io SCIENCE PROGRESS. 



little closed electric currents be true, these magnetic forces 

 should have some interatomic effects as well as the electric 

 twist he supposes superposed upon them. These compli- 

 cations seem, however, required by the apparently more 

 complicated nature of general chemical actions than the 

 particular case of simple electrolytic ones. In cosmology 

 we have innumerable suggestions as to the causes of 

 magnetic storms, aurorae, comets' tails, coronal streamers, 

 zodiacal light, all depending upon various electro-magnetic 

 actions. Some, such as the direct production of magnetic 

 storms by electro-magnetic changes on the sun, seem 

 disproved by the enormous expenditure of energy re- 

 quired ; but others, in which the electro-magnetic actions 

 are due to streams of ions in particular directions crossing 

 the earth's way, seem deserving of consideration. 



The greatest problems at present before physical in- 

 vestigators are the structure of ether and matter. We 

 can hardly doubt that they are dynamically constructed. 

 They are every day more conclusively shown to be 

 dynamical systems, subject to the laws of momentum, of 

 energy, of action and reaction. Are they so in their 

 minutest parts ? There seems little doubt but that they 

 are. If so, what is their structure? Is the fascinating 

 suggestion of vortex rings in a perfect liquid or in a 

 MacCullagh medium capable of explaining the phenomena 

 of matter ? What about the difficulties involved in the 

 momentum being greatest when the velocity is least? Is 

 it a more helpful view to be content for the present with 

 those horrible fictions of the pure mathematician, small 

 hard particles, and to treat combinations as planetary 

 systems with a measurable moment of momentum as well 

 as internal energy ? We want to get a road opened up 

 into these dark continents. We want to know the structure 

 of matter and its internal motions, and we look to the 

 physical investigator to study spectra, the laws of motion, 

 the sizes of molecules, their internal motions. We look to 

 the chemist to measure the forces between them, their 

 modes of combination, their structure when combined, and 

 how that structure affects their properties, physical and 



