II BIOLOGY AND THE STATE 69 



a mild form of the disease, such inoculation having 

 the result of rendering the cattle and sheep free from 

 the attacks of the severe form of disease, just as 

 vaccination or inoculation with cow-pox protects man 

 from the attack of the deadly small-pox. One other 

 case I may call to mind in which knowledge of the 

 presence of Bacteria as the cause of disease has led to 

 successful curative treatment. A not uncommon 

 affliction is inflammation of the bladder accompanied 

 by ammoniacal decomposition of the urine. Micro- 

 scopical investigation has shown that this ammoniacal 

 decomposition is entirely due to the activity of a 

 Bacterium. Fortunately this Bacterium is at once 

 killed by weak solutions of quinine, which can be 

 injected into the bladder without causing any injury 

 or irritation. This example appears to have great 

 importance, because it is the fact that many kinds of 

 Bacteria are not killed by solutions of quinine, but 

 require other and much more irritant poisons to destroy 

 their life, which could not be injected into the bladder 

 without causing disastrous effects. Since some 

 Bacteria are killed by one poison and some by 

 another, it becomes a matter of the keenest interest 

 to find out all such poisons ; and possibly among 

 them may be some which can be applied so as to 

 kill the Bacteria which produce phthisis, erysipelas, 

 glanders, anthrax, and other scourges of humanity, 

 whilst not acting injuriously upon the body of 

 the victim in which these infinitesimal parasites 

 are doing their deadly work. In such ways as 

 this biology has turned the toy "magnifying- glass" 



