Alexander Shulgin, Sasha to his friends, lives with his wife, Ann, 30 minutes inland from the San Francisco Bay on a hillside dotted with valley oak, Monterey pine and hallucinogenic cactus. At 79, he stoops a little, but he is still well over six feet tall, with a mane of white hair, a matching beard and a wardrobe that runs toward sandals, slacks and short-sleeved shirts with vaguely ethnic patterns. He lives modestly, drawing income from a small stock portfolio supplemented by his Social Security and the rent that two phone companies pay him to put cell towers on his...