66 Royal Society : — 



bead be saturated at a high temperature, and flamed, so that it 

 maybe filled with crystals of borate of jargonia, the spectrum shows 

 four distinct absorption-bands, unlike those due to any other known 

 substance." 



I have since applied myself almost exclusively to this subject, 

 hoping to be able to communicate to the Royal Society a full 

 account before the close of this session ; but so much still remains 

 to be done, that it is now impossible to give more than a brief outline 

 of some of the more important facts. The delay has not been 

 occasioned by any difficulty in proving it to be a new substance, 

 but because its properties are so unique and have so much interest 

 in connexion with physics that it appeared desirable to carefully 

 examine all other known elements, in order to ascertain whether 

 any exhibit analogous phenomena. 



That jargonium is quite distinct from zirconium is proved not 

 only by the spectra, but also by other facts. Both I and Mr. 

 David Forbes have succeeded, by entirely different processes, in se- 

 parating from jargon zirconia apparently quite free from jargonia, 

 and jargonia nearly, if not quite, free from zirconia ; and even if 

 the separation be not perfect, it is, at all events, more than suffi- 

 cient to prove that they are distinct. They are certainly closely 

 allied, and are deposited from borax blowpipe beads in microscopical 

 crystals of the same general forms, quite unlike those characteristic 

 of other known earths ; but beyond this the difference is as great 

 as that between any other two closely related elements. Judging 

 from Mr. D. Forbes' s analysis, kindly made at my request, and 

 from a comparison of the spectra, the amount of jargonia in differ- 

 ent jargons varies up to about 10 per cent. Its entire or compa- 

 rative absence from the zircons of Miask, Fredericksvarn, and various 

 other localities, appears to explain some of the facts which led Svan- 

 berg* to conclude that zircons contain more than one earth. He 

 was so far correct, but failed to establish the existence of any sub- 

 stance with special chemical or physical properties ; and if, as is pro- 

 bable, the Norwegian zircons, which, according to his views, contain 

 such a notable quantity of this supposed new earth as to have led 

 him to give it the name noria, were from Fredericksvarn, and if the 

 Siberian were from Miask, his norium cannot be looked upon as equi- 

 valent to my jargonium, which is almost or quite absent from those 

 zircons. 



The most remarkable peculiarity of jargonium is that its com- 

 pounds may exist in no less than three different crystalline states, 

 giving spectra which differ from one another as much as those of 

 any three totally different elements which give the most striking 

 and characteristic spectra. Several substances can be obtained in 

 two physical states, giving different spectra ; but usually only one 

 of them is crystalline, the other is the vitreous or colloid condi- 

 tion. Crystalline minerals, coloured by oxide of chromium, do 

 indeed show two types of spectra, but I am not aware that they 



* Pogg. Ann. 1845, vol. lxv. p. 317. 



