MILLER-UREY'S EXPERIMENTAL PROCEDURES -

• They recreated the probable conditions on the primitive earth in the laboratory.
• An atmosphere containing hydrogen, ammonia, methane in ratio of 2 : 1 : 2 and water vapour was created in one chamber of a spark discharge apparatus and condensed liquids were allowed to accumulate in the other chamber.
• Energy was supplied by heating the liquid containing chamber as well as by electric sparks from electrodes in the gaseous chamber. Experiment was performed at 800°C for 7 days.

• They observed that amino acids like glycine, alanine aspartic acid and some more complex organic compounds were formed in vitro when the mixture of water vapours, methane, ammonia and hydrogen gasses in a close chamber is subjected to electric discharge for a few days.
• This experiment confirmed the possibility of a biogenic synthesis of various containing complex organic compounds from the amino acids reducing mixture of simple gases.
• Calvin Melvin (1958) irradiated CO and H₂O directly in a cyclotron and obtained formic acid, succinic acid and oxalic acid.