Note on the homogeneity of physical equations

The manuscript of the preceding article was kindly sent to me by the author so that I could state my position in regard to it. Mrs. Ehrenfest-Afanassjewa (1) has presented in this paper a very satisfactory and general treatment of the conditions which must be fulfilled if a set of physical equations are to be homogeneous with respect to a given transformation, that is, if they are to remain unchanged when each of the quantities of a particular kind Yi occurring in the equations is multiplied by a factor Ei.