THE GASTRIC JUICE. 527 



believed, that the very decided effect of division of these pneumogastric 

 nerves on digestion, noticed by Reid and Bernard, was owing to those 

 perves having been cut in the neck, so as to interfere with respiration, 

 and thus disturb the whole economy ; for, he observed that, on divid- 

 ing them in the rabbit, close to the cardiac orifice of the stomach, no 

 interference with the appetite, the gastric secretion, or digestion, oc- 

 curred. Although, therefore, the secretion of the gastric juice appears 

 to be influenced by the cerebro-spinal nervous system, through the 

 pneumogastric nerves, it cannot be said to be dependent upon it. The 

 effects of mental emotion in arresting digestion, sufficiently prove this 

 influence. 



It has been stated by Bernard, that galvanism applied to the sym- 

 pathetic nerves of the stomach causes an immediate cessation of its 

 secretion, this effect being the reverse of what happens when the 

 pneumogastric nerves are so stimulated. If these two results are con- 

 firmed, they would correspond with those already detailed (p. 522) as 

 to the effects of stimulation of the sympathetic nerves and the chorda 

 tympani, on the secretion of the sublingual and submaxillary glands. 

 Neither division of the splanchnic nerves, nor section of the pneumo- 

 gastrics upon the stomach, that is to say, after the latter have received 

 the fibres from the former nerves, has appeared to interfere much, or 

 at all, with the gastric secretion (Schiff and others) ; even the coeliac 

 plexus, and the neighboring ganglia, have been removed without per- 

 manent effect (Budge). It would seem impossible, however, in any 

 such experiments, to remove, or divide all the sympathetic nerves of 

 the stomach. Finally, the influence of this part of the nervous system 

 on the gastric secretion is uncertain ; and it is not yet shown that the 

 secretion is either arrested by, or depends on, the sympathetic system. 



The quantity of the gastric juice secreted appears to be enormous. 

 In dogs, the daily quantity has been calculated as ^th (Corvisart) or 

 T ^th (Lehmann) part of the weight of the body ; the latter ratio would 

 give 14 Ibs. in a man of 140 Ibs. weight, a quantity equal to rather 

 more than 11 pints daily. That this estimate, however large, is not 

 extreme, is shown by the fact that, in a case of gastric fistula, in a 

 woman, the estimated daily quantity was 30J Ibs. av., the weight of 

 her body being 116 Ibs. From observations on dogs, having artificial 

 gastric fistulae, the secretion appears to be less abundantly excited by 

 mechanical, than by chemical or special irritants,- such as salt or pep- 

 per ; acid food excites a less abundant flow than food made slightly 

 alkaline ; but alkali in the solid state induces an abundant secretion 

 of mucus. Too powerful mechanical irritation has a similar effect, 

 lessening, or arresting, the secretion of proper gastric juice, and, in 

 both cases, vomiting, and the passage of bile into the stomach, may 

 take place. Powerful chemical irritants arrest digestion, and cause 

 signs of inflammation. The effect of cold water, or ice, is, after first 

 causing the gastric membrane to be pale, ultimately to increase the 

 flow of blood to it, and to excite a very active secretion ; ice, in larger 

 quantity, causes shivering, and delays digestion. A high tempera- 

 ture, even a small quantity of boiling water, produces collapse and 

 death within four hours, causing redness, turgescence, and ecchymosis 



