68 



CHEMISTRY. 



Composi- 

 tion. 



Ether*. 



always under proof, and sometimes indeed very 

 weak. 



Neither common air nor oxygen gas act upon al- 

 cohol at the common temperature, but in high tern- 

 perature* the case is differx-nt. When alcohol is 

 kindled in the open air, it burns all away without 

 leaving any residuum. The flame is blue, and if the 

 vapour* emitted he collected, they are found to con- 

 sist of carbonic acid and water, and the portion of 

 water formed is greater than the whole of the alco- 

 hol consumed. When the vapour of alcohol is mix- 

 ed with oxygen gas, it may be kindled by an electric 

 spark provided the temperature be above 70", a de- 

 tonation takes place, the alcohol is consumed, and 

 water and carbonic acid formed. When alcohol is 

 passed, in the state of vapour, through a red-hot 

 porcelain or metallic tube, it is decomposed, and a 

 variety of new products evolved. These are, 1 . A 

 great quantity of inflammable air, which, according 

 to Saussure junior, consists of oxygen, hydrogen, car- 

 bon, and azote ; 2. A little charcoal ; 3. A little oil, 

 partly in crystals, partly fluid ; 4. A portion of wa- 

 ter, holding in solution traces of acetic acid and am- 

 monia ; 5. A little of an acid which resembles the 

 benzoic. By estimating the proportions of ingredi- 

 ents formed in these decompositions, chemists have 

 endeavoured to ascertain the constituents of alcohol. 

 The following is the result obtained by Saussure ju- 

 nior, who has lately published an elaborate set of ex- 

 periments on the constituents of alcohol. It is com- 

 posed of 



Oxygen, - - - 87.85 

 Carbon, - - - 43.65 

 Hydrogen, ... 14.94 

 Azote, .... 3.52 

 Ashes, .... 0.0* 



100.00 



Alcohol has liltle action on the himple combusti- 

 bles. On hydrogen and charcoal it seems to pro- 

 duce no effect. But it dissolves a little phosphorus 

 and sulphur. If phosphurcted alcohol be dropt 

 into water, a lambent flame is observed playing on 

 the surface of the liquid, and the phosphorus is dis- 

 engaged. 



Alcohol dissolves the fixed alkalies. It is by 

 means of it, indeed, that these bodies are obtained 

 in a state of purity. The earths are scarcely acted 

 on by alcohol. It absorbs a quantity of nitrous gas, 

 which cannot afterwards be expelled by heat. 



The strong acids decompose alcohol. The rest 

 combine with it, and form a set of compounds hither- 

 to but little examined. It dissolves also a consider- 

 able number of salts, especially the acetates, muriates 

 and nitrates. The sulphates are all insoluble in it. 

 The colour of the flame of alcohol is tinged by va- 

 rious bodies. Thus nitrate of etrontian tinges it pur- 

 ple ; boracic acid and the cupreous salts tinge it 

 green ; muriate of lime gives it a light red colour ; 

 nitre and oxymuriate of mercury a yellow colour. 



SECT. II. OfElhert. 



When alcohol is acted upon by several of the acids, 

 a fragrant liquid is formed, to which the name of 



ether has been given. These ethers are namd from Element! 

 the acid employed in forming them. As they dif- 

 fer in their properties, it will be requisite to describe * 

 them separately. """Y^ 



1. Sulphuric Ether. 



This liquid was known about the end of the 15th Sulphuric 

 century, and some of its properties were described ca>cr- 

 by Boyle ; but the attention of chemists was first 

 drawn to it by a paper published in the Philosophi- 

 cal Transactions for 1730, by a German who called 

 himself Dr Frobenius. 



It may be obtained by distilling a mixture of equal How oS- 

 parls of alcohol and sulphuric acid in a glass retort, uincd. 

 to which a large receiver is attached. The ether 

 condenses in the receiver. When first prepared, it 

 contains some sulphurous acid, which is removed by 

 putting some powdered chalk into it, and agitating 

 repeatedly in a close phial,, till the sulphurous acid 

 smell is dissipated. The ether is then distilled a se- 

 cond time. It still retains a portion of alcohol, from 

 which it may be freed by adding to it dry muriate 

 of lime as long as it will dissolve that dry salt, and 

 leafing the solution in a well corked phial. The mu- 

 riate of lime dissolved in the alcohol gradually sub- 

 sides, and the pure ether floats on the top. It may 

 be decanted off. 



Ether thus obtained is a limpid and colourless fluid it: proper- 

 like water. It has a peculiar and agreeable smell, and ties, 

 a hot pungent taste. Its specific gravity when pure 

 is only 0.632 at 60 ; but the ether of commerce is 

 seldom lower than 0.775, owing to the alcohol which 

 it contains. 



It is so volatile that it cannot be poured from one 

 vessel to another without considerable loss. When 

 exposed to the open air, it disappears in a very short 

 time. It boils at 98, and in a vacuum at 20. 

 When evaporated, it produces a considerable degree 

 of cold, so that water may be easily frozen by means 

 of it even in summer. The specific gravity of the 

 vapour of ether, according to Dalton, is 2.25, that 

 of air beinc; 1.00. When ether is exposed to a cold 

 of 46, it freezes and crystallizes. 



Neither oxygen gas nor air produce any effect 

 upon ether at the common temperature of the atmo- 

 sphere ; but when kindled in contact with these fluids, 

 it burns with a strong white flame, giving out a great 

 deal of light and heat. The products in this case 

 are carbonic acid and water. It consumes, during 

 its combustion, about seven times its bulk of oxygen, 

 supposing the ether in the gaseous state. When 

 mixed with oxygen gas in that proportion, it ex- 

 plodes very loudly when an electric spark is passed 

 through the mixture. Various attempts have been 

 made to estimate the constituents of ether by con- 

 suming it with oxygen cas, a "d ascertaining the 

 products obtained. The following is the composi- 

 tion of ether, according to the experiments of Saus- 

 sure junior. 



Carbon, ... 58.20 romposi- 



Hydrogen, - - 22.14 '- 



Oxygen, 



19.6 



100.000 



