CHAPTER XI.

The comparison of some Tube and other Spectra with the Spectrum of the Aurora: pp. 108-120.

Hydrogen-tube: pp. 108-110.

Carbon- and oxygen-tubes: pp. 110-114.

Geissler mercury-tube and barometer mercurial vacuum: pp. 114, 115.

Air-tubes: pp. 115, 116.

Phosphorescent tube: pp. 116, 117.

Spark in air: p. 117.

Spark over water: p. 117.

Phosphoretted-hydrogen flame: pp. 117, 118.

Iron-spectrum: p. 118.

Spectrum of mercury: p. 119.

Table of coincidences: p. 119.