That caught Dr. Bada’s attention, because the addition of steam seemed to replicate what might have existed in lagoons and tidal pools around volcanoes.

This spring, Adam P. Johnson, a graduate student at Indiana University who was visiting Dr. Bada’s laboratory on an internship, jumped on the opportunity to work on the vials, although the material did not look remarkable. “They were just brown residue at the bottom of old vials,” Mr. Johnson said.

In his 1953 paper, Dr. Miller had reported that he had detected five amino acids produced by the original apparatus. Mr. Johnson’s work, using modern techniques, revealed small amounts of nine additional amino acids in those samples. In the residues from the apparatus with the steam injector, the scientists detected 22 amino acids, including 10 that had never before been identified from the Miller-Urey experiment.

Newsletter Sign Up Continue reading the main story Please verify you're not a robot by clicking the box. Invalid email address. Please re-enter. You must select a newsletter to subscribe to. Sign Up You will receive emails containing news content , updates and promotions from The New York Times. You may opt-out at any time. You agree to receive occasional updates and special offers for The New York Times's products and services. Thank you for subscribing. An error has occurred. Please try again later. View all New York Times newsletters.

“It just opens our eyes,” Dr. Bada said. “It’s still revealing new things. What else is there that we haven’t found out from this experiment?”

The findings by Mr. Johnson, Dr. Bada and other collaborators appear in Friday’s issue of the journal Science.

Although scientists no longer think that the early atmosphere resembled the gases Dr. Miller used, the gases released by volcanic eruptions do have similar properties. The scientists hypothesize that the sparks split apart water molecules in the steam, enabling a wider range of chemical reactions to take place.

In recent years, the Miller-Urey experiment lost importance. The discovery of amino acids in meteorites suggested that the building blocks of life came from space, eliminating the need for finding chemical processes that could produce them on Earth. Some scientists have since suggested places like the ocean bottom as most likely to be where the building blocks first came together as a living organism.

But, Dr. Bada said, the amount of amino acids that could have rained from the skies is still unclear, and the tidal pools would have been a place where the amino acids could have accumulated in concentrations, enabling more complex reactions to occur.

“My take on this is you want to consider everything,” Dr. Bada said. “If you can have a homegrown synthesis, perhaps by this mechanism we’ve described here, complemented by stuff falling from space, well, you’ve got a really rich inventory of compounds to work with and set the stage for the origin of life.”