“I no longer want to continue life, I'm happy to have the chance to end it."

They were the words of Australian scientist David Goodall, 104, who ended his life on Thursday (May 10) at a euthanasia clinic.

The practice is still illegal in Australia, so Goodall was forced to travel to Switzerland to take advantage of its liberal assisted-dying laws.

The centenarian, who does not have a terminal illness, spoke lucidly about his desire to choose the timing of his death.

"One should be free to choose the death, when death is at an appropriate time," said Goodall, wearing a pullover emblazoned with the words "Aging Disgracefully".

"My abilities have been in decline over the past year or two, my eyesight over the past six years.”

Assisted suicide has been legal in Switzerland since the 1940s, if performed by someone with no direct interest in the death. The Netherlands legalised euthanasia in 2002 for patients considered to be suffering unbearable pain with no cure.

In many countries, however, physician-assisted suicide or euthanasia are illegal.

Goodall hoped the publicity created by his case will push countries like Australia to change their euthanasia laws.

Speaking at a news conference on Wednesday, he said he’d been contemplating suicide for about two decades.

He cited a lack of mobility, doctor's restrictions and an Australian law prohibiting him from taking his own life among his complaints.

The best-known group to help foreigners end their days in Switzerland is Dignitas, but others include Life Circle in Basel - Goodall's choice.

He told reporters that his death would come by lethal injection, and some family members would be present.

Goodall had not given much thought to a last meal, as he said his culinary choices had grown more limited. He had not considered music to accompany his death, but thought Beethoven's 9th Symphony might be nice, he said, before singing a few lines.

Born in London in 1914, he moved to Australia in 1948 where he was a lecturer at the University of Melbourne. An expert in arid shrublands, he also worked in Britain and held academic posts at US universities.