On the Action of Carbonic Oxide on Sodium-ethyle. 505 



Our experience is therefore against a decrease of vapour pro- 

 ducing a decrease of lines in this region, but not perhaps against 

 a decrease of vapour producing a diminution in the intensity of 

 the group of lines near the most refrangible D line. This is the 

 group that Mr. Cooke has found to vanish altogether when the 

 amount of vapour is small. We have never found them to vanish, 

 but we have observed a change of intensity, which may perhaps 

 be due to vapour. 



I shall only make one further remark. An observation of the 

 spectrum of ignited sodium (made, I think, in the presence of 

 Mr. Huggins) discovered the existence of at least two sodium 

 lines between the two D lines. In this region, therefore, there 

 are at least four lines due to sodium ; and it might be natural to 

 suppose that the absorption lines due to the presence of sodium 

 vapour in the sun's atmosphere should be at least four in num- 

 ber for the same region. Besides these there is probably a 

 nickel line ; so that on these grounds I should hesitate in belie- 

 ving that Mr. Cooke's fig. 1, in which there are only three lines 

 in all, namely the two D lines and one intervening line, is the ulti- 

 mate representation of this region by a very powerful instrument. 



I remain, 



Yours very truly, 

 J. P. Gassiot, Esq., V.P.R.S. B. Stewart. 



LXXII. On the Action of Carbonic Oxide on Sodium-ethyle. By 

 J. Alfred Wanklyn, F.R.S.E., Professor of Chemistry at 

 the London Institution*. 



NEITHER carbonic acid nor carbonic oxide acts upon zinc- 

 ethyle ; but both of these gases attack sodium-ethyle. In 

 the case of carbonic acid, the product of the reaction upon 

 sodium-ethyle is, as I showed some yearslago, propionate of 

 soda. This reaction is very energetic, evolving much heat, and 

 taking place without the application of external heat when the 

 gas is simply passed over the sodium-compound. 



The action of carbonic oxide is much less energetic. When 

 the compound containing sodium-ethyle and zinc-ethyle, which 

 I have described on a former occasion f, is sealed up with car- 

 bonic oxide, there is no perceptible change at first, but after a 

 time a black deposit makes its appearance. If the apparatus be 

 kept at ordinary temperatures, a considerable time is required for 

 the production of this deposit ; but if it be heated to temperatures 

 approaching 100° C, then the blackening takes place imme- 

 diately. 



The black deposit is not carbonaceous, for it dissolves in hy- 



* Communicated by the Author. 



f Ann. der Chem. und Pharm. (1858), vol. cviii. p. 67. 



