THERAPEUTIC STUDIES ON IONS 7 1 



explorer who imagines himself upon an island until he 

 discovers a connection with the scarcely measurable 

 continent beyond. 



4. Therapeutic Studies on Ions.* 



"The acquisition of a new truth is like the acquisition 

 of a new sense, which renders a man capable of perceiving 

 and recognizing a large number of phenomena that are 

 invisible and hidden from another, as they were from him 

 originally." Chemische Brief e. 



WITH scarcely more fitting words than these of the old 

 master LIEBIG can we characterize the increase in scien- 

 tific knowledge and the establishment of new methods 

 of work and points of view for which we are indebted 

 to the application of the laws of physical chemistry to 

 questions in biology and even in practical medicine. If 

 we try to determine, from the varied and many advances 

 that have been made, along what lines these were made, 

 it can be easily shown that the application of three es- 

 pecially of the fundamental laws of physical chemistry to 

 biological problems has been most fruitful. These are 

 the law oj chemical mass action of GULDBERG and WAAGE, 

 which permits of an insight into the course, the velocity, 

 and the ultimate equilibrium of chemical reactions; the 

 theory 0} osmotic pressure, which has discovered to us 

 the common properties possessed by any series of solutions 

 independently of the nature of the dissolved substances; 

 and the theory of the electrolytic dissociation of certain 

 dissolved substances, the foundation of which resides 



* From Miinchener medizinalische Wochenschrift, 1903, p. 153. Ad- 

 dress delivered before the K. k. Gesellschaft der Aerzte, Vienna. 



