THE SMITHSONIAN INSTITUTION. 



315 



elements is modified in a certain decree or destroyed ; or, in otlier 

 words, nndcr the circnnistances mentioned, the oxygen in each par- 

 ticle of water will he attracted in two opposite directions — towards the 

 zinc in contact with the raolecnle of water, and also towards the par- 

 ticle of hydrogen contained in this molecule. 



"Now, since the least mcclianical molecular change taking place 

 in a hody disturhs its electrical e(iuilibrium, or its particles become 

 electrically polarized, the above described change, caused by the zinc 

 in the original chemical affinity of the oxygen for the hydrogen of the 

 water, is followed by the electrical polarization of the substances in 

 contact with each other. The particle of zinc nearest the water 

 becomes positive ; the oxygen side of the molecule of water touching 

 the zinc is negatively polarized ; the hydrogen side of the same 

 particle, positively. It is self-evident that the ]>article of water in 

 contact with the zinc will exert an inductive action on its adjoining 

 molecules, the latter upon the next particles, and so on, until all the 

 molecules of water connected together are in the state of electrical 

 opposition or polarization. Since an inductive action traverses the par- 

 ticles of w^ater from the place where the zinc and water are in im- 

 mediate contact, all the contiguous particles of zinc become polarized, 

 and in such a manner that the side of each particle turned from 

 the water indicates negative polarity, and the side towards the 

 water positive polarity. By placing in this polarized water a good; 

 conductor or a substance easily electrified, which is indifferent 

 towards the oxygen of the water, such as platinum, the sides of the 

 particles of this substance in immediate contact with the water 

 become negatively electrified, and the sides of the same particles 

 turned away from the w^ater positively in consequence of an inductive- 

 action, which is exerted by tlie polarized water upon the platinum. 



" All the other particles of the platinum are similarly affected, that 

 is, the side of each molecule turned from the water has positive 

 polarity ; that of each towards the water has negative. 



"The following diagram gives a clear representation of the electrical 

 condition in which the particles of zinc, water, and platinum are found : 



" It is very evident that this 

 condition of all the particles of 

 the substance in question will 

 last as long as the cause pro- 

 ducing the polarization exists ;, 

 that is, as long as the chemical 

 attraction of the zinc for the 

 oxygen of the water continues. 

 But if the contact of the zinc 

 and water be broken, the op- 

 posite electrical conditions in 

 which the hydrogen and oxygen 

 of each molecule of water exist 

 ,-j .,,,.,, ij are neutralized, which is ncces- 

 ^^"^' sarily fo-llowed by a like change 

 in the particles of platinum. 



" Now, by placing the particle 1} of the arrangement in contact 



Fig. 1. 



