Measurements of fragment-production cross sections have been made with 0 projectiles of 1.7 GeV/nucleon incident upon targets of Be, C, Al, Ti, Cu, Sn, W, Pb, and U at the LBL Bevalac. We have found that the enhancement with high-Z targets of cross sections for certain fragments agrees both in magnitude and ZT dependence with the predictions of the electromagnetic-dissociation process, which are based upon the known photonuclear cross sections and classical rel?tivistic virtual-photon theory. We have found as well that factorization of the cross sections for nuclear processes is valid to an accuracy of better than 4~. *This work was supported by the Director, Office of Energy Research, Division of Nuclear Physics of the Office of High Energy and Nuclear Physics of the u.s. Department of Energy under Contract W-7405-ENG-48. This manuscript was printed from originals provided by the author.