Changes produced in Mcitter hj Electric Warns. 



473 



(1) That ether waves produce molecular changes in matter. 



(2) That the molecular or allotropic changes are attended with 

 changes of electric conductivity, and this explains the action 

 of the so-called coherers. 



(3) That there are two classes of substances, positive and negative, 

 which exhibit opposite A'ariations of conductivity under the 

 action of radiation. 



(4) That the production of a particular allotropic modification 



depends on the intensity and duration of incident electric 

 radiation. 



(5) That the continuous action of radiation produces oscillatory 



changes in the molecular structure. 



(6) That these periodic changes are evidenced by the corresponding 

 electric reversals. 



(7) That the " fatigue " is due to the presence of the " radiation 

 product," or strained B variety. 



(8) That by means of mechanical disturbance or heat, the strained 

 product can be transformed into the normal form, and the 

 sensitiveness may thereby be restored. 



The method described above of detecting molecular changes is 

 extraordinarily delicate, and is full of promise in many lines of inquiry 

 in molecular physics. It is also seen that the phenomenon of contact 

 sensitiveness, contrary to previous suppositions, is perfectly regular. 

 There is no capriciousness in the response of sensitive substances to the 

 external stimuli, which may be mechanical, thermal, or electric. The 

 curves given above show it ; but they fail to give a fair idea of the rich- 

 ness and variety of the molecular phenomena, seen as it were reflected 

 in the fluttering galvanometer spot of light ; of the transitory varia- 

 tions, of the curious molecular hesitation at critical times as to the 

 choice of the structure to be adopted, and of the molecular inertia by 

 which the newly-formed structure is carried beyond the position of 

 stability, and the subsequent creeping back to the more stable position. 

 The varieties of phenomena are unlimited, for we have in each sub- 

 stance to take account of the peculiarity of its chemical constitution, 

 the nature of its response to ether waves, the lag and molecular 

 viscosity. All these combined give to each substance its peculiar charac- 

 teristic curve j it is not unlikely that these curves may give us much 

 information as to the chemical nature and the physical condition of the 

 different substances. I am at present trying to arrange an apparatus 

 which will, by means of the pulsating galvanometer spot of light, 

 automatically record the various molecular transformations caused by 

 the action of external forces. 



Before concluding, I take this opportunity of expressing my grateful 

 acknowledgments to the Eoyal Society for the encouragement J 



