PREFACE TO THE SECOND EDITION. 



WITH the steady advances made the division into parts 

 according to the class of organisms causing the diseases 

 has been justified. Even with intestinal diseases where 

 very different organisms may, as in dysentery, cause 

 similar symptoms, our knowledge is getting more 

 definite. In deference to the views expressed by some 

 kindly critics an alteration has been made in the arrange- 

 ment which it is hoped diminishes the amount of 

 repetition. 



C. W. D. 



