Generally speaking, museums put on exhibitions so that people can learn about things they don't already know. The Wellcome Collection does almost the reverse: it prefers to start with something that is familiar - in this case, skin - and make it unfamiliar. Its latest exhibition does this thoughtfully and artfully and, in doing so, forces viewers to think anew about something they believed they already understood.
“Skin" is about scars, wrinkles, tattoos, diseases and moisturiser, but it's also about the skin as the frontier between the outside world and the inner body. It starts with the 16th-century notion that the skin is an obstruction that must be removed to reveal the "real" body hidden beneath and ends with the idea that the skin is to be celebrated, as landscape, as home, as clothing.
If that sounds cerebral, it is - the exhibition was curated by Javier Moscoso, a Spanish professor of history and philosophy of science - but it is also absorbing, enjoyable and, in places, gloriously gruesome. The only drawback, as is often the case at the Wellcome, is that the content is so dense, it all but demands a second visit to take it all in.
The Wellcome Collection is adept at knotting together contemporary and classical art with scientific study. You could say that it sees the science in art and the art in science, but it scarcely seems to recognise any such distinction between the two worlds in the first place. So a set of functional suture tools is displayed as lovingly as Tamsin van Essen's apothecary jars, beautiful and delicate objects that have been painted to represent supposedly repellent skin diseases such as psoriasis and acne.
Such crossovers are legion. At one end, we have Brian Dettmer's exquisite dissection of Gray's Anatomy, in which he uses anatomical tools to strip away pages of the medical reference book tenderly, as if they were skin, revealing webs of text hidden beneath like life-giving organs.
At the other end, we have some extraordinary anatomical wax models, such as the sequence of hands made in the 19th century to show the various skin problems suffered by manual labourers. So the raw and bloody hands of the painter are eroded by turpentine, while the shrivelled claw of the bricklayer is desiccated by lime. Even the housewife gets a model hand, one coarsened by grime and dirt and cheap chemicals. These are not so much diseases as life conditions.
As ever at the Wellcome, some exhibits come close to the macabre. Ghouls will be delighted that there is room for some of the most grim objects acquired by the collection's founder, Henry Wellcome - squares of tattooed human skin that once adorned 19th-century French sailors (particularly impressive is one that features a tattoo of a pig on a bicycle). And then there are items that are morally repugnant, such as the pseudo-scientific paintings from Latin America which purport to demonstrate how people with different skin pigmentation should breed if they want to whiten the skin of their offspring.
Yet there is also much that is beautiful, often despite the content, such as the arresting opening photograph by Sophie Gerrard. This is a large, black-and-white portrait of a woman's back shortly after an operation. Stitches run from bottom to neck like thick black rope or barbed wire. The skin immediately on either side is wrinkled and pinched, like cloth or tapestry. It looks like something from a Victorian freak show, but it was taken this century and, despite the horror of the wound, has a serene beauty and dignity drawn largely from the surrounding expanse of naked skin.
Most poignant of all is Desiree Dolron's timeless photograph of a seemingly dead child lying on its back, eyes closed. The child is both sexless and ageless, and the skin has a luminescent pallor that suggests it is also lifeless. Even in death, skin has something to say, reversing the cliché that beauty is only skin deep. Here, skin is deeper than mere beauty.
“Skin" is at the Wellcome Collection, London NW1, until 26 September
Peter Watts blogs at greatwenlondon.wordpress.com