The documents made public today and the disclosure by the C.I.A. last week that it had found another cache of previously undiscovered records suggested broader experimentation on unwitting humans by the intelligence agency or its paid researchers than had been publicly known before. Mr. Marks said he had obtained or read about 1,000 C.I.A. documents, many of which were never turned over to the Senate intelligence committee for its 1975 investigation of agency activities.

C.I.A. spokesmen declined comment on Mr. Marks's charges. However, Admiral Turner told newsmen after leaving a meeting with senators that the agency was moving swiftly to review the documents it had found.

Mr. Marks distributed 20 documents that described the following incidents, among others:

¶In 1956, the C.I.A. contracted with a private physician to test “bulbocapnine,” a drug that can cause stupor or induce a catatonic state, on monkeys and “convicts incarcerated at” an unnamed state penitentiary. The agency wanted to known if the drug caused the “loss of speech in man,” “loss of sensitivity to pain—loss of memory, loss of will power.”

¶A letter from an unnamed C.I.A. official in 1949 discussed ways of killing people without leaving a trace. “I believe that there are two chemical substances which would le most useful in that they would leave no characteristic pathological findings, and the quantities needed could be easily transported to places where they were to be used,” the letter said. The letter also suggested exposure of an individual to X‐rays or to an environment in which he would freeze to death. If these methods were too difficult, two methods needing no special equipment, the letter said, would be to “smother the victim with a pillow or to strangle him with a wide piece of cloth, such as a bath towel.”

Aware of Questionable Nature

¶In 1952, two Russian agents who were “suspected of being doubled” were interrogated using “narcohypnotic” methods. Under medical cover, the documents said the two men were given sodium pentothal and a stimulant. One interrogation produced a “remarkable” regression, the papers said, during which “the subject actually relived certain past activities of his life, some dating back 15 years while, in addition, the subject totally accepted Mr. [name deleted] as an old and trusted and beloved personal friend whom the subject had known in years past in Georgia, U.S.S.R.”