The repertoire of the computer program Heuristic dendral has been extended to the solution of unknown saturated amines from their mass, and, when available, nmr spectra. From a library of 93 saturated amine mass spectra, 37 of which were supplemented by nmr data, the correct solution always appeared in the answer. The utilization of mass spectra alone resulted (Table I) in a drastic curtailment of the total search space, while if nmr data were available the final output consisted usually of one entry, the correct solution. As is apparent from Table I, the first part of the program, the preliminary inference maker, is capable of solving problems where the total search space far exceeds one million isomers.