326 THE INVISIBLE WORLD 



Certain it is that among the diseases, thus pre- 

 vented, rank some of the worst, smallpox, chol- 

 era, typhoid fever. 



Certain it is that, during the half century, great 

 progress has been made in knowing the value of, 

 and how to enforce, the quarantine. 



Certain it is that, if all contagious and infectious 

 diseases could be properly quarantined, they would 

 be prevented from spreading, and thus all epi- 

 demics prevented. 



Certain it is that during the half century great 

 progress has been made in understanding and in- 

 stituting sanitary measures. 



Certain it is that in proportion as such measures 

 are generally used, they serve to prevent all dis- 

 eases, and so to promote the general health. 



Certain it is, therefore, that, with the incoming 

 of the New Era, medical practice is placed, to a 

 large extent and for the first time, upon a scientific 

 basis. The cause of all contagious and infectious 

 diseases are known to be poisons generated in the 

 body by germs. In so far as antitoxins have been 

 discovered, the up-to-date physician knows exactly 

 what to do: By timely administering the anti- 

 toxin the poison is counteracted; the patient re- 

 covers. The cause is removed ; the disease is cured. 

 No guesswork. No experiment. Only scientific 

 certainty. 



Certain it is, also, that the knowledge, which has 

 brought about this New Era, is beginning to spread 

 among the people. The original investigators have 



