52 THE NATURE OF MATTER 



number of constituent elements the only features to be noted. 

 One of the most characteristic elements in the substance 

 is carbon, and it also contains a high proportion of water. 

 Each of these has an extraordinary power of linking other 

 atoms or molecules to itself, when they approach, in a loose, 

 labile connection that allows a vast amount of breaking-away 

 and recombining. A particle of plasm is, therefore, a thing 

 of wonderful and indeterminable potentialities. The most 

 advanced chemistry of our time could not attempt to deduce 

 the properties that would result from this unstable and 

 complicated system of millions of atoms. 



"Such a grouping is likely to have properties differing not 

 only in degree, but in kind, from the properties of simple 

 substances." The proposition seems to promise a basis for 

 a mechanical conception of life. As a fact, the particle of 

 plasm (our microbe) does show properties that differ very 

 considerably from the properties of ordinary matter, though 

 they seem to differ only in degree from the crystal's properties 

 of growth and reproduction. The analogy with the crystal 

 must not, however, be pressed too far. The crystal and 

 plasm lie on very different tracks of molecular development. 

 The crystal is a comparatively rigid system, growing by the 

 addition or accretion at the fringe of new particles. The 

 colloid substance is unstable, and allows particles to pass in 

 and out of its system of atoms it feeds by intussusception. 

 Hence, if even in the crystal we have remarkable powers of 

 growth and reproduction and multiplication, we shall certainly 

 not be surprised to find them in a subtler form in a substance 

 like plasm. We may or may not expect to find properties 



