ETHYL. 



ETHYL. 



98 



persture of about 880 Fahr. The following equation represents the 

 decomposition that takes place : 



C.H.,1 + Zn, + HO = Znl + ZnO + C.H..H 



Iodide of 

 ethyl. 



Zinc. 



Water. Iodide of Oxide of 

 zinc. zinc. 



Hydride of 

 ethyl. 



It may also be obtained by decomposing moist cyanide of ethyl with 

 potassium, as noticed under CYANETHINE. 



Hydride of ethyl is a permanent gas, insoluble in water, and may 

 therefore be collected by opening the vessel in which it has been made 

 under a bell jar in the pneumatic trough. It is colourless, odourless, 

 and tasteless. Sp. gr. 1-075. Alcohol absorbs rather more than its 

 own volume of this gas. Chlorine acts upon it, replacing the hydrogen 

 in it, to a greater or less extent according as the mixture of the gases 

 is exposed to the direct rays of the sun or merely to diffused daylight. 



Oxide of ethyl ; Ether ; jEther ; Ethylic ether ; Vinic ether; Sulphuric 



/jc.H.cn \ 



UC.H.OJ7 



ether 



This compound was first called ether.in 1730 by Frobenius. [FROBEN, 

 in Bioo. Drv.] It was known, however, long prior to that date. Conrad 

 Gesner, in a work published in 1552, transcribed the process of making 

 it from the dispensatory of Valerius Cordus, and gives to it the name 

 Olotin Vitrioli dulce. It is also said to have been known to Raymond 

 Lully, who lived hi the 13th century. During the last fifty years it 

 has been made the subject of research by several eminent chemist*, 

 and the theory put forward by Berzelius that it was the oxide of a 

 (then) hypothetical radical ethyl, has since been established by Liebig, 

 Williamson, and others. 



The best method of preparing ether is that known as Boullay's 

 Continuous Process. It consists of an arrangement by which a small 

 stream of alcohol (sp. gr. 0'880) supplied from a reservoir is made to 

 flow into a vessel containing equal volumes of alcohol and sulphuric 

 acid, the latter mixture being maintained at a temperature between 

 284 and 290 Fahr. The alcohol is then rapidly decomposed into 

 ether and water, which distil off hi vapour, and must be condensed 

 in a well-cooled refrigerating apparatus. This process may bo con- 

 tinued without interruption by means of some such arrangement of 

 apparatus as that figured under CONDENSER (the alcohol supply-tube 

 passing through the cork of the flask there represented), until full 

 thirty tunes the weight of the quantity of alcohol first mixed with the 

 sulphuric acid has been etherified. 



The ether thus obtained may be purified by agitating with an equal 

 bulk of water containing ^th its weight of carbonate of potash in solu- 

 tion. The jvater dissolves out any alcohol that may have distilled over 

 unchanged, and the carbonate of potash neutralises sulphurous acid 

 which is occasionally formed in small quantity from decomposition of a 

 little of the sulphuric acid. The ether, however, still contains in solu- 

 tion some of the water with which it has been agitated : this may, if 

 necessary, be removed by digesting some pieces of chloride of calcium, 

 or quicklime, in it for a day or two, and then rectifying by the heat of 

 a water-bath, and condensing by an ice-cooled refrigeratory. For some 

 economical methods of condensing and purifying ether on the large 

 scale, see article ' Ether ' in Muspratt's ' Chemistry as applied to Arts 

 and Manufactures.' 



The decomposition that occurs during the process above described is 

 usually explained in the following manner: Sulphethylic or sulpho- 

 vinic acid and water, are first formed from one equivalent of alcohol 

 and two equivalents of sulphuric acid, thus : 



H}O,.S,O. 



I / 



Double equir. of 

 sulphuric acid. 



The sulphovinic acid is then decomposed on coming into contact with 

 another equivalent of alcohol, its ethyl being replaced by the equiva- 

 lent of hydrogen turned out from the second equivalent of alcohol, and 

 sulphuric acid and ether formed : 



Ether. 



Alcohol. 



Sulphovinic acid. 



Water. 



Sulphovinic acid. 



Alcohol. 



Sulphuric acid. 



The sulphuric acid thus set at liberty is free to commence the same 

 round of re-actions over again. 



Other substances besides sulphuric acid are capable of etherifying 

 alcohol, but they are of no practical importance. 



Pure ether is a colourless, limpid, mobile liquid. It is a powerful 

 refractor of light, has a peculiarly penetrating odour, and a taste at 

 first hot but afterwards cooling. It is neutral to test-paper; has a 

 gp. gr. of 0724 at 55 Fahr. ; boiling point, 94'8 Fahr. ; and on being 

 cooled to 24 Fahr. crystallises in brilliant white plates. Ether 

 is exceedingly inflammable ; and as its vapour is heavy (2-565), 

 great caution is necessary that the operation of pouring it from one 

 vessel to another be not performed in the vicinity of a naked flame. 

 Moreover, the vapour forms, with certain proportions of atmospheric 

 air, a mixture that burns with explosive rapidity. Ether is miscible 



with alcohol in all portions. When agitated with water, each liquid 

 dissolves its companion to the extent of one-eighth of its own bulk. 



