The study is part of a last-minute effort to block the execution of Cleve Foster, who is scheduled to die by lethal injection in Texas at midnight Tuesday. Foster, an army veteran who fought in Desert Storm, was convicted for the murder of a woman he and a friend had met in a bar. Foster has said he had passed out from a drug overdose and that the other man killed the woman.

In executing Foster, Texas will use a protocol of three drugs that it has not used before, and this is where the anti-death penalty activists come in. The first drug in the protocol, pentobarbital, is intended to anesthetize the condemned man (or the animal), so that he does not suffer when the next two drugs are administered. They are pancuronium bromide, a paralytic agent, which paralyzes lung muscles and disguises any outward signs of pain before the third drug, potassium chloride, which stops the heart, is injected.

The Supreme Court has held, 7-2, that the Eighth Amendment proscription on cruel and unusual punishment does not bar lethal injection as a means of execution. In a concurring opinion, Justice John Paul Stevens noted nevertheless that most states do not allow pancuronium bromide in the euthanasia of animals.

Until now, Texas, as well as the other capital punishment states, used sodium thiobarbital as the anesthetic. But the American company that manufactured it ceased production last year, and states have had difficulty procuring it from abroad. Britain has prohibited the drug's export for execution purposes, and Germany and Austria have indicated they will not allow companies in their countries to export it. That has led capital punishment states to turn to pentobarbital.*

The major supplier of pentobarbital is the Danish company Lundbeck. A British-based human rights organization called Reprieve has launched a campaign to persuade the company not to sell the drug to states for use in executions. The company has said that it strongly opposes its drug being used for this purpose but that it has no control after selling the drug to wholesalers in America.

Clive Stafford Smith, founder and director of Reprieve, made an "extremely urgent" plea to Lundbeck last Friday asking the company to conduct an analysis of the use of pentobarbital with the other two drugs before they were used to execute Mr. Foster. The three drugs "have never been used together in clinical procedures," nor have there been any controlled trials, Mr. Stafford Smith wrote the company. (Ohio has used pentobarbital in an execution last month, however).

"The effects of the new procedure could be torturous," Mr. Stafford Smith wrote. If the Lundbeck drug does not work properly, Mr. Foster will be subject to "excruciating pain that has been likened to having one's veins set on fire," he wrote.

In response to Mr. Stafford Smith, Lundbeck said that its pentobarbital was not intended for use in executions and, therefore, it could not conduct the analysis.