Synonyms: 1,3,3-Trimethyl-2-((methyl(p-tolyl)hydrazono)methyl)-3H-indolium sulphate (2:1);3H-Indolium, 1,3,3-trimethyl-2-((methyl(4-methylphenyl)hydrazono)methyl)-, sulfate (2:1);N,4-dimethyl-N-[(1,3,3-trimethylindol-1-ium-2-yl)methyleneamino]aniline sulfate