Note 425 — Chapter IX · HELIUM STARS WITH BRIGHT LINES.
Reading edition
Professor Frost’s conjecture that such stars may possess atmospheres preferentially absorbent of the shorter radiations did not seem to himself plausible enough for publication. Astroph. Journ. vol. ii. p. 182. A similar explanation, however, has lately been recommended by Dr. Kayser. Ibid. vol. xiv. p. 313.