268 SCIENCE AND IMMORTALITY 



" respiratory centre " prevent the propagation to the 

 respiratory muscles of those molecular waves which 

 cause respiratory movements, and thus, again, by 

 depriving the protoplasm of oxygen, cause perma- 

 nent molecular changes in it, incompatible with the 

 processes known as vital^ which it had previously 

 shown. 



Life in living tissue is like nothing perhaps so 

 much as a candle-flame. In the candle-flame the 

 molecules are composed and decomposed, yet the 

 candle-flame keeps always the same shape ; but let us 

 change the environment of these dancing, partner- 

 changing molecules — let us conduct away their heat 

 by means of some copper wire, or let us deprive 

 the flame of oxygen — and out goes the candle. 



Protoplasm is only a slow flame, easily extin- 

 guished. It is easy to understand how a little thing 

 — a needle, a few grains of poison — may destroy 

 a large organism when we remember how intri- 

 cately correlated it is in its minutest parts. Break 

 but a single thread in the warp and woof of life 

 and the whole wonderful web, with its pictures and 

 patterns, all comes asunder. Take but a single 

 brick out of the great house of life and it falls into 

 ruin. The construction of the wonderful organ- 

 isms of vegetables and animals is a miracle and 

 mystery, but their death is merely a chemical or 

 mechanical commonplace. 



