246 Electricity and Galvanism, 



sufficient. For it is now pretty distinctly made out that the function 

 of digestion in the stomach is an action allied to simple solution, of 

 which water, — a temperature of 90°, and a free acid, the hydrochloric, 

 phosphoric, or both, are the active agents. The feeble current from 

 a single pair of zinc and silver plates is powerful enough to furnish, 

 in a short time, a sufficient supply of electricity to decompose some 

 chloride of sodium or common salt, and to evolve enough hydro- 

 chloric acid for the purpose of digestion ; and I shall have, indeed, 

 occasion to show in a future lecture that such a current, feeble as 

 it is in point of intensity, is capable of producing most remarkable 

 secondary effects on living tissues, actually effecting very important 

 chemical changes in the parts submitted to its influence. It is true 

 that objections have been started to this theory, but my own impres- 

 sion is that they are not sufficient to invalidate the accuracy of Dr. 

 Philip's statements ; and although I do not by any means consider 

 we are justified in admitting with him that electricity is capable of 

 performing all the functions of the nervous influence in the animal 

 economy, nor in regarding an electric current as constituting the real 

 digestive agent, we nevertheless possess sufficient evidence to induce 

 us to regard a current of electricity as the means by which the 

 saline constituents of the food are decomposed, and their constituent 

 acids, the real agents in digestion, act free in the stomach ; the soda 

 of the decomposed salts being conveyed to the liver to aid the 

 metamorphosis and depuration of the portal blood, and cause the 

 separation of matter, rich in carbon, in the form of a saline com- 

 bination in the bile. 



It is remarkable that although nothing is more frequently praised 

 than the certainty of the evidence of natural truths, and although 

 it would appear a simple thing to describe with fidelity and accuracy 

 the results of experiment and observation, still an observer has 

 scarcely had time to announce his discoveries and array his phalanx 

 of facts in a resistless manner, as he supposes, before some other 

 person repeats his experiments, and perhaps announces that he has 

 obtained exactly opposite results : such has been the case with Dr. 

 Philip's observations. Mr. Broughton, in this country, in particu- 

 lar, obtained nearly directly opposite results ; others have again 

 repeated their experiments, and have sufficiently corroborated the 



