To evaluate the safety and immunogenicity of SF-2 rgp120 vaccine in MF59 versus MN rgp120 vaccine in alum in volunteers who are seronegative for HIV-1. AS PER AMENDMENT 07/02/97: To determine the ability of immunization with MN rgp120/HIV-1 in combination with alum or SF-2 rgp120 in combination with MF59 to induce an HIV-1 envelope-specific delayed-type hypersensitivity (DTH) response in volunteers who receive rsgp120/MN skin testing.