﻿466 Prof. D. N. Mallik on the 



and aether) defined by the so-called specific inductive 

 capacity of the medium, which thus appears as a 

 constant of the medium. 

 (4) Conduction as well as convection currents (as in the 

 case of an electrical discharge) involves a tranference 

 ("a procession and not an arrangement " as Faraday 

 put it) dependent on a certain property of the con- 

 ductor (called its conductivity). This transference 

 is that of electric charge, but what this charge is — 

 whether it is material or sethereal — is not further 

 specified, or is rather left entirely open*. 



2. If we limit ourselves to two physical entities, matter 

 and sether, the electric charge whose motion constitutes 

 electric current must bo regarded as a mode of manifestation 

 of the aether. If, on the other hand, we agree to regard a 

 unit of electric charge as an actual physical entity, distinct 

 from matter and sether (but related to them and partaking 

 the nature of both in a manner that will require further 

 investigation), we are able to give an account of the various 

 phenomena which are left unexplained on the above 

 postulates. 



3. We are led to this additional postulate of a unit of electric 

 charge as a physical entity, not merely on theoretical grounds 

 but as a result of direct experiment. For during electrolysis, 

 each monovalent atom is known to carry with it to the anode 

 a determined quantity of what has hitherto been called a 

 negative electric charge which can be measured and which 

 is independent of the nature of the transported atom. If we 

 assume that this also is the unit charge, which takes part in 

 electric conduction or convection, and if we call it an 

 " electron/' we have to conceive a monovalent material 

 atom showing no electrical properties as the result of com- 

 bination of a single electron with what may fittingly be 

 called one or more units of "positive electricity." This 

 would amount then to the statement that the electrical pro- 

 perties of bodies (as well as those of a dielectric medium) 

 are due to the presence of " electrons" associated with atoms 

 of matter, forming systems of various complexity, and such 

 a theory is found to be consistent with observed facts. 



* Maxwell's pronouncement on this point, indeed, clearly sets forth 

 the position (' Electricity and Magnetism/ vol. i.) : 



" It appears to me that while we derive great advantage from the 

 recognition of the many analogies between electric current and current 

 of material fluid, we must carefully avoid making any assumption not 

 warranted by experimental evidence, and that there is as yet no ex- 

 perimental evidence to show whether the electric current is really a 

 current of a material substance or a double current, or whether' its 

 velocity is great or small as measured in feet per second." 



