of the Eighth Pair of Nenes. 3 13 



to confirm the opinion of Le Gallois, that it is through the im- 

 pediment put to respiration and the proper circulation of the 

 blood, that the organs of digestion suffer ; nnd in proportion to 

 the affection of the lungs is the distress which evidently op- 

 presses the stomach. 



With regard to the efforts to vomit, in those animals which are 

 incapable of doing so effectually, and the actual vomiting of 

 others, which soon, and often immediately occur, it may be 

 that this is an immediate affection of the stomach, upon the 

 same principle as that of concussion of the brain, or the motion 

 of a ship at sea exciting nausea and vomiting. The parsley 

 found in the oesophagus must be the result of ineffectual efforts 

 to throw it off the stomach, and, being that which lies upper- 

 most, and unaltered by digestion, forms a striking contrast to 

 what remains in the stomach, and which has undergone more or 

 less alteration. 



The expedient of Le Gallois for restoring the free access of 

 the air to the lungs, by cutting out a piece of the trachea, may 

 be supposed to give temporary relief to the symptoms, if the 

 obstruction depend, as he thinks, upon contraction of the larynx 

 in consequence of cutting off the recurrent nerve. But, if the 

 par vagum be considered as a nerve of sensation to the lungs, 

 then it cannot be conceived that this expedient is calculated to 

 restore their functions ; since, if they be robbed of their sensi- 

 bility, they cannot act as they do naturally by the stimulus of 

 the atmospheric air, which may be let in by an opening of the 

 trachea, it is true, but in vain ; for it cannot circulate when the 

 lungs are unable to continue their action. 



Having noticed this explanation of Le Gallois, I determined 

 to put it to the test of experiment. Mr. Field, to whom I have 

 before acknowledged ray obligations for his professional assist- 

 ance, afforded me an opportunity of observing the effects of 

 taking out a piece of the trachea after dividing the par vagum 

 in the centre of the neck on each side. The subject of the ex- 

 periment was an healthy pony of six years old. The animal 

 was seized with violent efforts to breathe directly following the 

 operation, and the excision of a large portion of the trachea 

 Vol. X. Y 



