Mr BAXTER, ON ORGANIC POLARITY. 255 



applied to the formation of the bile. So here in another class of secretions, additional evidence 

 has been obtained of the manifestation of current force during secretion. 



Before passing on to other secretions, I shall now notice the fallacy of supposing that the 

 stomach and liver form poles similar to those of a galvanic battery, an idea that has been en- 

 tertained by several individuals. No evidence could be obtained to shew that the stomach 

 forms the positive and the liver the negative electrode of a circuit similar to those of a voltaic 

 circle. It may just as well be supposed that the lungs and the stomach, or the lungs and 

 the kidneys, or the liver and the lungs, and the kidneys and the lungs are similarly related, 

 if we are to be guided by the mere circumstance of their relative connections in regard to the 

 circulation of the blood through these different organs. Each organ, the stomach and liver, 

 would appear to have, however, its own elementary circle, if I may so express it ; but no 

 evidence exists to shew that these two organs are so mutually related as to form one circle. 

 There is one fact which is of some interest and deserving of notice, it is this ; the blood, from 

 which the biliary secretion is formed, has previously undergone some most important changes 

 during its passage through the coats of the stomach and intestines, and thus an important re- 

 lationship must necessarily exist between these two organs ; and the question may naturally 

 arise. Is not the blood during its passage through the coats of the stomach and intestines, and 

 especially by the stomach, thus deprived of most of 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 all the 

 acids found in the stomach must 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 sh^iU 

 therefore leave it. 



Sect. III. On the Manifestation of Current Force during 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 contact with 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 S" to 5°. 



Should we be justified, in this instance, in supposing 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 galvanometer, when a more satisfactory explanation can be adduced by regarding the 

 effects as being consequent upon the separation of the acid product from the blood, as already 

 advanced in the previous sections with respect to the other secretions ? 



The amount of deviation of the needle being small, may be referred to the same causes 

 as were observed to exist with regard to the acid secretions and fluids in the stomach. The 

 secretion, urine, being acid, counter currents arise and are produced by the reaction of the acid 

 of the urine upon the fluids and substances with which it comes into contact. In judging, 

 therefore, of the effects upon the needle we must take into consideration the acting points in 

 the circuit ; there may be at least three acting points in a circuit, viz. at the point of secretion 



