CHAPTER XV. 



A POSSIBLE WAY OUT OF THEM. 



WE can easily understand, seeing that much of the spectro- 

 scopic work which had been done up to 1874 had had for its 

 object the connecting intermingling, so to speak of solar, 

 stellar, and terrestrial chemistry, that it was not a pleasant thing 

 to find that the path seemed about to be such a very rugged 

 one that we seemed after all not to be in the light, but in the 

 dark ; and because it was not probable that an observer, impressed 

 with the difficulties referred to in the preceding chapters, would 

 long be content with the position, the very practical question 

 was, what was to be done ? It became necessary to see if there 

 was any way out of the difficulties. But how was one to attempt 

 to grapple with them ? Was it the time to found new 

 theories ? or to rest and be thankful ? Was it not better to 

 appeal to what was known ; to proceed in accordance with 

 Newton's laws of philosophising; and start no new principle 

 unless one was absolutely bound to do so : to appeal, in fact, 

 to the law of continuity? 



How would the law of continuity help us ? In this way : 

 All unconsciously, spectroscopists had been working under more 

 transcendental conditions as regards temperature than had ever 

 been employed before. Now, seeing that the history of chemistry 

 had been the history of simplification by heat, was it not 



