What does Polyphenyl Ether of 3- and 4-ring oxythio look like?
CREATE TABLE "table_2_physical_properties_of_polypheny" (
  "polyphenyl_ether" text,
  "appearance" text,
  "thermal_stability_f_c" text,
  "viscosity_c_st_at_100_f_38_c" real,
  "viscosity_c_st_at_210_f_99_c" real
);
SELECT "appearance" FROM "table_2_physical_properties_of_polypheny" WHERE "polyphenyl_ether"='3- and 4-ring oxythio';