THE MECHANISM OF LIFE 227 



nitrogen, also occur, though in very mucli smaller 

 proportions, as also sodium and aluminium. There 

 is also some iron, this being the lightest in its 

 own particular group, and magnesium and sodium 

 are not wanting. The group to which iron belongs, 

 although consisting of tetrads, has many peculiarities 

 which distinguish it from the carbon group. 

 Iron is at any rate the lightest amongst the group 

 of nickel, cobalt, ruthenium, rhodium, osmium, 

 iridium, palladium, and platinum. 



The rate of transformation of the elements down- 

 wards in atomic rate may depend, and most pro- 

 bably does depend, upon the temperature when 

 the temperature is very high ; experiments on 

 radium emanation up to a temperature of about 

 1000° have not revealed so far any such increase 

 in rate of change. Nevertheless, since the con- 

 stituents of protoplasm, as we have shown, most 

 probably came together at a very high temperature, 

 the fact that it was only the lightest elements of 

 the groups that apparently took part in it seems 

 to indicate that transformation took place more 

 rapidly at that high temperature than it does at 

 comparatively low ones. It stands to reason, in 

 fact, that although all ordinary collisions between 

 radio-active atoms may not be sufficient to increase 

 their rate of disintegration, yet it should be possible 

 by making those collisions sufficiently violent to 

 affect that rate. In other words, by raising the 

 temperature to a sufficiently high degree it should 

 be possible to increase the rate of transformation. 



It is curious to note that those lighter elements, 



Q 2 



