FEEMEXT OILS. 371 



iiioderatelj hard, veiy friable, and grating between the teeth ; it 

 has no taste, but when heated smells like etherol. Melts at 110^ 

 C. Boils at 260^ C. without alteration. Insoluble in water, but 

 soluble in alcohol, and still more so in ether. Etherol is a 

 yellowish, viscid liquid of sp. gr. 0'921 (Serullas), boiling at 280° 

 C. By exposure to cold it becomes more viscid, but does not 

 solidify even at — 35° C. It has a peculiar, aromatic odour, is 

 insoluble in water, but dissolves easily in ether, less easily in 

 alcohol. Potassium immersed in it retains its lustre undiminished. 

 Heavy oil of wine, which passes over in the preparation of ether 

 towards the end of the distillation, when sulphurous anhydride 

 and olefiant gas are given off, is, according to Liebig, an etliyl- 

 sulfliate of etherol. On treating it with water, the etherol (holding 

 the isomeric body, etherin, in solution) separates out, and ethyl- 

 sulphuric acid remains in solution. An oil of similar character 

 and composition is oljtained by the distillation of perfectly dry 

 ethyl sulphates, the best process, according to Liebig, being to 

 distil the dry potassium salt with an equal weight of freshly- 

 burned lime. Marchand recommends the distillation of dry ethyl 

 sulphate of lead. The crude product is freed from alcohol, ether 

 and sulphurous ncid by agitation wdth cold water and drying in 

 vacuo over sulphuric acid." 



In Hirsch's Universal Pharmacopcpia, band ii., p. 273, it is stated 

 that " the so-called heavy oil of wine, of which one half of the 

 preparation (oleiun cethereum) consists, is to be regarded as a 

 solution of solid etherin and liquid etherol (both of the empirical 

 formula C. H^) in sulphurous ether (ethyl sulphite), (C, H.)., O.3 

 and sulphuric ether (ethyl sulphate), (Co H.)^ S 0^ in proportions 

 which have not been more accurately determined, and which are 

 also probably very variable." 



Schmidt, in his Pharmac. Chemie., band ii., pp. 201 and 202, 

 states in connection with ether, that " if in the manufacture of 

 the latter the supply of alcohol is deficient, or the temperature 

 during the process rises above 145° C, or if finally the sulphuric 

 acid becomes too hydrated, there is formed, besides sulphurous and 

 carbonic anhydrides, ethylene, which through polymerization 

 becomes partly converted into solid etherin (melting point 110° C; 

 boiling point 260° C.) and into liquid etherol, both of the formula 

 {Co H^)„. Besides the latter bodies, there also pass over in 

 the manufacture of ether small amounts of ethyl -sulphite 



