ETHERS 77 



Purification of Commercial Methylated Ether. 



This ether is made by the continuous process from methylated spirit and 

 contains water, alcohol and other impurities. The ether may be washed with 

 water to remove most of the alcohol. By distilling it over solid caustic 

 potash, aldehydic impurities are destroyed. It is dried by standing over 

 calcium chloride and then treated with metallic sodium. 



Sometimes, 'after treatment with sodium, ether is left in contact with 

 phosphorus pentoxide and then distilled from the solid dehydrating agent. 



Distillation of Ether. Precautions. 



As ether is very inflammable and exceedingly volatile no flame 

 should be in the neighbourhood. Ether should never be distilled 

 over a free flame and the most convenient way, if steam or electric 

 heaters are not available, is to heat a water-bath, extinguish the flame, 

 -and immerse the distilling flask containing the ether in the hot water. 



Large quantities of ether should not be distilled from a large flask, 

 but a small flask provided with a tap funnel should be employed. As 

 the ether distils a fresh quantity can be added without interrupting 

 the distillation. The ether should be collected in small receivers and 

 transferred to a larger reservoir. 



Properties. 



The first member of the series, dimethyl ether, is a gas. 



Ethyl ether, or simply ether, the chief representative of the group 

 is a very volatile, colourless liquid with a pleasant characteristic smell. 

 It boils at 35 and has a sp. gr. of 7195 at 15. It is sparingly 

 soluble in water, less soluble in glycerol. It mixes in all proportions 

 with alcohol, chloroform, benzene, ligroin, and is largely used as a sol- 

 vent for fats, resins, etc. The lower members of ethers of the aliphatic 

 series are also volatile liquids, like ethyl ether, which boil at a lower 

 temperature than the alcohol from which they are derived. The 

 highest members are odourless solids. 



The ethers are inert compounds and are not acted upon by 

 phosphorus pentachloride and sodium (distinction from alcohols), or by 

 .aqueous or alcoholic potash (distinction from halogen compounds and 

 ^esters). 



The lower members especially those containing methyl and ethyl 

 radicles are decomposed by heating with hydriodic acid fDrming 

 alkyl iodides (distinction from hydrocarbons). This reaction is used 

 in estimating methoxy CH 3 O and ethoxy C 2 H 5 O groups in organic 

 compounds (Zeisel's method). 



