NEW MECHANICS AND ASTRONOMY. 249 



There cannot, therefore, be attraction without ab- 

 sorption of light, and consequently without production 

 of heat, and it is this that determined Lorentz to 

 abandon this theory, which does not differ funda- 

 mentally from the Lesage-Maxwell-Bartholi theory. 

 He would have been still more alarmed if he had 

 pushed the calculations to the end, for he would have 

 found that the Earth's temperature must increase 10^^ 

 degrees a second. 



IV. 



Conclusions. 



I have attempted to give in a few words as com- 

 plete an idea as possible of these new doctrines ; I 

 have tried to explain how they took birth, as other- 

 wise the reader would have had cause to be alarmed 

 by their boldness. The new theories are not yet 

 demonstrated — they are still far from it, and rest 

 merely upon an aggregation of probabilities suffi- 

 ciently imposing to forbid our treating them with 

 contempt. Further experiments will no doubt teach 

 us what we must finally think of them. The root of 

 the question is in Kaufmann's experiment and such 

 as may be attempted in verification of it. 



In conclusion, may I be permitted to express a 

 wish? Suppose that in a few years from now these 

 theories are subjected to new tests and come out trium- 

 phant, our secondary education will then run a great 

 ri.sk. Some teachers will no doubt wish to make room 

 for the new theories. Novelties are so attractive, and 

 it is so hard not to appear sufficiently advanced ! At 

 least they will wish to open up prospects to the chil- 



