201 



flexible state, many particles are concerned at once, it is not possible 

 that all these should be broken through by a force applied on one 

 side of the place of adhesion, before particles on the opposite side 

 should have the opportunity of regelation, and so of continuing the 

 adhesion." 



The interpretation thus put by Prof. Faraday on his experiments 

 is not convincing to me ; but, on the contrary, I think the experi- 

 ments are in perfect accordance with my own theory, and tend to its 

 confirmation. My view of the phenomena of these experiments is as 

 follows : The first contact of the two pieces of ice cannot occur 

 without impact and consequent pressure ; and, small as the total 

 force may be, its intensity must be great, as the surface of contact 

 must be little more than a geometrical point. This pressure produces 

 union by the process of melting and regelation described by me in pre- 

 vious papers. On the application of the forces from the two feathers, 

 at one side of the point of contact, tending to cause separation, 

 the isthmus of ice formed by the union of the two pieces comes to 

 act as a tie or fulcrum subject to tensile force ; and consequently a 

 corresponding pressure will occur at the side of the isthmus, far from 

 the feathers ; and that pressure will effect the union of the ice at the 

 side where it occurs. The tensile force, it may readily be supposed, 

 tends to preserve the isthmus, internally at least, in the state of ice, 

 whatever may be its influence on the external molecules of the isth- 

 mus, and to solidify such water as, having occupied pores in the in- 

 terior during previous compression, may now, by the linear tension 

 or pull, be reduced in cubical pressure or hydrostatic pressure, be- 

 cause the melting-point of wet ice is raised by diminution of pressure 

 of the water in contact with it*. The pull applied to the isthmus 



* How the surface of a bar of ice immersed in cold water, as distinguished 

 from the interior of the bar, may in respect to tendency either to melt away, or 

 to solidify to itself additional ice from the water, be influenced by the applica- 

 tion of linear tension to the bar, I am not quite prepared to say positively. 

 The application of tension, whether linear, superficial, or cubical (that is, 

 whether simply in one direction, or in two directions crossing one another, or 

 in three directions crossing one another), to a piece of ice immersed in water at 

 any given pressure, atmospheric for instance, is very distinct from the applica- 

 tion of what might be called cubical tension, that is, diminution of hydrostatic 

 pressure, to the surrounding water. In the former case the pressure of the 

 water at the external surface of the ice will not be reduced by the application of 

 the tension to the ice ; though that of the water in the internal pores may, or 



