We may thus observe three principal absorption spectra.

We have just seen that in clinorhombic crystals the principal absorption directions of certain bands were completely different from the axis of optical elasticity of the crystal for the corresponding radiations.

Remarkably complete digestion and absorption follow.

The absorption lines of the terrestrial atmosphere would form the best standard for this purpose if those which are sufficiently fine can be photographed.

In various crystals the characters of the absorption phenomena differ strikingly from those which we might expect to find after an examination of the optical properties of the crystal.

It was the custom in R, and is now to quite an extent elsewhere, to elect as school committee those especially noted for their ignorance and unfitness for the duties, perhaps to keep them out of the almshouse, or to educate them by the absorption process while hearing pupils recite.

If we examine this anomaly, we perceive that the crystals manifesting these effects are complex bodies, formed of various matters, one, or sometimes several, of which absorb light and give each different absorption bands.

The absorption spectrum observed through a crystal varies with the direction of the rectilinear luminous vibration which propagates itself in this crystal.