A large range of N, O, C, and H compositions are being investigated for interesting and plausible combinations of factors. In these calculations an IBM 7090 computer is being used to obtain data on a very large number of combinations of chemicals. Other chemical species will be added as the research continues. Some results of this study give an insight into the variety of biologically significant chemicals which might have existed during Earth’s primitive prebiological condition or may now exist on the surfaces and in the atmospheres of other planets (refs. [ref.151]-[ref.153]). The general method described by White et al. ([ref.152]), minimizing the free energy of the system, was used. The solution was approached by an iterative process, starting with an initial guess of concentrations of the compounds. At each step, _M_+1 linear equations are solved where _M_ is the number of elements in the system. In addition to listing of the concentrations of all compounds included in each problem, the results of three-element problems have been expressed on a triangular composition diagram for convenience. A coarse grid of 60 points is used to survey all elemental compositions, with finer grids being used in regions of particular interest. The calculated concentrations of the compounds at each composition are stored, and finally a series of triangular diagrams is printed out, each showing the concentrations of as many as four compounds at the grid points. Figure 2 shows the results obtained in the C, H, and O systems. Organic compounds in concentrations greater than 10⁻²⁰ mole fraction are found everywhere except where free O₂, is present. Solid carbon theoretically becomes stable along the lower dashed line at 500° K. However, reactions producing it are very slow. The supersaturated region beyond the line of potential carbon formation was also investigated. A threshold was found where polynuclear aromatic compounds are sufficiently concentrated to form a liquid phase. These conditions may have been involved in the primordial formation of asphaltic petroleum. [Illustration: Figure 2.—_Equilibrium diagram for the system C-H-O._] Jukes and associates ([ref.154]) at the University of California at Berkeley have been investigating the code for amino acids in protein synthesis, the key for translating the sequence of bases in DNA into the sequence of amino acids in proteins. The amino acid code was solely a matter of theory until Nirenberg and Matthaei ([ref.155]) at the National Institutes of Health carried out a crucial experiment. This experiment bridged the last remaining gap separating theoretical genetics and test-tube biochemistry. It now became experimentally possible to search for codes for all 20 amino acids concerned in the synthesis of proteins.