Octet Mass Vector

It is shown that the concept of the octet mass vector, introduced previously by Glashow, may be used to provide an unambiguous criterion for the accuracy of the various mass sum rules that have been proposed on the basis of unitary symmetry. This criterion is applied to the experimental baryon and pseudoscalar meson masses. The electromagnetic mass splittings are discussed in detail. It is shown that the observed mass splittings correspond closely to the types that are favored in a simple bootstrap model, if the $\frac{F}{D}$ interaction angle for the meson-baryon interactions is set equal to a value suggested by other considerations.