INTRODUCTION 



Although the statement of Prof. Hoppe-Seyler that " The process of 

 life of the organism is, in the main, a complete mystery " is still true, 

 much has been accomplished by the researches of modern physiologists and 

 clinicians who have endeavored to find the key to this enigma. Perhaps in 

 no realm of medicine has labor fructified so richly as in the recent study 

 of metabolism. This has been of value not only in diagnosis but, even more 

 so, from the standpoint of treatment. It may be confidently stated that the 

 treatment of some diseases of metabolism, such as diabetes mellitus, gout, 

 and obesity, now rests on a scientific basis. This advance is almost exclu- 

 sively due to the labors of the modern German school of physiologists and 

 internal clinicians. 



What is true of the pathology of metabolism may also be asserted of 

 diseases of the blood. The study of maladies whose etiology and pathology 

 were formerly obscure has now been simplified, their relations classified, and 

 the whole arranged in exact scientific order. The processes of blood forma- 

 tion and blood degeneration, while not yet forming an open book, have in 

 part been clearly portrayed. That therapy has not kept pace with this ad- 

 vance affords an opportunity for the physician of the twentieth century, 

 bxit much has already been accomplished, and many problems have been 

 solved. For this progress also the medical world is indebted to modern 

 research. 



The object of this volume is to present a picture of diseases which were 

 formerly designated as of " obscure causation," and to outline their treat- 

 ment. Each article is the work of a master in his special field of labor. 



In the translation an endeavor has been made to adhere as closely as 

 possible to the individual style of each contributor without the subserviency 

 of clearness in the text. 



