609. SPONGIA.—SPONGE. Spon'gia officina'lis Linné. Class, Porifera; order, Ceratospongiae.
HABITAT.—Red Sea, Mediterranean Sea, Atlantic Ocean, and other bodies of salt water, upon the rocky bottom.
COLLECTION.—The best sponges are secured by diving and cutting away their fastenings from the rocks; those of inferior quality are usually torn away with an instrument made for the purpose. The fresh sponges are exposed to the sun and washed, for the purpose of removing the animal matter with which they are filled.
DESCRIPTION.—A soft, elastic skeleton or framework of fibrous tissue surrounding the original animal matter, which, being removed, leaves a number of large and small cavities. The color Is a light yellowish-brown.
VARIETIES.—The Turkey sponge is considered the best and belongs to the species Euspongia mollisima; Euspongia zimocca, from the coast of Greece, is harder and not so elastic. A still coarser sponge is Euspongia equina, collected along the north coast of Africa. The various sponges of the West Indies and Florida are different varieties of the three preceding species.
CONSTITUENTS.—A characteristic substance known as spongin, which yields leucin and glycocoll when treated with sulphuric acid, and when treated with KOH evolves ammonium hydrate. The ash is made up of various compounds of iodine, sodium, magnesium, calcium, etc.
USES.—Its power to absorb liquids and to expand at the same time makes sponge valuable as a surgical accessory in absorbing blood, dilating cavities, cleansing surfaces, etc., but great care should be exercised in its use, so that the same sponge may not be used more than once without being thoroughly washed in a dilute solution of carbolic acid; otherwise there is danger of contamination by infection, which is easily carried from one patient to another when the same sponge is used repeatedly. Burnt sponge is occasionally administered, on account of the iodides of sodium and potassium which it contains, in cases of goiter and scrofulous swellings.