148 On the Decomposition and Composition 



opposed by the conclusions of Mr. Dal ton*, and the expe- 

 riments of Messrs. Desormes and Clement t . 



After the gas had been passed several times through the 

 ignited tube from one gasometer to the other, the results 

 were examined. The iron wire became converted superfi- 

 cially into oxide, and had gained in weight -j^V parts of a 

 grain, about -fa of x grain of water were collected from the 

 cooled glass tubes by means of filtrating paper, and 33 ,l 8 

 cubic inches of gas were expanded into 55*3 cubic inches, 

 and by detonation with oxygen it was found that the hydro- 

 gen gas in these was to the nitrogen as 3-2 to 1 in volume. 



It will be useless to enter into the more minute details of 

 this experiment, as no perfectly accurate data for propor- 

 tions can be gained from them ; for the whole of the am- 

 monia was not decomposed; and as the gas had been pre- 

 pared by being sent from a heated mixture of sal ammoniac 

 and quicklime, into the airholder, it was possible that some 

 solution or ammonia might have been deposited, which, by 

 giving out new gas during the operation, would increase the 

 absolute quantity of the material acted upon. 



In examining the results of M.Berthollet's J elaborate ex- 

 periments on the decomposition of ammonia by electricity, I 

 was surprised to find that the weight of the hydrogen and 

 nitrogen produced, rather exceeded than fell short of that of 

 the ammonia considered as decomposed, which was evi- 

 dently contradictory to the idea of its containing oxygen. 

 This circumstance, as well as the want of coincidence be- 

 tween the results and those of Priestley and Van Marum on 

 the same subject, induced me to repeat the process of the 

 electrization of ammonia, and I soon found that the quan- 

 tities of the products in their relations to the apparent quan- 

 tity of gas destroyed were influenced by many different 

 causes. 



Ammonia procured over dry mercury from a mixture of 

 dry lime and muriate of ammonia, I found, deposited mois- 

 ture upon the sides of the vessel in which it was collected, 



* Manchester Memoirs, vol. v. part ii. page 535, 1785, 

 f Annates de Chimie, vol. xlii. p. V15. 

 \ Memoircs de I'Academie, 1785, page 324. 



and 



