ETHYL. 



ETRUSCAN ARCHITECTURE. 



Pyrocitric ether (itaconic ether) 



Pjrromucic ether C 4 H.O, C 10 H 3 O. 



Pyrotartric ether 2C.H.O, C,,,H { O, 



Quinic ether C.H,O, C,.H,,O,, 



Katie ether C.H,O, C 10 U,,O, 



S.licylic ether . . ... C.H.O, ,,11505 



Sebaclc ether 2C.H.O, C,,H,,O. 



Silicic ether C.II.o, SiO, 



DUUJcic ether 2C.H.O, S1O, 



Suberic ether 2C,H 5 O, C 14 H, ,O, 



Soecinic ether 2C.H.O, C.H.O, 



Solphocarbonic ether .... 2C.1I. S, C,O. 

 Dlndpbocarbonic ether .... 2C.H.O, C,8. 



TrUolphocarbonic ether .... 2C,1I S S, 0,8. 

 Sulphocjranhrdric ether . . . . (',11 .s, 0,143 

 Sulphuric ether (true) .... C.H.O, S,O, 



Tartario ether 2C.H S O, C.II.O,, 



Toluic ether C.H.O, C,,H,O, 



Valeric ether C.H.O, C,,H,O, 



Xanthlc ether (diinljihoctrbonic ether). 



Detailed information concerning the whole of the compounds of 

 I'thyl (except those discovered since the year 1856), will be found in 

 Gerhardt's ' Traitc! de Chiinie Organique.' 



KTH YL, used in chemical nomenclature as a prefix, is employed to 

 denote the presence of ethyl in the compound to which the name is 

 applied ; thus ethyl-camphoric acid denotes camphoric acid containing 

 ethyl. All such compounds will be found mentioned or described 

 under ETHTL. 



KTHVI.AMIXK. [ORGANIC BASES.] 



KTHYKKXE. (C.H.). Okfiant yat Slayl. Ethylene is one of the 

 illuminating constituents of coal gas. It is also a common gaseous 

 product of the destructive distillation of other organic substances 

 besides coal ; resins, fate, oik, caoutchouc, Ac., all yield ethylene 

 when heated in close vessels. When however this gas is required in a 

 state of purity, it is always produced by heating together one part of 

 alcohol and six or seven parts of concentrated sulphuric acid, and 

 r..n< I noting it first through a Woulfa bottle containing milk of lime to 

 remove any sulphurous acid, and then through a bottle containing 

 strong sulphuric acid to absorb vapours of alcohol and ether. The 

 reaction by which the olefiant gas is produced, simply consists in a 

 dehydration of the alcohol by the acid, thus : 



C.H.O, 



C.H. + 2110 



Alcohol. Olcflaut gat. Water. 



but other decompositions occur simultaneously, for the mixture in 

 the generating vessel gradually darkens in colour, and a black gela- 

 tinous mass is the final product. 



Ethylene is colourless, tasteless, and irrespirable, has a peculiar 

 ixloiir, is of sp. gr. 0*9784, and may be liquified by the combined aid 

 of great pressure and intense cold. It is almost insoluble in water, 

 and but slightly soluble in strong sulphuric acid. Anhydrous sul- 

 phuric acid absorbs it in large quantity. It is inflammable, burning 

 with a highly luminous flame. Mixed with twice its volume of 

 chlorine and the mixture ignited, rapid combustion ensues, hydro- 

 chloric acid gas is evolved, and a dense cloud of carbon at the same 

 ttme produced. 



Ethylene has the property of combining directly with two equi- 

 valents of chlorine or of bromine, iodine, and sulphur, forming the 

 compounds 



Chloride of ethylene 

 Bromide ,, 



Iodide 



Sulphide ,, 



C.H.C1, 

 C.II.Br, 

 C.H.I, 



and recently Dr. Outline has described combinations of ethylene with 

 dichloride of sulphur (Cl 8,), and with protochloride of sulphur (Cl S) ; 

 the names and formula; of the compounds being 



Biralphocbloride of etbjrlene , 

 Bichlororalphide 



C.H., 8,01 

 C.H., S.C1, 



just enumerated, two equivalents of chlorine or of bromine can 

 unite and form a second series of compounds. Such a compound is 

 the chloride of perchlorethylene (C 4 C1 4 , Cl.,), or sesquichloride of 

 carbon (C.C1 ), while perchlorethylene itself is the protochloride of 

 carbon (C.C1.). [CARBON, chlorides of.] 



