Note on the existence and determination of a vector potential
where f is a given vector function of position and F is to be found, is a classical one, and one would hardly think that there was anything fresh to be said about the matter to-day. In connection with some recent work, however, the writer had occasion to look into the matter somewhat closely, and as a result of this it appeared that the usual treatments1 are not satisfactory if f is only defined in a restricted region. Usually, in