358 NEW METHOD OF ANALYSING AMMONIA. 



IV. 



Experiments on Ammonia, and an Account of a new Me- 

 thod of analyzing it, by Combustion with Oxigen, and 

 other Gasses ; in a Letter to Humphry Davy, Esq. 

 Sec. R. S. Sfc, from William Henry, M. D. F. R. S., 

 V. P. of the Lit. and Phil. Society, and Physician to the 

 Infirmary at Manchester *. 



MY DEAR SIR. 



I 



Should sooner have communicated the account, which you 

 are so good as to request, of my further experiments on the 

 decomposition of ammonia, if I had not been anxious to ob- 

 tain, by frequent and careful repetition of them, results not 

 affected by any of those numerous causes of errour, which 

 easily insinuate themselves into processes of so much deli- 

 Supposed evo. cacy. You have already been informed, that the fact, which 

 101 \r a °s f^n I lately mentioned' to you, (tending to prove the existence 

 ammonia. of oxigen as an element of the volatile alkali, by the dis- 



covery of oxigen gas in the products of its analysis) is not 

 entitled to confidence, owing to the admission of a small 

 quantity of atmospherical air, in a way which was not at all 

 suspected. Frequent repetitions of the same process, under 

 circumstances wholly unobjectionable, have fully satisfied 

 me, that no portion whatsoever of oxigen gas is evolved by 

 electricity from ammonia, even when, by means of an appa- 

 ratus constructed for the purpose, the only mctallicsurface, 

 exposed to the gas, consists of the sections of two platina 

 wires, each ~% of an inch in diameter, the wires themselves 

 being enclosed in glass tubes which are sealed hermetically 

 round them, and then ground away, sq as to expose only 

 the points. Nor does any difference in the nature of the pro- 

 ducts arise from electrifying the gas either under increased 

 or diminished pressure, the latter of which, it appeared 



* Philos. Trans, for 1809', p. 130. This letter, in its original 

 form, was read to the Society, May the 18th, 1809, some new 

 observations were added, and some corrections furnished by 

 the author, in consequence of subsequent experiments made in 

 June; it was transmitted to the Secretary for publication, July 

 the 10th, 



to 



