THE 

 LONDON, EDINBURGH, and DUBLIN 



PHILOSOPHICAL MAGAZINE 



AND 



JOURNAL OF SCIENCE. 



[FOURTH SERIES.] 



SEPTEMBER 1864. 



XX. On the Spectra of Compounds and of Simple Substances. 

 By Alexander Mitscherlich*. 

 [With Two Plates.] 



IN a previous paper I have shown that compounds of the 

 metals have other spectra than the metals themselves. 

 This fact appeared to me of great importance, because by the 

 observation of the spectra a new method is found of recognizing 

 the internal structure of the hitherto unknown elements, and of 

 chemical compounds. Hence I have investigated the spectra of 

 all the metals which I could procure, and of many of their com- 

 pounds, and have found that compounds of the first order, in so 

 far as they are volatile and remain undecomposed when ade- 

 quately heated, always exhibit spectra which completely differ 

 from those of the metals. The observations which I have re- 

 cently made in this respect are communicated in the following 

 research. 



In the spectra of the compounds of the metals, to which I 

 shall subsequently recur in detail, a regularity is most observed 

 in the arrangement of the bright and obscure parts ; thus, for 

 example, in the spectrum of chloride, bromide, and iodide of 

 copper. (See the delineations of the spectra.) 



In these spectra, lines occur, or appear under special circum- 

 stances, which do not seem to me to belong to the spectra, 

 because they contravene their regularity ; such lines occur, for 

 instance, in the spectra of copper- and of bismuth-compounds. 

 It was obvious to suppose that these lines belonged to previously 

 unknown metals ; for the spectra produced by the introduction 

 of compounds of oxide of copper or bismuth into the flame, and 



* Translated from PoggendorfTs Annalen, No. 3, 1864, by Dr. E. At- 

 kinson. 



Phil. Mag. S. 4. Vol. 28. No. 188. Sept. 1864. N 



