CHEMICAL SCIENCE. 187 



union of a few atoms of nitrogen and oxygen, tlie comlaination 

 cannot extend throughout the mass, but occurs only along the 

 line of the spark, which, in this case, has to increase both affinity 

 and energy. 



IS NITROGEN AN ELEMENT? 



Chemistry and astronomy at the jiresent day seem to be twin 

 sisters iu science, as their independently obtained results remark- 

 ably confirm each other in many recent instances. A late exam- 

 ple of this is in reference to the constitution of nitrogen, and is 

 afforded by Mr. Huggins' observations of the sj^ectra of some of 

 the nebulae, taken in connection with observations of the nitrogen 

 spectrum made in the laboratory of Mr. Waltenhofcn. Botli 

 these observers have I)een led to the suspicion that nitrogen is 

 not an elementary substance, but a compound of more simple 

 forms of matter, — the former, by observing in the spectra of some 

 of the nebulae some, but not all, of the lines of the nitrogen spec- 

 trum, as if nitrogen were a compound bodv, and tliose neliultB 

 contained, among the materials of which they are composed, one 

 of its constituents and not the other; and the latter, by the dis- 

 covery that, in a highly rarified nitrogen atmosphere the violet 

 rays disappear before the blue and green rays. — Mechanics' 

 Magazine, Oct., 1865. 



Mr. Henry Kilgour, of Edinburgh, maintains that niti'ogen is 

 .carbonic oxide in an allotropic state, having had its activity 

 diminished by heat, electricity, or some other force at present 

 unknown. His chief points are that carbonic oxide and nitrogen 

 have exactly the same atomic weight and atomic volume, and 

 very nearly the same specific gravity and specific heat ; that both 

 are neutj-al, and capable in only a very few instances of entering 

 directly into combination with other bodies ; that neither of them 

 has either color, taste, or odor, or can support combustion or 

 respiration, or can combine with acids to form salts, but tliat both 

 can combine witli oxygen to form acids. He draws many other 

 equally striking parallels, for which see Mechanics' Magazine, 

 Nov., 1865. 



DISSOCIATION OF GASES AT HIGH TEMPERATURES. 



Some interesting researches on this subject have recently been 

 made by M. L. Cailletet, in developing the discovery of M. St. 

 ClaireDeville, that at a high temperature the constituents con- 

 tained in a mixture of gases will separate. As it is necessary to 

 cool the dissociated elements rapidl}', it was necessary to devise 

 an apparatus suited to the purpose. By means of this a^iparatus 

 some imiDortant facts were oljserved. Thus, that oxygen has no 

 action whatever on hydrogen, eai'bon, or carbonic oxide, placed 

 within a mass which is at a temioerature higher than the melting 

 point of platinum ; and the conclusion arrived at was, that all 

 bodies would most proljably be dissociated by a tem]perature suf- 

 ficiently high. — Intelleciuai Observer, 1866. 



