NEW METHOD OF ANALYSING* AMMONIA. 360 



its combustion by oxigen gas is likely to be completely 

 effected, and the whole of the hidrogen condensed into 

 water. But after the partial combustion of ammonia by 

 oxigen gas, a residuum is left of hidrogen and nitrogen 

 gaSses, of which the hidrogen usually composes less, and 

 sometimes considerably less, than one half the bulk. In 

 this case it may be suspected, that a small quantity of 

 hidrogen occasionally escapes being burned; and whenever 

 this happens, its proportion to the nitrogen will appear to 

 be less than the true one*. 



From the inflammability of a mixture of ammonia with Ammonia sus- 

 oxigen gas, it was natural to expect, that this alkali would ce f t ' b! ^. of sIow 

 prove susceptible of slow combustion. By means of a pecu- with oxigen. 

 liar apparatus (on a plan which I have described in the 

 Philosophical Transactions for 1808, part II +, but on a 

 smaller scale, and with the substitution of mercury for 

 water), I have found that ammonia, expelled from the 

 orifice of a small steel burner, may be kindled by electricity 

 in a vessel of oxigen gas; and that it is slowly consumed 

 with a pale yellow flame. The combustion, however, is not 

 sufficiently vivid to render the process of any use in the an- 

 alysis of ammonia. 



With nitrous oxide (containing only 5 per cent impurity) Mixture of am- 



ammonia forms a mixture which is extremely combustible. m°nia and ni- 

 -,- , . .-.,. ,i j. i trous oxide ex- 



If the nitrous oxide be in excess, the proportions have a tremely com- 

 considerable range; for any mixture may be fired by buslible « 

 electricity, of which the ammonia is not less than one sixth 

 of the whole. The combustion is followed by a dense 

 cloud, sometimes of an orange colour. When the nitrous 

 oxide greatly exceeds the ammonia, (as in the proportion, 

 for example, of 100 to 30) there is little or no diminution 

 after firing: and the residuum is composed of a small por. 



* This consideration suggests- the propriety of using no more 

 oxigen in the first combustion of ammonia, than is barely sufficient 

 to inflame it ; or if a larger quantity has been used than is required 

 for this purpose, and a residue consequently obtained, of which the 

 hidrogen forms only a small proportion, it is proper to add a farther 

 quantity of hidrogen, before the second combustion. An allowance 

 may afterward be made for this addition. 

 <f See Journal, vol. xxii, p. 83. 



Vol. XXIV.— Supplement. 1 B tion 



