R. Meldola—Bright Lines in the Solar Spectrum. 291 
disruptive sparks pass through the gas. Dr. Schuster has 
recently succeeded in obtaining a second or “compound” 
Spectrum of oxygen,* the fundamental lines of which he has 
shown with considerable certainty to be present as dark lines 
in the solar spectrum. 
Since the publication of Professor Draper's discovery, I have 
given much attention to the consideration of a cause for the 
apparently anomalous brightness of the oxygen lines; and in 
the present paper I venture to advance an explanation which has 
recommended itself as being worthy of notice, not only because 
it offers a reconciliation of the known solar spectrum with the 
generally accepted views of the constitution of the sun’s atmos- 
phere, but likewise because it furnishes a suggestive hypothesis 
for the attack of many other obscure problems in solar p ysics. 
; Nature, xvii, 148, December 20, 1877. : 
we, Proc. Roy. Soe., xvi, p. 2 and xvii, p. 1; Phil. Mag., August, 1868; Monthly 
otices Roy. Astr. Soc., Dec., 1867; Lockyer, Phil. Trans., 1873, elxiii, 265. 
