Professor Iain Stewart lived for two days in a glass box

Illusionist David Blaine attracted thousands of onlookers when he decided to swap his New York pad to live in a glass box dangling above the River Thames – and it seems that now even respected doctors are getting in on the act.

Professor Iain Stewart lived for two days in a glass cubicle with only plants for company in an outlandish experiment to prove that human life is dependent upon plants.

Royal Free consultant Dr Daniel Martin, who devised the project, drew his inspiration from the 18th Century chemist Joseph Priestly whose similar experiment with a mouse proved the existence of photosynthesis – albeit with mixed results for the rodents involved.

Dr Martin said: “Priestly did an almost identical experiment with a mouse in the bottle, although, he did kill the first mouse.

“There are not many people who would have been prepared to be locked in the box for two days. It was pretty brave of Iain. He had no privacy at all and had to try to go to sleep in a hammock.

“It is a very interesting way of getting to know someone. The box was completely sound proof so our only way of communicating with each other was through walkie-talkies while visitors were staring on.”

Most of the oxygen was sucked out of the box, which was instead packed with plants.

When they flagged, Prof. Stewart would embark on exercise, giving off carbon dioxide that would perk the flowers up. These, in turn, would produce oxygen which enabled the professor of geoscience to survive.

And members of the public could watch this miniature ecosystem unfold as the experiment took place at the Eden Project in Cornwall.

“If there weren’t any plants in there he would have become unconscious and eventually died,” explained Dr Martin.

Thankfully, the professor did not go the way of Priestly’s first mouse, and emerged fighting fit from his gruelling two day experiment.