Ethylene combines with anhydrous sulphuric acid, forming crystals 

 of anhydrous ethionic acid (C 4 H,, 4S0 3 ). Cold water converts the 

 latter into Kydrated ethionic acid (CJH 4 , 4S0 3 , 2HO), which is by 

 ebullition transformed into isethionic acid (C 4 H 4 , 2S0 3 , 2HO). Ethionic 

 acid is bibasic, isethionic acid monobasic ; they both combine with 

 bases to form salts that are mostly crystalline. 



Dutch liquid. Ethylene was discovered by some Dutch chemists in 

 1795. It was called olefant gas, because when brought into contact with 

 chlorine over water the two combined to form a yellowish oily liquid 

 that floated on the surface of the water. This oily chlorine compound 

 has always retained the name of Dutch liquid, though its true com- 

 position (C 4 H 4 C1,, chloride of ethylene, mentioned above) is well 

 known. It was the source of that interesting series of ethylene 

 derivatives already enumerated, and has thus greatly aided the 

 advancement of the now well known chemical doctrine of substitution. 



ETRUSCAN ARCHITECTURE. We have no remains of Etruscan 

 temples or other important buildings, but we know from ancient autho- 

 rities that the Etruscans constructed sumptuous public and private 

 edifices ; and we can form some idea of their style from their hypogei 

 or sepulchral monuments, and also from some of their cinerary urns 

 which have representations of temples (Micali, plate 72). Vitruvius, 

 although he lived in an age when Etruscan art had undergone con- 

 siderable alteration, characterises their buildings as " baricephalse, 

 humiles, lattE," low, wide, with heavy top ornaments. And this seems 

 to be hi keeping with the character of the people, grave, and more fond 

 of internal comfort than of external show. What is now called the 

 Tuscan order appears to have been a sort of rude Doric, which they 

 probably adopted from the Greeks, though varying the type consider- 

 ably. Vitruvius (iv. 7) gives a description of their temples, which 

 appear to have been circular with a single cella, or rectangular with 

 three cellse ; but they could have been neither large nor splendid : the 

 ornaments, bronzes, and plastic figures seem to have been more 

 elaborate than the structures themselves. 



The monuments which serve perhaps to throw most light on the 

 subject of Etruscan architecture are the.tombs, and especially those at 

 Castel d'Asso, the Asia of Cicero (' Pro Csceina,' 7), five miles south- 

 west of Viterbo, where the face of a perpendicular cliff forming one 

 side of the valley is sculptured all along for more than a mile with 

 hundreds of fronts or facades of sepulchral monuments, the vaults 

 themselves being excavated underneath. Similar sculptures on the 

 rock are found at Norchia, about 15 miles south-west of Viterbo. (See 

 Inghirami's/<fafe.) But there are other of these tombs, which instead 

 of presenting merely a facade cut out of the rock, are entirely de- 

 tached, the rock being hewn away all round. Occasionally, where the 

 rock is friable, the tomb is built instead of being hewn out of the 

 solid rock. These monuments, which represent a primitive style of 

 Etruscan building, strike by their resemblance to the Egyptian style 

 in its ruder and simpler form. Plate 62 of Micali represents a monu- 

 ment between Monte Romano and Corneto with projecting architrave 

 and lateral pillars. Another kind of tomb consists>f a tumulus of earth, 

 the base of which is surrounded by a podium or supporting wall of 

 masonry. Tumuli of this kind remain in immense [numbers about 

 the sites of the ancient cities of Etruria. Some of these tumuli are of 

 vast size. The largest, known as the Cocumella, at Vulci, is 240 feet 

 in diameter, and 50 feet high ; but is conjectured to have been 

 originally about 120 feet high. This tumulus hag near its centre two 

 large towers, one square and the other round. In all these tombs the 

 principal chamber resembles an abode of the living ; and when opened 

 has been found to contain biers or bedsteads, vases, and vessels of 

 various forms, shields, weapons, and other articles, often of exquisite 

 workmanship : it i from these chambers that the Etruscan vases 

 found in such profusion in every museum in Europe, have been 

 obtained. The walls of the chambers in the tombs are sometimes 

 panelled, and generally painted with mythic or festive scenes; and 

 around them are seats, with arm-chairs and foot-stools hewn out of the 

 solid rock. The vaulted roofs of these tombs show that the Etruscans 

 were acquainted with the arch from a very early period. They 

 employed the arch also in their gateways, bridges and aqueducts ; and 

 in constructing the Cloaca Maxima and other Roman cloacio. 



In the time of Vitruvius the houses of the wealthy Etruscans had 



