Complete with glossary and table of salient biographical events, this is an instructive introduction to scientific method in practice, a book that troubles to explicate (not just enumerate) the concepts behind the discoveries. Dr. Urey, a Nobel laureate for his isolation of deuterium, a hydrogen isotope, has restively applied his special knowledge to physical chemistry, the wartime nuclear energy project (less than complacently), oceanographic studies, the problem of life origins, the geology of the moon. The questions he asked, the experiments he initiated, the conclusions he reached and followed through into new hypotheses for new research evolve here into a coherent pattern uncommon at this level. Nevertheless the text is uneven, inasmuch as the chemistry is more rigorous than the boyhood chronology -- though even that relates significantly: Urey was first bent on teaching Latin in country schools and grew only gradually into his lifetime pursuit as exposure and opportunity coincided with readiness. Much is unsaid, but the rudiments are firmly gripped and fastidiously conveyed.