PHYSICAL PROPERTIES OF FLUORINE.
Fluorine possesses an odor which M. Moissan compares to a mixture of hypochlorous acid and nitrogen peroxide, but this odor is usually masked by that of the ozone which it always produces in moist air, owing to its decomposition of the water vapor. It produces most serious irritation of the bronchial tubes and mucous membrane of the nasal cavities, the effects of which are persistent for quite a fortnight.
When examined in a thickness of one meter, it is seen to possess a greenish yellow color, but paler, and containing more of yellow, than that of chlorine. In such a layer, fluorine does not present any absorption bands. Its spectrum exhibits thirteen bright, lines in the red, between wave lengths 744 and 623. Their positions and relative intensities are as follows:
| λ = | 744 | very feeble. |
| 740 | " | |
| 734 | " | |
| 714 | feeble. | |
| 704 | " | |
| 691 | " | |
| 687.5 | " | |
| 685.5 | " | |
| 683.5 | " | |
| 677 | strong | |
| 640.5 | " | |
| 634 | " | |
| 623 | " |
At a temperature of -95° at ordinary atmospheric pressure, fluorine remains gaseous, no sign of liquefaction having been observed.