COMPOUND ETHERS. 775 



surrounded by ice. But as prepared with nitric acid, by this 

 and other processes, nitrous ether always contains aldehyde, a 

 product of the oxidation of alcohol. M. Liebig recommends as 

 the best process for nitrous ether, to transmit a current of ni- 

 trous acid vapour, obtained by heating on a water-bath a spa- 

 cious retort, containing 1 part of starch and 10 parts of nitric 

 acid of 1.3, through a mixture of 2 parts of alcohol of 85 per 

 cent and 1 part of water, contained in a bottle of two tubulures, 

 and surrounded by cold water. The nitrous acid is immediately 

 absorbed by the alcohol, and combines with ether. The pro- 

 duct, at the same time, distils over, and may be conducted from 

 the vessel in which the reaction takes place, by means of a glass 

 tube, to a tube condenser. 



Nitrous ether, in a state of purity, is a volatile liquid, of a 

 pale yellow colour, possessing the agreeable odour of the Nor- 

 mandy rennet. Its density at 59 (15 cent.) is 0.947 ; it boils 

 at 61 .5 (16.4 cent.). It is converted by the tincture of hydrate 

 of potash into nitrate of potash and alcohol. 



Carbonate of oxide of ethyl, carbonic ether, EO,CO 2 ; ob- 

 tained by M. Ettling, by the action of potassium or sodium on 

 oxalic ether ; a colourless aromatic liquid, of density 0.965 at 

 66.2 (19 cent.), boiling at 258.8 (126 cent). 



Carbonate of oxide of ethyl and potash, KO,EO + C 2 O 4 ; is pre- 

 pared by dissolving in alcohol hydrate of potash, fused and still 

 red hot, and saturating the solution with dry carbonic acid gas. 

 When purified, it crystallizes in silky laminae, soft to the touch 

 (Dumas and Peligot). 



Oxalate of ether, oxalic ether, EO,C 2 O 5 . The following pro- 

 cess is given by M. Liebig, from Ettling, for the preparation of 

 this which is one of the most interesting of the ethers. A mix- 

 ture is distilled rapidly of 4 parts of binoxalate or quadroxalate 

 of potash, 5 parts of oil of vitriol, and 4 parts of alcohol of 90 

 percent (0.818). As soon as the liquid which passes is troubled 

 by an addition of water, it contains oxalic ether, and is collected 

 in a receiver which is not cooled. The product is afterwards 

 mixed with 4 times its volume of water ; the ether then sepa- 

 rates, and it is agitated immediately with pure water, which is 

 renewed frequently, till an acid re-action ceases to be mani- 

 fested. 



The washed ether is rectified in a small dry retort, which is 

 filled to 9-10ths j as soon as the product which passes is colour- 



