VARIOUS ETHER THEORIES 



stance, perfectly continuous : not granular or molecular 

 like ordinary matter; subtile, incompressible, pervad- 

 ing all space and penetrating between the molecules 

 of all ordinary matter. It also possesses rigidity, and 

 it is thought in so far must be a solid ! It is with 

 reason, therefore, that L. Graetz, of Munich, one of 

 the latest mathematicians and writers on the subject, 

 and who apparently accepts this idea of the Ether 

 when free in space, should say : " The various Ether 

 theories embrace many imperfections. Properties are 

 attributed to it that are widely different from those 

 of any other known bodies." * 



Even in the ideas of the same person views are 

 held absolutely incompatible one with another. It 

 is not to be expected that the Ether should possess 

 properties similar to other known bodies, but the 

 properties as attributed to it by any theory should 

 not be self-contradictory or otherwise impossible. All 

 theories, however, of whatever kind, as well as our 

 daily experiences, agree in asserting its exemption 

 from all gravitic action. This condition is not an 



* Den versehiedenen Ether Theorien aber haften noch vielen Un- 

 volkomraerheiten an, es werden in ihnen dem Ether Eigenschaften 

 beigelegt die ganz abweichend von den Eigenschaften der sonst be- 

 kannten Korper. Daher gehort der quasilabile Ether Lord Kel- 

 vin's; ferner der quasirigide Ether derselben, den auch Sommerfeld 

 und Reiff so wie Bolzmann acceptiren, und dem Sommerfeld ausser 

 dem, in den Leitern, Quasi viscoscitat zugeschrieben wird. 



Annalen der Physik, No. 6, 1901. L. Graetz, Miinchen, Marz, 

 1901. 



