herapathite

from The Century Dictionary.

• noun A little-used name for a crystalline iodoquinine sulphate used in medicine.

from the GNU version of the Collaborative International Dictionary of English.

• noun (Chem.) The sulphate of iodoquinine, a substance crystallizing in thin plates remarkable for their effects in polarizing light.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun Iodoquinine sulfate, a chemical compound whose crystals are dichroic and thus can be used for polarizing light.