88. The ultra-violet absorption spectra of 2 : 2′-, 2 : 4′-, 4 : 4′-dihydroxydiphenylmethanes, 2 : 2′-dihydroxy-5 : 5′-dimethyldiphenylmethane and its 3-, 4-, and 5-ring polymers, and of 4 : 4′-dihydroxydiphenylethane