ART / Bubble, bubble, boil and trouble: Helen Chadwick's new show is a melting pot of chocolate and Germolene and bodily fluids. Tom Lubbock is neither repulsed nor seduced

Nausea: it's a matter of taste. Some people contentedly spend their weekends with a squirming tub of maggots for company. Some people are happy to allow half-eaten take-aways to become thriving bacterial cultures at the bottom of the fridge. Some people have the most disgusting jobs and appetites. And some people, by contrast, come over queer at even the thought of changing a nappy, or a nice helping of pig's melts. What makes stomachs turn or not is so variable it can hardly ever be relied on. So an art whose effects depend on raising feelings of nausea is on uncertain ground.

Helen Chadwick's does partly depend on it. Her show of recent work at the Serpentine is called 'Effluvia', and its centre-piece is a bubbling pool of hot, thick, liquid chocolate. Circular, and 9ft across, in the middle stands a vaguely phallic stump, and from the knob at its top - though just where it's coming out is mysterious - chocolate flows and slides down it into the pool, where bubbles rise and break the surface, leaving concentric patterns of slowly subsiding stretch-marks. The piece, titled Cacao (after the bean), smells powerfully of milk chocolate. Visitors are advised not to get stuck in.

Now some people, perhaps, just thinking about such a quantity of molten brown viscosity, will already be wrinkling their noses, tightening their underlips, and going 'yuk'. And they'd be on the right lines, I'm sure. You are meant to feel the phenomenon is a bit disgusting. You're meant to feel a real excessive glut of sweet rich consumable. And you're meant to feel it's rather like shit (Cacao, after all, has caca in it). But then again, feeling that, you're meant also to feel that it's still an undeniably luscious, luxurious and even sexy fluid. And whatever order these feelings come in, they're meant to be all bubbling away in some fluid synthesis of seduction and repulsion.

That's probably the sort of response that's looked for. Indeed it does sound quite a likely one, and I can't say that you won't have it. I can only say, I don't myself - and I think I partly know why. The behaviour of mud geysers, for instance, can be disturbingly transfixing, because the mud blews and sucks and flaps as if it was something half alive. But here there is a too evident bubbling mechanism at work. The bubbles always come through at the same points on the surface, and there appears to be a programme which activates now one combination of bubble-sources, now another. The chocolate's not doing it itself.

And as for the chocolate, it doesn't seem to me to have much frisson, or to be like shit or primal ooze, or to be a particularly sensual either. As it is here, it strikes me as a pretty inert substance. All those resonances don't actually accrue to the experience in hand. I agree that another person, more sensitive to chocolate, might feel things differently. On the other hand, when the exhibition catalogue speaks of 'the molten pumping eruptions of a cacao phallus girded by the obscene venting of bubbles . . . nauseous and noisome . . .', I suspect that someone is taking the will for the deed.

Almost everywhere in this, show you sense a gap between intention and effect. That there are some active ideas behind the work needn't be doubted - for one thing because Chadwick has often articulated them herself in a vivid, learned, poetic prose. Over the last five or so years (the period covered here) her work has been devoted to a general celebration of flux, existential and physical. It proposes the dissolution of boundaries and distinctions: between spirit and flesh, insides and outsides, male and female, the self and the not-self, organic and inorganic, beauty and nausea. It revels in polymorphous delights, breakdown, symbiosis.

I think she takes this vision a bit lightly, as if it was obviously a liberation. Ideas of identity-loss and disintegration are always turned into a kind of bliss. And when, say, she writes of Viral Landscapes - five large photographic pieces, included in this show, which make some reference to Aids - that 'ideals of purity and contagion no longer apply . . . the living integrates with other in an infinite continuity of matter', I would call that looking on the bright side of sickness. But still, this is to dispute with an accompanying statement. The more immediate difficulty with Viral Landscapes is that they do need that statement, and a bit more too, to fill out the visible evidence. Even then, I can't think that these coastal views, overlayed with a pretty mess, can ever amount to what they're meant to mean.

It is a general problem. Admittedly, some of Chadwick's more piquant work from recent years hasn't, for whatever reason, found its way into this show. A photo-piece like Loop My Loop, an elegant intertwining of a lock of fairy- tale blond hair with a curling length of pig's bladder, did the seduction / repulsion, inner / outer thing plainly if simply. On the other hand, take the 12 sculptural pieces, Piss Flowers (which are here). These seem a quite wishful piece of symbolism. Chadwick and a male collaborator both pissed in some tight- packed blocks of snow, and casts were taken from where the snow was melted; these were turned out in bronze, painted white and up ended, to produced miniature landscapes of stalagmites.

But Piss Flowers? You expect at least some remarkable trouvaille: how surprisingly like the sexual parts of flowers the forms of piss-shafts come out. But the truth is, they don't look much like them; the thought wouldn't occur at all if they weren't given petal-shaped bases. The pieces have only a remote and contingent connection to piss. I take it hot water would have the same result. Sexuality? Bodily fluids? Melting? Any further response is caught short by the sheer arbitrariness of the simile.

But again the catalogue is interesting, with its talk of 'a unique, an unpredictable event in which the agency of the artist's hand is by-passed in favour of the creative power of urine, normally regarded as polluting and marginal. Here the pleasure of a taboo act is exalted through the object.' And what's interesting is the rather low standard for what counts as a taboo act. If pissing in the snow (under controlled conditions) is transgressive - well, we're all away, surely. Likewise in Chadwick's work, I never feel very clear how much of a sense of danger is seriously being invoked.

For instance: in the series of photographic roundels, Wreaths for Pleasure. These show from overhead the neatest little arrangements of flower-heads, floating on such substances as tomato- juice, Germolene, Swarfega, hair gel, soap-suds or a bed of blackberries - 'bad blooms', the artist apparently calls them. But though some of these juxtapositions of flower and stuff are a little weird, occasionally with echoes of Rude Food, it doesn't go beyond that. It's not as if sickening things are being resolved into beauty; they are immediately attractive (interestingly attractive sometimes, a bit kitschy at others). The hanging here actually stresses this, because you can only tell what the ingredients are close- up, and several are high on the wall, so you just see colour and design. But however close you look, you can't be too troubled by Germolene. And to find here emblems of organic and psychic flux is becoming precious.

Chadwick is just over 40 now. Her work has always been worth following, but things have somehow plateaued out. It's settled into a body of themes and variations (and even when it works, the seduction-repulsion riff is such common art-currency now anyway). What she was doing in, roughly, the previous five-year period had a real fecundity and variety of ideas, and a full retrospective would probably have been an impressive thing; it might have carried the later pieces in its embrace. On the other hand, most of the recent ideas were actually implicit and very effectively articulated in her big body-in-chaos installation, Of Mutability, shown at the ICA in 1986. That was a work which had some pain in it too. Now it's so chic and beady-eyed.

See below for details

(Photograph omitted)