Ether is acted upon by most of the energetic chemical reagents, as 

 will be abundantly seen on looking over the processes for the produc- 

 tion of many of the ethyl compounds that follow. It is of consider- 

 able value as a medicinal agent producing stimulating and intoxicating 

 effects when taken into the stomach. It was much used as an anaes- 

 thetic a few years ago, but for that [purpose is now quite superseded 

 by chloroform. [ANESTHETICS.] 



Ether, like potash, soda, &c., unites with the oxyacids, forming 

 many interesting and useful compounds. The method of preparing 

 the principal of these will be found described under the respective 

 acids. Many of them may be formed by acting upon the potash or 

 soda-salt of the acid, with a mixture of alcohol and sulphuric acid, 

 that is, with sulphovinic acid. The formulas of some of these ETHEREAL 

 SALTS, and their general relation to other ethyl compounds, will be 

 shown at the latter part of this article. 



Acetic ether has an agreeable odour somewhat like that of apples. 

 It occurs in several wines. Anyelic ether smells like rotten apples. 

 Hutyric ether is used as essence of pine-apples ; caproic and caiJi-yltc 

 ethers having a similar odour. Formic ether in taste and smell is like 

 peach kernels. Nitrous ether, dissolved hi alcohol, is the sweet spirit nf 

 nitre of pharmacy ; the spiritus etherit nitrosi of the London pharmaco- 

 poeia. CEitanthic ether causes the peculiar vinous odour of most wines. 



Hydrated oxide of ethyl (C t H 0, = C.H,0, HO), or Alcohol, has 

 already been fully treated of. [ALCOHOL.] 



Chlorine derivatives of oxide of ethyl. Chlorine acts upon ether, 

 giving rise to substitution compounds in which the hydrogen is more 

 or less replaced. The following formula! will conveniently show their 

 relation to ether : 



Oxide of chlorethyl . . . . C 4 1 ** J 



Oxide of bichlorethyl . . c * 1 el* } 

 Oxide of perchlorethyl .... C 4 C1 S , O 

 Oxide of perchlorbromethyl . c { Br* } 



Sulphides of ethyl. There are three of these, namely : 



1. Mercaptan (eulphydrate of ethyl, or ethylsul-f C 4 H S S ^ 



phydric acid) \ B. 8 f 



2. Sulphide of ethyl c'u's I 



3. Bisulphide of ethyl C'H'S* } 



1. Mercaptan may be produced in several ways. The following is the 

 most expeditious. Sulphovinate of potash is added to excess of 

 caustic potash that has previously been saturated with sulphuretted 

 hydrogen, and the whole submitted to distillation. An exceedingly 

 well cooled condenser must be used in the operation. 



KO, C 4 H 5 0, S 2 8 + KS, HS 



C 4 H 6 S, HS 

 Mercaptan. 



2(KO, 8O 3 ) 



Sulphate of 

 potash. 



Sulphovinate of Sulphydrate 



potash. of potassium. 



Mercaptan is a colourless, transparent, mobile liquid of an excessively 

 disgusting smell. Its sp. gr. at 70 Fahr. is 0'835. Vapour-density 

 2'11. Boiling point 142-145. Burns readily in air with a blue 

 flame ; is slightly soluble in water, readily so in alcohol or ether. Its 

 volatility is such that when a glass rod moistened with it is passed 

 quickly through the air, a temperature (-8 Fahr.) is produced suffi- 

 ciently low to solidify what may be remaining on the rod. 



Mercaptan forms compounds with the metals called mercaptlili-x nr 

 ethylsulphides. They are monobasic. The potash and soda salts may 

 be obtained by simply dropping potassium or sodium into mercaptan, 

 an equivalent of metal replacing one equivalent of hydrogen from one 

 of mercaptan. An alcoholic solution of mercaptan acts with great 

 energy upon oxide of mercury (hence the name mercaptan, from 

 mtrcurium captans), and forms white, crystalline, odourless, meraij>ti<le 

 of mercury (HgS, C,H 5 S). The gold, silver, and copper salts are 

 white ; those of platinum and lead are yellow. Mercaptan may be 

 regarded as alcohol in which the oxygen is replaced by sulphur. 



2. Sulphide of ethyl, or sulphydric ether, is readily prepared on 

 passing a current of chloride of ethyl into an alcoholic solution of 

 protosulphide of potassium to saturation, and then distilling the 

 mixture. It is a colourless liquid, odour almost as unpleasant as mer- 

 captan ; sp. gr. 0'825, vapour-density S'l, boiling point 163'4. It 

 forms combinations with some of the metallic chlorides. 



3. Bisulphide of ethyl. Obtained on distilling three parts of sul- 

 phovinate of potash with two or pentasulphide of potassium. It is 

 colourless, has a disagreeable odour, is slightly soluble in water, and 

 very soluble in alcohol or ether. Its sp. gr. is nearly that of water, 

 boiling point 304, vapour-density 4'27. 



Selenides of ethyl are two in number : 



1. Ethylselcnhydric acid . . 



J. Selenide of ethyl 



