Mr BAXTER, ON ORGANIC POLARITY. 257 



Sect. IV. On the Manifestation of Current Force during Mammary Secretion. 



In my original paper only one experiment was recorded as shewing the results that were 

 obtained in the Mammary gland; since then several other opportunities have occurred in which 

 similar results were observed. 



If we insert the electrodes one into a lactiferous vessel and the other into a vein from the 

 same part, the electrode in contact with the vein is positive to the other, 8° or 10". 



Here, in this instance, we get evidence of the secreted product {the milk) and the 

 venous blood being in opposite electric states. 



It will be now seen that wherever secretion occurs, whether in the stomach and intestines, 

 in the liver, in the kidneys, or in the mammary gland, it will be found that the act itself is 

 not only accompanied with the manifestation of current force, but that the venous blood is 

 also, in all these instances, in the same state, in a positive electric state. The next question 

 that would naturally arise is the following: — what is the state of the arterial blood? 

 Although it has been found that the arterial blood indicates a positive state when formed 

 into a circuit with the secreted product, the other necessary element, viz. its electro-negative 

 element, the cation, for example, has not yet been obtained. Reasoning from analogy, it is in 

 the lungs that a satisfactory explanation on this point must be sought for. 



Physiologists may not perhaps be disposed to admit that the function of the lungs 

 corresponds to that of a secretory organ ; or that the process by which carbonic acid is elimi- 

 nated from the blood corresponds to that by which the acid is eliminated from the stomach ; 

 fortunately a decision on this point will not be necessary, and therefore need not detain us- 

 One circumstance, however, is well known, viz. that carbon, in some form or other, is elimi- 

 nated from the blood during its passage through the lungs ; and it may so happen that during 

 the elimination of this carbon, its separation from the venous blood whilst traversing the 

 lungs, that current electricity becomes manifested. 



Sect. V. On the Manifestation of Current Force during Respiration. 



When one electrode is brought into contact with the mucous membrane of the bron- 

 chial tubes, and the other inserted into the left ventricle of the heart, the latter electrode is 

 positive to the former, from 2° to 5". When the electrode, instead of being inserted into the 

 left ventricle was inserted into the right ventricle, it still indicated a positive state. — Here 

 then are indications of the arterial blood being positive to the mucous surface of the lungs ; 

 how far this state may be due to the separation of the carbon from the venous blood 

 which traversed that organ may be a subject of dispute ; the fact, however, is of some 

 importance as indicating the electric condition of the arterial blood. 



In looking back upon the results that have now been obtained, some surprise may be felt 

 at the circumstance that all these experiments tend to indicate that, during life, the blood, 

 whether venous or arterial, is in a positive electrical state or condition, and that this state or 

 Vol. X.' Part I. 33 



