Albert Hofmann remembers very clearly the moment when, on a spring afternoon, riding his bicycle, the whole world - and his life - changed.
"Everything in my field of vision wavered and was distorted as if seen in a curved mirror" says the chemist, who celebrates his 100th birthday tomorrow. "I had the feeling that I could not move from the spot. I was cycling cycling, but the time seemed to stand still." It was 1943, and Hofmann was experiencing the world's first LSD trip.

By the time the frightened 37-year- old research chemist reached home, he was terrified. The room spun. The walls rippled. His worried neighbour resembled a malevolent witch. He felt like he was dying. After a few hours, the intensity of the experimental drug he'd dosed himself with fell and he was able to enjoy the "fantastic and impressive" effects. Next day, he felt wonderful: "A sensation of wellbeing and renewed life flowed through me. The world was as if newly created."

It all began with a peculiar accident. The doctor, employed by the Swiss chemical firm Sandoz, was pursuing respectable but unremarkable research into ergot. This poisonous fungus that grows on rye had been used for centuries as a folk remedy to bring on childbirth and ease headaches. The doctor believed that ergot could be a store- house of new medicines, and he set about synthesising new chemicals from it.
In 1938, Hofmann had synthesised the 25th chemical: lysergic acid diethylamide. It showed little effect in test animals, bar restlessness, and it was shelved.
Five years later, on a hunch - or a "peculiar presentiment", as Hofmann puts it - he brewed up a fresh batch. In the process, he was overcome by dizziness. Sent home, he "sank into a not unpleasant intoxicated-like condition, characterised by an extremely stimulated imagination".

The next day, Hoftnann concluded that the sensations could only have been caused by accidental exposure to something in his lab, perhaps the LSD. To be sure, the cautious doctor gave himself an extremely conservative amount of the chemical - 250 millionths of a gram. It was, in fact, the equivalent of a megadose of the mind- agent, still one of the most powerful known to man. Alarmed by the strength of the ensuing effects, he clambered on his bicycle and tried to make his way home. The rest is history.

Sandoz was keen to find a use for his new compound, and Hofmann thought it could have an important role to play in psychiatry. After animal tests showed it to be virtually non-toxic, it was made freely available to qualified clinical investigators. "Properties: causes hallucinations, depersonalisation, reliving of repressed memories and mild neurovegetative symptoms," read the label on the bottle.
LSD's effects did not come as much of a revelation to science. Such psyche-manifesting agents, or "psychedelics", were already well known. Mescaline had been discovered in the late 1800s and made famous in 1954 as the subject of Aldous Huxley's book The Doors of Perception. What was extraordinary about LSD was its power. It was about 10,000 times more powerful than mescaline, and a tiny amount was enough to trigger profound alterations in consciousness.

Through the late 1940s and most of the 1950s, LSD caused a revolution in psychiatry. Therapists and doctors used it to treat forms of mental illness, including neurosis, psychosis and depression. More than 40,000 people underwent psychedelic therapy. Respected figures considered it a wonder drug and gave their careers over to LSD research. Some believed it gave a glimpse into the way schizophrenics perceived the world. Others used it as a catalyst to accelerate traditional psychotherapy - and even took the drug themselves along with their patients.
By 1965, more than 2,000 papers had been published, many reporting extremely positive outcomes in treating anxiety, obsessive compulsive disorder and alcoholism. Hofmann's vision of LSD as a "medicine for the soul" seemed to becomingto fruition.

But LSD began to leak out into elite society. Artists, painters, performers and musicians began to experiment with it in looser, less formal contexts. Anais Nin, Ken Kesey, Alien Ginsberg and Huxley all explored its creative potential. Huxley believed such drugs gave normal people the gift of the spontaneous visionary experience usually reserved for mystics and saints. He would later request an injection of LSD on his deathbed.
In the United States, newspapers and magazines began to fill up with sensational reports of LSD experiments, miraculous effects, mystical rebirths and self-transformations. In 1959, the film star Gary Grant received the first of 60 LSD-assisted psychotherapy sessions, and concluded: "I have been born again."
The public grew more and more curious about this "miracle drug". Self-experimentation began to increase. In a society facing growing industrialisation and urbanisation, alienation and boredom, everyone wanted to be reborn.

