One of the best papers of the Association was that
of Mr. Huggins -on " Spectrum Analysis" as a means of telling the constitution of the stars. One very curious fact he seems to have brought out, that the application of this analysis to the constitution of the stars may not improbably be the means of enlarging our own .knowledge of chemistry. Thus there is a certain nebula which, when analyzed by its spectrum exhibits a dark line corresponding with one only of the group of bright lines constituting the spectrum of nitrogen, and it is thought that this may imply that nitrogen is after all a compound, and not a simple body,—not an element, as we have hitherto supposed,—biit is capable of analysis into elements of which one only exists in this particular nebula. Nothing would be more curious than if we were to learn by .gazing up at a distant nebula that there is an artful join, so to say, which we have never yet discovered, in a gas that has so long been under our eyes.