'J38 DR. PHILIP ON DIGESTION. 



nearly completed before the food is actually in contact with the stomach, as 

 may be seen by inspecting that of an animal killed a few hours after a meal ; 

 and consequently is not detained when in contact with it. There is therefore 

 a continual motion of the food in contact with its surface towards the pylorus, 

 and the less digested part is continually approaching its surface. 



It follows then that a failure of the function of the stomach may arise either 

 from a proper gastric juice not being supplied, or the muscular power of the 

 stomach failing to carry onward the digested part, and thus regularly to pre- 

 sent to the stomach a new surface of food to be acted upon by that juice. It 

 further appeared, that for the first of these purposes the power of the nervous 

 system is necessary, the secretion of gastric juice failing as soon as the stomach 

 is deprived of any considerable part of this power ; but that the nervous power 

 is not necessary for the other, the muscular power of the stomach still canying 

 on towards the pylorus any digested food which happens to be in it, or any 

 food which had been acted upon by gastric juice which happened to be in it at 

 the time, however much its nei^vous power be impaired ; and this office is, as 

 far as we can see, as readily performed as when the nervous power of the 

 organ is entire. 



The muscular fibres of the stomach therefore are stimulated by its contents, 

 in the same way as those of the heart by the blood, the usual action of both 

 being wholly independent of the nervous system, an inference confirmed by 

 many other experiments beside those here referred to. 



I have, as appears from the papers which the Society have done me the 

 honour to publish, attempted to go a step further, and to show experimentally 

 that the office of the nervous power in preparing the gastric juice, may be cor- 

 rectly imitated by exposing the living stomach to the influence of a voltaic 

 pile after the supply of nervous power is interrapted. Those who were at first 

 inclined to doubt this fact, have since publicly acknowledged, on witnessing 

 the experiments, that the digestive process of the stomach supported by gal- 

 vanism, is, as far as we can see, as perfect as that supported by the nervous 

 power itself. iib 



It is therefore evident that in the formation of the gastric juice, a chemical 

 power can be substituted for that of the nervous system. I do not mean that, 

 strictly speaking, its formation is to be regarded as a mere chemical process. 



