ETH´YL, the name given to the radicle C_2H_5, contained in ether, (C_2H_5)_2O, alcohol, C_2H_5OH, &c. _Ethyl_ has not been isolated, as it immediately combines with another _ethyl_ group forming diethyl or butane, C_2H_5--C_2H_5. _Ethyl chloride_, C_2H_5Cl, formed by the action of hydrochloric acid on alcohol, is much used for the production of low temperature--as a local anæsthetic. _Ethyl nitrite_, C_2H_5NO_2, constitutes _sweet spirits of nitre_ when dissolved in alcohol.
ETH´YLAMINE, C_2H_5NH_2, an organic base formed by the substitution of 1 atom of hydrogen in ammonia by ethyl group. Thus
H C_2H_5 / / N--H ammonia --> N--H ethylamine. \ \ H H
It has the odour and many of the characteristic reactions of ammonia, but unlike ammonia it is inflammable and liquid at ordinary temperature.
ETH´YLENE, or OLEFIANT GAS, C_2H_4, an unsaturated hydrocarbon, the first member of the olefine series. It is a colourless gas with a faint odour, and burns with a bright luminous flame. It is a constituent of ordinary coal-gas, and may be obtained from alcohol by heating it with twice its volume of concentrated sulphuric acid.
ÉTIENNE ([=a]-ti-[=a]n), ST., a town of Southern France, department of Loire, on the Furens, 32 miles S.W. of Lyons. It has spacious streets with substantial houses, but, owing to the number of public works, presents a dingy appearance. The principal buildings and institutions are the cathedral, an ancient Romanesque structure; the town house, court-house, exchange, communal college, mining school, gallery of arts, library, and museum. The town stands in the centre of one of the most valuable mineral fields of France; and in addition to the extensive collieries, blast-furnaces, and other ironworks in the vicinity, has manufactures of ribbons, silks, cutlery, and fire-arms. Pop. 148,656.
[Illustration: Two Seedlings of _Sinapis alba_ of Equal Age
B, Grown in ordinary daylight, normal. The roots bear root-hairs.]
ETIOLATION (Fr. _étioler_, to blanch), or BLANCHING, of plants, is a state produced by the absence of light, by which the green colour is prevented from appearing. It is effected artificially, as in the case of celery, by raising up the earth about the stalks of the plants; by tying the leaves together to keep the inner ones from the light; by covering with pots, boxes, or the like, or by setting in a dark place. The green colour of etiolated plants may be restored by exposure to light. Etiolated plants are also abnormal in other respects; the stems, or in some cases the leaves, become extraordinarily elongated, and the internal structure undergoes modification in various ways.