20 STUDIES IN ADVANCED PHYSIOLOGY. 



and that the heat made here was carried over the body by 

 the blood. The important fact that the oxidation is in the 

 tissues themselves was finally established by Liebig and 

 Pfliiger in their study of muscular tissue in 1867. The 

 nervous control and regulation of breathing studied first by 

 L,e Gallois in 1812 was extended by Flourens in 1842, 

 Traube 1847, and Rosenthal 1862. The processes of secre- 

 tion were also soon investigated. The notions of the an- 

 cients on this point were very primitive. They regarded the 

 discharge of the mucous phlegm from the nose as an elim- 

 ination from the brain which soaked through the ethmoid 

 bone into the nose. The study of glands by Peyer, Brun- 

 ner and Malpighi soon established the anatomy of secretory 

 tissues. The action of nerves on glands was brought to 

 light by the successful experiments of L,udwig and Bernard 

 of our own day, who succeeded in producing the salivary 

 secretion by the artificial stimulation of the nerves going 

 to the gland. The celebrated physiologist of Berlin, Du 

 Bois Reymond, brought to light a multitude of observations 

 on the electrical properties of living tissues. To that most 

 remarkable scientist, Helmholtz, of Berlin, we are indebted 

 largely for the accurate knowledge we now possess of the 

 physiology of the eye and the ear. The Young-Helmholtz 

 theory of color is still the best interpretation of color sen- 

 sations, and the studies in the physics of harmony have 

 solved for us to a very large extent the problem of the ear. 

 When to this is added the measuring of the rate of transmis- 

 sion of nervous impulses and the exposition of the law of 

 the conservation of energy, it will be seen how much has 

 been added by this scholar. 



The history of special problems in physiology will be 

 found noted in their respective places in the book. It is 

 hoped that the foregoing epitome may show the interested 

 reader the long road by which our familiar ideas have 

 reached us. It is believed that a clearer perception of the 

 efforts and the struggles which it has cost great men to 

 interpret for us these phenomena may result in a quickened 



