temperatures give different spectra, which means that they decompose 

 into other elements. The temperature of different parts of the sun 

 and of the same parts at different times, and of the stars, can be ob- 

 served. With small changes of temperature in the sun, different 

 forms of the same elements appear; with great changes of temperature 

 some elements disappear and new elements appear. In the stars there 

 is a great range of temperature. In stars, differing little in temperature, 

 we find different forms of the same element. But in stars differing 

 greatly in temperature, entirely different elements exist. Beginning 

 with the hottest stars, we have elements of the smallest atomic weight 

 and as we pass from cooler to cooler stars, the elements of heavier 

 and heavier atomic weight appear. As the heavier atomic weight in- 

 variably appear in the cooler stars, we believe that the heavy atoms 

 have evolved from the light atoms, which alone are found in the 

 hottest stars. 



We note that the evidence is of observed relations between the 

 elements under different conditions. The scientist observes directly 

 the gradual dissolution of radium and uranium into other elements. 

 He can with the small range of temperature under his control, ma- 

 terially change many elements. He observes the sun and sees the 

 heavier atoms appear as the sun spots dwindle and disappear as the 

 sun spots approach the maximum. And in the stars, which give him 

 the greatest range of temperature, he observes the relation between 

 temperature and the existence of atoms of different weights. As 

 certainly and as directly as we see a seed germinate and grow into 

 a tree, does the scientist see the lighter atoms, as the temperature 

 falls, change into atoms of heavier weight. To be sure, he does not 

 view the atom change directly, but he views the lines in his spectro- 

 scope, which he has learned by experience, faithfully represent the 

 atoms; and they tell with equal certainty the history of the evolving 

 atom. In acquiring this knowledge, the scientist has made neither 

 assumption nor inference. He has simply read the report of the 

 spectroscope, the trustworthiness of which long experience has taught 

 him. 



THE THEORY THAT MATTER Is ELECTRICAL. 



By experiment it was found that atoms were composed partly 

 of corpuscles, and that corpuscles were small, negatively charged 

 bodies moving with great velocity. The mass of these corpuscles, 

 when at rest, was experimentally compared with their mass when in 

 motion. The supposition was then made that the corpuscles were 

 merely electrical charges; and the mass when at rest and in motion, 



