1870.] 



of Sodium and Ethyl-iodide on Acetic Ether. 



229 



trustworthy result. In the first case because the sodium, which fuses 

 during the reaction, breaks up into a vast number of very minute globules, 

 the final disappearance of which in the highly coloured and pasty product 

 it is impossible to verify. In the second case because the thickening of 

 the liquid prevents the reaction being pushed far enough to decompose the 

 whole of the acetic ether employed. In a quantitative experiment, in which 

 4*857 grammes of acetic ether were acted upon by sodium in slight excess, 

 344*79 cub. centims. of hydrogen at 0° C. and 760 millims. pressure were 

 obtained. If one molecule of acetic ether had lost one atom of hydrogen, 

 615*9 cub. centims. of gas ought to have been collected. It was evident, 

 however, that a large proportion of acetic ether still remained unattacked 

 at the close of the experiment. 



Such, then, was our mode of operating ; the hydrogen evolved was 

 allowed freely to escape, the whole process was conducted at the ordinary 

 atmospheric pressure, and the temperature varied from the boiling-point 

 of acetic ether to 130° C. Moreover the acetic ether used was prepared 

 with the greatest care so as to ensure the absence of alcohol and water. 

 By our method of preparation, described in the memoir already cited, no 

 traces of the former could be detected even in the crude ether ; nevertheless 

 it was first placed for several days over fragments of fused calcic chloride, 

 which apparently remained perfectly dry and unaffected ; it was then in 

 some cases boiled for ten days or a fortnight upon many pounds of sodium- 

 amalgam, which we find to be entirely without action upon pure acetic 

 ether, whilst it rapidly attacks and removes alcohol, if the latter be added 

 even in very small proportion to the acetic ether. When acetic ether, so 

 treated and then distilled from the sodium-amalgam, was brought into 

 contact with the sodium, an abundant evolution of hydrogen immediately 

 commenced, and continued during the entire treatment, which, as already 

 remarked, frequently lasted several days. The general impression, how- 

 ever, produced upon us by the whole of our operations was, that the evo- 

 lution of hydrogen was not quite so great as that theoretically required by 

 the reactions which we believe to take place ; nevertheless it was obvious 

 that no equations, from which free hydrogen was excluded, could possibly 

 correctly express the chemical changes effected in this action. Certain 

 experiments were undertaken to trace the missing hydrogen, but as thev 

 have not hitherto been completed we will not further allude to them here. 



We now r turn to Mr. Wanklyn's mode of experimenting. This is not 

 stated in his communication to the Royal Society, but is given in the 

 Journal of the Chemical Society, vol. xvii. p. 371, and in the Ann. Chem. 

 u. Pharm. for January 1869, as follows : — 



Exp. 1. "I sealed up a quantity of sodium with acetate of ethyl, which 

 had been very carefully deprived of alcohol and water, and weighed the 

 tube containing these materials. I then heated the tube to 130° C. for 

 some time, until the contents had changed from liquid to solid. After 

 opening the tube and allowing any gas that might have formed to escape, I 

 weighed it again. The loss amounted to 0*5 in 100 parts of acetic ether." 



