276 SCIENCE AND IMMORTALITY 



of alcohol. With accidental mechanical interference 

 with the machinery of life science is only indirectly 

 concerned, but chemical interference is her special 

 province, and she battles this under such titles as 

 pharmacy, pathology, and medicine. Science, 

 within the last sixty years, has found a host of 

 poisonous microscopic vegetables that grow in the 

 human tissues and chemically interfere with the 

 chemical processes of life, and science has not only 

 found these vegetables but has found ways and 

 means of avoiding or destroying them and their 

 poisons. We cannot here enter into the big sub- 

 ject of bacteriological medicine, but we may just 

 recall here how science has found an antitoxin able 

 to neutralise the poison of diphtheria, and has thus 

 saved thousands of children's lives. 



Not only thus, but in many other ways, such as 

 by providing fresh air or advocating wise feeding, 

 or by killing rats and mosquitoes, science has also 

 checked the chemical assaults of death, and has 

 lengthened the average life of civilised man. 



Still, even when such recognised attacks of death 

 are all baffled — still, what are called old age and 

 natural death are inevitable, and cannot be long 

 postponed by any known means. 



Metchnikov is of the opinion that old age is 

 in most cases due chiefly to poisons secreted by 

 microbes in the intestine, and he suggests that these 



