Carbonic Oxide Gas. S4Sf 



and may be collected in the usual manner over water. If the heat 

 be duly moderated, the first and last products, as obtained in the re- 

 ceivers, will be pure carbonic oxide gas. The sulphuric acid seems 

 to act, by resolving the oxalate into oxalic acid and ammonia ; then 

 to decompose the oxalic acid into its elements, and to put the whole 

 into such a state, as to enable the constituents to recombrne, so as to 

 form the pure gas. That carbonic acid is actually evolved, cannot be 

 doubted, but it seems to join the ammonia instantly, forming the car- 

 bonate of Ammonia, which is absorbed by the water, as fast as it is 

 produced. If it is inquired, how it happens that the sulphuric acid 

 does not instantly seize the ammonia and form a sulphate, I have only 

 to say, that although the moderate heat employed, is amply sufficient 

 to drive over the gaseous elements of the oxalate, it is inadequate to 

 cause the sulphuric acid to do so. 



The above statement will be better understood, by the use of a di- 

 agram ; premising, that the equivalents or combining numbers of the 

 several articles, are as as follow ; oxalic acid 36, made up of 24, or 

 3 equivalents of oxygen, and 12, or 2 equivalents of carbon ; am- 

 monia 17, making the salt 53 ; carbonic acid 22, made up of 16, or 

 2 equivalents of oxygen, and 6, or 1 equivalent of carbon ; carbonic 

 oxide 14, composed of 8, or 1 equivalent of oxygen, and 6, or 1 

 equivalent of carbon. 



g r ^ oxygen 8 14 carbonic oxide. 



oxygen 8^ 

 36 oxalic acid, ^oxygen 8^ 



carbon 6- 



carbon 6- 22 c. acid 



17 ammonia 17am'nia 



1 39 carb. 



ammonia. 



53 53 



If a very gentle heat be continued for some time, the same pro- 

 ducts will be had, independently of the use of sulphuric acid ; but 

 the latter seems to accelerate the process. 



When we employ oxalic acid to make the carbonic oxide gas, a 

 portion of carbonic acid is unavoidably formed, and must be removed 

 by means of lime water. In like manner, this acid gas is generated 

 or evolved, when the oxalate of ammonia is used, but as it combines 

 instantly with the ammonia, it does not contaminate the desired pro^ 

 duct. A small portion of the carbonate of ammonia will be found 

 along the beak of the retort, but for the most part, it is taken up by 



Vol, XXV.— No. 2. 44 



