1869.] 



Mr. H. C. Sorby on Jargonium. 



511 



VIII. " On Jargonium, a new Elementary Substance associated with 

 Zirconium By H. C. Sorby, F.R.S. &c. Received June 4, 

 1869. 



At the Soiree of the President of the Royal Society on March 6th, I 

 exhibited various spectra, differing so much from those characteristic of 

 any known substance, that I considered myself warranted in concluding 

 that they -were evidence of a new element. Since this may be studied to 

 the greatest advantage in the jargons of Ceylon, it appeared to me that, 

 like as the name zirconium has been adopted for the principal constituent 

 of zircons, so that of jargonium would be very suitable for this constituent 

 of jargons. 



At the above-named Soiree I gave away a printed account of the 

 objects I exhibited, and in this I said that the earth jargonia "is distin- 

 guished from zirconia and all other known substances by the following very 

 remarkable properties. The natural silicate is almost, if not quite colour- 

 less, and yet it gives a spectrum which shows above a dozen narrow black 

 lines, much more distinct than even those characteristic of salts of didymium. 

 When melted with borax it gives a glassy bead, clear and colourless both 

 hot and cold, and no trace of absorption-bands can be seen in the spec- 

 trum ; but if the borax bead be saturated at a high temperature, and 

 flamed, so that it may be filled with crystals of borate of jargonia, the 

 spectrum shows four distinct absorption-bands, unlike those due to any 

 other known substances" *. 



I have since applied myself almost exclusively to this subject, hoping to 

 have been 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 im- 

 portant 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 de- 

 sirable to carefully examine all other known elements, in order to ascer- 

 tain 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 separating from jargons 

 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 sufficient 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 



* For the further history of this subject see Professor Church's papers, Intellectual 

 Observer, 1866, vol. ix. p. 291, Chemical News, March 12 and 19, 1869, vol. xix. 

 pp. 121 & 142, Athenaeum, March 27 ; and also my own, Chemical News, vol. xix. 

 p. 122, and Athenieum, April 3, 1869. 