Already, a counterculture had sprung up to oppose the wealth-driven homogeneity of capitalist America. LSD was rapidly adopted as the sacrament for this bohemian "hippie" movement. In the age of the moon landings and the exploration of space, here was a tool that allowed a similar, metaphorical journey, a short cut to enlightenment. By the mid-1960s, the drug was booming.

Hofmann remembers the time distinctly. "I had not expected that LSD, with its unfathomable, uncanny, profound effects, so unlike the character of a recreational drug, would ever find worldwide use as an inebriant. People had the mistaken opinion that it would be sufficient simply to take LSD in order to have such miraculous effects."
Rampant use led inevitably to "bad trips" among recreational users, and Hofmann could only watch with a mixture of astonishment and dismay. "They did not use it in the right way, and they did not have the right conditions. So they were not adequately prepared for it" he says. "It is such a delicate and deep experience, if used the right way." He was stricken by doubt and concern that misuse and fear of the drug would lead to it being taken out of the hands of responsible investigators and psychiatrists. Would LSD - the drug which, on that spring day in 1943, reconnected Hoftnann with the "deeply euphoric" visionary encounters he'd experienced in nature as a boy - become a blessing for humanity, or a curse?

A curse, the authorities concluded. In 1966, the drug was outlawed around the world. Psychiatric treatment continued but was steadily throttled by red tape and LSD's reputation as an "insanity drug" By the 1970s, research had stopped altogether. Today, it languishes in near obscurity, banished to the fringes of science and society.
Hofmann saw his discovery slip from psychiatric miracle medicine, to psychedelic sacrament of the Sixties, to outlawed, feared street drug. Today, he is saddened but sanguine. "Wrong and inappropriate use has caused LSD to become my problem child " he says. "The history of LSD to date amply demonstrates the catastrophic consequences that can ensue when its profound effect is misjudged and the substance is mistaken for a pleasure drug."
Hofmann himself continued his career as a chemist, and developed several other medicines. All the time, a steady stream of people continued to visit the "father of LSD" in Basel during the 1970s and 1980s. Many were en route to India and the Far East in search of gurus and a context for the LSD-driven mystical experiences. Many stopped off in Zurich seeking his counsel - often trying to score some of Hofmann's "secret stash".

Only now, 40 years later, is there renewed interest in the therapeutic potential of LSD and other psychedelic drugs. "The British Journal of Psychiatry last year called for a reappraisal of psychedelics "based upon scientific reasoning and not influenced by social or political pressures".
An international symposium convenes on Friday in Basel to discuss LSD research. By today's standards, much of the research from the 1950s is flawed. Clinical studies are slated to restart at Harvard this year, organised by the Multidisciplinary Association for Psychedelic Study (maps.org), this time looking at LSD as a treatment for cluster headaches.
Hofmann hopes research will continue, but he believes LSD should remain a controlled substance. "As long as people fail to truly understand psychedelics and continue to use them as pleasure drugs, and fail to appreciate the very deep psychic experience they may induce, then their medical use will be held back."

Today, he lives with his wife in a house overlooking the countryside around Basel. He is head of a large family, including eight grandchildren and six great-grandchildren.
He took the drug many times, but now, he says, he has no use for LSD. He believes it is just another means to attain extraordinary states of con- sciousness. "Breathing techniques, yoga, fasting, dance, art" are, he thinks, equally good.
He takes pleasure in recalling his boyhood experiences in nature that he links with psychedelics. "LSD brings about a reduction of intellectual powers in favour of an emotional experiencing of the world. It can help to refill our consciousness with this feeling of wholeness and being one with nature."

David McCandless. The Independent. 10.1.06

Background: Through the Looking-glass Blotter Acid.