APPLICATION OF PHYSICAL LAWS TO ABSORPTION. 501 



vanic battery, this result was produced " in a few minutes and 

 even in a few seconds, according to the power of the pile and 

 the energy of its action." This is only one of a number of ex- 

 periments by Fodera illustrating the influence of the galvanic 

 current upon imbibition and absorption. 1 



The only definite applications of these facts to physiology 

 have been made in connection with the influences of the 

 nervous system upon absorption; and this has been done 

 under the idea that there is something in common between 

 the nervous force and electricity. If we are to determine the 

 existence of electrical action by the usual methods, the gal- 

 vanic current cannot be regarded as identical with nervous 

 power. The only way which we have of detecting a gal- 

 vanic current is by instruments known as galvanometers; 

 and those used at the present day in accurate investigations 

 are exceedingly sensitive. "With the most delicate instru- 

 ments known, it is impossible to detect any galvanic current 

 during endosmosis, or during the conduction by nerves of 

 the so-called nervous force. There is no reason, therefore, to 

 suppose that absorption is affected by galvanic action operat- 

 ing through the nervous system, and we must be content 

 with the explanations of nervous influence already given. 3 

 Nevertheless, galvanic currents have been detected between 

 different tissues and different parts of the same tissue during 

 life and immediately after death; but we have not as yet 

 been able to determine positively the influence of these cur- 

 rents upon any of the important functions. 



Applications of Physical Laws to the Function of 

 Absorption. 



In no experiments performed out of the body, can the 

 conditions favorable to the passage of liquids through mem- 

 branes in accordance with purely physical laws be realized as 



1 FODERA, Recherches Experimental es 'sur V Absorption et Exhalation, Paris, 

 1824, p. 22. 



2 See page 468. 



