the past pierces the present, are lost in ordinary passages of reminiscence and enumeration. The archaeological detective begins to sound like the unorthodox author of a family memoir. At one point he concludes a chain of recollections with the two-word sentence: "Et cetera". That is the problem with Low Life and The Factory of Facts. Too many sentences, too many passages, are versions of that one phrase.

Everything that is interesting about Sante as a writer - about any writer - lies in what resists summary by those two words: Et cetera.