In La Chambre claire (Camera Lucida, 1980), his luminious, melancholy study of the nature of photography, Roland Barthes parenthetically banishes from the field of his photographic fascinations the image of exploding milk drops over which Harold Edgerton laboured for 50 years: 'I am too much of a phenomenologist to like anything but appearances to my own measure.' The rigorously subjective frame of Barthes' reference, the oblique sensitivity of his work of visual mourning, renders him aesthetically allergic to this apparently most objective, most implacably 'scientific', of photographic projects. Everything in the scientific image is as if already determined; the shock of the frozen moment is actually wholly predictable, a mere visual index of the arduous technical labour that produced it. No room here for the spectator's giddy skating across the surface of the image, no hope of the spectral dialectic between identification and exclusion that grips the author elsewhere. In short, no pose, only the 'prowess' of a technique mastered, a form captured.
Yet surely Barthes has missed something here: something of the formal fascination of such photographs, as well as of their intimate connection to a long history of the enigmatic marriage of the scientific and the aesthetic. Quite apart from its immediate iconic, even kitsch, resonance (it is impossible to see an exploding milk drop without superimposing an atomic mushroom cloud), work such as Edgerton's responds to a venerable tradition of confusion between art and science, a subtle collision still darkly visible in contemporary scientific photography.
In 1658 the English author and physician Sir Thomas Browne had conjured up a universal image of divine and human creation. His extravagantly speculative essay The Garden of Cyrus imagines a geometrical figure, the quincunx, which seems to found and govern the whole created world: a motif 'which being doubled at the angle, makes up the Letter x, that is the Emphaticall decussation, or fundamentall figure'. Browne finds the points and connecting lines of the quincunx everywhere: in spiders' webs, trees, seaweed, Roman pavements and Gothic architecture. The whole visual realm, natural and artificial, is remade as so many geometrical meetings and branchings. Where Browne's account is a masterpiece of visual and rhetorical ingenuity, later proponents of universal organic form are more convinced of the scientific veracity of their speculations. From the public gardens at Palermo, Goethe writes in 1787 of the burgeoning growth about him; the flourishing spring convinces him that it must all originate somewhere, in some archetypal plant, an Urpflanze whose form is replicated throughout the natural world. Distraught at the failure of science to find this Ur-plant, Goethe can only imagine it in all its oddity, 'the strangest growth the world has ever seen'. It might, he ventures, be a kind of primordial leaf: a vision of divine symmetry, of endless branching about an original axis.
By the beginning of the 19th century, with the photography that would give it concrete expression already distantly visible, a whole complex ideology of organic form is in place, given philosophical momentum by writers such as Coleridge, for whom the imagination was nothing less than the mind's ability to harmonize with the forms of nature: to see, as Wordsworth put it, 'into the life of things'. The truth of nature and its visual form coalesce in the image of growth, of life slowly exploding from one original point or axis: 'such is the life, such the form'. At the same time Lorenz Oken, in his Elements of Physiophilosophy (1809-11), adds to the formal symmetries of Goethe and Coleridge another hypothetical form: the globule (the sphere as perfect symmetry). Organic matter, says Oken, is comprised of 'infinitely numerous mucus points', a mass of continually reproducing spheres. For all these thinkers form is the key: the scientific and aesthetic imagination of the early 19th century is a monstrous menagerie of vital shapes: branches, spirals, spheres and tendrils that would ensnare the coming photographic imagination for a century or more.
Before Sir John Herschel suggested to his friend William Henry Fox Talbot the more capacious term 'photography', the latter had referred to his early experiments in the medium as products of 'sciagraphy': writing with shadows. The word describes accurately Fox Talbot's early leaf pictures: their skeletal forms gloomily outlined, the living thing reduced to the purity of form, descendants of Goethe's fantasized original leaf. But the technique finds its most radiant expression in the work of Anna Atkins, whose British Algae: Cyanotype Impressions (1843) records a ghostly host of spindly forms clearly indebted to Romantic notions of visual form as organic truth. The cyanotype (ravishing precursor of the architect's blueprint, as well as of Yves Klein's anthropometries) seems especially suited to the notion of scientific truth emerging from aesthetic structure. In her image of Halymenia fucellata the fragile tendrils are alive with an inner light, weakened as it reaches the extremities of a flattened figure (a shining inversion of Fox Talbot's shadows) at once definitively deceased and somehow glimmeringly alive as it reaches out into the infinite blue.
