Comment on "Magnetic Field Independence of the Spin Gap in YBa_2Cu_3O_{7-d}" by K. Gorny et al., Phys. Rev. Lett. 82, 177 (1999)

In a recent Letter of Gorny et al. it was reported that the spin-lattice relaxation rate in YBCO_{7-d} is magnetic field independent. These authors point out that their results are inconsistent with prior reports of Borsa et al., Carretta et al., and Mitrovic et al., which concluded that there is a small but significant magnetic field dependence. In this comment we propose an explanation for this discrepancy.