SYXTHETICAL EESEAECHES ON ETHEES. 51 



to the influence of light. Silver caproate crystallizes in large and very thin plates, which 

 are nearly insoluble in water and but very slightly sensitive to light, whilst silver dieth- 

 acetate is deposited in frond-like crystals, which are quite as soluble as silver acetate, 

 and become rapidly brown when exposed to light. We therefore conclude that these 

 acids are isomeric and not identical. Theoretical considerations leading to the same 

 conclusion are given below. 



Action of Sodium and Methyl Iodide upon Acetic Ether. 



Acetic ether was treated with sodium, as in the corresponding reaction described 

 above ; but in the subsequent treatment of the sodium-compound it was not found 

 necessary to expose the mixture of the latter with methyl iodide to heat in a digester. 

 These materials act upon each other with gi-eat energy and completeness at a tem- 

 perature below the boiling-point of methyl iodide. At the conclusion of the sodium- 

 reaction, therefore, the temperature was allowed to fall until the liquid in the flask 

 began to solidify, and the receiver, C (see figure, p. 39), with the residue of sodium 

 being removed, the extremity of the condenser was inserted into the neck of the 

 flask. Methyl iodide in excess was then slowly added by pouring it down the con- 

 denser. An energetic action immediately took place, a large quantity of sodium iodide 

 being formed. To complete this reaction, one atom of methyl iodide for each atom of 

 sodium employed was found to be sufficient. The ethereal part of the product in the 

 flask now remained liquid, even after cooling, the sodium iodide; subsiding as a dense 

 precipitate. Water was then added, and the contents of the flask submitted to distilla- 

 tion. Water, alcohol, and an oily liquid which floated on the aqueous portion of the 

 distillate, condensed in the receiver. When the oily liquid ceased to come over, the 

 contents of the retort were slightly acidified with dilute sulphuric acid, more water 

 added, and the distillation continued into a fresh receiver. The acid distillate thus- 

 obtained did not contain any formic acid, and consisted chiefly of acetic acid, with traces 

 of other higher acids belonging to the same series. 



The aqueous portion of the distillate was separated from the oily, and submitted to 

 distillation in an oil-bath. A considerable quantity of a spirituous liquid passed over, 

 which, after xectification from quicklime, boiled" at 78°"5, and consisted of pure alcohol. 

 It yielded on combustion 52"29 per cent, of carbon and 12"98 per cent, of hydrogen- 

 Alcohol requires 52"17 per cent, of carbon and 13-04 per cent, of hydrogen. 



The oily portion of the distillate was repeatedly washed with water, dried over cal- 

 cium chloride, and rectified. It began to boil at 75°, but the thermometer rapidly rose 

 to 183°, between which temperature and 184° nearly the whole of the remaining large 

 portion of liquid came over. 



Notwithstanding the constancy of boiling-point of this liquid, numerous analyses 

 showed it to be a mixture, and the numbers obtained were consistent with the assump- 

 tion that it was composed of two. bodies having respectively the formulae 



C7H12O3 and C^ll.^O.,. . 



