88 S. L. MILLER 



The optical rotation of a sample of alanine was o-ooo ± 0-003°. If this sample 

 had been either pure enantiomorph, the rotation would have been 0-12°. The 

 5delds of compoimds from the various runs are shown in Table 2. 



Absence of Purines and Pyrimidines 



The mixture of compounds from a run similar to Rvm i was evaporated to 

 dryness and the whole sample was chromatographed on a column of Dowex 50 

 (H"^) [10]. The eluent showed no 260 m/x absorption maximum where the 

 naturally occvirring purines and pyrimidines would have been eluted, and paper 

 chromatography of the evaporated fractions showed no spots with an ultraviolet 

 lamp. It is concluded that the presence of any purine was less than 0-2 x io~^ 

 moles and of any pyrimidine was less than o-i x io~^ moles. 



The Effect of Adding Ferrous Ammonium Sulphate 



Since iron is one of the more abundant elements on the Earth, and would be 

 present as both the metal and ferrous compounds, an experiment was performed 

 to compare the organic compounds synthesized by a spark discharge in the 

 system with and without added ferrous ammonium sulphate. About 16% of 

 the iron had been oxidized to ferric by the end of the run. The organic com- 

 pounds were the same as in Run i, and the quantitative values were only slightly 

 different. 



THE SILENT DI SCHARGE — RUN 3 

 An experiment was performed using a silent electrical discharge (ozonizer) 

 instead of a spark. As seen in Table 2, the yields are about one-fourth that of 

 the spark, but the products are similar. 



SPARKING A MIXTURE OF METHANE, NITROGEN, 

 WATER AND HYDROGEN — RUN 6 



The equilibrium constant for the reaction N2 + 3H2 = 2NH3 is 7 x lo^ 

 atm ~2j at 25°, which predicts that the nitrogen would remain as ammonia instead 

 of N2 until the partial pressure of hydrogen fell below io~2 atm by escape into 

 outer space. However, the disruptive effect of ultraviolet light and electric 

 discharges might result in a steady-state concentration of ammonia less than the 

 equilibrium value. To see which organic compotmd would be formed under these 

 conditions, a mixture of methane, nitrogen, hydrogen, and water was sparked. 

 The same products are formed as in Run i, but the yields are somewhat less. 



THE MECHANISM OF SYNTHESIS 

 There is the question of whether the compounds observed in this system were 

 synthesized by micro-organisms. To check this point, blank runs with the same 

 gases but no spark were made. The amino acid production was less than 10 /xg. 

 There is the possibility that the micro-organisms might sjmthesize amino acids 

 from some of the products of the discharge. To check this point the apparatus 

 was filled with water and the reduced gases, sealed, autoclaved for 18 hours at 

 130°, and sparked for one week. The yield of organic compounds was the same 



