i28 FRAGMENTS OF SCIENCE 



detection. But no particles were seen. Under the micro- 

 scope the turbid liquid was not to be distinguished from 

 distilled water.* 



But we have it in our power to imitate, far more 

 closely than we have hitherto done, the natural conditions 

 of this problem. We can generate, in air, artificial skies, 

 and prove their perfect identity with the natural one, as 

 regards the exhibition of a number of wholly unexpected 

 phenomena. By a continuous process of growth, more- 

 over, we are able to connect sky-matter, if I may use the 

 term, with molecular matter on the one side, and with 

 molar matter, or matter in sensible masses, on the other. 

 In illustration of this, I will take an experiment suggested 

 by some of my own researches, and described by M. Mor- 

 ren of Marseilles at the Exeter meeting of the British As- 

 sociation. Sulphur and oxygen combine to form sulphur- 

 ous acid gas, two atoms of oxygen and one of sulphur 

 constituting the molecule of sulphurous acid. It has been 

 recently shown that waves of ether issuing from a strong 

 source, such as the sun or the electric light, are competent 

 to shake asunder the atoms of gaseous molecules. * A 

 chemist would call this "decomposition" by light; but it 

 behooves us, who are examining the power and function 

 of the imagination, to keep constantly before us the phys- 

 ical images which underlie our terms. Therefore I say, 

 sharply and definitely, that the components of the mole- 

 cules of sulphurous acid are shaken asunder by the ether- 



* Like Dr. Burdon Sanderson's ''pyrogen," the particles of mastic passed, 

 without sensible hinderance, through filtering- paper. By such filtering no free- 

 dom from suspended particles is secured. The application of a condensed beam 

 to the filtrate renders this at once evident. 



^ See "New Chemical Reactions produced by Light," vol. i. p. 103. 



