358 Chemical Notices :—M. Sawitsch on Acetylene. 
means of this principle, I propose to give of physical and che- 
mical phenomena be found liable to serious objection, I hope 
the above remarks will have made this conception of Atoms 
sufficiently clear to be applied with greater success by others. 
6 Stone Buildings, Lincoln’s Inn, 
April 11, 1861. 
[To be continued. | 
LIV. Chemical Notices from Foreign Journals. 
By H. Atxinson, PA.D., F.CS. 
[Continued from p. 301.] 
AWITSCH* found that, under certain circumstances, mono- 
brominated ethylene, €? H® Br (bromide of vinyle), parted with 
hydrobromic acid and became converted into acetylene, €* H?, the 
gas discovered by Edmund Davy and investigated by Berthelot. 
He was led to investigate this deportment more minutely, and 
having tried the action of monobrominated ethylene on amylate 
of sodium, has found in it a mode of preparing this gas. 
About 45 grammes of brominated ethylene were heated in a 
closed vessel with amylate of sodium. An abundant precipitate 
of bromide of sodium was formed, and the mass became liquid 
from the regenerated amylic alcohol. The vessel was then care- 
fully cooled down in a freezing mixture and opened, when 
about 4 litres of a gas escaped, which, agitated with an ammo- 
niacal solution of chloride of copper, gave an abundant red pre- 
cipitate. When this precipitate was treated with dilute hydro- 
chloric acid, it gave off about a litre of a colourless gas with a 
peculiar odour, and which burned with a very fuliginous flaine. 
The analysis of this gas, and its combination with copper, left no 
doubt that it was acetylene. 
Its formation may be thus expressed :-— 
o FJ ll 
‘ i 04+C?H?Br= C?H?+NaBr+@ HO. 
pe ae F Monobrominated Acety- Amylic 
Ba tia ethylene. lene. alcohol. 
This reaction is important, as it will probably lead to the for- 
mation of a new series of hydrocarbons of the general formula 
©; He»-2, of which acetylene, €* H?, is the first member, from 
the hydrocarbons of the general formula C, H.,. In fact 
Sawitsch has subsequently { examined the action of monobromi- 
* Bulletin de la Société Chimique, p. 7. 
+ Phil. Mag. vol. xx. p. 196. 
{ Comptes Rendus, March 4, 1861. 
