Correct spelling for the English word "Mesmerical" is [mɛsmˈɛɹɪkə͡l], [mɛsmˈɛɹɪkəl], [m_ɛ_s_m_ˈɛ_ɹ_ɪ_k_əl] (IPA phonetic alphabet).
Pert. to mesmerism.
Etymological and pronouncing dictionary of the English language. By Stormonth, James, Phelp, P. H. Published 1874.