162 DISEASES OF THE LUNGS. 



have since fully verified by examination and dissection of 

 a considerable number of cases of broken-wind, and found it 

 to be a constant appearance. This extravasation of air in the 

 substance of the lungs, is, perhaps, occasioned by rupture of 

 the air-cells, as suggested by Mr. Coleman at the time; 

 unless it be formed in them, and thrown out by some morbid 

 operation of the blood-vessels, as sometimes happens in the 

 intestines and vagina : for the exact way in which this emphy- 

 sema arises has not yet been ascertained.^^ 



The late Professor Coleman's theory of broken- 

 wind. — ^'This is a disease which, in all probability, is some- 

 times present in man, but has hitherto been unattended to. 

 In horses it is a very common disease; and though I am 

 not aware that its nature has ever been described by any 

 author, yet it would appear that those who called it broken- 

 windy thought that something was brolcen. It is a rupture 

 of the air-cells, in consequence of which an extravasation of 

 air takes place into the fine cellular membrane which connects 

 them together, and this at once explains the characteristic 

 symptom; which is, that the animal occupies considerable 

 time in performing the act of expiration, but a very short 

 time in inspiring. If you observe attentively the flanks of 

 a horse under this disease, you will perceive that he is a 

 long time in contracting or drawing them up, during which 

 he is expiring ; that act being accomplished, however, the 

 flanks fall almost instantaneously into the successive act of 

 inspiration. The horse is, in fact, a length of time in 

 squeezing out the extravasated air from the reticular mem- 

 brane, where it has not the same easy egress it had before, 

 into the bronchi; though, notwithstanding this act is attended 

 with so much difficulty, it is evident that the vacuum 

 formed within this membrane is as easily restored to an 

 equilibrium as before any rupture had taken place. 



"It is very common in this disease for horses to discharge 

 air from the rectum: the same circumstance, however, is ob- 

 servable in roarers and thick-winded horses, but not in the 

 peculiar manner in which it occurs in broken- wind. This cir- 

 cumstance has given rise to a very ridiculous operation, viz. 



