Intelligence and Miscellaneous Articles, 233; 



ihat the remaining gas will burn with its ordinary appearance. The 

 same remark will apply to carbonic oxide prepared by any of the 

 ordinary methods described in the books. Indeed, I am constantly 

 in the habit of preparing the gas in the morning, when it is to be 

 used in the afternoon, and thus avoid the occasion of using any 

 alkali. 



" Although from the above experiments I was quite satisfied that 

 carbonic acid is always produced in the above-mentioned experi- 

 ments, yet, that I might be able to speak with perfect confidence, I 

 was induced to make a complete analysis of the gas obtained after 

 Dr. Mitchell's plan. Taking a given weight of the oxalate of am- 

 monia, and the proportion directed of sulphuric acid, I collected the 

 whole gas evolved from the materials over mercury, that none should 

 be absorbed during the operation. One hundred equal parts having 

 been set aside for examination, pure liquid potassa was thrown up 

 by means of a syringe, and the vessel agitated until no more absorp- 

 tion took place, when fifty parts of the gas had disappeared. The 

 residual gas, on being detonated with oxygen, was found to be nearly 

 pure carbonic oxide. In order to ascertain whether the gas dif- 

 fered in its qualities at different stages of the process, I collected 

 portions of it at regular intervals, throughout the operation, and 

 subjected them to careful examination. The result of these expe- 

 riments was pretty uniform, not varying in any case two per cent, 

 from fifty measures of each gas ; and hence I infer, that the oxalate 

 of ammonia, treated as above, for obtaining carbonic oxide, yields 

 the same products as the binoxalate of potassa or oxalic acid, treated 

 according to the methods described in the books. 



"Professor Mitchell states, that ' on examining the residuary mat- 

 ter left in the retort, it is found to be strong sulphuric acid.' I 

 must confess, 1 am at a loss to know in what way he made an ex- 

 amination, to arrive at such a conclusion, unless it be that he used 

 more than ' one or two drachms of sulphuric acid,' for in each case 

 in which I examined the residue, where an ounce of the oxalate and 

 two drachms of acid were used, I found crystals in the retort, after 

 the materials had cooled, answering in every respect to the acid 

 sulphate of ammonia. If the quantity of sulphuric acid be increased 

 to four or five drachms, and the heat be stopped a little before the 

 gas ceases to come over, the acid will then hold the sulphate in solu- 

 tion and exhibit to the eye an appearance of sulphuric acid j but a 

 single and very simple experiment, namely, the evaporation of a 

 few drops of the liquid on a platinum or glass capsule, until a part 

 of the acid is expelled, will indicate the presence of some salt, and 

 that, on examination, will be found as above mentioned. That am- 

 monia should escape from the retort, in a free state, while it is in 

 contact with a large excess of free sulphuric acid, and then combine 

 with the carbonic acid resulting from the decomposition of the oxalic 

 acid, appears to me unphilosophical, and is disproved by experi- 

 ment, for we recover the whole, or very nearly all the ammonia in 

 combination with sulphuric acid." 



Third Series. Vol. 6. No. 33. March 1835. 2 H 



