CHAPTER III 



GENERAL METHODS OF INVESTIGATION AND THE VALUE 

 OF THE RESULTS WHICH MAY BE OBTAINED 

 BY SUCH METHODS 



IN the investigation of a subject of such wide physiological 

 import as internal secretion, it is natural that all methods 

 employed in general physiological research should be utilized 

 as occasion demands. The usual methods of experimental 

 physiology, recording devices, and all the appurtenances 

 belonging to the graphic method, are in regular requisition. 

 Physiological chemistry is no longer a mere handmaiden, but 

 is rapidly becoming mistress of the situation. No attempt 

 will be made to pass in review all these details of scientific 

 biological technique. A few of the more important methods 

 which have been of especial service in the development of the 

 subject of internal secretion will be briefly referred to, and an 

 opportunity will at the same time be seized to deal with a few 

 side issues which could not conveniently be treated in any other 

 chapter. 



The subject of internal secretion is, of course, a physiological 

 one, but we shall again and again have occasion to make 

 reference to pathological methods and pathological data. This 

 is perhaps more emphatically the case than in any other chapter 

 in physiology, because such a large proportion of our knowledge 

 of internal secretion is derived from the realm of pathology, 

 not only from human pathology, but also from experimental 

 pathology, the result of experiments upon animals. 



The fact discovered by Addison in 1855 that the symptoms 

 nf what is nn\\ known as Addison's disease are due to a lesion 

 of t he adrenal bodies is still one of the most important pieces of 

 Information we possess about these structures. The association 

 of <l<-fr( -t ivr thyroid development or atrophy with cretinoid and 

 myxo2dematous conditions is still the sheet anchor of our 



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