ON NITROGEN AND AMMONIA. 5] 



Assuming the common estimations of the specific gravity Specific gravi- 



of ammonia, of hidrooen, and nitrocren, the conclusions ^'^^ °^ '^® ^j^' 

 ' n ' o ggs examined, 



which I have advanced in the Bakenan lecture for 180? 

 would be supported by these new experiments, but as the 

 moisture and oxigen viaibJy separated cannot be conceived 

 to be as much as ^V ^t tV of the weight of the ammonia ; I 

 resolved to investigate more precisely, than 1 had reason to 

 think had been hitherto done, the specific gravities of the 

 gasses concerned in their dry state; and the very delicate 

 balance belonging to the Royal Institution placed the means 

 of doing this in my power. 



Nitrogen, hidrogen, and ammonia, were dried by a long Sp.grav.of ni- 

 continued exposure to potash, and were very carefully ^i^ogen, hidro- 

 weighed. Their relative specific gravities proved to be, at monia. 

 30'5in. barometer, 51° Fahrenheit's thermometer. 



For nitrogen, the 100 cubical inches. ... 29*8 grains. 



For hidrogen, ditto. 2'27 



For ammonia • 18'4 



Now, if these data be calculated upon, it will be found, Lossinthede- 



that in the decomposition of 100 of ammonia, taking even compositwi of 

 , , . „ 111-1 ammonia, 



the largest proportions or gasses evolved; there is a loss 



in the electrical decomposition of ammonia, which he supposes I rate 

 at 20 per cent : and at the same time he confutes some experiments, 

 which he is pleased to attribute to me, of the combustion of charcoal 

 and iron in ammonia. His arguments and his facts upon these points 

 appear to me perfectly conclusive ; but as I never formed such an opi- 

 nion, as that 20 of oxigen were separated in the experiment, and neyer 

 imagined such results as the combustion of iron and charcoal in am- 

 monia, and never published any thing which could receive such an, 

 interpretation, I shall not enter into any criticism on this part of his 

 paper. The experiments of this ingenious chemist on the direct de- 

 composition of ammonia seem to have been conducted vdth much care, 

 except as to the circumstance of hia not boiling the quicksilver j which 

 I conceive has occasioned him to overrate the increase of volume. At 

 sJl events a loss of weight is more to be expected than an increase of 

 weight, in all very refined experiments of this kind. It is possible, 

 that the volume may be exactly doubled, and that the nitrogen may 

 be to the hidrogen as one to three j but, neither the numerous experi- 

 ments of Dr. Henry, nor those that I have tried, establish this ; it is ■■ 

 one of the hypothetical inferences that may bs made, but it cannot 

 be regarded as an absolute fact. 



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