Royal Society. 65 



tantes." Here again, then, I must leave Father Secchi to settle 

 the matter with himself. With regard especially to the bright 

 lines at times visible in spots, which Father Secchi considers due 

 to the radiation of the interior gaseous nucleus of the sun, I can 

 only state that I have seen in the spots no bright lines which are 

 not at times visible in the ordinary solar spectrum ; it is true 

 that in the spots they are better seen. 



In conclusion, I may state : — that the method of observation 

 I employ, of which I regret to find Father Secchi thinks so 

 little, consists in observing the actual images of the sun cast by 

 a reflector of 625 inches aperture and 100 inches focal length, 

 or an image enlarged to 6 inches in diameter, according to 

 the state of the air ; that my spectroscope is furnished with a 

 train of seven prisms of the densest flint glass, giving me a 

 refracting-angle of over 300°; that this dispersion is increased by 

 another dense flint-glass prism of 60°, and a direct-vision prism 

 of equal power ; and, finally, that I am not satisfied with this 

 dispersion, which is more than double that employed by Father 

 Secchi, and in a few days I hope to double my present power. 



X. Proceedings of Learned Societies. 



ROYAL SOCIETY. 



[Continued from vol. xxxviii. p. 465.] 



June 17, 1869. — Lieut. -General Sabine, President, in the Chair. 



r T^HE following communications were read : — 

 -*- " On Jargonium, a new Elementary Substance associated with 

 Zirconium." By H. C. Sorby, F.R.S. &c. 



At the Soiree of the President of the Royal Society on March 

 6th, I exhibited various spectra, differing so much from those cha- 

 racteristic of any known substance, that I considered myself war- 

 ranted 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 jargo- 

 nium 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 

 distinguished from zirconia and all other known substances by the 

 following very remarkable properties. The natural silicate is almost, 

 if not quite colourless ; and yet it gives a spectrum which shows above 

 a dozen narrow black lines, much more distinct than even those cha- 

 racteristic 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 spectrum ; but if the borax 



Phil. Mag. S.4. Vol. 39. No. 258. Jan. 1870. F 



