198 Mayow 



viscera and the throat, arising from nerve communi- 

 cation may contribute something to this. But 

 certainly such a constriction of the chest does not 

 seem to be caused at all by the convulsed and 

 elevated diaphragm (as the renowned Dr Willis has 

 supposed), for we have shown above that when the 

 diaphragm is convulsed in inordinate systole and 

 violently contracted, it descends and dilates the 

 chest. 



As for asthmatic paroxysms, in which the raised 

 and distended lungs almost cause suffocation, there is 

 no reason to think that the lungs are inflated by 

 convulsion of the pulmonary nerves and thrown into 

 excessive diastole. For granting that the lungs 

 sometimes suffer convulsions, the contraction and 

 convulsion of their fibres (if they have any) would 

 involve rather the collapse and contraction of the 

 lungs, as was previously pointed out. Nor is it 

 probable that the lungs are thus inflated by vapours, 

 for flatus contained in the pulmonary veins and 

 arteries cannot inflate them. For even though flatus 

 be introduced by a tube attached to the pulmonary 

 artery the lungs will not swell. And any vapours 

 contained in the vesicles of the lungs could certainly 

 be expelled with ease along with the air. And 

 therefore, I think, we should maintain that this kind 

 of suffocation is caused by the convulsed intercostal 

 muscles and diaphragm, for by their convulsion the 

 chest is kept dilated too long, so that the lungs 

 remain inflated and respiration is interrupted. 



Nor should that affection be overlooked here in 

 which the patient draws breath with difficulty and 

 with a whistling sound. This ailment does not seem 

 to arise always from phlegmatic humours choking 

 the bronchia, but sometimes also in the following 



