BROKEN WIND. 
409 
this disease derived its name. This portion of the lung was con¬ 
siderably lighter than the neighbouring ones ; and when I cut 
into it (what 1 have never been able otherwise to do, although 
some anatomists speak of it), I have had a distinct view of the 
separate air-cells, and the termination of the air-tubes, now 
dilated. If you wish to have proof of this, inflate the lungs of a 
horse that has had bad broken wind, and hang them up where 
there is a thorough draught, so that they may be dried as speedily 
as possible. Incisions being then made into them, will shew the 
actual state of the cells. I can conceive that broken wind may 
proceed from hepatization of the lung, or thickening of the 
bronchial membrane; but I have never seen it without this em¬ 
physematous state of the lungs, although sometimes existing in 
so slight a degree, that it would have eluded the eye, and was 
recognizable only by the crackling, when the edges of the lobe 
were pressed. 
Cause .—Broken wind is preceded or accompanied by cough ; 
a cough perfectly characteristic, and by which the horseman 
would detect the existence of the disease in the dark. The cough 
of thick wind, which I should have noticed before, is a peculiar 
one ; it is short, hollow, yet feeble: the cough of the broken- 
winded horse is still shorter, cut short, grunting, yet generally 
followed by a wheeze ; and when the animal is suddenly struck 
or threatened, there is a low grunt, of the same nature, but not 
so loud as that of roaring. Broken wind is usuall}’^ preceded by 
cough ; that cough becomes chronic, leads on to thick wind, and 
then there is but a step to broken wind. It is the consequence of 
the cough which accompanies catarrh and bronchitis oftener 
than that of or following pneumonia; and of inflammation and 
probably thickening of the membrane of the bronchise, rather 
than of congestion of the air-cells. 
The frequoit consequence of Bronchitis. —Laennec, whose 
illustrations of the diseases of the chest are invaluable to the 
human surgeon, comes to our assistance; and, while describing 
emphysema of the lungs of the human being, gives us an expli¬ 
cation of broken wind, more satisfactory than I have found in 
any of our veterinary writers. I will endeavour to condense his 
description. He attributes what he calls dry catarrh “ to the 
partial obstruction of the smaller bronchial tubes, by the swell¬ 
ing of their inner membrane. The muscles of inspiration are 
numerous and powerful, while expiration is chiefly left to the 
elasticity of the parts : then it may happen that the air which, 
during inspiration, had overcome the resistance opposed to its 
entrance by the tumid state of the membrane, is unable to force 
its w'ay through the same obstacle during expiration, and remains 
VOL. VI. Vr 
