Spiro[isobenzofuran-1(3H),9'-[9H]xanthen]-3- one,3',6'-dihydroxy-2',4',5',7'-tetraiodo-,disodium salt,mixt. with 3',6'-dihydroxyspiro[isobenzofuran-1(3H),9'- [9H]xanthen]-3-one disodium salt
Spiro[isobenzofuran-1(3H),9'-[9H]xanthen]-3- one,3',6'-dihydroxy-2',4',5',7'-tetraiodo-,disodium salt,mixt. with 3',6'-dihydroxyspiro[isobenzofuran-1(3H),9'- [9H]xanthen]-3-one disodium salt