1813.] On Vomiting, 4SS 



this constitutes one of the most conclusive arguments in favour 

 of the opinion which he embraced ; but though the dog sub-* 

 jected to this experiment vomited without having taken any 

 emetic, and exhibited the nausea, and other symptoms which 

 characterise vomiting, the column of air did not enter and tak©^ 

 the place of the ejected food. This shows us that other condi- 

 tions besides the mere pressure of the stomach are necessary to 

 produce vomiting. This experiment revealed to M. Magendie 

 the principal of these conditions. When he held the stomach 

 in his hands without compressing it, he perceived that when he 

 drew it too far out of the belly he immediately produced nausea 

 and vomiting. He conceived that it was the stretching of the 

 oesophagus which produced this double effect ; and he took ad- 

 vantage of this discovery to make dogs vomit at pleasure which 

 had taken no emetic, or to hasten vomiting when the emetic 

 did not act with sufficient promptness. It was only necessary 

 in either case to agitate the stomach, and draw the oesophagus 

 a little, to produce immediate vomiting. It is easy to perceive 

 here the effect of those profound inspirations which, as well as 

 nausea, precede vomiting, and by means of which, the dia- 

 phragm embracing the oesophagus between its pillars, draws it 

 along with it towards the intestines, and makes it undergo those 

 tractions which M. Magendie has so happily imitated. This 

 explains why in the palsy of the oesophagus there is no vomiting,, 

 and why it is so difficult to produce it after cutting the pneumo- 

 gastric nerves. 



If we examine a person just going to vomit, if he does not 

 succeed after a strong inspiration, we see him repeat it again and 

 again, and multiply the movements of expiration, which are 

 always more irregular. By this means the diaphragm agitated 

 up and down gives to the oesophagus that agitation without 

 which, in all probability, vomiting would not be produced. 



It is well known that vomiting often takes place without all 

 those efforts. This is an objection which may be started against 

 either opinion. But, besides that we do not speak of those 

 individuals, who, from the frequent practice of vomiting, have 

 acquired the habit of it, we must distinguish, in infants at the 

 breast, for example, the regurgitation of vomiting; and, in per=" 

 sons who ruminate, the voluntary and tranquil act of bringing 

 from the stomach to the mouth the food to be swallowed a 

 second time, from the painful and involuntary act of vomiting. 

 Besides, in persons who ruminate, as has lately been observed 

 by one of your commissioners in a young man of 24 years of 

 age, the return of the food to the mouth is preceded by a kind 

 of noise, sometimes pretty loud, whicii announces the instanta- 

 neous agitation of the oesophagus, produced by the diaphragm^ 



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