Intelligence and Miscellaneous Articles, 155 



It appears from these experiments, that 



10 carbon 10 hydrogen 1 concrete oil of peppermint. 



1 8 1 oxygen, form common camphor. 



10 — — 8 ■ oil of turpentine. 



1 ■ 6' 1 concrete oil of aniseed. 



10 4 naphthaline 



M. Dumas is disposed to believe that the absorption of oxygen by 

 essential oils, produces different effects according as it occurs under 

 the influence of water or when dry. The constitution of pure oil of 

 lemons appears to be perfectly similar to that of oil of turpentine 

 by M. Dumas's analysis, and it differs very little from that of M. Th. 

 de Saussure. M. Dumas finds naphtha to be composed of 6 atoms 

 carbon + 5 hydrogen -, a conclusion which also agrees nearly with 

 that of M. de Saussure j the density of its vapour should therefore be 

 2-870, which varies but slightly from that obtained by experiment. 



Ann. de Chim. et de Phys. July 1832. 



FORMATION OF ACETIC ACID FROM CARBONIC OXIDE AND 

 HYDROGEN. 



M. Matteuci succeeded in procuring acetic acid by passing oxide 

 of carbon through water in which copper was suspended. The cop- 

 per was prepared by passing a current of hydrogen over its oxide 

 obtained by calcining acetate of copper - 3 the oxide of carbon was pro- 

 cured by heating a mixture of one part of well calcined charcoal with 

 three parts of carbonate of lime in a gun-barrel ; in order to separate 

 the small quantity of carbonic acid formed, lime was placed in a part 

 of the barrel, and the gas passed over it. 



The oxide of carbon was then passed into distilled water containing 

 the copper : in a short time the water became greenish, and its intensity 

 of colour was increased the longer the current of the gas continued to 

 pass through the water. M. Matteuci therefore concluded that the sub- 

 stance dissolved was acetate of copper, derived from the decomposition 

 of the water by the carbonic oxide and copper, the hydrogen uniting 

 with the former to give acetic acid, and the oxygen with the latter 

 forming oxide. 



To verify this conclusion the solution was filtered, and a portion 

 of it evaporated ; to another portion a solution of ferrocyanate of potash 

 was added, and an abundant red brown precipitate" was obtained j 

 sulphuretted hydrogen gave a black precipitate, and left an acid liquor, 

 which, after being heated, was combined with oxide of lead, and formed 

 a soluble salt. The solution when treated with iron produced a greenish 

 soluble salt, which decomposed on exposure to the atmosphere, and 

 deposited a reddish powder. 



The evaporated liquor gave a small quantity of a crystallized sub- 

 stance of a greenish colour, which treated with sulphuric acid effer- 

 vesced slightly, and disengaged vapours which had the properties of 

 acetic acid. 



When oxide of copper was substituted for the metal, no acetic acid 

 was formed ; but it was produced when a current of cyanogen was 

 passed into water containing copper. 



X2 



