1880.] 



Note on the Spectrum of Carbon. 



335 



April 29, 1880. 



THE TREASURER in the Chair. 



The Presents received were laid on the table, and thanks ordered 

 for them. 



The following Papers were read : — 



I. " Note on the Spectrum of Carbon." By J. Norm AN 

 Lockyer, F.R.S. Received April 8, 1880, 



In the year 1878 * I communicated to the Royal Society a paper in 

 which the conclusion was drawn that the vapour of carbon was present 

 in the solar atmosphere. 



This conclusion was founded upon the reversal in the solar spectrum 

 of a set of flutings in the ultra-violet. f The conclusion that these 

 flutings were due to the vapour of carbon, and not to any compound of 

 carbon, was founded upon experiments similar to those employed in the 

 researches of Attfield and Watts, who showed that the other almost 

 exactly similar sets of flutings in the visible part of the spectrum 

 were seen when several different compounds of carbon were exposed 

 to the action of heat and electricity. In my photographs the ultra- 

 violet flutings appeared under conditions in which carbon was the only 

 constant, and it seemed therefore reasonable to assume that the flutings 

 were due to carbon itself, and not to any compound of carbon. 



Professors Liveing and Dewar have recently on several occasions 

 called this result in question. Professor Dewar, in a paper received by 

 the Royal Society on January 8, 1880, writes as follows : — 



" The almost impossible problem of eliminating hydrogen from 

 masses of carbon, such as can be employed in experiments of this 

 kind, prove conclusively that the inference drawn by Mr. Lockyer as 

 to the elementary character of the so-called carbon spectrum from an 

 examination of the arc in dry chlorine, cannot be regarded as satis- 

 factory, seeing that undoubtedly hydrogen 'was present in the carbon% used 

 as the poles." 



Subsequently, in a paper received by the Royal Society on 

 February 2, Messrs. Liveing and Dewar wrote as follows : — 



* " Proc. Roy. Soc," vol. 27, p. 308. 



f The approximate wave-length, of the brightest member on the least refrangible 

 edge is 3881 -0. 



X The italics are mine. — J. N. L. 



