Arts: Notes in anatomy

Theatre: AN EXPERIMENT WITH AN AIR PUMP; HAMPSTEAD THEATRE LONDON

PRE-MILLENNIAL tension (it's that time of the century, darling) charges the atmosphere of An Experiment with an Air Pump. Shelagh Stephenson's play jumps, Arcadia-fashion, between 1999 and 1799 to establish continuities in the way each era wrestles with the problem of how morally neutral scientific research impacts on human values.

The setting, handsomely evoked in Julian McGowan's curiosity-crammed design, is a grand Newcastle house which, in the 18th century, is a centre for experimental inquiry and radical dissent. Two hundred years later, the house is on the point of being sold off to the heritage and corporate hospitality industry.

But then the owner, Ellen, a brilliant geneticist, finds herself being offered a lucrative job with a genetic engineering company. Already depressed because he's just been made redundant, her English lecturer husband Tom is not made any cheerier by his wife's ethical dilemma, or when a surveyor unearths a bag of human bones under the kitchen.

An Experiment with an Air Pump won the 1997 Margaret Ramsay Award and it is certainly never less than interesting. But watching Matthew Lloyd's involving, well-acted production (now transferred from the Royal Exchange to Hampstead), I felt that the play comes across as an over-inclusive draft that would benefit greatly from pruning. The central questions and connections keep getting elbowed to one side, and some of them could be thrown into much sharper relief.

For example, scientific ruthlessness in the earlier period is personified by Martin Ledwith's Armstrong, a cad so laughably villainous that an audience has to fight the urge to hiss at him. He heartlessly seduces Isobel, an intelligent young hunchbacked servant girl (excellent Pauline Lockhart) because he wants to study her unusually deformed spine, and he is quite without compunction when she is reduced to an anatomical specimen somewhat sooner than he'd bargained for.

But on the debates in the later period about the prediction of disorders and the termination of pregnancies, the figure of Isobel (who doesn't have a modern counterpart) seems to cast no shadow. There are some excellent rebuttals of the pushy genetic-engineering entrepreneur's blithe claim that there'd be no place for manic depression in the brave new world (in which case we'd have to kiss goodbye to a lot of art).

It's odd, though, that a play that makes an admirable defence of human diversity should overlook, at such points, one of its own characters - Isobel- whose defect has condemned her to a bitter life without love. I'm not asking the play to make a judgement, but to trace a relationship.

The production begins with a spectacular coup - Joseph Wright of Derby's famous painting An Experiment on a Bird in the Air Pump dissolves into a tableau vivant and then startlingly comes to life. Would that the ideas in the play were animated as arrestingly.

But despite the authoritative acting of Barbara Flynn and David Horowitz - who play the central married couple in both eras, with the science/art divide between them gender-reversed - many of the exchanges between the modern pair and Louise Yates's hard-faced female entrepreneur ("It's like for me everything is total possiblity and for you everything is total remembrance") seem designed to put Coles Notes out of business.

The most piquant character is Tom Smith's Roget (of Thesaurus fame); as he might have put it, this play is "deserving, meritorious, commendable, estimable, worthy, creditable".

To 7 Nov (0171-722 9301)

Paul Taylor