456 Prof. J, C. Bose. On Electric Touch and the Molecular 



be presently described which would show that the theory of coherence 

 is inadequate. From the above it would appear that the subject 

 is far more complex than was at first supposed. For various reasons 

 it would be best to distinguish between the two different actions, which 

 may conveniently be described as mass action and molecular action. 



Mass Action. — By this is meant the general action, say, between two 

 masses when placed in a very strong electric field. Under the given 

 circumstance, sparking may take place between the bodies, and the 

 two may thus be welded together. From what has been said it will 

 be seen that such action is non-discriminative — that is to say, the 

 action will be the same whatever the chemical or physical nature of 

 the substance may be. The best way of showing this action is with 

 drops of liquid, with surface contamination, for any incipient welding 

 will be at once exhibited by the complete coalescence of the drops. The 

 non-discriminative nature of the action is shown in a striking manner in 

 the following experiment. I may mention here that fragments of solid 

 potassium, and in a lesser degree sodium, exhibit an increase of con- 

 tact-resistance under the action of electric waves. I made a liquid 

 alloy of potassium and sodium, and drops of this alloy were allowed to 

 float on the stratum separating dense Rangoon oil from lighter kero- 

 sine, the alloy being of an intermediate density. The drops coalesced 

 when placed in an intense alternating electric field. The next experi- 

 ment was made with potassium heated under melted (hard) paraffin. 

 By stirring the molten K with a glass rod, the metal was broken up 

 into numerous spherical drops. These also coalesced under similar 

 electric influence. It is, however, to be borne in mind (1) that in the 

 above experiment the substance is in the form of a liquid, and that in 

 this particular condition certain important molecular changes, to be 

 presently described, cannot very well take place j (2) that the condi- 

 tions of the experiment are abnormal. 



Experiments will be presently described which will show that the 

 observed variation of conductivity produced by radiation is not due to 

 coherence, but to certain molecular changes of an allotropic nature. 



Molecular Action. — By this I mean the allotropic modification pro- 

 duced in a substance by the action of electric waves, the allotropic 

 change being due to a difference in the atomic or molecular aggrega- 

 tion. It will be shown that such molecular change does take place by 

 the action of electric waves, and that all the observed effects of varia- 

 tion of resistance of the sensitive substance may be explained on the 

 theory of allotropic transformation due to the above cause. The 

 effect due to molecular changes in a substance is also expected to be 

 modified by the chemical nature of the substance ; thus the molecular 

 action due to radiation, giving rise ultimately to the variation of con- 

 ductivity of the sensitive substance, will be discriminative, in contra- 

 distinction to the non-discriminative mass action. 



