PEEFAOE TO THE EEYISED EDITION. 



The first edition of this book, published in 1890, gave 

 the world a new theory and established new principles. 

 Its teachings were that there is only one disease— decay ; 

 that it is caused by fermentation; and that all fermenta- 

 tion is caused by microbes. It was sent forth as a mes- 

 senger that the doors of Science had been opened, and 

 the seed scattered has borne abundant fruit. 



The three or four so-called diseases then admitted by 

 scientists to be caused by microbes have multiplied, until 

 the number includes all diseases, and the author's theory 

 has been permanently established. But a book written 

 in the infancy of a new discovery is necessarily incom- 

 plete. Scarcely had the first edition appeared when the 

 author began the preparation of the revised edition. 

 Step by step he proved the correctness of his new prin- 

 ciples, until they can be no longer doubted. Ceaselessly 

 he toiled in his laboratory with the fermentation of dis- 

 ease, propagating the microbes which caused that fer- 

 mentation, watching them grow in physicians' medicines 

 or die in his own antiseptics, or photographing them w^ith 

 the object of making them visible to everybody. 



The results of those years of patient investigation are 

 given in this revised edition. His photographs of the 

 microbes which cause the fermentation of the various 

 so-called diseases are reproduced with exactness, making 

 a valuable contribution to medical science. In place of 

 the cumbersome appendix, which treated of subjects 

 then held as possibilities, but which are now generally 

 admitted, are special chapters giving the results of the 

 author's personal investigations. 



No attempt has been made to make the revised edition 

 a literary effort. The author has a message to give to 

 the world, to science, to humanity, and it is given in 

 simple words and in the plainest manner possible. 



William Radam. 



New York City, March, 1895. 



