GASTRIC DIGESTION. 1G3 



Both Budge ami Schiff maintain that these nerves are the conductors by 

 which gentory and painful impressions affecting the stomach, are conveyed 

 to the mind. The inquiries which have been made in reference to the action 

 of the Sympathetic upon the secretion of the gastric juice, arc, owing to the 

 difficulties which attend experiments upon this point, comparatively few. 

 Budge extirpated the coeliac and meseraic ganglia, as well as divided the 

 pueumogastrics, and still found (with one exception) that after the lapse of 

 nine hours the stomach gave an acid reaction ; and his results were fully 

 corroborated by Ravitsch, 1 who found that section of the vagi at the cesopha- 

 geal opening, involving section of the sympathetic, had little or no influence 

 upon either the secretion of the gastric juice or the absorption of the chyme, 

 though the latter was somewhat prolonged ; and by Schiff, who divided the 

 splanchnic nerve? without effect. Adrian 2 only obtained negative results as 

 regards the gastric secretion after extirpation of the Coeliac Plexus, which 

 he must have accomplished with great dexterity, as the animals lived for 

 months after the operation. 3 What influence is exerted by these nerves is 

 probably effected by their vaso-motor action. It must be held as demon- 

 strated by these experiments, then, that all the arguments which have been 

 drawn from the effects of lesion of the Pueumogastric and Sympathetic 

 nerves upon the functions of the Stomach, in favor of the doctrine that Se- 

 cretion depends upon Nervous agency, must be set aside. That these nerves 

 have an important influence on the gastric secretion, is evident from the de- 

 ficiency in its amount soon after their section, as well as from other facts. 

 But this is a very different proposition from that just alluded to, and the 

 difference has been very happily illustrated by Dr. Reid. "The movements 

 of a horse," he observes, " are independent of the rider on his back in 

 other words, the rider does not furnish the conditions necessary for the move- 

 ments of the horse but every one knows how much these movements may 

 be influenced by the hand and heel of the rider." 



114. Our knowledge of the nature of the process of Gastric Digestion has 

 been greatly advanced by recent inquiries ; and we are now in a condition to 

 state with considerable precision what it is, and what it is not, the province 

 of the gastric juice to effect. There can no longer be any doubt, that the 

 operation is one essentially of chemical solution ; and that the vital attributes 

 of the Stomach are only exercised in the preparation of the solvent, and in 

 the performance of those movements which promote its action on the ali- 

 mentary matters submitted to it. The first series of facts which clearly de- 

 monstrated this position, were those that resulted from the very painstaking 

 observations made by Dr. Beaumont, in the case of St. Martin already re- 

 ferred to. By introducing a tube of india-rubber into the empty Stomach, 

 Dr. B. was able to obtain a supply of gastric juice whenever he desired it, 

 the tube serving the purpose of stimulating the follicles to pour forth their 

 secretion, and at the same time conveying it away ; and with the fluid thus 

 obtained, he was able to make various experiments, which showed that the 

 change which it effects upon alimentary matter, when it is kept at a temper- 

 ature of 98 or 100, and frequently agitated, is not less complete than that 

 which takes place when the same matter is submitted to its operation within 

 the stomach, but requires a longer time. This is readily accounted for when 

 we remember that no ordinary agitation can produce the same effect with the 



1 Physiologie, p. 421, 1861 ; and Lo9ons sur la Phys. de la Digestion, 18G8, Lc^on 

 xxxii, p. 347. 



a Eckhard, Beitrage, Bd. iii, 1862. 



3 Bernard, however, states (Med. Times and Gazette, 1860, vol. ii) that on gal- 

 vanizing the sympathetic nerves distributed to the stomach, a sudden arrest of the 

 secretion occurred. 



