VOMITING. 303 



More importance is to be attached to the action of the 

 oesophagus in vomiting than is usually assigned to it by 

 writers. The following remark by Hunter, on this point, 

 is interesting : " The muscles of the cavity of the abdomen 

 act, in which is to be included the diaphragm ; so that 

 the capacity of the abdomen is lessened, and the action 

 of the diaphragm rather raises the ribs ; and there is also an 

 attempt to raise them by their proper muscles, to make a 

 kind of vacuum in the thorax, so that the oesophagus may be 

 rather opened than shut, while the glottis is shut so as to 

 let no air enter the lungs. 1 A little reflection will make it 

 evident that the descent of the diaphragm, the most power- 

 ful of the inspiratory muscles, with the glottis firmly closed, 

 makes a virtual vacuum in the chest, by the force of which, 

 a canal so dilatable as the oesophagus would undoubtedly be 

 distended. This action must powerfully assist in vomiting, 

 by drawing the food into the oesophagus and by dilating 

 the cardiac opening, which, as we have seen, is ordinarily 

 closed. Experiments, particularly those of Beclard and of 

 Legallois, have further shown that there is a violent and ex- 

 tensive contraction of the longitudinal fibres of the oesoph- 

 agus with each act of vomiting. This was demonstrated 

 by dividing the oesophagus near the stomach, drawing it out 

 at a wound in the neck, and causing the animal to make 

 efforts at vomiting, by injecting emetic into the veins. "With 

 each act, the oesophagus was observed to undergo sudden 

 and marked contraction in its length. 2 This act assists in 

 vomiting, as the shortening of the oesophagus has a tendency 



had the stomach been returned into the belly, when the same effort produced ex- 

 pulsion of aliments." 



It is remarkable that the authors of the above-mentioned excellent and com- 

 prehensive works upon physiology should have been content to take a quotation 

 so important as the one in question at second-hand, when a reference to the origi- 

 nal would have enabled them to avoid making an important statement precisely 

 opposite to the fact. 



1 HUNTER, op. cit. t p. 200. 



1 LEGALLOIS, (Euvres, Paris, 1824, tome ii., p. 91. 



