These are some of the heroes of self-experimentation: John Hunter, self-educated surgeon to King George III, in 1767 sought to learn how gonorrhea was transmitted, a matter of great debate in that uninformed day. He injected himself with pus from an infected patient, showing that the disease could be transmitted from person to person.

He contracted lifetime cases of both gonorrhea and syphilis, suffered from heart spasms for the last 15 years of his life and died at 65 from what was very possibly a syphilitic blood vessel defect. On Oct. 16, 1846, in a day when surgeons commonly held suffering patients down while they feverishly operated, Dr. William Morton successfully gave ether to a patient at Boston's Massachusetts General Hospital, enabling Dr. John Warren to painlessly remove a large tumor from the patient's jaw. Morton, a dentist and medical student, had previously given ether to several of his dental patients. But first of all, he had rendered himself unconscious with the drug.

In the words of Dr. Lawrence Altman, who describes these incidents, "a new era of medicine had begun." In 1892 Max von Pettenkofer, a German public health pioneer who developed Munich's pure water system, the first in a large city, sought to study the onset of cholera by swallowing bouillon laced with cholera bacilli. He escaped with a mild case, but said: "Even if I had deceived myself and the experiment endangered my life, I would have looked Death quietly in the eye, for mine would have been no foolish or cowardly suicide. I would have died in the service of science like a soldier on the field of honor." :: In 1900 Dr. Walter Reed led a U.S. Army team to Cuba and, by human experiments, proved that mosquitoes transmitted the then deadly scourge of yellow fever. Three of the team allowed themselves to be bitten by infected mosquitoes.

Of the three, Dr. Jesse Lazear died as a result, Dr. James Carroll became gravely ill and was left with what were apparently lifelong complications, and Dr. Aristides Agramonte escaped unscathed.

Reed's name became synonymous with self-experimentation, and Walter Reed Army Hospital and a Walter Reed Society of self-experimenters were named for him. Many history books repeat the myth that he, too, was bitten. With the others, he had pledged to take part, but, "perplexingly," says Altman, he did not. Reed's colleagues may have urged him not to participate after the first grim results. In 1909 Dr. Joseph Goldberger of the U.S. Public Health Service was asked to investigate "Schamberg's disease," a mysterious itch invading Philadelphia. He did it in two days by discovering that each patient had slept on a straw mattress, then extending his bare left arm between two such mattresses for an hour. He caught the itch, then sifted the straw to find the tiny insects that caused it. In 1914 Goldberger was put in charge of a commission to seek the cause of pellagra, a serious disease spreading through the country. It was thought to be infectious, so Goldberger -- and his wife -- swallowed capsules containing secretions from patients, and also rubbed them into his nose and mouth. Nothing happened.

Noticing that pellagra was most common among the poor, he gradually and correctly theorized that the disease resulted from a deficient diet. He cured it at one orphanage by adding milk, eggs, beans, peas, oatmeal and meat to the diet. In the 1950s Dr. John Paul Stapp, Air Force colonel, set out to improve aircraft safety harnesses. To do it, he took 29 wrenching rides on a rocket sled on rails, reaching a speed of 632 miles an hour before being slammed to a 1 1/2-second stop.

He suffered retinal hemorrhages that damaged his vision, an abdominal hernia, broken bones, a concussion and a permanent difficulty with balance. But he said, "They ordered me to see to it that the project got carried out." He felt that human experiments, not just tests of dummies, were needed, and "I felt fortunate that my goal was to save lives, not to shoot. I went on orders and did it in the same way that a soldier charging a hill gets shot at." In the past nine years, the drug cyclosporine has revolutionized transplantation by its ability to combat rejection. The drug was discovered at the Sandoz Corp. in Switzerland. In animal studies there, Dr. Jean Borel showed that the drug was a powerful immunosuppressant. But when Borel and other volunteers themselves took it inside a gelatin capsule, it was not absorbed into their bloodstreams.

The persistent Borel kept swallowing different preparations until he showed that it could be well absorbed by humans when mixed with alcohol, water and a solvent.

A new transplant era could then begin.