For an artist, the genesis of any artwork is often a mystery, but David Hewson has a greater sense of the origins of his latest work than usual. The inspiration comes from his powerful sense of the natural world.

A year ago, Hewson read in a psychology magazine that people react in a positive way to images from nature; there's a tendency for the blood pressure to drop when they look at, for instance, butterflies. In a word, people relax. This notion stuck.

Shortly after this, First Health commissioned him to come up with an idea for a huge space between the main entrance and their Oncology Unit and he immediately remembered that magazine. In Hewson's mind, butterflies had another connection, too. They symbolised the regeneration of life; the transformation from caterpillar to chrysalis to butterfly had the aura of optimism he wanted to capture, the sense that an end of one thing, is the beginning of another.

The scale of his idea was ambitious. There are three panels filling over twenty feet, and that doesn't include a number of butterflies flying freely from out of the work itself; instead of paint, he used the entire colour spectrum of clays from the earth - unprecedented in a work of this size; all dominated by gilding in precious metals.

The overall effect is rich and layered. The natural, textured blues of the clay allow the cosmos setting to be both background and yet come to the forefront at times, enhancing the ever-changing nature of time and the universe. And across it, all the perpetual progression of the cycle of life, chaotic, magical, mysterious, but ultimately comforting.

The multi-coloured butterflies shine out from the work, creating its real focus, set off perfectly by the golds, silvers and platinums of gilding, a technique Hewson learned during a seven year apprenticeship in Italy.