363 NEW METHOD OF ANALYSING AMMONIA. 



and 402 : 978 : : 100 : 198-78. These proportions, you 

 will find, correspond very nearly with those long ago stated 

 by BerthoIIet *, who converted 17 measures of ammonia, 

 by electrization, into 33 measuses of permanent gas, which 

 Untthispro ft at the rate of 194 from 100 +. Having lately, however, 

 truth. carried on the process with the observance of additional 



precaution, (the mercury being first boiled in the tube, be- 

 fore admitting the ammonia, andstiil remaining hot when the 

 gas was passed up), I have obtained from the alkali less 

 than double its volume of permanent gas, viz. 280 measures 

 from 155, or at the rate of 180-6 from 100. The variable- 

 ness of the first set of results arises, I believe, from the un- 

 certainty of the quantity of ammonia decomposed. For if 

 the smallest portion of moisture remain in the tube, a little 

 ammoniacal gas will be absorbed, and will be slowly given 

 out again as the electrization goes on, thus rendering the 

 actual quantity submitted to experiment greater than ap- 

 pears. It is probable, also, from a fact which I shall after- 

 ward state, that mercury itself, unless when heated, may 

 absorb a small portion of alkaline gas. 

 Proportions of The proportion of the hidrogen and nitrogen gasses- to 

 nitrogen. each other in the products of ammonia decomposed by 



electricity, I am satisfied, by recent experiments (June, 

 1809) is as nearly as possible what you have determined, 

 viz. 74 measures of hidrogen gas to 26 of nitrogen. The 

 nearest approximation I have made to these numbers is 

 73*75 to 26-25. Our only methods of analyzing mixtures 

 of these two gasses, (viz. by combustion with a redundancy 

 of oxigen) is not, I believe, sufficiently perfect to afford a 

 nearer coincidence. 



The extreme labour and tediousness of the decomposition 



of ammonia by electricity influenced me, to attempt the dis- 



Auemptat a covery of a shorter and more summary method of analysis. 



shorter method >pj ie nios fc obvious one was its decompositihn by oximu- 

 of analysis. < p . 



riatic acid gas; but this plan was abandoned, from the im- 

 possibility of confining both the gasses by any one fluid • 

 since water acts powerfully on the one, and mercury on the 



* Journal de Physique, 1786, ii, 176. 



-f- BerthoIIet, jun. lately found the mean of a number of expe- 

 riments to be 20* from 100. See the following article. C. 



other 



