As Shulgin turned toward making psychedelics, Dow remained true to its word. When the company asked, he patented his compounds. When it didn't, Shulgin published his findings in places like Nature and The Journal of Organic Chemistry. Eventually, however, Dow decided that Shulgin's work wasn't something it wanted to endorse and asked that he not use the company address in his publications. He began to work out of a lab he had set up at home, eventually leaving Dow altogether to freelance as a consultant to research labs and hospitals.

All along he made drugs: 2,5-dimethoxy-4-ethoxyamphetamine, or MEM for short, was his Rosetta stone, a "valuable and dramatic compound" that opened the door to a whole class of drugs based on changes at the "4 position" of a molecule's central carbon ring. A compound he dubbed Aleph-1 gave him "one of the most delicious blends of inflation, paranoia and selfishness that I have ever experienced." Another, Ariadne, was patented and tested under the name Dimoxamine as a drug for "restoring motivation in senile geriatric patients." Still another, DIPT, created no visual hallucinations but distorted the user's sense of pitch.

Shulgin tested for activity by taking the chemicals himself. He would start many times below the active dose of a compound's closest analog and work his way up on alternate days. When he found something of interest, Ann, whom he married in 1981, would try it. If he thought further study was warranted, he would invite over his "research group" of six to eight close friends -- among them two psychologists and a fellow chemist -- and try the drugs out on them. In case of a truly dangerous reaction, Shulgin kept an anti-convulsant on hand. He used it twice, both times on himself.

Shulgin's pace has slowed recently -- the research group hardly meets anymore. Nevertheless, Ann figures that she's had more than 2,000 psychedelic experiences. Shulgin puts his own figure above 4,000. Asked if they had suffered any effects from their remarkable drug histories, they laughed. "You mean negative effects?" Ann said. In more than a dozen hours of conversation, her memory proved sharp. But Shulgin, while a nimble conversationalist, can have trouble with names -- of people and places, never chemicals. At one point, while explaining a mnemonic device he uses to remember world geography, he paused and asked me, "Where's that place where Ann is from?" (She was born in New Zealand.) He is, though, also nearing 80. Once a Shulgin compound develops a reputation, it is almost invariably placed on the Drug Enforcement Agency's list of Schedule I drugs, those deemed to have no accepted medical use and the highest potential for abuse or addiction. It is therefore rather striking that Shulgin is not only still a free man, but also still at work. His own explanation is that, quite simply, "I'm not doing anything illegal." For more than 20 years, until a government crackdown, he had a D.E.A.-issued Schedule I research license. And many of the drugs in his lab weren't illegal because they hadn't existed until he created them.

Shulgin's knack for befriending the right people hasn't hurt. A week after I visited him, he was headed to Sonoma County for the annual "summer encampment" of the Bohemian Club, an exclusive, secretive San Francisco-based men's club that has counted every Republican president since Herbert Hoover among its members.

For a long time, though, Shulgin's most helpful relationship was with the D.E.A. itself. The head of the D.E.A.'s Western Laboratory, Bob Sager, was one of his closest friends. Sager officiated at the Shulgins' wedding and, a year later, was married on Shulgin's lawn. Through Sager, the agency came to rely on Shulgin: he would give pharmacology talks to the agents, make drug samples for the forensic teams and serve as an expert witness -- though, he is quick to point out, he appeared much more frequently for the defense. He even wrote the definitive law-enforcement desk-reference work on controlled substances. In his office, Shulgin has several plaques awarded to him by the agency for his service. (Shulgin denies that this had anything to do with his being given his Schedule I license.)

Nevertheless, in the early 80's, Shulgin began having grim fantasies of the D.E.A. throwing him in jail, ransacking his lab and destroying all of his records. At the same time, he was finding it harder to get his work published: journals were either uninterested in or leery about human psychedelic research. He decided to make as much of what he knew public as quickly as possible. He and Ann started work on a book called "PiHKAL" (short for "Phenethylamines I Have Known and Loved," after a family of compounds particularly rich in psychoactivity), self-publishing it in 1991.