96 



of the food in the gastric juice, out of the stomach, and that which oc- 

 curs in digestion within the organ. Every thing tends to show, that the 

 stomach ought not to be considered as a chemical vessel, in which there 

 takes place a mixture giving rise to new combinations. The tying the 

 nerves of the eighth pair, the use of narcotic and of opium, intense 

 thought, every powerful affection of the mind, trouble or even gaiety, 

 entirely suspend digestion in the stomach, which cannot take place inde- 

 pendently of nervous influence. Yet this nervous influence may possi- 

 bly not concur directly, and of itself, to stomachic digestion; it is perhaps 

 merely relative to the secretion of the gastric juice, which the ligature of 

 the nerves, the action of narcotics or of other substances may impede, 

 alter, or even completely suspend. 



It is now very generally admitted, that digestion in the stomach cn- 

 sists in the solution of the Ibod in the gastric juice. This powerful sol- 

 vent penetrates, in every direction, the alimentary mass, removes from 

 one another, or divides its molecules, combines with it, alters its inward 

 composition, and imparts to it qualities very different from those which 

 it possessed before the mixture. If, in fact a mouthful of wine or of 

 food is. rejected, a few minutes after being swallowed, the smell, the fla- 

 vour, all the sensible and chemical qualities of such substances, are so 

 completely altered, that they can scarcely be recognized; the vinous 

 substances turned, to a certain degree, sour, are no longer capable of the 

 acetous fermentation. The energy of the solvent power of the gastric 

 juice, perhaps over-rated by some physiologists, is sufficient to dissolve 

 and reduce into a pulp, the hardest bones on which some animals feed. 

 It is highly probable, that its chemical composition varies at different 

 times; that it is acid, alkaline or saponaceous, according to the nature of 

 the food. Although the gastric juice be the most powerful agent of di- 

 gestion, its solvent power requires to be aided by several secondary 

 causes, as warmth, which seems to increase, and, in a manner, to concen- 

 trate itself in the epigastric region as long as the stoti'.ach is engaged 

 in digestion ; a sort of inward fermentation which cannot be, strictly 

 speaking, compared to the decomposition which substances, subject to- 

 putrefaction and acescency undergo. The gentle and peristaltic action 

 of the muscular fibres of the stomach, which press in every direction, on 

 the alimentary substance, performs on it a slight trituration, while the 

 moisture of the stomach softens and macerates the food, before it is dis- 

 solved ; one might therefore say, that the process of digestion is at once 

 chemical, mechanical, and vital ; in that case, the authors of the theories 

 that have been broached, have been wrong, only in ascribing to one cause, 

 such as heat, fermentation, putrefaction, trituration, maceration, and the 

 action of the gastric juice, a process which is the result of a concurrence 

 of these causes united*. 



The food remains in the stomach, during a longer or shorter space of 



* Dr. A. Wilson Philip has lately made some experiments to prove, that when the 

 nerves going- to the stomach are divided, the digestion of the food may, notwithstand- 

 ing, be produced, by passing* a current of the galvanic fluid, so as to form a communi- 

 cation between the ends of the cut nerves. We are not, however, so willing to draw 

 the inference, that the nervous power, or influence, is identical with the galvanic agent. 

 The nerves, in his experiments, were not all divided ; and we can readily conceive how 

 so powerful a stimulus as galvanism, might excite the remaining nerves sufficiently to 

 produce the effect reported by Dr. Wilson. Godman. 



