CHAP. IV. §. in. DURING UEINABY SECRETION. 41 



the elements of its fixed acids, such as the muriatic 

 acid for example, and so far accounting for the small 

 proportion of these elements that are found in the 

 bile? It must be observed, that I am not now 

 supposing that aU the acids found in the stomach 

 mmt necessarily come from the blood, for there can 

 be no doubt that some of the acids are formed in 

 that viscus independent of those that are secreted by 

 that organ. But to enter upon this subject would 

 carry us away from our main object, and I shall 

 therefore leave it. 



Sect. III. On the Manifestation of Current Force 

 dwring Urinary Secretion. 



Upon inserting one of the extremities of the 

 electrodes of the galvanometer into the pelvis of the 

 kidney, and the extremity of the other electrode into 

 the renal vein of the same kidney, an effect upon the 

 needle is produced indicating the electrode in con- 

 tact Vith the blood to be positive to the other. A 

 difficulty may sometimes arise in obtaining any 

 effect. The amount of deflection of the needle, 

 when obtained, varies from 3° to 5°. 



Should we be justified, in this instance, in sup- 

 posing that the blood is acid to the urine, and not 

 only so, but combines with the urine, in order to 

 account for the effects observed upon the galva- 

 nometer, when a more satisfactory explanation can 

 be adduced, by regarding the effects as being con- 

 sequent upon the separation of the acid product from 



