SCOPE AND AIMS 11 



both that which is dead and that which is 

 alive. Changes even in the minute structure 

 of both dead and living matter may occur. 

 For example, it is known that slow changes 

 may happen in the structure of even hard 

 metals. Particles of gold may penetrate 

 into a mass of solid lead, and solid bodies 

 may even, by slow movements, sink into an 

 apparently brittle mass of cobblers' wax. 

 Slow changes probably occur in all kinds of 

 matter, even the most dense and durable. 

 Thus molecular changes, or, in other words, 

 movements, may occur in matter which we 

 call dead. Molecular movements also occur 

 in living matter, so that such minute move- 

 ments do not enable us to distinguish between 

 what is dead and what is alive. Both dead 

 and living matter, again, are subject to the 

 laws of gravitation, and many electrical and 

 optical phenomena are manifested in a 

 similar way by so-called dead and by so-called 

 living matter. 



4. There is no difficulty, however, in recog- 

 nizing many of the phenomena of life in one 

 of the higher forms, whether it be a plant 



