THE 

 LONDON, EDINBURGH, and DUBLIN 



PHILOSOPHICAL MAGAZINE 



AND 



JOURNAL OF SCIENCE 



[FOURTH SERIES.] 



OCTOBER 1869. 



XXX. On the Spectra of Carbon. By W. M. Watts, D.Sc, 



Physical- Science Master in the Manchester Grammar School*. 

 [With a Plate.] 



ALTHOUGH considerable progress has been made in spec- 

 trum-analysis since its first principles were enunciated by 

 Bimsen and Kirchhoff, we still seem to be in considerable un- 

 certainty as to the changes in the spectrum of an element which 

 it is possible to bring about by altering the conditions under 

 which it is produced. The interesting investigations of Pliicker 

 and Hittorf and of Wiillner have shown that it is possible for 

 an element to have more than one spectrum ; and these totally 

 different spectra have been supposed to belong to different allo- 

 typic modifications, apparently on the supposition that changes 

 of temperature produce changes in the spectrum consisting 

 merely in the addition of new lines. The following observa- 

 tions, in which four different spectra are described as belonging 

 to the element carbon, are offered as contributions to our know- 

 ledge of this subject. 



The principal previous investigations on the spectra of the 

 carbon-compounds, to some of which reference is afterwards 

 made, are comprised in the following list : — 



Swan, Edinb. Phil. Trans, vol. xxi. p. 411 (1856). 



Attfield, Phil. Trans. 1862, p. 221. 



Pliicker, Pogg. Ann. vol. cvii. p. 497. 



Dibbits, Pogg. Ann. vol. cxxii. p. 499, and De Spectraal 

 Analyse. 



* Communicated by the Author. 



Phil Mag. S. 4. Vol. 38. No. 255. Oct. 1869. S 



