On Respiration 197 



respiration goes on afterwards with difficulty. This 

 happens not infrequently in the horse when driven 

 furiously immediately after a rather full meal. For, 

 since there is need of more vigorous breathing 

 when great exertions are made, and the diaphragm, 

 for the wide dilatation of the chest, strives to 

 descend further than usual, while the much dis- 

 tended stomach resists its movement, it comes about 

 that its nervous fibres suffer not a little and are some- 

 times even broken. And hence when the breathing 

 of a horse is injured in this way it is often, and not 

 improperly, said to be broken. But when the 

 diaphragm is thus weakened, respiration is carried on 

 exclusively by means of the intercostal muscles, for 

 these, when violently contracted, raise the ribs in a 

 notable manner and enlarge the space within the 

 chest, so that the defect of the diaphragm is to some 

 extent supplied. 



Similarly in Orthopnoea, in which the patient can 

 only breathe in an erect position, it is probable that 

 the abdominal viscera press too much on the 

 diaphragm and keep it up in the chest, so that space 

 enough for breathing cannot be provided in the 

 thorax. If, however, the patient be placed in an 

 upright position, the diaphragm, feeble though it be, 

 aided by the weight of the same viscera, can force them 

 downwards. And so, as the abdomen sinks, the chest 

 dilates and the patient is able to breathe. 



And quite similarly in the hysteric passion, when 

 the organs in the lower part of the belly, convulsed 

 and swollen, rise in a mass, and keep the diaphragm 

 up, respiration must necessarily cease and suffocation 

 follow, as it does. And it is reasonable to think that 

 this is the cause of uterine suffocation, although I 

 would not deny that the sympathy between the 



