430 



On Vom'uingi 



[June, 



the diaphragm and abdominal muscles are the essential agents; 

 but we have found that Bayle entertained the same opinion long 

 before that physician, and that he confirmed it by experiments, 

 which, if they were really made, must deprive Chirac of the 

 priority, without injuring the proofs by which he confirmed his 

 opinion. Senac informs us that Bayle, having caused a dog to 

 swallow an emetic, made a deep incision opposite to the stomach, 

 through which he introduced his finger while the animal was 

 in the act of vomiting, and found by repeated trials that the 

 stomach was not in motion. He found that the whole action 

 was produced by the diaphragm and abdominal muscles, the 

 most powerful of which, according to Senac, are the two trans- 

 verse muscles, the only ones which have a semicircular direction, 

 and which are capable of forming those hollows that appear in 

 the belly in the act of vomiting, it is needless at present to 

 discuss this subject. 



The system of Bayle, or of Chirac, had its partisans ; but it 

 met likewise with, opponents. These indeed could not but be 

 numerous at a time when it was believed that the food was 

 triturated in the human stomach in the same way as it is in the 

 gizzards of birds. 



On this occasion tliere occurred a pretty keen discussion 

 between two members of the Academy of Sciences, Litre and 

 Puverney; one of whom employed inaccurate reasoning, the 

 other inconclusive experiments ; and neither was able either to 

 convince the followers of Chirac, or persuade his antagonists. 

 Lieutaud and Flaller, almost at the same time, put themselves 

 at the head of the last party. They endeavoured to prove that 

 vomiting is exclusively performed by the stomach,^ and that it is 

 independent of the diaphragm and abdominal muscles, w hich in 

 their opinion only concur accidentally with the action of the 

 stomach. Lieutaud observed that the action of the diaphragm 

 and abdominal muscles being subject to the will, vomiting ought 

 to be voluntary if it was occasioned by any such action ; yet this 

 is the case only in a small number of instances. Halier opposed 

 the opinion of Chirac in order to strengthen his own system of 

 irritability, under which he wished to arrange ail the phenomena 

 of animal organisation. 



Wepfer took the same side, and he deceived himself still 

 more than his predecessors ; for he had recourse to experiments, 

 and was niisled by the results. Fie employed poisons by way of 

 emetics, which excited in the stomach, sometimes in its place, 

 sometimes out of the body, movements which he considered as 

 muscular actions, though they were only the effect of .that con- 

 traction wliich takes place in living substances when attacked 

 by corrosives. 



The high reputation of Halier^ and the infiuence of his 

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