“…Polarographic studies of heterocyclic compounds containing more than one nitrogen atom continue actively. Data are reported for ergothioneine (781), diantipyrylmethane (775), nitrosoantipyrine ( 625), 1-phenyl-3-pyrazolidinone (338), 1-hydroxethy 1-2-methyl-5-nitroimidazole, 1,2-dimethyl-5-nitro-1 midazole (419), 2-mercaptoimidazole (110), di-(imidazol-2-yl) disulfide (111), 5benzalhydantoins (882), murexide (798), benzoyl derivatives of barbituric acids (1046), alloxan (319), chlordiazepoxide (707), purines, pyrimidines , adenine (738), cytosine (729), 2methyl-3-(o-tolyl) -quinazolone (665), pterins (479), pteridines (481), dibenzo [c,f [1,2]diazepin-l 1-one (387), 1-benzyl-2 (1 H)-cycloheptimidazolone (652), and phenazine (297).…”