OHAP. IV. §. I. IN THE STOMACH AND INTESTINES. 29 



Although experiments performed upon the living 

 animal may he considered as affording more satis- 

 factory results, nevertheless, as the results can he 

 obtained when sensibility is destroyed, 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 galva- 

 nometer 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 wiU 

 most probably indicate a positive state. Now these 

 are the fundamental facts and the results, which are 

 readily obtained with proper precautions, may be thus 

 summed up : when the electrodes of a galvanometer 



