Investigating the initial curve of various ferromagnetic materials a novel effect was found: when a specimen is demagnetized by an ac field with decreasing amplitude using a small number of cycles, the initial magnetization curve exhibits a distinct peaky structure. This structure can be explained by the Preisach model [see Mayergoyz,MathematicalModelsofHysteresis(Springer, New York, 1991), e.g., p. 1] thus providing new means of testing and applying this model using a noncyclic measurement.