In the first paper a symmetric second-rank spinor was shown to be expressible by one potential spinor with one dotted and one undotted index. This result allowed us, when considering a general field defined by a second-rank symmetric spinor and by his complex conjugate, to derive all field equations from a variational principle, by varying the potential spinor and his complex conjugate. In this second paper former results are applied: by choosing the Lagrangian density in a suitable way, Maxwell's equations in spinor form and Dirac equations for particles of spin one are derived.