316 MAGNALIA NATURAE: OR THE GREATER 



forces that are acting or have acted upon it; in this strict 

 and particular sense, it is a diagram : in the case of a solid 

 of the forces that have been impressed upon it when its con- 

 formation was produced, together with those that enable it 

 to retain its conformation ; in the case of a liquid (or of a 

 gas) of the forces that are for the moment acting on it to 

 restrain or balance its own inherent mobility. In an organism, 

 great or small, it is not merely the nature of the motions 

 of the living substance that we must interpret in terms of 

 Force (according to Kinetics), but also the conformation of the 

 organism itself, whose permanence or equilibrium is explained 

 by the interaction or balance of forces, as described in Statics. 



If we look at the living cell of an Amoeba or a SpirogjTa, we 

 see a something which exhibits certain active movements, 

 and a certain fluctuating, or more or less lasting, form ; and 

 its form at a given moment, just like its motions, is to be 

 investigated by the help of physical methods, and explained 

 by the invocation of the mathematical conception of force. 



Now the state, including the shape or form, of a portion 

 of matter, is the resultant of a number of forces, which repre- 

 sent or symbolise the manifestations of various kinds of 

 Energy ; and it is obvious, accordingly, that a great part of 

 physical science must be understood or taken for granted, 

 as the necessary preliminary to the discussion on which we 

 are engaged. 



I am not going to attempt to deal with, or even to enume- 

 rate, all the physical forces or the properties of matter with 

 which the pursuit of this subject would oblige us to deal, 

 with gravity, pressure, cohesion, friction, viscosity, elas- 

 ticity, diffusion, and all the rest of the physical factors that 

 have a bearing on our problem. I propose only to take one 

 or two illustrations from the subject of Surface-tension, 

 which subject has already so largely engaged the attention 

 of the physiologists. Nor will I even attempt to sketch 

 the general nature of the phenomenon, but will only state 



