Several works show a tiger placed against a dragon. The tiger is yin (earth, valleys, wind), the dragon yang (heaven, mountains and water), and the two together symbolise the universe held in harmony, manifested through the science of fung shui, or wind-water.

So for example there is a statue of the Taoist god of medicine, with a dragon whispering in his ear and a tiger at his feet. The medicine deity helps those whose bodies are out of balance: he uses the power of these creatures to strengthen those elements that are weak, and weaken those elements that are too strong.

Tigers are elusive, and some of the treasures proved to have similar challenges. The hardest piece for the team to source was something to represent Tipu Sultan, the eccentric 18th-century Muslim ruler of Mysore, India, who chose a tiger as his symbol. Images of the animal were everywhere in his palace and he was most famous for a mechanical wooden tiger built for him by French engineers.

'I found a life-size replica of it in a crate at the National Gallery in Edinburgh, but they are doing renovations right now and when we came to ask for it, it was somewhere under 10 other crates,' Hazell says.

Then she found the National Trust in Wales had a ruby-encrusted tiger finial from Tipu's palace, but they said it was their greatest treasure and could not be loaned.

'Then at the absolute last minute we heard from Bonhams [auction house] that an identical finial was available: so in the end, we had one, after all,' Hazell says.

One of the moments of revelation for the curator was learning to decode those formal photographs of religious figures sitting on tiger skins. 'I had just thought they indicated that somebody was important, or rich. But what I learned was that it was a symbol of suppressing one's ego. To be shown on a tiger pelt indicated that you had tamed your baser instincts, and the wild impulses of the mind,' she says.

One of the key treasures on show is a scroll of a tiger running through a snowstorm, through a forest of bamboos that you can hardly see, so white is the world. It was painted by the Japanese master, Hokusai, just before he died, and is entitled Old Man Mad About Painting, Ninety Years of Age.

At one level it fascinates scholars: how could such an old man, who could scarcely hold a brush, have created such a fine depiction of tiger fur? But the real power of the painting is found somewhere quite different - in the energy, and its poignant depiction of an old, proud animal careering fearlessly into an unknown world.

It also symbolises the fate of the animals themselves. A century ago there were more than 100,000 tigers - including some on Hong Kong Island. Today there are fewer than 3,500. One reason is deforestation, another is poaching of animals that tigers like to eat, including deer.

Another is hunting - and the show starts with a photograph from the 1890s showing three young British soldiers with beards, guns and bearers, sitting amid a theatrical display of tiger pelts, with two tiny, trusting cubs on their laps, destined for circuses.

But the key reason today is traditional Chinese medicine, which used to recommend tiger parts - penises, claws, bones - for those in need of virility.

In 2002 the China Taoist Association announced that not only would those ingredients not function any more, but they would actually be dangerous to those who took them. They argue that it is a form of medicine that works by righting the balance of the body, and any action that so destabilises the world that it destroys its precious species cannot put anything else in balance.

Its practitioners hope the message reaches people before the only time anyone can see tigers is on an old piece of film footage.

Or in an art gallery.