NATURE AND DECOMPOSITION OF THE FIXED ALKALIS. 327 



ammonia might hare been deposited, which, by giving out 

 new gas during the operation, would increase the absolute 

 quantify of the material acted upon. 



In examining the results of Mr, Bertholiet's* elaborate Berthollet's de- 

 experiments on the decomposition of ammonia by electricity, ^^^0",^!^'^" °^ 

 I was surprised to find, that the weight of the hidrogen and electricity. 

 nitrogen produced rather exceeded tlian fell short of that of J'j^Jg^''^ ^^' 

 the ammonia considered as decomposed, which Avas evidently 

 contradictory to the idea of its containing oxigen. This cir- 

 cumstance, as well as the want of coincidence between the 

 results and those of Priestley and Van Marum on the same 

 subject, induced me to repeat the process of electrization 

 of ammonia, and I soon found, that the quantities of the Quantities of 

 products in their relations to the apparent quantity of gas ^h^P''«'^'"ctsin- 

 A . 1 • n ^^ A-a- / fluenced by va- 



destroyed were intluenced by many different causes. rious causes. 



Ammonia procured over dry mercury from a mixture of 

 dry lime and muriate of ammonia, I found, deposited moisture 

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

 passing the gas into the tube for electrization, it was not easy 

 to avoid introducing some of this moisture, which must have 

 been a saturated solution of ammonia, at the same time. 



In my first trials, made upon gas passed immediately from 

 the vessel in which it had been collected into the apparatus, 

 I found the expansion of 1 of ammonia vary in different in- 

 stances from 2-8 to 2-2 measures, but the proportions of the 

 nitrogen and hidrogen appeared uniform, as determined by 

 detonation of the mixed gas with oxigen, and nearly as 1 

 to 3 in volum.e. 



To exclude free moisture entirely, I carefully prepared 

 ammonia in a mercurial airholder, and after it had been some 

 hours at rest, passed a quantity of it into tho tube for decora- 

 position, which had been filled with dry mercury. In this 

 case 60 parts became 103 parts by electrization, and there 

 was still reason to suspect sources of errour. 



I had used iron wires not perfectly free from rust for 

 takinw the spark, and a black film from the mercury appeared 

 on the sides of the tube. It was probable, that some ammo- 

 nia had been absorbed by the metallic oxides both upon the 



* M/moires de rJcademie, 1785, page 324. 



iroa 



