Prof. Norton on Molecular Physics. 109 



of electric aether from their outer sides. The like tendency of 

 roughness of surface may be explained in a similar manner. 



The tension of the electricity obtained should depend upon 

 the degree of polarization which the surface-molecules are ena- 

 bled to retain ; for upon this will depend the limit of the resist- 

 ance which they are capable of offering to the free now of the 

 electricity from molecule to molecule (p. 105). It should there- 

 fore be independent of the velocity, the pressure, and the extent 

 of the rubbing surfaces, as established by Peclet. The electrical 

 state of the surface, whether positive or negative, must depend 

 upon the mutual relations of the surfaces, and the comparative 

 energy of the disturbing force in operation upon each (p. 108). 



Voltaic Electricity. — In entering upon this topic, we must first 

 endeavour to obtain, from our present point of view, an insight 

 into the nature of chemical union. When two dissimilar mole- 

 cules, a and b, are brought into close proximity, the effective 

 action of a upon the atmosphere of b may be quite different in 

 amount from that exerted by b upon the atmosphere of «*. As a 

 consequence, the relative condition of these atmospheres may be 

 disturbed ; in other words, they may become polarized. As the 

 act of polarization proceeds, an electric current, or series of 

 waves (p. 101), will pass through the two molecules, and at the 

 same time they will approach each other. As this approxima- 

 tion continues the density of the electric sether between them 

 will increase (p. 99, fig. 5), and a true electric or conducting 

 union may thus be established between them. Under these 

 circumstances, it would seem that finally the non-conducting 

 resistance offered by the polarized molecules (p. 104) should be 

 in a great degree overcome, a comparative equilibrium of ten- 

 sion be established between the outer envelopes of the two atmo- 

 spheres, and, as a consequence, the polarization materially de- 

 crease if not ultimately disappear. In this event the final union 

 would be due chiefly, or entirely, to the molecular attraction 

 proper, as in the case of similar molecules. It is in this final 

 condition essentially that we suppose a particle of water to exist. 

 The two constituent molecules, oxygen and hydrogen, are not 

 polarized, or but feebly so ; and they are to a certain degree in 

 conducting communication with each other f. 



* A disturbing action from the molecular attraction may even come into 

 operation when the molecules are beyond the range of effective attraction 

 — that is, beyond Oc, tig. 1. For it is to be observed that, in the action of 

 each molecule upon the atmosphere of the next, the attractive impulses 

 prevail over the repulsive beyond Oc as well as between Oa and Oc. 



t It is not absolutely essential to the explanation of the voltaic current 

 that the two molecules, when combined, should be regarded as devoid of 

 polarization. 



According to the received theory of the constitution of a molecule of 



