344 Carbonic Oxide Gas. 



Art. X. — Carbonic oxide gas, obtained, free of carbonic acid ; by 

 Thomas D. Mitchell, M. D. Professor of Chemistry and Phar- 

 macy in the Medical College of Ohio. 



It will be readily conceded, that a process, by which a difficulty 

 can be avoided entirely, will be more acceptable to the practical 

 chemist, than one, however ingenious, that instructs him how to get 

 rid of that difficulty, after it has occurred. Several foreign writers 

 have recently proposed methods, for ridding carbonic oxide of car- 

 bonic acid ; and in a late number of the American Journal, conduct- 

 ed by Professor Silliman, 1 find a communication from Professor 

 Hare, on this point. He has furnished a drawing of his apparatus, 

 intended to accomplish the object in view, with such explanations, as 

 he supposed necessary. It is obvious however, that if such an ex- 

 pedient were at all requisite, many persons would fail in its construc- 

 tion, by the aid of the description and drawing alone ; for although 

 it may be perfectly plain to the inventor, it will not follow, that others 

 may easily imitate him. 



The plan which I adopted is very simple and perfectly successful. 

 I was led to its use, not because I supposed the formation of carbonic 

 acid would be obviated, but because 1 had found considerable diffi- 

 culty by other processes. It was my design to have employed the 

 super or bin-oxalate of potash, as recommended by Dumas, and in 

 that case, it would have been necessary to have washed the product 

 with lime water. Fortunately, however, my bottle containing that 

 article was mislaid, and, in its place, I substituted the oxalate of Am- 

 monia, uncertain what would be the precise result. My first notice of 

 this experiment, is contained in the Western Medical Gazette for Jan- 

 uary 1 5th of the present year, but as I have had opportunities since 

 that date of confirming the views then entertained, I think it may 

 not be unacceptable to chemical teachers, to give the subject a brief 

 notice, through the medium of a journal that has a wider circulation. 



I repeat then, that I have obtained the carbonic oxide, of an ex- 

 cellent quality, independently of the use of lime water, or any other 

 agent, for the purpose of detaching carbonic acid, by the action of 

 sulphuric acid on the oxalate of ammonia. Take an ounce of the 

 oxalate, reduced to powder, and a drachm or two of sulphuric acid, 

 and put them into a six-ounce tubulated retort, and apply a very gen- 

 tle lamp heat. In a (ew minutes, large quantities of gas are evolved, 



