ETEOCLES ETEOCLES (e-te'6-klez), and POLY- NICES (pol-i-ni'sez), two heroes of ancient Greek legend, sons of OEdipus, King of Thebes. After their father's banishment from Thebes, Eteocles usurped the throne to the exclusion of his brother, an act which led to an ex- pedition of Polynices and others against Thebes. The two brothers fell by each other's hand. See Antigone. ETHELBERT, King of Kent; born about 560. He succeeded his father, Hermenric, and reduced all the Anglo- Saxon states, except Northumberland, to the condition of his dependents. Ethel- bert married Bertha, the daughter of Caribert, King of Paris, and a Christian princess, an event which led indirectly to the introduction of Christianity into England by St. Augustine. Ethelbert was the first Anglo-Saxon king to draw up a code of laws. He died 616. ETHELBERT, King of England, son of Ethelwulf, succeeded to the govern- ment of the E. side of the kingdom in 857, and in 860, on the death of his brother, Ethelbald, became sole king. His reign was much disturbed by the inroads of the Danes. He died in 866. ETHELBED I., King of England, son of Ethelwnlf, succeeded his brother Ethelbert in 866. The Danes became so formidable in his reign as to threaten the conquest of the whole kingdom. Ethelred died in consequence of a wound received in an action with the Danes in 871, and was succeeded by his brother Alfred. ETHELRED II., King of England, son of Edgar; born 968; succeeded his brother, Edward the Martyr, in 978, and, for his want of vigor and capacity, was surnamed the Unready. In his reign be- gan the practice of buying off the Danes by presents of money. After repeated payments of tribute he effected, in 1002, a massacre of the Danes; but this led to Sweyn gathering a large force together and carrying fire and sword through the country. They were again bribed to de- part; but, upon a new invasion, Sweyn obliged the nobles to swear allegiance to him as King of England; while Ethelred, in 1013, fled to Normandy. On the death of Sweyn he was invited to resume the government, and died in London in the midst of his struggle with Canute (1016). ETHELWULFE, King of Etigland, succeeded his father, Egbert, about 837. His reign was in great measure occupied in repelling Danish incursions; but he is best remembered for his donation to the clergy, which is often quoted as the 51 ETHICAL CULTURE SOCIETY origin of the system of tithes. He died 857. ETHENDUN, BATTLE OF, the vic- tory which Alfred the Great gained over the Danes (878), and which led to the treaty with Guthrum, the Danish King of East England. The locality is doubt- ful. ETHER, or ^THER, a medium filling all space. The ether seems to be of the nature of an elastic solid, and, in order to account for the immense rapid- ity of its vibrations when radiation passes through it, its rigidity must be exces- sively large compared with its density. It may be asked, how, if this be so, the earth can move through the ether at the rate of nearly a million miles per day. But, if we consider that shoemaker's wax is so brittle a solid that it splinters under the blow of a hammer and that it yet flows slowly like a liquid into the crevices of a vessel in which it is placed, and that bullets sink slowly down through it, and corks float slowly up through it, the motion of the earth through the ether does not seem so in- comprehensible. From magneto-optic phenomena it seems certain that some- thing of the nature of molecular rotation is going on in the ether. ETHERS, compounds conti^ining two alkyl groups, which may be identical or different, united to an oxygen atom. For instance, methyl ether has the formula CHs.O.CHi, and consists of the two iden- tical methyl groups, CHj, united to the oxygen atom. Methyl ethyl ether has the formula CH3.O.C2H5, the alkyl groups in this case being different. Methyl ether is a gas, but all other ethers are mobile, volatile, inflammable liquids. The best known is ethyl ether, C2H0.O.C2H5, some- times known as sulphuric ether, and this is the ether used in surgery as an anaes- thetic. It is prepared from alcohol, by heating with sulphuric acid, ethyl hy- drogen sulphate being first produced, this compound reacting with more alcohol to yield ether and sulphuric acid. Sul- phuric ether is a colorless liquid, boiling at 35" C, and having a specific gravity of 0.720. It is highly inflammable, and its vapor forms an explosive mixture with air. Its odor to some is pleasant, but to those on whom it has been used as an anagsthetic it is apt, afterward, to produce nausea. Large quantities of it are used in the manufacture of smokeless powder and as a solvent for fats, resins, alkaloids, etc, ETHICAL CULTURE SOCIETY, an organization founded in New York in 1876 by Dr. Felix Adler for the purpose of associating together those who be-
