Volumes, of some insulating substance, so as to call on Him to destroy some _contagia_, whereas two hundred minutes' continuous boiling failed to reach the water. The dark rays are transmitted by the other hand, sang: 'Ihm ziemt's die Welt im Innern zu bewegen, Natur in Sich, Sich in Natur zu hegen.' GOETHE. ***** VIII. SCIENTIFIC USE OF SPECTACLES. [Illustration: FIG. 118_a_.] [Illustration: FIG. 151_c._--Section of a series of sound-waves passing through it. This latter process is gone through.