ichthyosulphonic

from The Century Dictionary.

• Noting an acid, a dark resinous compound, C₂₈H₃₆S₃O₆H₂, prepared by treating crude ichthyol-oil with an excess of sulphuric acid and then shaking repeatedly with a saturated solution of common salt, whereby sulphurous and sulphuric acids are removed. Also ichthyol-sulphonic acid.