546 



Dr. W« Huggin8 on the Spectra of 



[June 16, 



DESCBIPTIOX OF THE PLATES. 



Plate VIII. 



Plate IX 

 Fig. 10. Cants lupus. 



Fig. 1. Felis leo (max.). 



2. tigris (max.). 



3. jubata (mean). 



4. Ursus fcrax (mean). 



5. arctos (mean). 



11. aureus. 



12. wipes. 



13. bengalensis (fosailis). 



14. (hodie). 



15. zerda. 



16. Sus scrofa (ferns). 



17. domesticus. 



18. Eauus caballus. 



6. maritimus (mean). 



7. Hyena crocuta (mean). 



8. ^ brunnea (mean). 



9. striata (mean). 



XI. " Note on the Spectra of Erbia and some other Earths." By 

 William Huggixs, LL.D., F.R.S. Received May 26, 1870. 



Bahr and Bunsen hare shown* that erbia, rendered incandescent in a 

 Bunsen' s gas-flame, gives a spectrum of bright lines in addition to a 

 brilliant continuous spectrum. As they were unable to discover the bright 

 liues in the flame beyond the limits of the solid erbia, they suggest that 

 the light which is dispersed by the prism iuto bright lines is emitted by 

 the solid erbia, which substance therefore appears to stand alone, as a re- 

 markable exception, among solid bodies. Bahr and Bunsen found the 

 spectrum of bright lines to coincide very nearly with the absorption 

 spectrum of some compounds of erbium. 



A few weeks since, when in Ireland, I made the observation that the 

 spectrum of the ordinary lime-Ught contains bright lines-f\ Dr. Emerson 

 Reynolds, Director of the Laboratory of the Royal Dublin Society, kindly 

 undertook to make experiments to ascertain from the position of the lines 

 if they were due to the cylinder of lime, or to impurities contained in it. 



Upon my return to town I made the following experiments ; shortly 

 after commencing them I received from Dr. Reynolds the account of his 

 experiments, which, with his permission, I have added to this note. 



Erbia. — A few months since I received, through the kindness of Dr. 

 Roscoe, F.R.S., a few grains of nitrate of erbia, which he had procured 

 from a trustworthy source. I followed Bunsen' s method of placing it with 

 syrupy phosphoric acid upon a platinum wire. The erbia, obtained by 

 this method in a finely divided state, was then submitted to the heat of the 

 oxyhydrogen blowpipe. 



In all the experiments described in this paper hydrogen alone was first 

 turned on, and the effect of the heat of the flame on the substance under 

 examination observed with the spectroscope. Oxygen was then admitted 

 slowly, and the effect of the increased heat carefully noted. 



With the flame of hydrogen alone, the lines represented in the map 



* Liebig's Aonalen, B<L IaL (1866) S. L 



t Dr. W. Allen Miller informs me that in 1845 he noticed a bright line in the 

 spectrum of the diffused light of the oxyhydrogen jet reflected from a sheet of paper. 



