250 Mr BAXTER, ON ORGANIC POLARITY. 



Dismissing the notion that the stomach and liver are related to each other in the same 

 manner as the poles of a galvanic circle are mutually dependent, and with a more correct 

 knowledge of the origin of the power in the galvanic circle derived from Faraday's memoirs, 

 the thought arose that it might be during the formation of the secretions where the changes 

 were actually going on, that the evidence sought for could possibly be obtained. How far 

 these surmises were correct will now be seen. 



Sect. I. On the Manifestation of Current Force during the formation of the Secretions in 

 the mucous membrane of the alimentary canal, viz. the stomach and intestines. 



As the mode of employing the galvanometer and of conducting the experiments, together 

 with the precautions necessary to be observed, have already appeared in the Philosophical 

 Transactions of the Royal Society* for the years 1848 and 1852, it will not be necessary to 

 enter into a minute detail of these particulars. The results also of the experiments in the 

 present paper need only be related, as it is my intention to enter more deeply into the theo- 

 retical part of the question than could have been prudently attempted on the former occasion ; 

 for the time has now arrived, when, considering the great development that has taken place in 

 regard to electrical science in general, we may reasonably hope to be enabled by means of 

 scientific discussion, combined with experimental observation, to reduce the mass of unconnected 

 facts with which the science of Animal Electricity abounds within some more general laws. 



Although experiments performed upon the living animal may be considered as affording 

 more satisfactory results, nevertheless, as the results can be obtained, when sensibility is de- 

 stroyed, the following mode may be adopted in preference to the use of chloroform. 



Let a few drops of strong prussic acid be dropped on the nose, insensibility is thus quickly 

 produced; or let the animal be pithed, and upon laying open the chest or abdomen the heart will 

 be found to beat and the circulation to continue. Under these circumstances, if the platinum 

 electrodes of a galvanometer are placed one in contact with the mucous surface of the small or 

 large intestine, the other in contact with the blood in a vein from the same part, a deflection 

 of the needle will be obtained indicating a current through the instrument, the electrode in 

 contact with the blood being positive to the other in contact with the mucous surface. If 

 the same experiment be repeated with the mucous membrane of the stomach, the effects may 

 vary. If the stomach be empty, then the electrode in contact with the blood of the vein 

 coming from the same part will also be positive, but if there be any food in the stomach and 

 should it contain much acid, then the electrode in contact with its mucous surface will most 

 probably indicate a. positive state. Now these are the fundamental facts and the results, which 

 are readilv obtained with proper precautions, and may be thus stated : when the electrodes of a 

 galvanometer are brought into contact one with the mucous surface of the intestine in a living 

 or recently-killed animal, and the other with the venous blood from the same part, an effect 

 occurs upon the needle indicating the secreted product and the venous blood to be in opposite 

 electric states. 



• Philosophical Transactions, 1848 p. 243, 1852 p. 27». 



