Hall coefficients of evaporated films.---The Hall coefficients for films of Fe, Co, Ni, Pd, and Pt, 6 to 270\ensuremath{\mu}\ensuremath{\mu} thick, deposited on surfaces at a distance less than the mean free path from the evaporating filament, were measured. For films of the ferromagnetic metals, Fe, Co, Ni, the Hall coefficients were respectively 1.4, 4.9, and 7.8 times the values for the corresponding metals in bulk, these factors being in the order of the atomic numbers of the elements. For the paramagnetic, negative Hall effect metals, Pd and Pt, the Hall coefficients were 0.66 and 0.64 times the values for the metals in bulk. The increased Hall effect for the films of the ferromagnetic metals seems closely related to ferromagnetism, although Ni, the least ferromagnetic of the three, shows the greatest variation. Films of Ir and Rh, formed at a distance less than the mean free path from the evaporating filament, showed for Ir a positive Hall effect as in bulk, and for Rh no detectable effect.Specific resistance of evaporated films.---The ratios of the specific resistances of the evaporated films to the specific resistances of the corresponding metals in bulk were found to be 3.1 (Fe), 23.0 (Co), 25.0 (Ni), 4.4 (Pd), 14.0 (Pt), 10.8 (Ir), 12.0 (Rh).Saturation of the Hall e.m.f.---Curves show that the saturation of the Hall e.m.f. occurs for evaporated Fe at a slightly lower magnetic induction than for Fe in bulk; for Co, at about 12,500 gauss as compared with 13,500 for bulk; and for Ni, at about 2500-3000 as compared with 6000 for bulk. It is significant that the magnitudes of these variations from bulk values, like the corresponding variations in the Hall coefficient, occur in the order of these elements in the periodic table.Effects of Heating.---Heating films of the ferromagnetic metals during or after deposition decreased the Hall coefficients and specific resistances to approximately the values for the metals in bulk. It also caused a shift in the value of the magnetic induction necessary to produce saturation of the Hall e.m.f. toward that for the metals in bulk. No effect of heating was observed in the paramagnetic metals.Interpretation.---Evaporated films may differ from bulk metal in the size of the crystalline grains, in the nature of the material between them or in an asymmetry of the crystalline grains which may be an important factor in the causes of the Hall effect.