J. .N. Lockyer—New Method of Spectrum Observation. 308 
Arr. XXXVIL—On a New Method of Spectrum Observation ; 
by J. N. LockygEr.* 
In anticipation of my report on the Methods of Mapping 
Spectra, which I have been requested to prepare for the Solar 
Committee, I beg to present to them the following account of 
some recent work which has been suggested during the prepa- 
ration of that report. 
the “atom” in the region of greatest electrical excitement, 
and that these vibrations were obliterated or prevented from 
arising by cooling or admixture with dissimilar atoms. 
_ Subsequent work, however, has shownt+ that of these short 
lines some are common to two or more spectra. These lines I 
have called basic. Among the short lines, then, we have some 
which are basic, and some which are not. 
The different behavior of these basic lines seemed, therefore, 
to suggest that not all of the short lines of spectra were, in re- 
me true products of high pr aria 
hat some would be thus produced ‘and would therefore b 
common to two or more spectra we could understand by ap- 
aling to Newton’s rule: “Causas rerum naturalium non 
and changes observed in the spectra of vapors of the elemen- 
tary bodies when volatilized at different temperatures in vac- 
wum tubes. Many of the lines thus seen alone and of sur- 
passing brilliancy, are those seen as short and faint in ordinary 
* Received for publication from the author. 
+ Proc. Roy. Soc., vol. xxviii, p. 159. 
