A 100-YEAR-OLD man stood before an adoring crowd in Basle yesterday and described the bliss of tripping on acid.

This was no antique hippy, but the oracle himself. Albert Hofmann, an unassuming Swiss chemist, is the discoverer of lysergic acid diethylamide (LSD), the drug that altered the consciousness of two generations, whether they took it or not.

“It gave me inner joy and peace. It opened my eyes to the miracle of creation,” Dr Hofmann said of the substance he synthesised from fungus in his Basle laboratory in 1938. “This is one of the sacred drugs that change human consciousness.”

This weekend the great and the good of the world’s “psychedelic community” have gathered to wish happy birthday to the father of the hallucinogenic chemical, which was used for therapy and recreation until it was banned worldwide in the mid-1960s after flooding the streets of America and Europe.

The LSD tribe of scientists, psychiatrists, artists, shamans and musicians has converged for a congress in this prim city on the Rhine to celebrate the achievement of Dr Hofmann, who is mentally sharp and gets around on crutches. His “divine revelation” inspired writers such as Aldous Huxley, Ken Kesey and Jack Kerouac, Andy Warhol and many other painters; it powered the 1960s summer of love and fuelled the creative juices of the first rock generation.

Without LSD, the Beatles would not have written Lucy in the Sky with Diamonds, the culture would have been less counter, Jimi Hendrix might have gone unnoticed and the Sixties would not have been candy- coloured. The late Timothy Leary, the Harvard professor who became LSD’s guru, would never have urged the world to “turn on, tune in and drop out”.

“LSD is the only pharmaceutical product that has had a political effect,” said Felix Hasler, a Zurich University scientist. “It is not just a drug. It is Heaven, Hell and visions all at the same time.”

The fans in Basle are unanimous that LSD, which was widely used in psychiatry in the 1950s, must be allowed again, at least for medical purposes. Clearly some in Basle — including Dr Hofmann — have not exactly been abstaining since the 1960s but the Swiss police took little interest in a gathering that is less a happening than an academic convention. The Swiss Government even congratulated Dr Hofmann on his century.

Dapper in suit and tie, the chemist said that raw eggs and muesli were the secret of his longevity, not magic mushrooms. “But LSD is a gift of the plants. It is like a vitamin for the mind,” he added.

Dr Hofmann was working for Sandoz pharmaceuticals, now Novartis, when he stumbled across the mind-bending powers of LSD, which he had been researching as a medicine. He was bicycling home in April 1943 when he began seeing colours and “had a wonderful feeling”, he said. He suspected LSD that he had absorbed at work. He tried a bigger dose. “It was very frightening. It was the first bad trip. But then the horror turned into a wonderful experience. I felt as if I was reborn.”

He does not agree with the transcendental devotees in Basle who dream of having LSD approved for public consumption. It should be allowed to researchers and to doctors in the same way as they have access to morphine and mood-altering drugs, he said.

He calls himself a mystic, “because all scientists must be mystics”, but he believes that the same epiphanies and higher states can be achieved through meditation, yoga, music or other pursuits. “LSD is just a tool to turn us into what we are supposed to be: human beings and not creatures focused on technology and nothing else,” he said.

There was little talk of the dangers of LSD among the enthusiasts. A star turn was performed at the opening by Rolf Verres, director of the Heidelburg University Clinic in Germany. He drew applause by saying that LSD “is a sacred drug” and there should be centres where it could be administered.

He then sat down at a grand piano and rendered a technically impeccable performance of a piece which he had composed in Dr Hofmann’s honour.