Mr. J. N. Lockyer'a Spectroscopic Notes. 323 



Zn. Continuous absorption in the blue. (An unknown line 

 sometimes appears in the green, but certainly no line 

 of Zn.) 



Cd. Continuous absorption in the blue. 



Sb. New spectrum, with channelled spaces and absorption in 

 the blue. 



P. The same. (This, however, in consequence of the ex- 

 treme delicacy of the spectrum, requires confirmation.) 



S. Channelled-space spectrum (previously observed by Salet). 



As. Probable channelled-space spectrum. (Observations to 

 be repeated.) 



Bi. No absorption. 



I. Channelled spectrum in the green and intense bank of 

 general absorption in the violet, where at the ordinary 

 temperature the vapour transmits light. 



Hg. No absorption. 



10. These results may be tabulated as follows : — 



No visible absorption. 



Line absorption. 



Probable channelled-space absorp- 

 tion. 



Continuous absorption in the blue. 



Channelled-space absorption -f band 

 of absorption in violet. 



No absorption. 



Channelled-space spectrum probable. 

 Line absorption. 



Continuous absorption in the violet. 

 Channelled-space spectrum and ab- 

 sorption in the blue. 

 Channelled- space spectrum. 

 No absorption. 



11. It will be seen from the foregoing statement that if similar 

 spectra be taken as indicating similar molecular conditions, then 

 the vapours, the densities of which have been determined, have 

 not been in the same molecular condition among themselves. Thus 

 the vapours of K, S, and Cd, at the fourth stage of heat, gave us 

 line, channelled-space, and continuous absorption in the blue re- 

 spectively. This is also evidence that each vapour is non-homo- 

 geneous for a considerable interval of time, the interval being 

 increased as the temperature is reduced. 



" Spectroscopic Notes. — No. IY. On a new Class of Absorption 

 Phenomena." By J. Norman Lockyer, F.B..S. 



1. In the experiments on the absorption-spectrum of Na and 

 K vapour heated in a red-hot tube, to which further reference is 

 made in separate notes, I have observed phenomena quite new 





V.d. 



Modern 

 atomic weight. 



H ... 



. 1 



1 



K ... 



. 39 



39 



As ... 



. 150 



75 



Cd ... 



. 56 



112 



I ... 



127 



127 



Hg... 



100 



200 



N ... 



14 



14 



P .... 



62 



31 



Na . . . 



(?) 



23 



Zn . . . . 



(?) 



65 



Sb . . . . 



(?) 



122 



S ... 



32 



32 



Bi 



(?) 



208 



