We generalise the baryon vertex configuration of AdS/CFT by adding magnetic
field on its worldvolume, dissolving D-string charge. A careful analysis of the
configuration shows that there is an upper bound on the number of dissolved
strings. We provide a microscopical description of this configuration in terms
of a dielectric effect for the dissolved strings.Comment: 6 pages, 2 figures. Contribution to the proceedings of the RTN
workshop in Napoli, Octobre 200