Radiating dendritic symmetry is everywhere in these earliest scientific photographs: a minute forest of perfect forms. In Andreas Ritter von Ettingshausen's daguerreotype Section of Clematis (1840) the search for symmetry combines with the more recent globular hypothesis to produce an image of almost alien eeriness: a star-like concentration of 'globules' branches out along its axes to larger chambers, a web of bubbles. The whole seems to pulsate with life, reminding us that the advent of photography meant that Goethe's 'strangest growth' was now creepily manifesting itself in the first photographs of the microscopic forms of nature.
The idealization of organic form is nowhere more apparent than in 19th-century photographs of fossils and the shells of marine creatures (themselves mere formal vestiges of once living things). Here the object is suspended in elaborately symmetrical proximity to its fellows: calcified remnants photographed as if, having long left their watery graves, they have now ascended to the heavens, forming intricate constellations (as though spinning around the gravitational pull of some as yet undiscovered origin). But they also recall other - less celestial but equally spectacular - arrangements. Arrangement of Fossil Shells (1837-9) and the Bisson brothers' Molluscs and Zoophytes (1853) resemble nothing so much as the grand displays of commodities that would appear in the first department stores, or the catalogue of the Great Exhibition at Crystal Palace in 1851, where Victorian ornamentalism responds to these bizarre shapes with its own technological organicism, a fantastic universe of decorative symmetries. Science is aestheticized at the same time as new technology allows for ever more elaborately 'natural' forms. These photographs record the moment when the earlier scientist's 'cabinet of curiosities' bursts open in the overlapping spaces of commerce and the museum.
If the discovery of X-rays in 1895 seems to put an end to the photographic dramatization of the century's romance with form, to usher in an age of photographic materialism, the opposite is equally true. The age of the atom is also the era of the dematerialization of scientific knowledge: if anything, form here has its final say over the imagined materiality of the scientific object. Fox Talbot had written in 1844 that 'the picture, divested of the ideas which accompany it, and considered only in its ultimate nature, is but a succession or variety of stronger lights thrown upon one part of the paper, and of deeper shadows on another'. In the 20th century photography assists at the scientist's entry into a world of shadows.
On 11 October 1955 Erwin Muller saw for the first time the images from the field ion microscope that he would later capture in haunting monochrome. A colleague recalled waiting outside, 'imagining Muller waiting for his eyes to become dark adapted, in order to see the image [...] When Muller emerged from the room, he walked quickly across our lab to his office muttering simply, "Atoms, ja, atoms".' The image is a resonant one: the scientist in the dark chamber, waiting for a picture of the invisible to develop before him. His images may now evoke the sublime expanses of their Abstract Expressionist contemporaries (as well as a monochrome psychedelia, the grainy forms of an early Dr Who title sequence), but they capture too an undeniable melancholy: the doomed, deathly dance of the 20th century with its phantom partner, the whirling atom. It is also impossible not to see here, in the spheres, axes and blurred symmetries of Muller's photographs, or in the fizzing Klee-like whorls of a CERN bubble chamber, the ghosts of earlier forms.
In her recent book Envisioning Science: The Design and Craft of the Science Image (2002) the photographer Felice Frankel sets out clearly the terms of a contemporary scientific aesthetics. The aim of the book, 'to make good pictures of good science', is also 'a metaphor for the scientific process'. While there are startling evocations of an almost Goethean concern with form here - tentative spirals in a Petri dish that could serve as a primer in Romantic notions of formal perfection and symmetrical growth - it is the surfaces that are most intriguing. Even at their most impervious, they seem to evanesce under the photographer's gaze. If outline is everything for the 19th-century imagination, here all is texture, ceaselessly shifting beneath a variety of lighting techniques. Frankel's photographs prompt a return to photography's etymology, to a pure fascination with light: objects emerge, radiant, from the frame's dark field, only to descend into shadow again. A luminous mutability sketches the uncertainty of the scientist's object: an ambiguity painfully acknowledged by Sir John Herschel in 1843, mourning his turn away from photography towards astronomy: 'Light was my first love!'.