A high-pressure chamber filled with molecular hydrogen at 1-kbar pressure was exposed to 10-MeV bremsstrahlung γ quanta produced by an electron beam of 20–21 μA intensity for 14 h. Postirradiation investigations of the structure and elemental composition of the irregularities at the surface, as well as of two largest synthesized particles among those detected after irradiation, made it possible to reveal the presence of light elements from carbon to calcium in them. Multiple lead particles of small size were found and studied. The detected synthesized particles have a complex shape and composition. On both sides of inner surfaces of the cut brass sleeve, thin-walled microtubes and other objects of complex shape are found. The observed anomalies are discussed on the basis of a model of the fusion reactions of hydrogen nuclei and heavier nuclei (“upstream” reactions) and of the fission (“downstream”) and fusion (“upstream”) reactions in nuclei of the chamber walls.